OPENSSL(1) BSD Reference Manual OPENSSL(1)
openssl - OpenSSL command line tool
openssl command [command_opts] [command_args]
openssl [list-standard-commands | list-message-digest-commands | list-
cipher-commands]
openssl no-XXX [arbitrary options]
OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer
(SSL v2/v3) and Transport Layer Security (TLS v1) network protocols and
related cryptography standards required by them.
The openssl program is a command line tool for using the various cryptog-
raphy functions of OpenSSL's crypto library from the shell. It can be
used for
• Creation of RSA, DH and DSA key parameters
• Creation of X.509 certificates, CSRs and CRLs
• Calculation of Message Digests
• Encryption and Decryption with Ciphers
• SSL/TLS Client and Server Tests
• Handling of S/MIME signed or encrypted mail
The openssl program has actually two manual pages under MirBSD. This one,
openssl(1), is actually static content and not updated automatically. The
openssltool(1) manual page may look not so good, but provides a good and
always up-to date description of the openssl synopsis, subcommands and
options.
The openssl program provides a rich variety of commands (command in the
SYNOPSIS above), each of which often has a wealth of options and argu-
ments (command_opts and command_args in the SYNOPSIS).
The pseudo-commands list-standard-commands, list-message-digest-commands,
and list-cipher-commands output a list (one entry per line) of the names
of all standard commands, message digest commands, or cipher commands,
respectively, that are available in the present openssl utility.
The pseudo-command no-XXX tests whether a command of the specified name
is available. If no command named XXX exists, it returns 0 (success) and
prints no-XXX; otherwise it returns 1 and prints XXX. In both cases, the
output goes to stdout and nothing is printed to stderr. Additional com-
mand line arguments are always ignored. Since for each cipher there is a
command of the same name, this provides an easy way for shell scripts to
test for the availability of ciphers in the openssl program.
Note: no-XXX is not able to detect pseudo-commands such as quit, list-
...-commands, or no-XXX itself.
asn1octetstream Provides encryption in PEM format, as used by
vnconfig(8).
asn1parse Parse an ASN.1 sequence.
ca Certificate Authority (CA) Management.
ciphers Cipher Suite Description Determination.
crl Certificate Revocation List (CRL) Management.
crl2pkcs7 CRL to PKCS#7 Conversion.
dgst Message Digest Calculation.
dh Diffie-Hellman Parameter Management. Obsoleted by
dhparam.
dhparam Generation and Management of Diffie-Hellman Parameters.
dsa DSA Data Management.
dsaparam DSA Parameter Generation.
enc Encoding with Ciphers.
errstr Error Number to Error String Conversion.
gendh Generation of Diffie-Hellman Parameters. Obsoleted by
dhparam.
gendsa Generation of DSA Parameters.
genrsa Generation of RSA Parameters.
nseq Create or examine a Netscape certificate sequence.
ocsp Online Certificate Status Protocol utility.
passwd Generation of hashed passwords.
pkcs7 PKCS#7 Data Management.
pkcs8 PKCS#8 Data Management.
pkcs12 PKCS#12 Data Management.
rand Generate pseudo-random bytes.
req X.509 Certificate Signing Request (CSR) Management.
rsa RSA Data Management.
rsautl RSA utility for signing, verification, encryption, and
decryption.
s_client This implements a generic SSL/TLS client which can es-
tablish a transparent connection to a remote server
speaking SSL/TLS. It's intended for testing purposes
only and provides only rudimentary interface functional-
ity but internally uses mostly all functionality of the
OpenSSL ssl library.
s_server This implements a generic SSL/TLS server which accepts
connections from remote clients speaking SSL/TLS. It's
intended for testing purposes only and provides only ru-
dimentary interface functionality but internally uses
mostly all functionality of the OpenSSL ssl library. It
provides both an own command line oriented protocol for
testing SSL functions and a simple HTTP response facili-
ty to emulate an SSL/TLS-aware webserver.
s_time SSL Connection Timer.
sess_id SSL Session Data Management.
smime S/MIME mail processing.
speed Algorithm Speed Measurement.
spkac SPKAC printing and generating utility.
verify X.509 Certificate Verification.
version OpenSSL Version Information.
x509 X.509 Certificate Data Management.
md2 MD2 Digest.
md4 MD4 Digest.
md5 MD5 Digest.
ripemd160 RIPEMD-160 Digest.
sha1 SHA-1 Digest.
sha224 SHA-224 Digest.
sha256 SHA-256 Digest.
sha384 SHA-384 Digest.
sha512 SHA-512 Digest.
aes-128-cbc | aes-128-ecb | aes-192-cbc | aes-192-ecb |
aes-256-cbc | aes-256-ecb
AES Cipher.
base64 Base64 Encoding.
bf | bf-cbc | bf-cfb | bf-ecb | bf-ofb
Blowfish Cipher.
cast | cast-cbc
CAST Cipher.
cast5-cbc | cast5-cfb | cast5-ecb | cast5-ofb
CAST5 Cipher.
des | des-cbc | des-cfb | des-ecb | des-ede | des-ede-cbc
des-ede-cfb | des-ede-ofb | des-ofb
DES Cipher.
des3 | desx | des-ede3 | des-ede3-cbc | des-ede3-cfb | des-ede3-ofb
Triple DES Cipher.
rc2 | rc2-40-cbc | rc2-64-cbc | rc2-cbc | rc2-cfb | rc2-ecb | rc2-ofb
RC2 Cipher.
rc4 | rc4-40
RC4 Cipher.
Several commands accept password arguments, typically using -passin and
-passout for input and output passwords, respectively. These allow the
password to be obtained from a variety of sources. Both of these options
take a single argument whose format is described below. If no password
argument is given and a password is required, then the user is prompted
to enter one: this will typically be read from the current terminal with
echoing turned off.
pass:password
The actual password is password. Since the password is visible
to utilities (like ps(1) under UNIX) this form should only be
used where security is not important.
env:var Obtain the password from the environment variable var. Since
the environment of other processes is visible on certain plat-
forms (e.g. ps(1) under certain UNIX OSes) this option should
be used with caution.
file:path The first line of path is the password. If the same path argu-
ment is supplied to -passin and -passout, then the first line
will be used for the input password and the next line for the
output password. path need not refer to a regular file: it
could, for example, refer to a device or named pipe.
fd:number Read the password from the file descriptor number. This can be
used to send the data via a pipe for example.
stdin Read the password from standard input.
openssl asn1octetstream [-in file] [-passin arg] [-out file]
[-passout arg] [-e] [-d] [-algo]
The asn1octetstream command encapsulates arbitrary binary data in ASN.1
octet strings and stores them, optionally (usually) encrypted, in PEM
format. It also handles conversion of the PEM encoding, such as changing
the passphrase and crypto type.
The options are as follows:
-algo If writing PEM output, write it in a symmetrically encrypt-
ed manner, with algo as cryptographic algorithm. This op-
tion is highly recommended. See the list-cipher-commands
command for a list of valid ciphers.
-d Instead of writing a PEM encoded ASN.1 octet string to the
output stream, write the binary data content of it.
-e Instead of expecting a PEM encoded ASN.1 octet string on
the input stream, read arbitrary binary data (up to 2 GiB -
1 Byte) and encapsulate it into an ASN.1 octet stream for
further processing.
-in file This specifies the input file to read, or standard input if
not used.
-out file This specifies the output file to write, or standard output
if not used.
-passin arg The input file password source. For more information about
the format of arg, see the PASS PHRASE ARGUMENTS section
above.
-passout arg The output file password source. For more information about
the format of arg, see the PASS PHRASE ARGUMENTS section
above.
ASN.1 OCTET STRING NOTES
The PEM encapsulation format uses the header and footer lines:
-----BEGIN ASN1 OCTET STRING-----
-----END ASN1 OCTET STRING-----
This format is a MirBSD extension. The MirOS Project hopes this will some
day be integrated into stock OpenSSL.
openssl asn1parse [-dump] [-i] [-noout] [-dlimit number] [-in file]
[-inform DER | PEM | TXT] [-length number] [-offset number] [-oid file]
[-out file] [-strparse offset]
The asn1parse command is a diagnostic utility that can parse ASN.1 struc-
tures. It can also be used to extract data from ASN.1 formatted data.
The options are as follows:
-dlimit number
Dump the first number bytes of unknown data in hex form.
-dump Dump unknown data in hex form.
-i Indents the output according to the "depth" of the structures.
-in file
The input file; default is standard input.
-inform DER | PEM | TXT
The input format. DER (Distinguished Encoding Rules) is binary
format and PEM (Privacy Enhanced Mail), the default, is base64-
encoded. TXT is plain text.
-length number
Number of bytes to parse; default is until end of file.
-noout Don't output the parsed version of the input file.
-offset number
Starting offset to begin parsing; default is start of file.
-oid file
A file containing additional object identifiers (OIDs). The for-
mat of this file is described in the ASN1PARSE NOTES section
below.
-out file
Output file to place the DER-encoded data into. If this option is
not present, no encoded data will be output. This is most useful
when combined with the -strparse option.
-strparse offset
Parse the content octets of the ASN.1 object starting at offset.
This option can be used multiple times to "drill down" into a
nested structure.
The output will typically contain lines like this:
0:d=0 hl=4 l= 681 cons: SEQUENCE
.....
229:d=3 hl=3 l= 141 prim: BIT STRING
373:d=2 hl=3 l= 162 cons: cont [ 3 ]
376:d=3 hl=3 l= 159 cons: SEQUENCE
379:d=4 hl=2 l= 29 cons: SEQUENCE
381:d=5 hl=2 l= 3 prim: OBJECT :X509v3 Subject Key Identifier
386:d=5 hl=2 l= 22 prim: OCTET STRING
410:d=4 hl=2 l= 112 cons: SEQUENCE
412:d=5 hl=2 l= 3 prim: OBJECT :X509v3 Authority Key Identifier
417:d=5 hl=2 l= 105 prim: OCTET STRING
524:d=4 hl=2 l= 12 cons: SEQUENCE
.....
This example is part of a self-signed certificate. Each line starts with
the offset in decimal. d=XX specifies the current depth. The depth is in-
creased within the scope of any SET or SEQUENCE. hl=XX gives the header
length (tag and length octets) of the current type. l=XX gives the length
of the content octets.
The -i option can be used to make the output more readable.
Some knowledge of the ASN.1 structure is needed to interpret the output.
In this example, the BIT STRING at offset 229 is the certificate public
key. The content octets of this will contain the public key information.
This can be examined using the option -strparse 229 to yield:
0:d=0 hl=3 l= 137 cons: SEQUENCE
3:d=1 hl=3 l= 129 prim: INTEGER :E5D21E1F5C8D208EA7A2166C7FA
F9F6BDF2059669C60876DDB70840F1A5AAFA59699FE471F379F1DD6A487E7D5409AB6A88D4A
9746E24B91D8CF55DB3521015460C8EDE44EE8A4189F7A7BE77D6CD3A9AF2696F486855CF58
BF0EDF2B4068058C7A947F52548DDF7E15E96B385F86422BEA9064A3EE9
135:d=1 hl=2 l= 3 prim: INTEGER :010001
If an OID (object identifier) is not part of OpenSSL's internal table it
will be represented in numerical form (for example 1.2.3.4). The file
passed to the -oid option allows additional OIDs to be included. Each
line consists of three columns: the first column is the OID in numerical
format and should be followed by whitespace. The second column is the
"short name" which is a single word followed by whitespace. The final
column is the rest of the line and is the "long name". asn1parse displays
the long name. Example:
"1.2.3.4 shortname A long name"
There should be options to change the format of output lines. The output
of some ASN.1 types is not well handled (if at all).
openssl ca [-batch] [-gencrl] [-infiles] [-msie_hack] [-noemailDN]
[-notext] [-preserveDN] [-updatedb] [-verbose] [-cert file]
[-config file] [-crl_CA_compromise time] [-crl_compromise time]
[-crl_hold instruction] [-crl_reason reason] [-crldays days]
[-crlexts section] [-crlhours hours] [-days arg] [-enddate date]
[-engine id] [-extensions section] [-extfile section] [-in file]
[-key keyfile] [-keyfile arg] [-keyform ENGINE | PEM] [-md arg]
[-name section] [-out file] [-outdir dir] [-passin arg] [-policy arg]
[-revoke file] [-spkac file] [-ss_cert file] [-startdate date]
[-status serial] [-subj arg]
The ca command is a minimal CA application. It can be used to sign certi-
ficate requests in a variety of forms and generate CRLs. It also main-
tains a text database of issued certificates and their status.
The options descriptions will be divided into each purpose.
-batch
This sets the batch mode. In this mode no questions will be asked
and all certificates will be certified automatically.
-cert file
The CA certificate file.
-config file
Specifies the configuration file to use.
-days arg
The number of days to certify the certificate for.
-enddate date
This allows the expiry date to be explicitly set. The format of the
date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
-engine id
Specifying an engine (by it's unique id string) will cause ca to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-extensions section
The section of the configuration file containing certificate exten-
sions to be added when a certificate is issued (defaults to
x509_extensions unless the -extfile option is used). If no exten-
sion section is present, a V1 certificate is created. If the exten-
sion section is present (even if it is empty), then a V3 certifi-
cate is created.
-extfile file
An additional configuration file to read certificate extensions
from (using the default section unless the -extensions option is
also used).
-in file
An input file containing a single certificate request to be signed
by the CA.
-infiles
If present, this should be the last option; all subsequent argu-
ments are assumed to be the names of files containing certificate
requests.
-key keyfile
The password used to encrypt the private key. Since on some systems
the command line arguments are visible (e.g. UNIX with the ps(1)
utility) this option should be used with caution.
-keyfile file
The private key to sign requests with.
-keyform ENGINE | PEM
Private key file format.
-md alg
The message digest to use. Possible values include md5 and sha1.
This option also applies to CRLs.
-msie_hack
This is a legacy option to make ca work with very old versions of
the IE certificate enrollment control "certenr3". It used Univer-
salStrings for almost everything. Since the old control has various
security bugs, its use is strongly discouraged. The newer control
"Xenroll" does not need this option.
-name section
Specifies the configuration file section to use (overrides
default_ca in the ca section).
-noemailDN
The DN of a certificate can contain the EMAIL field if present in
the request DN, however it is good policy just having the e-mail
set into the altName extension of the certificate. When this option
is set, the EMAIL field is removed from the certificate's subject
and set only in the, eventually present, extensions. The
email_in_dn keyword can be used in the configuration file to enable
this behaviour.
-notext
Don't output the text form of a certificate to the output file.
-out file
The output file to output certificates to. The default is standard
output. The certificate details will also be printed out to this
file.
-outdir directory
The directory to output certificates to. The certificate will be
written to a file consisting of the serial number in hex with
".pem" appended.
-passin arg
The key password source. For more information about the format of
arg, see the PASS PHRASE ARGUMENTS section above.
-policy arg
This option defines the CA "policy" to use. This is a section in
the configuration file which decides which fields should be manda-
tory or match the CA certificate. Check out the CA POLICY FORMAT
section for more information.
-preserveDN
Normally, the DN order of a certificate is the same as the order of
the fields in the relevant policy section. When this option is set,
the order is the same as the request. This is largely for compati-
bility with the older IE enrollment control which would only accept
certificates if their DNs matched the order of the request. This is
not needed for Xenroll.
-spkac file
A file containing a single Netscape signed public key and chal-
lenge, and additional field values to be signed by the CA. See the
SPKAC FORMAT section for information on the required format.
-ss_cert file
A single self-signed certificate to be signed by the CA.
-startdate date
This allows the start date to be explicitly set. The format of the
date is YYMMDDHHMMSSZ (the same as an ASN1 UTCTime structure).
-status serial
Show status of certificate with serial number serial.
-updatedb
Update database for expired certificates.
-verbose
This prints extra details about the operations being performed.
-crl_CA_compromise time
This is the same as -crl_compromise, except the revocation reason
is set to CACompromise.
-crl_compromise time
This sets the revocation reason to keyCompromise and the compromise
time to time. time should be in GeneralizedTime format, i.e.
YYYYMMDDHHMMSSZ.
-crl_hold instruction
This sets the CRL revocation reason code to certificateHold and the
hold instruction to instruction which must be an OID. Although any
OID can be used, only holdInstructionNone (the use of which is
discouraged by RFC 2459), holdInstructionCallIssuer or holdInstruc-
tionReject will normally be used.
-crl_reason reason
Revocation reason, where reason is one of: unspecified, keyComprom-
ise, CACompromise, affiliationChanged, superseded, cessa-
tionOfOperation, certificateHold or removeFromCRL. The matching of
reason is case insensitive. Setting any revocation reason will make
the CRL v2. In practice, removeFromCRL is not particularly useful
because it is only used in delta CRLs which are not currently im-
plemented.
-crldays num
The number of days before the next CRL is due. This is the days
from now to place in the CRL nextUpdate field.
-crlexts section
The section of the configuration file containing CRL extensions to
include. If no CRL extension section is present then a V1 CRL is
created; if the CRL extension section is present (even if it is
empty) then a V2 CRL is created. The CRL extensions specified are
CRL extensions and not CRL entry extensions. It should be noted
that some software (for example Netscape) can't handle V2 CRLs.
-crlhours num
The number of hours before the next CRL is due.
-gencrl
This option generates a CRL based on information in the index file.
-revoke file
A file containing a certificate to revoke.
-subj arg
Supersedes the subject name given in the request. The arg must be
formatted as /type0=value0/type1=value1/type2=...; characters may
be escaped by '\' (backslash), no spaces are skipped.
The section of the configuration file containing options for ca is found
as follows: If the -name command line option is used, then it names the
section to be used. Otherwise the section to be used must be named in the
default_ca option of the ca section of the configuration file (or in the
default section of the configuration file). Besides default_ca, the fol-
lowing options are read directly from the ca section:
RANDFILE
preserve
msie_hack
With the exception of RANDFILE, this is probably a bug and may change in
future releases.
Many of the configuration file options are identical to command line op-
tions. Where the option is present in the configuration file and the com-
mand line, the command line value is used. Where an option is described
as mandatory, then it must be present in the configuration file or the
command line equivalent (if any) used.
certificate
The same as -cert. It gives the file containing the CA certificate.
Mandatory.
copy_extensions
Determines how extensions in certificate requests should be han-
dled. If set to none or this option is not present, then extensions
are ignored and not copied to the certificate. If set to copy, then
any extensions present in the request that are not already present
are copied to the certificate. If set to copyall, then all exten-
sions in the request are copied to the certificate: if the exten-
sion is already present in the certificate it is deleted first. See
the CA WARNINGS section before using this option.
The main use of this option is to allow a certificate request to
supply values for certain extensions such as subjectAltName.
crl_extensions
The same as -crlexts.
database
The text database file to use. Mandatory. This file must be
present, though initially it will be empty.
default_crl_hours, default_crl_days
The same as the -crlhours and -crldays options. These will only be
used if neither command line option is present. At least one of
these must be present to generate a CRL.
default_days
The same as the -days option. The number of days to certify a cer-
tificate for.
default_enddate
The same as the -enddate option. Either this option or default_days
(or the command line equivalents) must be present.
default_md
The same as the -md option. The message digest to use. Mandatory.
default_startdate
The same as the -startdate option. The start date to certify a cer-
tificate for. If not set, the current time is used.
email_in_dn
The same as -noemailDN. If the EMAIL field is to be removed from
the DN of the certificate, simply set this to "no". If not present,
the default is to allow for the EMAIL field in the certificate's
DN.
msie_hack
The same as -msie_hack.
name_opt, cert_opt
These options allow the format used to display the certificate de-
tails when asking the user to confirm signing. All the options sup-
ported by the x509 utilities' -nameopt and -certopt switches can be
used here, except that no_signame and no_sigdump are permanently
set and cannot be disabled (this is because the certificate signa-
ture cannot be displayed because the certificate has not been
signed at this point).
For convenience, the value ca_default is accepted by both to pro-
duce a reasonable output.
If neither option is present, the format used in earlier versions
of OpenSSL is used. Use of the old format is strongly discouraged
because it only displays fields mentioned in the policy section,
mishandles multicharacter string types and does not display exten-
sions.
new_certs_dir
The same as the -outdir command line option. It specifies the
directory where new certificates will be placed. Mandatory.
oid_file
This specifies a file containing additional object identifiers.
Each line of the file should consist of the numerical form of the
object identifier followed by whitespace, then the short name fol-
lowed by whitespace and finally the long name.
oid_section
This specifies a section in the configuration file containing extra
object identifiers. Each line should consist of the short name of
the object identifier followed by '=' and the numerical form. The
short and long names are the same when this option is used.
policy
The same as -policy. Mandatory. See the CA POLICY FORMAT section
for more information.
preserve
The same as -preserveDN.
private_key
Same as the -keyfile option. The file containing the CA private
key. Mandatory.
RANDFILE
A file used to read and write random number seed information, or an
EGD socket (see RAND_egd(3)).
serial
A text file containing the next serial number to use in hex. Manda-
tory. This file must be present and contain a valid serial number.
x509_extensions
The same as -extensions.
The policy section consists of a set of variables corresponding to certi-
ficate DN fields. If the value is "match", then the field value must
match the same field in the CA certificate. If the value is "supplied",
then it must be present. If the value is "optional", then it may be
present. Any fields not mentioned in the policy section are silently
deleted, unless the -preserveDN option is set, but this can be regarded
more of a quirk than intended behaviour.
The input to the -spkac command line option is a Netscape signed public
key and challenge. This will usually come from the KEYGEN tag in an HTML
form to create a new private key. It is, however, possible to create
SPKACs using the spkac utility.
The file should contain the variable SPKAC set to the value of the SPKAC
and also the required DN components as name value pairs. If it's neces-
sary to include the same component twice, then it can be preceded by a
number and a '.'.
Note: these examples assume that the ca directory structure is already
set up and the relevant files already exist. This usually involves creat-
ing a CA certificate and private key with req, a serial number file and
an empty index file and placing them in the relevant directories.
To use the sample configuration file below, the directories demoCA,
demoCA/private and demoCA/newcerts would be created. The CA certificate
would be copied to demoCA/cacert.pem and its private key to
demoCA/private/cakey.pem. A file demoCA/serial would be created contain-
ing, for example, "01" and the empty index file demoCA/index.txt.
Sign a certificate request:
$ openssl ca -in req.pem -out newcert.pem
Sign a certificate request, using CA extensions:
$ openssl ca -in req.pem -extensions v3_ca -out newcert.pem
Generate a CRL:
$ openssl ca -gencrl -out crl.pem
Sign several requests:
$ openssl ca -infiles req1.pem req2.pem req3.pem
Certify a Netscape SPKAC:
$ openssl ca -spkac spkac.txt
A sample SPKAC file (the SPKAC line has been truncated for clarity):
SPKAC=MIG0MGAwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAn7PDhCeV/xIxUg8V70YRxK
CN=Steve Test
emailAddress=steve@openssl.org
0.OU=OpenSSL Group
1.OU=Another Group
A sample configuration file with the relevant sections for ca:
[ ca ]
default_ca = CA_default # The default ca section
[ CA_default ]
dir = ./demoCA # top dir
database = $dir/index.txt # index file
new_certs_dir = $dir/newcerts # new certs dir
certificate = $dir/cacert.pem # The CA cert
serial = $dir/serial # serial no file
private_key = $dir/private/cakey.pem# CA private key
RANDFILE = $dir/private/.rand # random number file
default_days = 365 # how long to certify for
default_crl_days= 30 # how long before next CRL
default_md = md5 # md to use
policy = policy_any # default policy
email_in_dn = no # Don't add the email into cert DN
name_opt = ca_default # Subject name display option
cert_opt = ca_default # Certificate display option
copy_extensions = none #Don't copy extensions from request
[ policy_any ]
countryName = supplied
stateOrProvinceName = optional
organizationName = optional
organizationalUnitName = optional
commonName = supplied
emailAddress = optional
Note: the location of all files can change either by compile time op-
tions, configuration file entries, environment variables, or command line
options. The values below reflect the default values.
/etc/ssl/openssl.cnf - master configuration file
./demoCA - main CA directory
./demoCA/cacert.pem - CA certificate
./demoCA/private/cakey.pem - CA private key
./demoCA/serial - CA serial number file
./demoCA/serial.old - CA serial number backup file
./demoCA/index.txt - CA text database file
./demoCA/index.txt.old - CA text database backup file
./demoCA/certs - certificate output file
./demoCA/.rnd - CA random seed information
OPENSSL_CONF reflects the location of the master configuration file; it
can be overridden by the -config command line option.
The text database index file is a critical part of the process, and if
corrupted it can be difficult to fix. It is theoretically possible to re-
build the index file from all the issued certificates and a current CRL;
however there is no option to do this.
V2 CRL features like delta CRL support and CRL numbers are not currently
supported.
Although several requests can be input and handled at once, it is only
possible to include one SPKAC or self-signed certificate.
The use of an in-memory text database can cause problems when large
numbers of certificates are present because, as the name implies, the da-
tabase has to be kept in memory.
It is not possible to certify two certificates with the same DN; this is
a side effect of how the text database is indexed and it cannot easily be
fixed without introducing other problems. Some S/MIME clients can use two
certificates with the same DN for separate signing and encryption keys.
The ca command really needs rewriting or the required functionality ex-
posed at either a command or interface level so a more friendly utility
(perl script or GUI) can handle things properly. The scripts CA.sh and
CA.pl help a little but not very much.
Any fields in a request that are not present in a policy are silently
deleted. This does not happen if the -preserveDN option is used. To en-
force the absence of the EMAIL field within the DN, as suggested by RFCs,
regardless of the contents of the request's subject the -noemailDN option
can be used. The behaviour should be more friendly and configurable.
Cancelling some commands by refusing to certify a certificate can create
an empty file.
The ca command is quirky and at times downright unfriendly.
The ca utility was originally meant as an example of how to do things in
a CA. It was not supposed to be used as a full blown CA itself: neverthe-
less some people are using it for this purpose.
The ca command is effectively a single user command: no locking is done
on the various files, and attempts to run more than one ca command on the
same database can have unpredictable results.
The copy_extensions option should be used with caution. If care is not
taken, it can be a security risk. For example, if a certificate request
contains a basicConstraints extension with CA:TRUE and the
copy_extensions value is set to copyall and the user does not spot this
when the certificate is displayed, then this will hand the requestor a
valid CA certificate.
This situation can be avoided by setting copy_extensions to copy and in-
cluding basicConstraints with CA:FALSE in the configuration file. Then if
the request contains a basicConstraints extension, it will be ignored.
It is advisable to also include values for other extensions such as
keyUsage to prevent a request supplying its own values.
Additional restrictions can be placed on the CA certificate itself. For
example if the CA certificate has:
basicConstraints = CA:TRUE, pathlen:0
then even if a certificate is issued with CA:TRUE it will not be valid.
openssl ciphers [-h] [-ssl2 | -ssl3 | -tls1] [-v] [cipherlist]
The ciphers command converts OpenSSL cipher lists into ordered SSL cipher
preference lists. It can be used as a test tool to determine the ap-
propriate cipherlist.
The options are as follows:
-h, -? Print a brief usage message.
-ssl2 Only include SSL v2 ciphers.
-ssl3 Only include SSL v3 ciphers.
-tls1 Only include TLS v1 ciphers.
-v Verbose option. List ciphers with a complete description of pro-
tocol version (SSLv2 or SSLv3; the latter includes TLS), key ex-
change, authentication, encryption and mac algorithms used along
with any key size restrictions and whether the algorithm is
classed as an export cipher. Note that without the -v option, ci-
phers may seem to appear twice in a cipher list; this is when
similar ciphers are available for SSL v2 and for SSL v3/TLS v1.
cipherlist
A cipher list to convert to a cipher preference list. If it is
not included, the default cipher list will be used. The format is
described below.
The cipher list consists of one or more cipher strings separated by
colons. Commas or spaces are also acceptable separators, but colons are
normally used.
The actual cipher string can take several different forms:
It can consist of a single cipher suite such as RC4-SHA.
It can represent a list of cipher suites containing a certain algorithm,
or cipher suites of a certain type. For example SHA1 represents all ci-
pher suites using the digest algorithm SHA1, and SSLv3 represents all SSL
v3 algorithms.
Lists of cipher suites can be combined in a single cipher string using
the '+' character. This is used as a logical and operation. For example,
SHA1+DES represents all cipher suites containing the SHA1 and the DES al-
gorithms.
Each cipher string can be optionally preceded by the characters '!', '-',
or '+'.
If '!' is used, then the ciphers are permanently deleted from the list.
The ciphers deleted can never reappear in the list even if they are ex-
plicitly stated.
If '-' is used, then the ciphers are deleted from the list, but some or
all of the ciphers can be added again by later options.
If '+' is used, then the ciphers are moved to the end of the list. This
option doesn't add any new ciphers, it just moves matching existing ones.
If none of these characters is present, the string is just interpreted as
a list of ciphers to be appended to the current preference list. If the
list includes any ciphers already present, they will be ignored; that is,
they will not be moved to the end of the list.
Additionally, the cipher string @STRENGTH can be used at any point to
sort the current cipher list in order of encryption algorithm key length.
The following is a list of all permitted cipher strings and their mean-
ings.
DEFAULT
The default cipher list. This is determined at compile time and is
normally ALL:!ADH:RC4+RSA:+SSLv2:@STRENGTH. This must be the first
cipher string specified.
COMPLEMENTOFDEFAULT
The ciphers included in ALL, but not enabled by default. Currently
this is ADH. Note that this rule does not cover eNULL, which is not
included by ALL (use COMPLEMENTOFALL if necessary).
ALL All cipher suites except the eNULL ciphers which must be explicitly
enabled.
COMPLEMENTOFALL
The cipher suites not enabled by ALL, currently being eNULL.
HIGH "High" encryption cipher suites. This currently means those with
key lengths larger than 128 bits.
MEDIUM
"Medium" encryption cipher suites, currently those using 128-bit
encryption.
LOW "Low" encryption cipher suites, currently those using 64- or 56-bit
encryption algorithms, but excluding export cipher suites.
EXP, EXPORT
Export encryption algorithms. Including 40- and 56-bit algorithms.
EXPORT40
40-bit export encryption algorithms.
EXPORT56
56-bit export encryption algorithms.
eNULL, NULL
The "NULL" ciphers; that is, those offering no encryption. Because
these offer no encryption at all and are a security risk, they are
disabled unless explicitly included.
aNULL
The cipher suites offering no authentication. This is currently the
anonymous DH algorithms. These cipher suites are vulnerable to a
"man in the middle" attack, so their use is normally discouraged.
kRSA, RSA
Cipher suites using RSA key exchange.
kEDH Cipher suites using ephemeral DH key agreement.
kDHr, kDHd
Cipher suites using DH key agreement and DH certificates signed by
CAs with RSA and DSS keys respectively. Not implemented.
aRSA Cipher suites using RSA authentication, i.e. the certificates carry
RSA keys.
aDSS, DSS
Cipher suites using DSS authentication, i.e. the certificates carry
DSS keys.
aDH Cipher suites effectively using DH authentication, i.e. the certi-
ficates carry DH keys. Not implemented.
kFZA, aFZA, eFZA, FZA
Cipher suites using FORTEZZA key exchange, authentication, encryp-
tion or all FORTEZZA algorithms. Not implemented.
TLSv1, SSLv3, SSLv2
TLS v1.0, SSL v3.0 or SSL v2.0 cipher suites, respectively.
DH Cipher suites using DH, including anonymous DH.
ADH Anonymous DH cipher suites.
AES Cipher suites using AES.
3DES Cipher suites using triple DES.
DES Cipher suites using DES (not triple DES).
RC4 Cipher suites using RC4.
RC2 Cipher suites using RC2.
MD5 Cipher suites using MD5.
SHA1, SHA
Cipher suites using SHA1.
The following lists give the SSL or TLS cipher suites names from the
relevant specification and their OpenSSL equivalents. It should be noted
that several cipher suite names do not include the authentication used,
e.g. DES-CBC3-SHA. In these cases, RSA authentication is used.
SSL_RSA_WITH_NULL_MD5 NULL-MD5
SSL_RSA_WITH_NULL_SHA NULL-SHA
SSL_RSA_EXPORT_WITH_RC4_40_MD5 EXP-RC4-MD5
SSL_RSA_WITH_RC4_128_MD5 RC4-MD5
SSL_RSA_WITH_RC4_128_SHA RC4-SHA
SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5 EXP-RC2-CBC-MD5
SSL_RSA_WITH_IDEA_CBC_SHA IDEA-CBC-SHA
SSL_RSA_EXPORT_WITH_DES40_CBC_SHA EXP-DES-CBC-SHA
SSL_RSA_WITH_DES_CBC_SHA DES-CBC-SHA
SSL_RSA_WITH_3DES_EDE_CBC_SHA DES-CBC3-SHA
SSL_DH_DSS_EXPORT_WITH_DES40_CBC_SHA Not implemented.
SSL_DH_DSS_WITH_DES_CBC_SHA Not implemented.
SSL_DH_DSS_WITH_3DES_EDE_CBC_SHA Not implemented.
SSL_DH_RSA_EXPORT_WITH_DES40_CBC_SHA Not implemented.
SSL_DH_RSA_WITH_DES_CBC_SHA Not implemented.
SSL_DH_RSA_WITH_3DES_EDE_CBC_SHA Not implemented.
SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA EXP-EDH-DSS-DES-CBC-SHA
SSL_DHE_DSS_WITH_DES_CBC_SHA EDH-DSS-CBC-SHA
SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA EDH-DSS-DES-CBC3-SHA
SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA EXP-EDH-RSA-DES-CBC-SHA
SSL_DHE_RSA_WITH_DES_CBC_SHA EDH-RSA-DES-CBC-SHA
SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA EDH-RSA-DES-CBC3-SHA
SSL_DH_anon_EXPORT_WITH_RC4_40_MD5 EXP-ADH-RC4-MD5
SSL_DH_anon_WITH_RC4_128_MD5 ADH-RC4-MD5
SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA EXP-ADH-DES-CBC-SHA
SSL_DH_anon_WITH_DES_CBC_SHA ADH-DES-CBC-SHA
SSL_DH_anon_WITH_3DES_EDE_CBC_SHA ADH-DES-CBC3-SHA
SSL_FORTEZZA_KEA_WITH_NULL_SHA Not implemented.
SSL_FORTEZZA_KEA_WITH_FORTEZZA_CBC_SHA Not implemented.
SSL_FORTEZZA_KEA_WITH_RC4_128_SHA Not implemented.
TLS_RSA_WITH_NULL_MD5 NULL-MD5
TLS_RSA_WITH_NULL_SHA NULL-SHA
TLS_RSA_EXPORT_WITH_RC4_40_MD5 EXP-RC4-MD5
TLS_RSA_WITH_RC4_128_MD5 RC4-MD5
TLS_RSA_WITH_RC4_128_SHA RC4-SHA
TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5 EXP-RC2-CBC-MD5
TLS_RSA_WITH_IDEA_CBC_SHA IDEA-CBC-SHA
TLS_RSA_EXPORT_WITH_DES40_CBC_SHA EXP-DES-CBC-SHA
TLS_RSA_WITH_DES_CBC_SHA DES-CBC-SHA
TLS_RSA_WITH_3DES_EDE_CBC_SHA DES-CBC3-SHA
TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA Not implemented.
TLS_DH_DSS_WITH_DES_CBC_SHA Not implemented.
TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA Not implemented.
TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA Not implemented.
TLS_DH_RSA_WITH_DES_CBC_SHA Not implemented.
TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA Not implemented.
TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA EXP-EDH-DSS-DES-CBC-SHA
TLS_DHE_DSS_WITH_DES_CBC_SHA EDH-DSS-CBC-SHA
TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA EDH-DSS-DES-CBC3-SHA
TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA EXP-EDH-RSA-DES-CBC-SHA
TLS_DHE_RSA_WITH_DES_CBC_SHA EDH-RSA-DES-CBC-SHA
TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA EDH-RSA-DES-CBC3-SHA
TLS_DH_anon_EXPORT_WITH_RC4_40_MD5 EXP-ADH-RC4-MD5
TLS_DH_anon_WITH_RC4_128_MD5 ADH-RC4-MD5
TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA EXP-ADH-DES-CBC-SHA
TLS_DH_anon_WITH_DES_CBC_SHA ADH-DES-CBC-SHA
TLS_DH_anon_WITH_3DES_EDE_CBC_SHA ADH-DES-CBC3-SHA
TLS_RSA_WITH_AES_128_CBC_SHA AES128-SHA
TLS_RSA_WITH_AES_256_CBC_SHA AES256-SHA
TLS_DH_DSS_WITH_AES_128_CBC_SHA DH-DSS-AES128-SHA
TLS_DH_DSS_WITH_AES_256_CBC_SHA DH-DSS-AES256-SHA
TLS_DH_RSA_WITH_AES_128_CBC_SHA DH-RSA-AES128-SHA
TLS_DH_RSA_WITH_AES_256_CBC_SHA DH-RSA-AES256-SHA
TLS_DHE_DSS_WITH_AES_128_CBC_SHA DHE-DSS-AES128-SHA
TLS_DHE_DSS_WITH_AES_256_CBC_SHA DHE-DSS-AES256-SHA
TLS_DHE_RSA_WITH_AES_128_CBC_SHA DHE-RSA-AES128-SHA
TLS_DHE_RSA_WITH_AES_256_CBC_SHA DHE-RSA-AES256-SHA
TLS_DH_anon_WITH_AES_128_CBC_SHA ADH-AES128-SHA
TLS_DH_anon_WITH_AES_256_CBC_SHA ADH-AES256-SHA
Note: These ciphers can also be used in SSL v3.
TLS_RSA_EXPORT1024_WITH_DES_CBC_SHA EXP1024-DES-CBC-SHA
TLS_RSA_EXPORT1024_WITH_RC4_56_SHA EXP1024-RC4-SHA
TLS_DHE_DSS_EXPORT1024_WITH_DES_CBC_SHA EXP1024-DHE-DSS-DES-CBC-SHA
TLS_DHE_DSS_EXPORT1024_WITH_RC4_56_SHA EXP1024-DHE-DSS-RC4-SHA
TLS_DHE_DSS_WITH_RC4_128_SHA DHE-DSS-RC4-SHA
SSL_CK_RC4_128_WITH_MD5 RC4-MD5
SSL_CK_RC4_128_EXPORT40_WITH_MD5 EXP-RC4-MD5
SSL_CK_RC2_128_CBC_WITH_MD5 RC2-MD5
SSL_CK_RC2_128_CBC_EXPORT40_WITH_MD5 EXP-RC2-MD5
SSL_CK_IDEA_128_CBC_WITH_MD5 IDEA-CBC-MD5
SSL_CK_DES_64_CBC_WITH_MD5 DES-CBC-MD5
SSL_CK_DES_192_EDE3_CBC_WITH_MD5 DES-CBC3-MD5
The non-ephemeral DH modes are currently unimplemented in OpenSSL because
there is no support for DH certificates.
Some compiled versions of OpenSSL may not include all the ciphers listed
here because some ciphers were excluded at compile time.
Verbose listing of all OpenSSL ciphers including NULL ciphers:
$ openssl ciphers -v 'ALL:eNULL'
Include all ciphers except NULL and anonymous DH then sort by strength:
$ openssl ciphers -v 'ALL:!ADH:@STRENGTH'
Include only 3DES ciphers and then place RSA ciphers last:
$ openssl ciphers -v '3DES:+RSA'
Include all RC4 ciphers but leave out those without authentication:
$ openssl ciphers -v 'RC4:!COMPLEMENTOFDEFAULT'
Include all ciphers with RSA authentication but leave out ciphers without
encryption:
$ openssl ciphers -v 'RSA:!COMPLEMENTOFALL'
The COMPLEMENTOFALL and COMPLEMENTOFDEFAULT selection options were added
in version 0.9.7.
openssl crl [-fingerprint] [-hash] [-issuer] [-lastupdate] [-nextupdate]
[-noout] [-text] [-CAfile file] [-CApath dir] [-in file]
[-inform DER | PEM] [-out file] [-outform DER | PEM]
The crl command processes CRL files in DER or PEM format.
The options are as follows:
-CAfile file
Verify the signature on a CRL by looking up the issuing certificate
in file.
-CApath directory
Verify the signature on a CRL by looking up the issuing certificate
in dir. This directory must be a standard certificate directory,
i.e. a hash of each subject name (using x509 -hash) should be
linked to each certificate.
-fingerprint
Print the CRL fingerprint.
-hash
Output a hash of the issuer name. This can be used to look up CRLs
in a directory by issuer name.
-in file
This specifies the input file to read from, or standard input if
this option is not specified.
-inform DER | PEM
This specifies the input format. DER format is a DER-encoded CRL
structure. PEM (the default) is a base64-encoded version of the DER
form with header and footer lines.
-issuer
Output the issuer name.
-lastupdate
Output the lastUpdate field.
-nextupdate
Output the nextUpdate field.
-noout
Don't output the encoded version of the CRL.
-out file
Specifies the output file to write to, or standard output by de-
fault.
-outform DER | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-text
Print out the CRL in text form.
The PEM CRL format uses the header and footer lines:
-----BEGIN X509 CRL-----
-----END X509 CRL-----
Convert a CRL file from PEM to DER:
$ openssl crl -in crl.pem -outform DER -out crl.der
Output the text form of a DER-encoded certificate:
$ openssl crl -in crl.der -inform DER -text -noout
Ideally, it should be possible to create a CRL using appropriate options
and files too.
openssl crl2pkcs7 [-nocrl] [-certfile file] [-in file]
[-inform DER | PEM] [-out file] [-outform DER | PEM]
The crl2pkcs7 command takes an optional CRL and one or more certificates
and converts them into a PKCS#7 degenerate "certificates only" structure.
The options are as follows:
-certfile file
Specifies a file containing one or more certificates in PEM format.
All certificates in the file will be added to the PKCS#7 structure.
This option can be used more than once to read certificates from
multiple files.
-in file
This specifies the input file to read a CRL from, or standard input
if this option is not specified.
-inform DER | PEM
This specifies the CRL input format. DER format is a DER-encoded
CRL structure. PEM (the default) is a base64-encoded version of the
DER form with header and footer lines.
-nocrl
Normally, a CRL is included in the output file. With this option,
no CRL is included in the output file and a CRL is not read from
the input file.
-out file
Specifies the output file to write the PKCS#7 structure to, or
standard output by default.
-outform DER | PEM
This specifies the PKCS#7 structure output format. DER format is a
DER-encoded PKCS#7 structure. PEM (the default) is a base64-encoded
version of the DER form with header and footer lines.
Create a PKCS#7 structure from a certificate and CRL:
$ openssl crl2pkcs7 -in crl.pem -certfile cert.pem -out p7.pem
Create a PKCS#7 structure in DER format with no CRL from several dif-
ferent certificates:
$ openssl crl2pkcs7 -nocrl -certfile newcert.pem \
-certfile demoCA/cacert.pem -outform DER -out p7.der
The output file is a PKCS#7 signed data structure containing no signers
and just certificates and an optional CRL.
This utility can be used to send certificates and CAs to Netscape as part
of the certificate enrollment process. This involves sending the DER-
encoded output as MIME type application/x-x509-user-cert.
The PEM-encoded form with the header and footer lines removed can be used
to install user certificates and CAs in MSIE using the Xenroll control.
openssl dgst -sha384 | -sha512 [-dss1 | -md2 | -md4 | -md5 | -ripemd160 |
-sha1 | -sha224 | -sha256 |] [-binary] [-c] [-d] [-hex] [-engine id]
[-keyform ENGINE | PEM] [-out file] [-passin arg] [-prverify file]
[-rand file ...] [-sign file] [-signature file] [-verify file] [file ...]
openssl
md2 | md4 | md5 | ripemd160 | sha | sha1 | sha224 | sha256 | sha384 | sha512
[-c] [-d] [file ...]
The digest functions output the message digest of a supplied file or
files in hexadecimal form. They can also be used for digital signing and
verification.
The options are as follows:
-binary Output the digest or signature in binary form.
-c Print out the digest in two-digit groups separated by colons;
only relevant if hex format output is used.
-d Print out BIO debugging information.
-engine id
Specifying an engine (by it's unique id string) will cause dgst
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be
set as the default for all available algorithms.
-hex Digest is to be output as a hex dump. This is the default case
for a "normal" digest as opposed to a digital signature.
-keyform ENGINE | PEM
Key file format.
-out file
The file to output to, or standard output by default.
-passin arg
The key password source. For more information about the format
of arg, see the PASS PHRASE ARGUMENTS section above.
-prverify file
Verify the signature using the private key in file. The output
is either "Verification OK" or "Verification Failure".
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified separated by a ':'.
-sign file
Digitally sign the digest using the private key in file.
-signature file
The actual signature to verify.
-verify file
Verify the signature using the public key in file. The output is
either "Verification OK" or "Verification Failure".
file ...
File or files to digest. If no files are specified then standard
input is used.
The digest of choice for all new applications is SHA1. Other digests are,
however, still widely used.
If you wish to sign or verify data using the DSA algorithm, the dss1 dig-
est must be used.
A source of random numbers is required for certain signing algorithms, in
particular DSA.
The signing and verify options should only be used if a single file is
being signed or verified.
Diffie-Hellman Parameter Management. The dh command has been replaced by
dhparam. See DHPARAM below.
openssl dhparam [-2 | -5] [-C] [-check] [-dsaparam] [-noout] [-text]
[-engine id] [-in file] [-inform DER | PEM] [-out file]
[-outform DER | PEM] [-rand file ...] [numbits]
The dhparam command is used to manipulate DH parameter files.
The options are as follows:
-2, -5
The generator to use, either 2 or 5. 2 is the default. If present,
the input file is ignored and parameters are generated instead.
-C This option converts the parameters into C code. The parameters can
then be loaded by calling the get_dhnumbits() function.
-check
Check the DH parameters.
-dsaparam
If this option is used, DSA rather than DH parameters are read or
created; they are converted to DH format. Otherwise, "strong"
primes (such that (p-1)/2 is also prime) will be used for DH param-
eter generation.
DH parameter generation with the -dsaparam option is much faster,
and the recommended exponent length is shorter, which makes DH key
exchange more efficient. Beware that with such DSA-style DH parame-
ters, a fresh DH key should be created for each use to avoid small-
subgroup attacks that may be possible otherwise.
-engine id
Specifying an engine (by it's unique id string) will cause dhparam
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be set
as the default for all available algorithms.
-in file
This specifies the input file to read parameters from, or standard
input if this option is not specified.
-inform DER | PEM
This specifies the input format. The argument DER uses an ASN1 DER-
encoded form compatible with the PKCS#3 DHparameter structure. The
PEM form is the default format: it consists of the DER format
base64-encoded with additional header and footer lines.
-noout
This option inhibits the output of the encoded version of the
parameters.
numbits
This argument specifies that a parameter set should be generated of
size numbits. It must be the last option. If not present, a value
of 512 is used. If this value is present, the input file is ignored
and parameters are generated instead.
-out file
This specifies the output file to write parameters to. Standard
output is used if this option is not present. The output filename
should not be the same as the input filename.
-outform DER | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified, separated by a ':'.
-text
This option prints out the DH parameters in human readable form.
The program dhparam combines the functionality of the programs dh and
gendh in previous versions of OpenSSL and SSLeay. The dh and gendh pro-
grams are retained for now, but may have different purposes in future
versions of OpenSSL.
PEM format DH parameters use the header and footer lines:
-----BEGIN DH PARAMETERS-----
-----END DH PARAMETERS-----
OpenSSL currently only supports the older PKCS#3 DH, not the newer X9.42
DH.
This program manipulates DH parameters not keys.
There should be a way to generate and manipulate DH keys.
The dhparam command was added in OpenSSL 0.9.5. The -dsaparam option was
added in OpenSSL 0.9.6.
openssl dsa [-aes128 | -aes192 | -aes256 | -des | -des3] [-modulus]
[-noout] [-pubin] [-pubout] [-text] [-engine id] [-in file]
[-inform DER | PEM] [-out file] [-outform DER | PEM] [-passin arg]
[-passout arg]
The dsa command processes DSA keys. They can be converted between various
forms and their components printed out.
Note: This command uses the traditional SSLeay compatible format for
private key encryption: newer applications should use the more secure
PKCS#8 format using the pkcs8 command.
The options are as follows:
-aes128 | -aes192 | -aes256 | -des | -des3
These options encrypt the private key with the AES, DES, or the
triple DES ciphers, respectively, before outputting it. A pass
phrase is prompted for. If none of these options is specified, the
key is written in plain text. This means that using the dsa utility
to read in an encrypted key with no encryption option can be used
to remove the pass phrase from a key, or by setting the encryption
options it can be use to add or change the pass phrase. These op-
tions can only be used with PEM format output files.
-engine id
Specifying an engine (by it's unique id string) will cause dsa to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-in file
This specifies the input file to read a key from, or standard input
if this option is not specified. If the key is encrypted, a pass
phrase will be prompted for.
-inform DER | PEM
This specifies the input format. The DER argument with a private
key uses an ASN1 DER-encoded form of an ASN.1 SEQUENCE consisting
of the values of version (currently zero), P, Q, G, and the public
and private key components, respectively, as ASN.1 INTEGERs. When
used with a public key it uses a SubjectPublicKeyInfo structure: it
is an error if the key is not DSA.
The PEM form is the default format: it consists of the DER format
base64-encoded with additional header and footer lines. In the case
of a private key, PKCS#8 format is also accepted.
-modulus
This option prints out the value of the public key component of the
key.
-noout
This option prevents output of the encoded version of the key.
-out file
This specifies the output file to write a key to, or standard out-
put if not specified. If any encryption options are set then a pass
phrase will be prompted for. The output filename should not be the
same as the input filename.
-outform DER | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-passin arg
The input file password source. For more information about the for-
mat of arg, see the PASS PHRASE ARGUMENTS section above.
-passout arg
The output file password source. For more information about the
format of arg, see the PASS PHRASE ARGUMENTS section above.
-pubin
By default, a private key is read from the input file. With this
option a public key is read instead.
-pubout
By default, a private key is output. With this option a public key
will be output instead. This option is automatically set if the in-
put is a public key.
-text
Prints out the public/private key components and parameters.
The PEM private key format uses the header and footer lines:
-----BEGIN DSA PRIVATE KEY-----
-----END DSA PRIVATE KEY-----
The PEM public key format uses the header and footer lines:
-----BEGIN PUBLIC KEY-----
-----END PUBLIC KEY-----
To remove the pass phrase on a DSA private key:
$ openssl dsa -in key.pem -out keyout.pem
To encrypt a private key using triple DES:
$ openssl dsa -in key.pem -des3 -out keyout.pem
To convert a private key from PEM to DER format:
$ openssl dsa -in key.pem -outform DER -out keyout.der
To print out the components of a private key to standard output:
$ openssl dsa -in key.pem -text -noout
To just output the public part of a private key:
$ openssl dsa -in key.pem -pubout -out pubkey.pem
openssl dsaparam [-C] [-genkey] [-noout] [-text] [-engine id] [-in file]
[-inform DER | PEM] [-out file] [-outform DER | PEM] [-rand file ...]
[numbits]
The dsaparam command is used to manipulate or generate DSA parameter
files.
The options are as follows:
-C This option converts the parameters into C code. The parameters can
then be loaded by calling the get_dsaXXX() function.
-engine id
Specifying an engine (by it's unique id string) will cause dsaparam
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be set
as the default for all available algorithms.
-genkey
This option will generate a DSA either using the specified or gen-
erated parameters.
-in file
This specifies the input file to read parameters from, or standard
input if this option is not specified. If the numbits parameter is
included, then this option will be ignored.
-inform DER | PEM
This specifies the input format. The DER argument uses an ASN1 DER-
encoded form compatible with RFC 2459 (PKIX) DSS-Parms that is a
SEQUENCE consisting of p, q and g, respectively. The PEM form is
the default format: it consists of the DER format base64-encoded
with additional header and footer lines.
-noout
This option inhibits the output of the encoded version of the
parameters.
numbits
This option specifies that a parameter set should be generated of
size numbits. If this option is included, the input file (if any)
is ignored.
-out file
This specifies the output file to write parameters to. Standard
output is used if this option is not present. The output filename
should not be the same as the input filename.
-outform DER | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified, separated by a ':'.
-text
This option prints out the DSA parameters in human readable form.
PEM format DSA parameters use the header and footer lines:
-----BEGIN DSA PARAMETERS-----
-----END DSA PARAMETERS-----
DSA parameter generation is a slow process and as a result the same set
of DSA parameters is often used to generate several distinct keys.
openssl enc -ciphername [-AadePp] [-debug] [-engine id] [-nopad]
[-nosalt] [-salt] [-bufsize number] [-in file] [-iv IV] [-K key]
[-k password] [-kfile file] [-out file] [-pass arg] [-S salt]
The symmetric cipher commands allow data to be encrypted or decrypted us-
ing various block and stream ciphers using keys based on passwords or ex-
plicitly provided. Base64 encoding or decoding can also be performed ei-
ther by itself or in addition to the encryption or decryption.
The options are as follows:
-A If the -a option is set, then base64 process the data on one line.
-a Base64 process the data. This means that if encryption is taking
place, the data is base64-encoded after encryption. If decryption
is set, the input data is base64 decoded before being decrypted.
-bufsize number
Set the buffer size for I/O.
-d Decrypt the input data.
-debug
Debug the BIOs used for I/O.
-e Encrypt the input data: this is the default.
-engine id
Specifying an engine (by it's unique id string) will cause enc to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-in file
The input file; standard input by default.
-iv IV
The actual IV (initialisation vector) to use: this must be
represented as a string comprised only of hex digits. When only the
key is specified using the -K option, the IV must explicitly be de-
fined. When a password is being specified using one of the other
options, the IV is generated from this password.
-K key
The actual key to use: this must be represented as a string
comprised only of hex digits. If only the key is specified, the IV
must be additionally specified using the -iv option. When both a
key and a password are specified, the key given with the -K option
will be used and the IV generated from the password will be taken.
It probably does not make much sense to specify both key and
password.
-k password
The password to derive the key from. This is for compatibility with
previous versions of OpenSSL. Superseded by the -pass option.
-kfile file
Read the password to derive the key from the first line of file.
This is for compatibility with previous versions of OpenSSL. Super-
seded by the -pass option.
-nopad
Disable standard block padding.
-nosalt
Don't use a salt in the key derivation routines. This is the de-
fault for compatibility with previous versions of OpenSSL and
SSLeay.
-out file
The output file, standard output by default.
-P Print out the salt, key, and IV used, then immediately exit; don't
do any encryption or decryption.
-p Print out the salt, key, and IV used.
-pass arg
The password source. For more information about the format of arg,
see the PASS PHRASE ARGUMENTS section above.
-S salt
The actual salt to use: this must be represented as a string
comprised only of hex digits.
-salt
Use a salt in the key derivation routines. This option should
ALWAYS be used unless compatibility with previous versions of
OpenSSL or SSLeay is required. This option is only present on
OpenSSL versions 0.9.5 or above.
The program can be called either as openssl ciphername or openssl enc -
ciphername.
A password will be prompted for to derive the key and IV if necessary.
The -salt option should ALWAYS be used if the key is being derived from a
password unless compatibility with previous versions of OpenSSL and
SSLeay is necessary.
Without the -salt option it is possible to perform efficient dictionary
attacks on the password and to attack stream cipher encrypted data. The
reason for this is that without the salt the same password always gen-
erates the same encryption key. When the salt is being used the first
eight bytes of the encrypted data are reserved for the salt: it is gen-
erated at random when encrypting a file and read from the encrypted file
when it is decrypted.
Some of the ciphers do not have large keys and others have security im-
plications if not used correctly. A beginner is advised to just use a
strong block cipher in CBC mode such as bf or des3.
All the block ciphers normally use PKCS#5 padding also known as standard
block padding: this allows a rudimentary integrity or password check to
be performed. However, since the chance of random data passing the test
is better than 1 in 256, it isn't a very good test.
If padding is disabled, the input data must be a multiple of the cipher
block length.
All RC2 ciphers have the same key and effective key length.
Blowfish and RC5 algorithms use a 128-bit key.
aes-128-cbc 128-bit AES in CBC mode
aes128 Alias for aes-128-cbc
aes-128-cfb 128-bit AES in CFB mode
aes-128-ecb 128-bit AES in ECB mode
aes-128-ofb 128-bit AES in OFB mode
aes-192-cbc 192-bit AES in CBC mode
aes192 Alias for aes-192-cbc
aes-192-cfb 192-bit AES in CFB mode
aes-192-ecb 192-bit AES in ECB mode
aes-192-ofb 192-bit AES in OFB mode
aes-256-cbc 256-bit AES in CBC mode
aes256 Alias for aes-256-cbc
aes-256-cfb 256-bit AES in CFB mode
aes-256-ecb 256-bit AES in ECB mode
aes-256-ofb 256-bit AES in OFB mode
base64 Base 64
bf-cbc Blowfish in CBC mode
bf Alias for bf-cbc
blowfish Alias for bf-cbc
bf-cfb Blowfish in CFB mode
bf-ecb Blowfish in ECB mode
bf-ofb Blowfish in OFB mode
cast-cbc CAST in CBC mode
cast Alias for cast-cbc
cast5-cbc CAST5 in CBC mode
cast5-cfb CAST5 in CFB mode
cast5-ecb CAST5 in ECB mode
cast5-ofb CAST5 in OFB mode
des-cbc DES in CBC mode
des Alias for des-cbc
des-cfb DES in CBC mode
des-ecb DES in ECB mode
des-ofb DES in OFB mode
des-ede-cbc Two key triple DES EDE in CBC mode
des-ede Two key triple DES EDE in ECB mode
des-ede-cfb Two key triple DES EDE in CFB mode
des-ede-ofb Two key triple DES EDE in OFB mode
des-ede3-cbc Three key triple DES EDE in CBC mode
des-ede3 Three key triple DES EDE in ECB mode
des3 Alias for des-ede3-cbc
des-ede3-cfb Three key triple DES EDE CFB mode
des-ede3-ofb Three key triple DES EDE in OFB mode
desx-cbc DESX algorithm
desx Alias for desx-cbc
idea-cbc IDEA algorithm in CBC mode
idea same as idea-cbc (see below)
idea-cfb IDEA in CFB mode
idea-ecb IDEA in ECB mode
idea-ofb IDEA in OFB mode
rc2-cbc 128-bit RC2 in CBC mode
rc2 Alias for rc2-cbc
rc2-cfb 128-bit RC2 in CFB mode
rc2-ecb 128-bit RC2 in ECB mode
rc2-ofb 128-bit RC2 in OFB mode
rc2-64-cbc 64-bit RC2 in CBC mode
rc2-40-cbc 40-bit RC2 in CBC mode
rc4 128-bit RC4
rc4-64 64-bit RC4
rc4-40 40-bit RC4
rc5-cbc RC5 cipher in CBC mode
rc5 Alias for rc5-cbc
rc5-cfb RC5 cipher in CBC mode
rc5-ecb RC5 cipher in CBC mode
rc5-ofb RC5 cipher in CBC mode
Just base64 encode a binary file:
$ openssl base64 -in file.bin -out file.b64
Decode the same file:
$ openssl base64 -d -in file.b64 -out file.bin
Encrypt a file using triple DES in CBC mode using a prompted password:
$ openssl des3 -salt -in file.txt -out file.des3
Decrypt a file using a supplied password:
$ openssl des3 -d -in file.des3 -out file.txt -k mypassword
Encrypt a file then base64 encode it (so it can be sent via mail for ex-
ample) using Blowfish in CBC mode:
$ openssl bf -a -salt -in file.txt -out file.bf
Base64 decode a file then decrypt it:
$ openssl bf -d -a -in file.bf -out file.txt
The -A option when used with large files doesn't work properly.
There should be an option to allow an iteration count to be included.
The enc program only supports a fixed number of algorithms with certain
parameters. Therefore it is not possible to use RC2 with a 76-bit key or
RC4 with an 84-bit key with this program.
To use the idea algorithm, you need to obtain a patent licence, cf. e.g.
http://www.mediacrypt.com/_contents/10_idea/102040_li_nc.asp or the site
map, but it might not always be disabled by default.
openssl errstr [-stats] errno ...
The errstr command performs error number to error string conversion, gen-
erating a human-readable string representing the error code errno. The
string is obtained through the ERR_error_string_n(3) function and has the
following format:
error:[error code]:[library name]:[function name]:[reason string]
[error code] is an 8-digit hexadecimal number. The remaining fields
[library name], [function name], and [reason string] are all ASCII text.
The options are as follows:
-stats Print debugging statistics about various aspects of the hash
table.
The following error code:
27594:error:2006D080:lib(32):func(109):reason(128):bss_file.c:107:
...can be displayed with:
$ openssl errstr 2006D080
...to produce the error message:
error:2006D080:BIO routines:BIO_new_file:no such file
Generation of Diffie-Hellman Parameters. Replaced by dhparam. See DHPARAM
above.
openssl gendsa [-aes128 | -aes192 | -aes256 | -des | -des3] [-engine id]
[-out file] [-rand file ...] [paramfile]
The gendsa command generates a DSA private key from a DSA parameter file
(which will typically be generated by the openssl dsaparam command).
The options are as follows:
-aes128 | -aes192 | -aes256 | -des | -des3
These options encrypt the private key with the AES, DES, or the
triple DES ciphers, respectively, before outputting it. A pass
phrase is prompted for. If none of these options are specified, no
encryption is used.
-engine id
Specifying an engine (by it's unique id string) will cause gendsa
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be set
as the default for all available algorithms.
-out file
The output file. If this argument is not specified, standard output
is used.
paramfile
This option specifies the DSA parameter file to use. The parameters
in this file determine the size of the private key. DSA parameters
can be generated and examined using the openssl dsaparam command.
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified separated by a ':'.
DSA key generation is little more than random number generation so it is
much quicker than RSA key generation, for example.
openssl genrsa [-aes128 | -aes192 | -aes256 | -des | -des3] [-engine id]
[-3 | -f4] [-out file] [-passout arg] [-rand file ...] [numbits]
The genrsa command generates an RSA private key.
The options are as follows:
-aes128 | -aes192 | -aes256 | -des | -des3
These options encrypt the private key with the AES, DES, or the
triple DES ciphers, respectively, before outputting it. If none of
these options are specified, no encryption is used. If encryption
is used, a pass phrase is prompted for, if it is not supplied via
the -passout option.
-engine id
Specifying an engine (by it's unique id string) will cause genrsa
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be set
as the default for all available algorithms.
-3 | -f4
The public exponent to use, either 3 or 65537. The default is
65537.
numbits
The size of the private key to generate in bits. This must be the
last option specified. The default is 512.
-out file
The output file. If this argument is not specified, standard output
is used.
-passout arg
The output file password source. For more information about the
format of arg, see the PASS PHRASE ARGUMENTS section above.
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified separated by a ':'.
RSA private key generation essentially involves the generation of two
prime numbers. When generating a private key, various symbols will be
output to indicate the progress of the generation. A '.' represents each
number which has passed an initial sieve test; '+' means a number has
passed a single round of the Miller-Rabin primality test. A newline means
that the number has passed all the prime tests (the actual number depends
on the key size).
Because key generation is a random process, the time taken to generate a
key may vary somewhat.
A quirk of the prime generation algorithm is that it cannot generate
small primes. Therefore the number of bits should not be less that 64.
For typical private keys this will not matter because for security rea-
sons they will be much larger (typically 1024 bits).
openssl nseq [-toseq] [-in file] [-out file]
The nseq command takes a file containing a Netscape certificate sequence
and prints out the certificates contained in it or takes a file of certi-
ficates and converts it into a Netscape certificate sequence.
The options are as follows:
-in file
This specifies the input file to read, or standard input if this
option is not specified.
-out file
Specifies the output file, or standard output by default.
-toseq Normally, a Netscape certificate sequence will be input and the
output is the certificates contained in it. With the -toseq op-
tion the situation is reversed: a Netscape certificate sequence
is created from a file of certificates.
Output the certificates in a Netscape certificate sequence:
$ openssl nseq -in nseq.pem -out certs.pem
Create a Netscape certificate sequence:
$ openssl nseq -in certs.pem -toseq -out nseq.pem
The PEM-encoded form uses the same headers and footers as a certificate:
-----BEGIN CERTIFICATE-----
-----END CERTIFICATE-----
A Netscape certificate sequence is a Netscape specific form that can be
sent to browsers as an alternative to the standard PKCS#7 format when
several certificates are sent to the browser: for example during certifi-
cate enrollment. It is used by the Netscape certificate server, for exam-
ple.
This program needs a few more options, like allowing DER or PEM input and
output files and allowing multiple certificate files to be used.
openssl ocsp [-no_cert_checks] [-no_cert_verify] [-no_certs] [-no_chain]
[-no_intern] [-no_nonce] [-no_signature_verify] [-nonce] [-noverify]
[-req_text] [-resp_key_id] [-resp_no_certs] [-resp_text] [-text]
[-trust_other] [-CA file] [-CAfile file] [-CApath directory] [-cert file]
[-host hostname:port] [-index indexfile] [-issuer file] [-ndays days]
[-nmin minutes] [-nrequest number] [-out file] [-path path]
[-port portnum] [-reqin file] [-reqout file] [-respin file]
[-respout file] [-rkey file] [-rother file] [-rsigner file]
[-serial number] [-sign_other file] [-signer file] [-signkey file]
[-status_age age] [-url responder_url] [-VAfile file]
[-validity_period nsec] [-verify_other file]
The Online Certificate Status Protocol (OCSP) enables applications to
determine the (revocation) state of an identified certificate (RFC 2560).
The ocsp command performs many common OCSP tasks. It can be used to print
out requests and responses, create requests and send queries to an OCSP
responder, and behave like a mini OCSP server itself.
The options are as follows:
-CAfile file, -CApath directory
file or path containing trusted CA certificates. These are used to
verify the signature on the OCSP response.
-cert file
Add the certificate file to the request. The issuer certificate is
taken from the previous -issuer option, or an error occurs if no
issuer certificate is specified.
-host hostname:port, -path path
If the -host option is present, then the OCSP request is sent to
the host hostname on port port. -path specifies the HTTP path name
to use, or '/' by default.
-issuer file
This specifies the current issuer certificate. This option can be
used multiple times. The certificate specified in file must be in
PEM format.
-no_cert_checks
Don't perform any additional checks on the OCSP response signer's
certificate. That is, do not make any checks to see if the signer's
certificate is authorised to provide the necessary status informa-
tion: as a result this option should only be used for testing pur-
poses.
-no_cert_verify
Don't verify the OCSP response signer's certificate at all. Since
this option allows the OCSP response to be signed by any certifi-
cate, it should only be used for testing purposes.
-no_certs
Don't include any certificates in signed request.
-no_chain
Do not use certificates in the response as additional untrusted CA
certificates.
-no_intern
Ignore certificates contained in the OCSP response when searching
for the signer's certificate. With this option, the signer's certi-
ficate must be specified with either the -verify_certs or -VAfile
options.
-no_signature_verify
Don't check the signature on the OCSP response. Since this option
tolerates invalid signatures on OCSP responses, it will normally
only be used for testing purposes.
-nonce, -no_nonce
Add an OCSP nonce extension to a request or disable an OCSP nonce
addition. Normally, if an OCSP request is input using the -respin
option no nonce is added: using the -nonce option will force addi-
tion of a nonce. If an OCSP request is being created (using the
-cert and -serial options) a nonce is automatically added; specify-
ing -no_nonce overrides this.
-noverify
Don't attempt to verify the OCSP response signature or the nonce
values. This option will normally only be used for debugging since
it disables all verification of the responder's certificate.
-out file
Specify output file; default is standard output.
-req_text, -resp_text, -text
Print out the text form of the OCSP request, response, or both,
respectively.
-reqin file, -respin file
Read an OCSP request or response file from file. These option are
ignored if an OCSP request or response creation is implied by other
options (for example with the -serial, -cert, and -host options).
-reqout file, -respout file
Write out the DER-encoded certificate request or response to file.
-serial num
Same as the -cert option except the certificate with serial number
num is added to the request. The serial number is interpreted as a
decimal integer unless preceded by '0x'. Negative integers can also
be specified by preceding the value with a '-' sign.
-sign_other file
Additional certificates to include in the signed request.
-signer file, -signkey file
Sign the OCSP request using the certificate specified in the
-signer option and the private key specified by the -signkey op-
tion. If the -signkey option is not present, then the private key
is read from the same file as the certificate. If neither option is
specified, the OCSP request is not signed.
-trust_other
The certificates specified by the -verify_certs option should be
explicitly trusted and no additional checks will be performed on
them. This is useful when the complete responder certificate chain
is not available or trusting a root CA is not appropriate.
-url responder_url
Specify the responder URL. Both HTTP and HTTPS (SSL/TLS) URLs can
be specified.
-VAfile file
file containing explicitly trusted responder certificates.
Equivalent to the -verify_certs and -trust_other options.
-validity_period nsec, -status_age age
These options specify the range of times, in seconds, which will be
tolerated in an OCSP response. Each certificate status response in-
cludes a notBefore time and an optional notAfter time. The current
time should fall between these two values, but the interval between
the two times may be only a few seconds. In practice the OCSP
responder and clients' clocks may not be precisely synchronised and
so such a check may fail. To avoid this the -validity_period option
can be used to specify an acceptable error range in seconds, the
default value is 5 minutes.
If the notAfter time is omitted from a response, then this means
that new status information is immediately available. In this case
the age of the notBefore field is checked to see it is not older
than age seconds old. By default, this additional check is not per-
formed.
-verify_other file
file containing additional certificates to search when attempting
to locate the OCSP response signing certificate. Some responders
omit the actual signer's certificate from the response; this option
can be used to supply the necessary certificate in such cases.
-CA file
CA certificate corresponding to the revocation information in
indexfile.
-index indexfile
indexfile is a text index file in ca format containing certificate
revocation information.
If the -index option is specified, the ocsp utility is in responder
mode, otherwise it is in client mode. The request(s) the responder
processes can be either specified on the command line (using the
-issuer and -serial options), supplied in a file (using the -respin
option) or via external OCSP clients (if port or url is specified).
If the -index option is present, then the -CA and -rsigner options
must also be present.
-nmin minutes, -ndays days
Number of minutes or days when fresh revocation information is
available: used in the nextUpdate field. If neither option is
present, the nextUpdate field is omitted, meaning fresh revocation
information is immediately available.
-nrequest number
The OCSP server will exit after receiving number requests, default
unlimited.
-port portnum
Port to listen for OCSP requests on. The port may also be specified
using the -url option.
-resp_key_id
Identify the signer certificate using the key ID; default is to use
the subject name.
-resp_no_certs
Don't include any certificates in the OCSP response.
-rkey file
The private key to sign OCSP responses with; if not present, the
file specified in the -rsigner option is used.
-rother file
Additional certificates to include in the OCSP response.
-rsigner file
The certificate to sign OCSP responses with.
OCSP Response follows the rules specified in RFC 2560.
Initially the OCSP responder certificate is located and the signature on
the OCSP request checked using the responder certificate's public key.
Then a normal certificate verify is performed on the OCSP responder cer-
tificate building up a certificate chain in the process. The locations of
the trusted certificates used to build the chain can be specified by the
-CAfile and -CApath options or they will be looked for in the standard
OpenSSL certificates directory.
If the initial verify fails, the OCSP verify process halts with an error.
Otherwise the issuing CA certificate in the request is compared to the
OCSP responder certificate: if there is a match then the OCSP verify
succeeds.
Otherwise the OCSP responder certificate's CA is checked against the is-
suing CA certificate in the request. If there is a match and the
OCSPSigning extended key usage is present in the OCSP responder certifi-
cate, then the OCSP verify succeeds.
Otherwise the root CA of the OCSP responder's CA is checked to see if it
is trusted for OCSP signing. If it is, the OCSP verify succeeds.
If none of these checks is successful, the OCSP verify fails.
What this effectively means is that if the OCSP responder certificate is
authorised directly by the CA it is issuing revocation information about
(and it is correctly configured), then verification will succeed.
If the OCSP responder is a global responder which can give details about
multiple CAs and has its own separate certificate chain, then its root CA
can be trusted for OCSP signing. For example:
$ openssl x509 -in ocspCA.pem -addtrust OCSPSigning \
-out trustedCA.pem
Alternatively, the responder certificate itself can be explicitly trusted
with the -VAfile option.
As noted, most of the verify options are for testing or debugging pur-
poses. Normally, only the -CApath, -CAfile and (if the responder is a
`global VA') -VAfile options need to be used.
The OCSP server is only useful for test and demonstration purposes: it is
not really usable as a full OCSP responder. It contains only a very sim-
ple HTTP request handling and can only handle the POST form of OCSP
queries. It also handles requests serially, meaning it cannot respond to
new requests until it has processed the current one. The text index file
format of revocation is also inefficient for large quantities of revoca-
tion data.
It is possible to run the ocsp application in responder mode via a CGI
script using the -respin and -respout options.
Create an OCSP request and write it to a file:
$ openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem \
-reqout req.der
Send a query to an OCSP responder with URL http://ocsp.myhost.com/, save
the response to a file and print it out in text form:
$ openssl ocsp -issuer issuer.pem -cert c1.pem -cert c2.pem \
-url http://ocsp.myhost.com/ -resp_text -respout resp.der
Read in an OCSP response and print out in text form:
$ openssl ocsp -respin resp.der -text
OCSP server on port 8888 using a standard ca configuration, and a
separate responder certificate. All requests and responses are printed to
a file:
$ openssl ocsp -index demoCA/index.txt -port 8888 -rsigner \
rcert.pem -CA demoCA/cacert.pem -text -out log.txt
As above, but exit after processing one request:
$ openssl ocsp -index demoCA/index.txt -port 8888 -rsigner \
rcert.pem -CA demoCA/cacert.pem -nrequest 1
Query status information using internally generated request:
$ openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA \
demoCA/cacert.pem -issuer demoCA/cacert.pem -serial 1
Query status information using request read from a file and write the
response to a second file:
$ openssl ocsp -index demoCA/index.txt -rsigner rcert.pem -CA \
demoCA/cacert.pem -reqin req.der -respout resp.der
openssl passwd [-1 | -apr1 | -crypt] [-noverify] [-quiet] [-reverse]
[-stdin] [-table] [-in file] [-salt string] [password]
The passwd command computes the hash of a password typed at run-time or
the hash of each password in a list. The password list is taken from the
named file for option -in, from stdin for option -stdin, or from the com-
mand line, or from the terminal otherwise. The UNIX standard algorithm
crypt and the MD5-based BSD password algorithm 1 and its Apache variant
apr1 are available.
The options are as follows:
-1 Use the MD5 based BSD password algorithm 1.
-apr1
Use the apr1 algorithm (Apache variant of the) BSD algorithm.
-crypt
Use the crypt algorithm (default).
-in file
Read passwords from file.
-noverify
Don't verify when reading a password from the terminal.
-quiet
Don't output warnings when passwords given on the command line are
truncated.
-reverse
Switch table columns. This only makes sense in conjunction with the
-table option.
-salt string
Use the specified salt. When reading a password from the terminal,
this implies -noverify.
-stdin
Read passwords from stdin.
-table
In the output list, prepend the cleartext password and a TAB char-
acter to each password hash.
$ openssl passwd -crypt -salt xx password
prints "xxj31ZMTZzkVA".
$ openssl passwd -1 -salt xxxxxxxx password
prints "$1$xxxxxxxx$UYCIxa628.9qXjpQCjM4a.".
$ openssl passwd -apr1 -salt xxxxxxxx password
prints "$apr1$xxxxxxxx$dxHfLAsjHkDRmG83UXe8K0".
openssl pkcs7 [-noout] [-print_certs] [-text] [-engine id] [-in file]
[-inform DER | PEM] [-out file] [-outform DER | PEM]
The pkcs7 command processes PKCS#7 files in DER or PEM format.
The options are as follows:
-engine id
Specifying an engine (by it's unique id string) will cause pkcs7 to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-in file
This specifies the input file to read from, or standard input if
this option is not specified.
-inform DER | PEM
This specifies the input format. DER format is a DER-encoded PKCS#7
v1.5 structure. PEM (the default) is a base64-encoded version of
the DER form with header and footer lines.
-noout
Don't output the encoded version of the PKCS#7 structure (or certi-
ficates if -print_certs is set).
-out file
Specifies the output file to write to, or standard output by de-
fault.
-outform DER | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-print_certs
Prints out any certificates or CRLs contained in the file. They are
preceded by their subject and issuer names in a one-line format.
-text
Prints out certificate details in full rather than just subject and
issuer names.
Convert a PKCS#7 file from PEM to DER:
$ openssl pkcs7 -in file.pem -outform DER -out file.der
Output all certificates in a file:
$ openssl pkcs7 -in file.pem -print_certs -out certs.pem
The PEM PKCS#7 format uses the header and footer lines:
-----BEGIN PKCS7-----
-----END PKCS7-----
For compatibility with some CAs it will also accept:
-----BEGIN CERTIFICATE-----
-----END CERTIFICATE-----
There is no option to print out all the fields of a PKCS#7 file.
The PKCS#7 routines only understand PKCS#7 v 1.5 as specified in RFC
2315. They cannot currently parse, for example, the new CMS as described
in RFC 2630.
openssl pkcs8 [-embed] [-nocrypt] [-noiter] [-nooct] [-nsdb] [-topk8]
[-engine id] [-in file] [-inform DER | PEM] [-out file]
[-outform DER | PEM] [-passin arg] [-passout arg] [-v1 alg] [-v2 alg]
The pkcs8 command processes private keys in PKCS#8 format. It can handle
both unencrypted PKCS#8 PrivateKeyInfo format and EncryptedPrivateKeyInfo
format with a variety of PKCS#5 (v1.5 and v2.0) and PKCS#12 algorithms.
The options are as follows:
-embed
This option generates DSA keys in a broken format. The DSA parame-
ters are embedded inside the PrivateKey structure. In this form the
OCTET STRING contains an ASN1 SEQUENCE consisting of two struc-
tures: a SEQUENCE containing the parameters and an ASN1 INTEGER
containing the private key.
-engine id
Specifying an engine (by it's unique id string) will cause pkcs8 to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-in file
This specifies the input file to read a key from, or standard input
if this option is not specified. If the key is encrypted, a pass
phrase will be prompted for.
-inform DER | PEM
This specifies the input format. If a PKCS#8 format key is expected
on input, then either a DER- or PEM-encoded version of a PKCS#8 key
will be expected. Otherwise the DER or PEM format of the tradition-
al format private key is used.
-nocrypt
PKCS#8 keys generated or input are normally PKCS#8
EncryptedPrivateKeyInfo structures using an appropriate password-
based encryption algorithm. With this option, an unencrypted
PrivateKeyInfo structure is expected or output. This option does
not encrypt private keys at all and should only be used when abso-
lutely necessary. Certain software such as some versions of Java
code signing software use unencrypted private keys.
-noiter
Use an iteration count of 1. See the PKCS12 section below for a de-
tailed explanation of this option.
-nooct
This option generates RSA private keys in a broken format that some
software uses. Specifically the private key should be enclosed in
an OCTET STRING, but some software just includes the structure it-
self without the surrounding OCTET STRING.
-nsdb
This option generates DSA keys in a broken format compatible with
Netscape private key databases. The PrivateKey contains a SEQUENCE
consisting of the public and private keys, respectively.
-out file
This specifies the output file to write a key to, or standard out-
put by default. If any encryption options are set, a pass phrase
will be prompted for. The output filename should not be the same as
the input filename.
-outform DER | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-passin arg
The input file password source. For more information about the for-
mat of arg, see the PASS PHRASE ARGUMENTS section above.
-passout arg
The output file password source. For more information about the
format of arg, see the PASS PHRASE ARGUMENTS section above.
-topk8
Normally, a PKCS#8 private key is expected on input and a tradi-
tional format private key will be written. With the -topk8 option
the situation is reversed: it reads a traditional format private
key and writes a PKCS#8 format key.
-v1 alg
This option specifies a PKCS#5 v1.5 or PKCS#12 algorithm to use. A
complete list of possible algorithms is included below.
-v2 alg
This option enables the use of PKCS#5 v2.0 algorithms. Normally,
PKCS#8 private keys are encrypted with the password-based encryp-
tion algorithm called pbeWithMD5AndDES-CBC; this uses 56-bit DES
encryption but it was the strongest encryption algorithm supported
in PKCS#5 v1.5. Using the -v2 option PKCS#5 v2.0 algorithms are
used which can use any encryption algorithm such as 168-bit triple
DES or 128-bit RC2, however not many implementations support PKCS#5
v2.0 yet. If using private keys with OpenSSL then this doesn't
matter.
The alg argument is the encryption algorithm to use; valid values
include des, des3, and rc2. It is recommended that des3 is used.
The encrypted form of a PEM-encoded PKCS#8 file uses the following
headers and footers:
-----BEGIN ENCRYPTED PRIVATE KEY-----
-----END ENCRYPTED PRIVATE KEY-----
The unencrypted form uses:
-----BEGIN PRIVATE KEY-----
-----END PRIVATE KEY-----
Private keys encrypted using PKCS#5 v2.0 algorithms and high iteration
counts are more secure than those encrypted using the traditional SSLeay
compatible formats. So if additional security is considered important,
the keys should be converted.
The default encryption is only 56 bits because this is the encryption
that most current implementations of PKCS#8 support.
Some software may use PKCS#12 password-based encryption algorithms with
PKCS#8 format private keys: these are handled automatically but there is
no option to produce them.
It is possible to write out DER-encoded encrypted private keys in PKCS#8
format because the encryption details are included at an ASN1 level
whereas the traditional format includes them at a PEM level.
PKCS#5 V1.5 AND PKCS#12 ALGORITHMS
Various algorithms can be used with the -v1 command line option, includ-
ing PKCS#5 v1.5 and PKCS#12. These are described in more detail below.
PBE-MD2-DES | PBE-MD5-DES
These algorithms were included in the original PKCS#5 v1.5 specifi-
cation. They only offer 56 bits of protection since they both use
DES.
PBE-SHA1-RC2-64 | PBE-MD2-RC2-64 | PBE-MD5-RC2-64 | PBE-SHA1-DES
These algorithms are not mentioned in the original PKCS#5 v1.5
specification but they use the same key derivation algorithm and
are supported by some software. They are mentioned in PKCS#5 v2.0.
They use either 64-bit RC2 or 56-bit DES.
PBE-SHA1-RC4-128 | PBE-SHA1-RC4-40 | PBE-SHA1-3DES | PBE-SHA1-2DES
PBE-SHA1-RC2-128 | PBE-SHA1-RC2-40
These algorithms use the PKCS#12 password-based encryption algo-
rithm and allow strong encryption algorithms like triple DES or
128-bit RC2 to be used.
Convert a private key from traditional to PKCS#5 v2.0 format using triple
DES:
$ openssl pkcs8 -in key.pem -topk8 -v2 des3 -out enckey.pem
Convert a private key to PKCS#8 using a PKCS#5 1.5 compatible algorithm
(DES):
$ openssl pkcs8 -in key.pem -topk8 -out enckey.pem
Convert a private key to PKCS#8 using a PKCS#12 compatible algorithm
(3DES):
$ openssl pkcs8 -in key.pem -topk8 -out enckey.pem \
-v1 PBE-SHA1-3DES
Read a DER-unencrypted PKCS#8 format private key:
$ openssl pkcs8 -inform DER -nocrypt -in key.der -out key.pem
Convert a private key from any PKCS#8 format to traditional format:
$ openssl pkcs8 -in pk8.pem -out key.pem
Test vectors from this PKCS#5 v2.0 implementation were posted to the
pkcs-tng mailing list using triple DES, DES and RC2 with high iteration
counts; several people confirmed that they could decrypt the private keys
produced and therefore it can be assumed that the PKCS#5 v2.0 implementa-
tion is reasonably accurate at least as far as these algorithms are con-
cerned.
The format of PKCS#8 DSA (and other) private keys is not well documented:
it is hidden away in PKCS#11 v2.01, section 11.9; OpenSSL's default DSA
PKCS#8 private key format complies with this standard.
There should be an option that prints out the encryption algorithm in use
and other details such as the iteration count.
PKCS#8 using triple DES and PKCS#5 v2.0 should be the default private key
format; for OpenSSL compatibility, several of the utilities use the old
format at present.
openssl pkcs12 [-aes128 | -aes192 | -aes256 | -des | -des3] [-cacerts]
[-chain] [-clcerts] [-descert] [-export] [-info] [-keyex] [-keysig]
[-maciter] [-nocerts] [-nodes] [-noiter] [-nokeys] [-nomaciter]
[-nomacver] [-noout] [-twopass] [-CAfile file] [-CApath directory]
[-caname name] [-certfile file] [-certpbe alg] [-engine id] [-in file]
[-inkey file] [-keypbe alg] [-name name] [-out file] [-passin arg]
[-passout arg] [-rand file ...]
The pkcs12 command allows PKCS#12 files (sometimes referred to as PFX
files) to be created and parsed. PKCS#12 files are used by several pro-
grams including Netscape, MSIE and MS Outlook.
There are a lot of options; the meaning of some depends on whether a
PKCS#12 file is being created or parsed. By default, a PKCS#12 file is
parsed; a PKCS#12 file can be created by using the -export option (see
below).
-aes128 | -aes192 | -aes256 | -des | -des3
Use AES, DES, or triple DES, respectively, to encrypt private keys
before outputting. The default is triple DES.
-cacerts
Only output CA certificates (not client certificates).
-clcerts
Only output client certificates (not CA certificates).
-in file
This specifies the file of the PKCS#12 file to be parsed. Standard
input is used by default.
-info
Output additional information about the PKCS#12 file structure, al-
gorithms used, and iteration counts.
-nocerts
No certificates at all will be output.
-nodes
Don't encrypt the private keys at all.
-nokeys
No private keys will be output.
-nomacver
Don't attempt to verify the integrity MAC before reading the file.
-noout
This option inhibits output of the keys and certificates to the
output file version of the PKCS#12 file.
-out file
The file to write certificates and private keys to, standard output
by default. They are all written in PEM format.
-passin arg
The PKCS#12 file (i.e. input file) password source. For more infor-
mation about the format of arg, see the PASS PHRASE ARGUMENTS sec-
tion above.
-passout arg
Pass phrase source to encrypt any outputed private keys with. For
more information about the format of arg, see the PASS PHRASE
ARGUMENTS section above.
-twopass
Prompt for separate integrity and encryption passwords: most
software always assumes these are the same so this option will
render such PKCS#12 files unreadable.
-CAfile file
File of CAs (PEM format).
-CApath directory
Directory of CAs (PEM format).
-caname name
This specifies the "friendly name" for other certificates. This op-
tion may be used multiple times to specify names for all certifi-
cates in the order they appear. Netscape ignores friendly names on
other certificates, whereas MSIE displays them.
-certfile file
A file to read additional certificates from.
-certpbe alg, -keypbe alg
These options allow the algorithm used to encrypt the private key
and certificates to be selected. Although any PKCS#5 v1.5 or
PKCS#12 algorithms can be selected, it is advisable to only use
PKCS#12 algorithms. See the list in the PKCS12 NOTES section for
more information.
-chain
If this option is present, an attempt is made to include the entire
certificate chain of the user certificate. The standard CA store is
used for this search. If the search fails, it is considered a fatal
error.
-descert
Encrypt the certificate using triple DES; this may render the
PKCS#12 file unreadable by some "export grade" software. By de-
fault, the private key is encrypted using triple DES and the certi-
ficate using 40-bit RC2.
-engine id
Specifying an engine (by it's unique id string) will cause pkcs12
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be set
as the default for all available algorithms.
-export
This option specifies that a PKCS#12 file will be created rather
than parsed.
-in file
The file to read certificates and private keys from, standard input
by default. They must all be in PEM format. The order doesn't
matter but one private key and its corresponding certificate should
be present. If additional certificates are present, they will also
be included in the PKCS#12 file.
-inkey file
File to read private key from. If not present, a private key must
be present in the input file.
-keyex | -keysig
Specifies that the private key is to be used for key exchange or
just signing. This option is only interpreted by MSIE and similar
MS software. Normally, "export grade" software will only allow 512-
bit RSA keys to be used for encryption purposes, but arbitrary
length keys for signing. The -keysig option marks the key for sign-
ing only. Signing only keys can be used for S/MIME signing, authen-
ticode (ActiveX control signing) and SSL client authentication;
however, due to a bug only MSIE 5.0 and later support the use of
signing only keys for SSL client authentication.
-maciter
This option is included for compatibility with previous versions;
it used to be needed to use MAC iterations counts but they are now
used by default.
-name name
This specifies the "friendly name" for the certificate and private
key. This name is typically displayed in list boxes by software im-
porting the file.
-nomaciter, -noiter
These options affect the iteration counts on the MAC and key algo-
rithms. Unless you wish to produce files compatible with MSIE 4.0,
you should leave these options alone.
To discourage attacks by using large dictionaries of common pass-
words, the algorithm that derives keys from passwords can have an
iteration count applied to it: this causes a certain part of the
algorithm to be repeated and slows it down. The MAC is used to
check the file integrity but since it will normally have the same
password as the keys and certificates it could also be attacked. By
default, both MAC and encryption iteration counts are set to 2048;
using these options the MAC and encryption iteration counts can be
set to 1. Since this reduces the file security you should not use
these options unless you really have to. Most software supports
both MAC and key iteration counts. MSIE 4.0 doesn't support MAC
iteration counts, so it needs the -nomaciter option.
-out file
This specifies file to write the PKCS#12 file to. Standard output
is used by default.
-passin arg
Pass phrase source to decrypt any input private keys with. For more
information about the format of arg, see the PASS PHRASE ARGUMENTS
section above.
-passout arg
The PKCS#12 file (i.e. output file) password source. For more in-
formation about the format of arg, see the PASS PHRASE ARGUMENTS
section above.
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified separated by a ':'.
Although there are a large number of options, most of them are very rare-
ly used. For PKCS#12 file parsing, only -in and -out need to be used for
PKCS#12 file creation. -export and -name are also used.
If none of the -clcerts, -cacerts, or -nocerts options are present, then
all certificates will be output in the order they appear in the input
PKCS#12 files. There is no guarantee that the first certificate present
is the one corresponding to the private key. Certain software which re-
quires a private key and certificate and assumes the first certificate in
the file is the one corresponding to the private key: this may not always
be the case. Using the -clcerts option will solve this problem by only
outputting the certificate corresponding to the private key. If the CA
certificates are required, they can be output to a separate file using
the -nokeys and -cacerts options to just output CA certificates.
The -keypbe and -certpbe algorithms allow the precise encryption algo-
rithms for private keys and certificates to be specified. Normally, the
defaults are fine but occasionally software can't handle triple DES en-
crypted private keys; then the option -keypbe PBE-SHA1-RC2-40 can be used
to reduce the private key encryption to 40-bit RC2. A complete descrip-
tion of all algorithms is contained in the PKCS8 section above.
Parse a PKCS#12 file and output it to a file:
$ openssl pkcs12 -in file.p12 -out file.pem
Output only client certificates to a file:
$ openssl pkcs12 -in file.p12 -clcerts -out file.pem
Don't encrypt the private key:
$ openssl pkcs12 -in file.p12 -out file.pem -nodes
Print some info about a PKCS#12 file:
$ openssl pkcs12 -in file.p12 -info -noout
Create a PKCS#12 file:
$ openssl pkcs12 -export -in file.pem -out file.p12 \
-name "My Certificate"
Include some extra certificates:
$ openssl pkcs12 -export -in file.pem -out file.p12 \
-name "My Certificate" -certfile othercerts.pem
Some would argue that the PKCS#12 standard is one big bug :-)
Versions of OpenSSL before 0.9.6a had a bug in the PKCS#12 key generation
routines. Under rare circumstances this could produce a PKCS#12 file en-
crypted with an invalid key. As a result some PKCS#12 files which trig-
gered this bug from other implementations (MSIE or Netscape) could not be
decrypted by OpenSSL and similarly OpenSSL could produce PKCS#12 files
which could not be decrypted by other implementations. The chances of
producing such a file are relatively small: less than 1 in 256.
A side effect of fixing this bug is that any old invalidly encrypted
PKCS#12 files can no longer be parsed by the fixed version. Under such
circumstances the pkcs12 utility will report that the MAC is OK but fail
with a decryption error when extracting private keys.
This problem can be resolved by extracting the private keys and certifi-
cates from the PKCS#12 file using an older version of OpenSSL and re-
creating the PKCS#12 file from the keys and certificates using a newer
version of OpenSSL. For example:
$ old-openssl -in bad.p12 -out keycerts.pem
$ openssl -in keycerts.pem -export -name "My PKCS#12 file" \
-out fixed.p12
openssl rand [-base64] [-hex] [-engine id] [-out file] [-rand file ...]
num
The rand command outputs num pseudo-random bytes after seeding the random
number generator once. As in other openssl command line tools, PRNG seed-
ing uses the file $HOME/.rnd or .rnd in addition to the files given in
the -rand option. A new $HOME/.rnd or .rnd file will be written back if
enough seeding was obtained from these sources.
The options are as follows:
-base64
Perform base64 encoding on the output.
-engine id
Specifying an engine (by it's unique id string) will cause rand to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-hex Specify hexadecimal output.
-out file
Write to file instead of standard output.
-rand file ...
Use specified file or files, or EGD socket (see RAND_egd(3)) for
seeding the random number generator. Multiple files can be speci-
fied separated by a ':'.
openssl req [-asn1-kludge] [-batch] [-md2 | -md4 | -md5 | -sha1]
[-modulus] [-new] [-newhdr] [-nodes] [-noout] [-pubkey] [-subject]
[-text] [-utf8] [-verbose] [-verify] [-x509] [-config file] [-days n]
[-engine id] [-extensions section] [-in file] [-inform DER | PEM]
[-key keyfile] [-keyform DER | PEM] [-keyout file] [-nameopt option]
[-newkey dsa:file] [-newkey rsa:bits] [-out file] [-outform DER | PEM]
[-passin arg] [-passout arg] [-rand file ...] [-reqexts section]
[-reqopt option] [-set_serial n] [-subj arg]
The req command primarily creates and processes certificate requests in
PKCS#10 format. It can additionally create self-signed certificates, for
use as root CAs, for example.
The options are as follows:
-asn1-kludge
By default, the req command outputs certificate requests containing
no attributes in the correct PKCS#10 format. However certain CAs
will only accept requests containing no attributes in an invalid
form: this option produces this invalid format.
More precisely, the Attributes in a PKCS#10 certificate request are
defined as a SET OF Attribute. They are not optional, so if no at-
tributes are present then they should be encoded as an empty SET
OF. The invalid form does not include the empty SET OF, whereas the
correct form does.
It should be noted that very few CAs still require the use of this
option.
-batch
Non-interactive mode.
-config file
This allows an alternative configuration file to be specified; this
overrides the compile time filename or any specified in the
OPENSSL_CONF environment variable.
-days n
When the -x509 option is being used, this specifies the number of
days to certify the certificate for. The default is 30 days.
-engine id
Specifying an engine (by it's unique id string) will cause req to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-extensions section, -reqexts section
These options specify alternative sections to include certificate
extensions (if the -x509 option is present) or certificate request
extensions. This allows several different sections to be used in
the same configuration file to specify requests for a variety of
purposes.
-in file
This specifies the input file to read a request from, or standard
input if this option is not specified. A request is only read if
the creation options -new and -newkey are not specified.
-inform DER | PEM
This specifies the input format. The DER argument uses an ASN1 DER-
encoded form compatible with the PKCS#10. The PEM form is the de-
fault format: it consists of the DER format base64-encoded with ad-
ditional header and footer lines.
-key keyfile
This specifies the file to read the private key from. It also ac-
cepts PKCS#8 format private keys for PEM format files.
-keyform DER | PEM
The format of the private key file specified in the -key argument.
PEM is the default.
-keyout file
This gives the file to write the newly created private key to. If
this option is not specified, the filename present in the confi-
guration file is used.
-md2 | -md4 | -md5 | -sha1
This specifies the message digest to sign the request with. This
overrides the digest algorithm specified in the configuration file.
This option is ignored for DSA requests: they always use SHA1.
-modulus
This option prints out the value of the modulus of the public key
contained in the request.
-nameopt option, -reqopt option
These options determine how the subject or issuer names are
displayed. The option argument can be a single option or multiple
options separated by commas. Alternatively, these options may be
used more than once to set multiple options. See the X509 section
below for details.
-new This option generates a new certificate request. It will prompt the
user for the relevant field values. The actual fields prompted for
and their maximum and minimum sizes are specified in the configura-
tion file and any requested extensions.
If the -key option is not used, it will generate a new RSA private
key using information specified in the configuration file.
-newhdr
Adds the word NEW to the PEM file header and footer lines on the
outputed request. Some software (Netscape certificate server) and
some CAs need this.
-newkey arg
This option creates a new certificate request and a new private
key. The argument takes one of two forms: rsa:nbits, where nbits is
the number of bits, generates an RSA key nbits in size. dsa:file
generates a DSA key using the parameters in the file file.
-nodes
If this option is specified and a private key is created, it will
not be encrypted.
-noout
This option prevents output of the encoded version of the request.
-out file
This specifies the output file to write to, or standard output by
default.
-outform DER | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-passin arg
The input file password source. For more information about the for-
mat of arg, see the PASS PHRASE ARGUMENTS section above.
-passout arg
The output file password source. For more information about the
format of arg, see the PASS PHRASE ARGUMENTS section above.
-pubkey
Outputs the public key.
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified separated by a ':'.
-set_serial n
Serial number to use when outputting a self-signed certificate.
This may be specified as a decimal value or a hex value if preceded
by '0x'. It is possible to use negative serial numbers but this is
not recommended.
-subj arg
Sets subject name for new request or supersedes the subject name
when processing a request. The arg must be formatted as
/type0=value0/type1=value1/type2=...; characters may be escaped by
'\' (backslash), no spaces are skipped.
-subject
Output the request's subject.
-text
Prints out the certificate request in text form.
-utf8
This option causes field values to be interpreted as UTF8 strings;
by default they are interpreted as ASCII. This means that the field
values, whether prompted from a terminal or obtained from a confi-
guration file, must be valid UTF8 strings.
-verbose
Print extra details about the operations being performed.
-verify
Verifies the signature on the request.
-x509
This option outputs a self-signed certificate instead of a certifi-
cate request. This is typically used to generate a test certificate
or a self-signed root CA. The extensions added to the certificate
(if any) are specified in the configuration file. Unless specified
using the -set_serial option, 0 will be used for the serial number.
The configuration options are specified in the req section of the confi-
guration file. As with all configuration files, if no value is specified
in the specific section (i.e. req) then the initial unnamed or default
section is searched too.
The options available are described in detail below.
attributes
This specifies the section containing any request attributes: its
format is the same as distinguished_name. Typically these may con-
tain the challengePassword or unstructuredName types. They are
currently ignored by OpenSSL's request signing utilities, but some
CAs might want them.
default_bits
This specifies the default key size in bits. If not specified, 512
is used. It is used if the -new option is used. It can be overrid-
den by using the -newkey option.
default_keyfile
This is the default file to write a private key to. If not speci-
fied, the key is written to standard output. This can be overridden
by the -keyout option.
default_md
This option specifies the digest algorithm to use. Possible values
include md5 and sha1. If not present, MD5 is used. This option can
be overridden on the command line.
distinguished_name
This specifies the section containing the distinguished name fields
to prompt for when generating a certificate or certificate request.
The format is described in the next section.
encrypt_key
If this is set to no and a private key is generated, it is not en-
crypted. This is equivalent to the -nodes command line option. For
compatibility, encrypt_rsa_key is an equivalent option.
input_password | output_password
The passwords for the input private key file (if present) and the
output private key file (if one will be created). The command line
options -passin and -passout override the configuration file
values.
oid_file
This specifies a file containing additional OBJECT IDENTIFIERS.
Each line of the file should consist of the numerical form of the
object identifier, followed by whitespace, then the short name fol-
lowed by whitespace and finally the long name.
oid_section
This specifies a section in the configuration file containing extra
object identifiers. Each line should consist of the short name of
the object identifier followed by '=' and the numerical form. The
short and long names are the same when this option is used.
prompt
If set to the value no, this disables prompting of certificate
fields and just takes values from the config file directly. It also
changes the expected format of the distinguished_name and
attributes sections.
RANDFILE
This specifies a file in which random number seed information is
placed and read from, or an EGD socket (see RAND_egd(3)). It is
used for private key generation.
req_extensions
This specifies the configuration file section containing a list of
extensions to add to the certificate request. It can be overridden
by the -reqexts command line switch.
string_mask
This option masks out the use of certain string types in certain
fields. Most users will not need to change this option.
It can be set to several values: default, which is also the default
option, uses PrintableStrings, T61Strings and BMPStrings; if the
pkix value is used, then only PrintableStrings and BMPStrings will
be used. This follows the PKIX recommendation in RFC 2459. If the
-utf8only option is used, then only UTF8Strings will be used: this
is the PKIX recommendation in RFC 2459 after 2003. Finally, the
nombstr option just uses PrintableStrings and T61Strings: certain
software has problems with BMPStrings and UTF8Strings: in particu-
lar Netscape.
utf8 If set to the value yes, then field values are interpreted as UTF8
strings; by default they are interpreted as ASCII. This means that
the field values, whether prompted from a terminal or obtained from
a configuration file, must be valid UTF8 strings.
x509_extensions
This specifies the configuration file section containing a list of
extensions to add to a certificate generated when the -x509 switch
is used. It can be overridden by the -extensions command line
switch.
There are two separate formats for the distinguished name and attribute
sections. If the -prompt option is set to no, then these sections just
consist of field names and values: for example,
CN=My Name
OU=My Organization
emailAddress=someone@somewhere.org
This allows external programs (e.g. GUI based) to generate a template
file with all the field names and values and just pass it to req. An ex-
ample of this kind of configuration file is contained in the REQ EXAMPLES
section.
Alternatively if the -prompt option is absent or not set to no, then the
file contains field prompting information. It consists of lines of the
form:
fieldName="prompt"
fieldName_default="default field value"
fieldName_min= 2
fieldName_max= 4
"fieldName" is the field name being used, for example commonName (or CN).
The "prompt" string is used to ask the user to enter the relevant de-
tails. If the user enters nothing, the default value is used; if no de-
fault value is present, the field is omitted. A field can still be omit-
ted if a default value is present, if the user just enters the '.' char-
acter.
The number of characters entered must be between the fieldName_min and
fieldName_max limits: there may be additional restrictions based on the
field being used (for example countryName can only ever be two characters
long and must fit in a PrintableString).
Some fields (such as organizationName) can be used more than once in a
DN. This presents a problem because configuration files will not recog-
nize the same name occurring twice. To avoid this problem, if the
fieldName contains some characters followed by a full stop, they will be
ignored. So, for example, a second organizationName can be input by cal-
ling it "1.organizationName".
The actual permitted field names are any object identifier short or long
names. These are compiled into OpenSSL and include the usual values such
as commonName, countryName, localityName, organizationName,
organizationUnitName, stateOrProvinceName. Additionally, emailAddress is
included as well as name, surname, givenName initials and dnQualifier.
Additional object identifiers can be defined with the oid_file or
oid_section options in the configuration file. Any additional fields will
be treated as though they were a DirectoryString.
Examine and verify a certificate request:
$ openssl req -in req.pem -text -verify -noout
Create a private key and then generate a certificate request from it:
$ openssl genrsa -out key.pem 1024
$ openssl req -new -key key.pem -out req.pem
The same but just using req:
$ openssl req -newkey rsa:1024 -keyout key.pem -out req.pem
Generate a self-signed root certificate:
$ openssl req -x509 -newkey rsa:1024 -keyout key.pem -out req.pem
Example of a file pointed to by the oid_file option:
1.2.3.4 shortName A longer Name
1.2.3.6 otherName Other longer Name
Example of a section pointed to by oid_section making use of variable ex-
pansion:
testoid1=1.2.3.5
testoid2=${testoid1}.6
Sample configuration file prompting for field values:
[ req ]
default_bits = 1024
default_keyfile = privkey.pem
distinguished_name = req_distinguished_name
attributes = req_attributes
x509_extensions = v3_ca
dirstring_type = nobmp
[ req_distinguished_name ]
countryName = Country Name (2 letter code)
countryName_default = AU
countryName_min = 2
countryName_max = 2
localityName = Locality Name (eg, city)
organizationalUnitName = Organizational Unit Name (eg, section)
commonName = Common Name (eg, YOUR name)
commonName_max = 64
emailAddress = Email Address
emailAddress_max = 40
[ req_attributes ]
challengePassword = A challenge password
challengePassword_min = 4
challengePassword_max = 20
[ v3_ca ]
subjectKeyIdentifier=hash
authorityKeyIdentifier=keyid:always,issuer:always
basicConstraints = CA:true
Sample configuration containing all field values:
RANDFILE = $ENV::HOME/.rnd
[ req ]
default_bits = 1024
default_keyfile = keyfile.pem
distinguished_name = req_distinguished_name
attributes = req_attributes
prompt = no
output_password = mypass
[ req_distinguished_name ]
C = GB
ST = Test State or Province
L = Test Locality
O = Organization Name
OU = Organizational Unit Name
CN = Common Name
emailAddress = test@email.address
[ req_attributes ]
challengePassword = A challenge password
The header and footer lines in the PEM format are normally:
-----BEGIN CERTIFICATE REQUEST-----
-----END CERTIFICATE REQUEST-----
Some software (some versions of Netscape certificate server) instead
needs:
-----BEGIN NEW CERTIFICATE REQUEST-----
-----END NEW CERTIFICATE REQUEST-----
which is produced with the -newhdr option but is otherwise compatible.
Either form is accepted transparently on input.
The certificate requests generated by Xenroll with MSIE have extensions
added. It includes the keyUsage extension which determines the type of
key (signature only or general purpose) and any additional OIDs entered
by the script in an extendedKeyUsage extension.
The following messages are frequently asked about:
Using configuration from /some/path/openssl.cnf
Unable to load config info
This is followed some time later by...
unable to find 'distinguished_name' in config
problems making Certificate Request
The first error message is the clue: it can't find the configuration
file! Certain operations (like examining a certificate request) don't
need a configuration file so its use isn't enforced. Generation of certi-
ficates or requests, however, do need a configuration file. This could be
regarded as a bug.
Another puzzling message is this:
Attributes:
a0:00
This is displayed when no attributes are present and the request includes
the correct empty SET OF structure (the DER encoding of which is 0xa0
0x00). If you just see:
Attributes:
then the SET OF is missing and the encoding is technically invalid (but
it is tolerated). See the description of the command line option -asn1-
kludge for more information.
The variable OPENSSL_CONF, if defined, allows an alternative configura-
tion file location to be specified; it will be overridden by the -config
command line switch if it is present. For compatibility reasons the
SSLEAY_CONF environment variable serves the same purpose but its use is
discouraged.
OpenSSL's handling of T61Strings (aka TeletexStrings) is broken: it ef-
fectively treats them as ISO 8859-1 (Latin 1); Netscape and MSIE have
similar behaviour. This can cause problems if you need characters that
aren't available in PrintableStrings and you don't want to or can't use
BMPStrings.
As a consequence of the T61String handling, the only correct way to
represent accented characters in OpenSSL is to use a BMPString: unfor-
tunately Netscape currently chokes on these. If you have to use accented
characters with Netscape and MSIE then you currently need to use the in-
valid T61String form.
The current prompting is not very friendly. It doesn't allow you to con-
firm what you've just entered. Other things, like extensions in certifi-
cate requests, are statically defined in the configuration file. Some of
these, like an email address in subjectAltName, should be input by the
user.
openssl rsa [-aes128 | -aes192 | -aes256 | -des | -des3] [-check]
[-modulus] [-noout] [-pubin] [-pubout] [-sgckey] [-text] [-engine id]
[-in file] [-inform DER | NET | PEM] [-out file]
[-outform DER | NET | PEM] [-passin arg] [-passout arg]
The rsa command processes RSA keys. They can be converted between various
forms and their components printed out.
Note: this command uses the traditional SSLeay compatible format for
private key encryption: newer applications should use the more secure
PKCS#8 format using the pkcs8 utility.
The options are as follows:
-aes128 | -aes192 | -aes256 | -des | -des3
These options encrypt the private key with the AES, DES, or the
triple DES ciphers, respectively, before outputting it. A pass
phrase is prompted for. If none of these options is specified the
key is written in plain text. This means that using the rsa utility
to read in an encrypted key with no encryption option can be used
to remove the pass phrase from a key, or by setting the encryption
options it can be used to add or change the pass phrase. These op-
tions can only be used with PEM format output files.
-check
This option checks the consistency of an RSA private key.
-engine id
Specifying an engine (by it's unique id string) will cause rsa to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-in file
This specifies the input file to read a key from, or standard input
if this option is not specified. If the key is encrypted, a pass
phrase will be prompted for.
-inform DER | NET | PEM
This specifies the input format. The DER argument uses an ASN1 DER-
encoded form compatible with the PKCS#1 RSAPrivateKey or Sub-
jectPublicKeyInfo format. The PEM form is the default format: it
consists of the DER format base64-encoded with additional header
and footer lines. On input PKCS#8 format private keys are also ac-
cepted. The NET form is a format described in the RSA NOTES sec-
tion.
-noout
This option prevents output of the encoded version of the key.
-modulus
This option prints out the value of the modulus of the key.
-out file
This specifies the output file to write a key to, or standard out-
put if this option is not specified. If any encryption options are
set, a pass phrase will be prompted for. The output filename should
not be the same as the input filename.
-outform DER | NET | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-passin arg
The input file password source. For more information about the for-
mat of arg, see the PASS PHRASE ARGUMENTS section above.
-passout arg
The output file password source. For more information about the
format of arg, see the PASS PHRASE ARGUMENTS section above.
-pubin
By default, a private key is read from the input file; with this
option a public key is read instead.
-pubout
By default, a private key is output; with this option a public key
will be output instead. This option is automatically set if the in-
put is a public key.
-sgckey
Use the modified NET algorithm used with some versions of Microsoft
IIS and SGC keys.
-text
Prints out the various public or private key components in plain
text, in addition to the encoded version.
The PEM private key format uses the header and footer lines:
-----BEGIN RSA PRIVATE KEY-----
-----END RSA PRIVATE KEY-----
The PEM public key format uses the header and footer lines:
-----BEGIN PUBLIC KEY-----
-----END PUBLIC KEY-----
The NET form is a format compatible with older Netscape servers and Mi-
crosoft IIS .key files; this uses unsalted RC4 for its encryption. It is
not very secure and so should only be used when necessary.
Some newer version of IIS have additional data in the exported .key
files. To use these with the rsa utility, view the file with a binary ed-
itor and look for the string "private-key", then trace back to the byte
sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data from
this point onwards to another file and use that as the input to the rsa
utility with the -inform NET option. If there is an error after entering
the password, try the -sgckey option.
To remove the pass phrase on an RSA private key:
$ openssl rsa -in key.pem -out keyout.pem
To encrypt a private key using triple DES:
$ openssl rsa -in key.pem -des3 -out keyout.pem
To convert a private key from PEM to DER format:
$ openssl rsa -in key.pem -outform DER -out keyout.der
To print out the components of a private key to standard output:
$ openssl rsa -in key.pem -text -noout
To just output the public part of a private key:
$ openssl rsa -in key.pem -pubout -out pubkey.pem
The command line password arguments don't currently work with NET format.
There should be an option that automatically handles .key files, without
having to manually edit them.
openssl rsautl [-asn1parse] [-certin] [-decrypt] [-encrypt] [-hexdump]
[-oaep | -pkcs | -raw | -ssl] [-pubin] [-sign] [-verify] [-engine id]
[-in file] [-inkey file] [-keyform DER | PEM] [-out file]
The rsautl command can be used to sign, verify, encrypt and decrypt data
using the RSA algorithm.
The options are as follows:
-asn1parse
Asn1parse the output data; this is useful when combined with the
-verify option.
-certin
The input is a certificate containing an RSA public key.
-decrypt
Decrypt the input data using an RSA private key.
-encrypt
Encrypt the input data using an RSA public key.
-engine id
Specifying an engine (by it's unique id string) will cause rsautl
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be set
as the default for all available algorithms.
-hexdump
Hex dump the output data.
-in file
This specifies the input file to read data from, or standard input
if this option is not specified.
-inkey file
The input key file, by default it should be an RSA private key.
-keyform DER | PEM
Private ket format. Default is PEM.
-oaep | -pkcs | -raw | -ssl
The padding to use: PKCS#1 OAEP, PKCS#1 v1.5 (the default), no pad-
ding, or special padding used in SSL v2 backwards compatible
handshakes, respectively. For signatures, only -pkcs and -raw can
be used.
-out file
Specifies the output file to write to, or standard output by de-
fault.
-pubin
The input file is an RSA public key.
-sign
Sign the input data and output the signed result. This requires an
RSA private key.
-verify
Verify the input data and output the recovered data.
rsautl, because it uses the RSA algorithm directly, can only be used to
sign or verify small pieces of data.
Sign some data using a private key:
$ openssl rsautl -sign -in file -inkey key.pem -out sig
Recover the signed data:
$ openssl rsautl -verify -in sig -inkey key.pem
Examine the raw signed data:
$ openssl rsautl -verify -in file -inkey key.pem -raw -hexdump
0000 - 00 01 ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
0010 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
0020 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
0030 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
0040 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
0050 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
0060 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff ................
0070 - ff ff ff ff 00 68 65 6c-6c 6f 20 77 6f 72 6c 64 .....hello world
The PKCS#1 block formatting is evident from this. If this was done using
encrypt and decrypt, the block would have been of type 2 (the second
byte) and random padding data visible instead of the 0xff bytes.
It is possible to analyse the signature of certificates using this utili-
ty in conjunction with asn1parse. Consider the self-signed example in
certs/pca-cert.pem: running asn1parse as follows yields:
$ openssl asn1parse -in pca-cert.pem
0:d=0 hl=4 l= 742 cons: SEQUENCE
4:d=1 hl=4 l= 591 cons: SEQUENCE
8:d=2 hl=2 l= 3 cons: cont [ 0 ]
10:d=3 hl=2 l= 1 prim: INTEGER :02
13:d=2 hl=2 l= 1 prim: INTEGER :00
16:d=2 hl=2 l= 13 cons: SEQUENCE
18:d=3 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption
29:d=3 hl=2 l= 0 prim: NULL
31:d=2 hl=2 l= 92 cons: SEQUENCE
33:d=3 hl=2 l= 11 cons: SET
35:d=4 hl=2 l= 9 cons: SEQUENCE
37:d=5 hl=2 l= 3 prim: OBJECT :countryName
42:d=5 hl=2 l= 2 prim: PRINTABLESTRING :AU
....
599:d=1 hl=2 l= 13 cons: SEQUENCE
601:d=2 hl=2 l= 9 prim: OBJECT :md5WithRSAEncryption
612:d=2 hl=2 l= 0 prim: NULL
614:d=1 hl=3 l= 129 prim: BIT STRING
The final BIT STRING contains the actual signature. It can be extracted
with:
$ openssl asn1parse -in pca-cert.pem -out sig -noout -strparse 614
The certificate public key can be extracted with:
$ openssl x509 -in test/testx509.pem -pubkey -noout >pubkey.pem
The signature can be analysed with:
$ openssl rsautl -in sig -verify -asn1parse -inkey pubkey.pem -pubin
0:d=0 hl=2 l= 32 cons: SEQUENCE
2:d=1 hl=2 l= 12 cons: SEQUENCE
4:d=2 hl=2 l= 8 prim: OBJECT :md5
14:d=2 hl=2 l= 0 prim: NULL
16:d=1 hl=2 l= 16 prim: OCTET STRING
0000 - f3 46 9e aa 1a 4a 73 c9-37 ea 93 00 48 25 08 b5 .F...Js.7...H%..
This is the parsed version of an ASN1 DigestInfo structure. It can be
seen that the digest used was MD5. The actual part of the certificate
that was signed can be extracted with:
$ openssl asn1parse -in pca-cert.pem -out tbs -noout -strparse 4
and its digest computed with:
$ openssl md5 -c tbs
MD5(tbs)= f3:46:9e:aa:1a:4a:73:c9:37:ea:93:00:48:25:08:b5
which it can be seen agrees with the recovered value above.
openssl s_client [-4 | -6] [-bugs] [-crlf] [-debug] [-ign_eof] [-msg]
[-nbio] [-nbio_test] [-no_ssl2] [-no_ssl3] [-no_tls1] [-pause] [-prexit]
[-quiet] [-reconnect] [-serverpref] [-showcerts] [-ssl2] [-ssl3] [-state]
[-tls1] [-CAfile file] [-CApath directory] [-cert file]
[-cipher cipherlist] [-connect host:port | host/port] [-engine id]
[-key keyfile] [-rand file ...] [-starttls protocol] [-verify depth]
The s_client command implements a generic SSL/TLS client which connects
to a remote host using SSL/TLS. It is a very useful diagnostic tool for
SSL servers.
The options are as follows:
-4 Specify that s_client should attempt connections using IPv4 only.
-6 Specify that s_client should attempt connections using IPv6 only.
-bugs
There are several known bugs in SSL and TLS implementations. Adding
this option enables various workarounds.
-CAfile file
A file containing trusted certificates to use during server authen-
tication and to use when attempting to build the client certificate
chain.
-CApath directory
The directory to use for server certificate verification. This
directory must be in "hash format"; see -verify for more informa-
tion. These are also used when building the client certificate
chain.
-cert file
The certificate to use, if one is requested by the server. The de-
fault is not to use a certificate.
-cipher cipherlist
This allows the cipher list sent by the client to be modified.
Although the server determines which cipher suite is used, it
should take the first supported cipher in the list sent by the
client. See the CIPHERS section above for more information.
-connect host:port | host/port
This specifies the host and optional port to connect to. If not
specified, an attempt is made to connect to the local host on port
4433. Alternatively, the host and port pair may be separated using
a forward-slash character. This form is useful for numeric IPv6 ad-
dresses.
-crlf
This option translates a line feed from the terminal into CR+LF as
required by some servers.
-debug
Print extensive debugging information including a hex dump of all
traffic.
-engine id
Specifying an engine (by it's unique id string) will cause s_client
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be set
as the default for all available algorithms.
-ign_eof
Inhibit shutting down the connection when end of file is reached in
the input.
-key keyfile
The private key to use. If not specified, the certificate file will
be used.
-msg Show all protocol messages with hex dump.
-nbio
Turns on non-blocking I/O.
-nbio_test
Tests non-blocking I/O.
-no_ssl2 | -no_ssl3 | -no_tls1 | -ssl2 | -ssl3 | -tls1
These options disable the use of certain SSL or TLS protocols. By
default, the initial handshake uses a method which should be compa-
tible with all servers and permit them to use SSL v3, SSL v2, or
TLS as appropriate.
Unfortunately there are a lot of ancient and broken servers in use
which cannot handle this technique and will fail to connect. Some
servers only work if TLS is turned off with the -no_tls option,
others will only support SSL v2 and may need the -ssl2 option.
-pause
Pauses 1 second between each read and write call.
-prexit
Print session information when the program exits. This will always
attempt to print out information even if the connection fails. Nor-
mally, information will only be printed out once if the connection
succeeds. This option is useful because the cipher in use may be
renegotiated or the connection may fail because a client certifi-
cate is required or is requested only after an attempt is made to
access a certain URL. Note: the output produced by this option is
not always accurate because a connection might never have been es-
tablished.
-quiet
Inhibit printing of session and certificate information. This im-
plicitly turns on -ign_eof as well.
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified separated by a ':'.
-reconnect
Reconnects to the same server 5 times using the same session ID;
this can be used as a test that session caching is working.
-serverpref
Use server's cipher preferences (SSLv2 only).
-showcerts
Display the whole server certificate chain: normally only the
server certificate itself is displayed.
-starttls protocol
Send the protocol-specific message(s) to switch to TLS for communi-
cation. protocol is a keyword for the intended protocol. Currently,
the only supported keywords are "esmtp", "smtp" and "pop3". The
"esmtp" sends an EHLO before attempting to start TLS.
-state
Prints out the SSL session states.
-verify depth
The verify depth to use. This specifies the maximum length of the
server certificate chain and turns on server certificate verifica-
tion. Currently the verify operation continues after errors so all
the problems with a certificate chain can be seen. As a side effect
the connection will never fail due to a server certificate verify
failure.
If a connection is established with an SSL server, any data received from
the server is displayed and any key presses will be sent to the server.
When used interactively (which means neither -quiet nor -ign_eof have
been given), the session will be renegotiated if the line begins with an
R; if the line begins with a Q or if end of file is reached, the connec-
tion will be closed down.
s_client can be used to debug SSL servers. To connect to an SSL HTTP
server the command:
$ openssl s_client -connect servername:443
would typically be used (HTTPS uses port 443). If the connection
succeeds, an HTTP command can be given such as "GET" to retrieve a web
page.
If the handshake fails, there are several possible causes; if it is noth-
ing obvious like no client certificate, then the -bugs, -ssl2, -ssl3,
-tls1, -no_ssl2, -no_ssl3, and -no_tls1 options can be tried in case it
is a buggy server. In particular these options should be tried before
submitting a bug report to an OpenSSL mailing list.
A frequent problem when attempting to get client certificates working is
that a web client complains it has no certificates or gives an empty list
to choose from. This is normally because the server is not sending the
client's certificate authority in its "acceptable CA list" when it re-
quests a certificate. By using s_client the CA list can be viewed and
checked. However some servers only request client authentication after a
specific URL is requested. To obtain the list in this case it is neces-
sary to use the -prexit option and send an HTTP request for an appropri-
ate page.
If a certificate is specified on the command line using the -cert option,
it will not be used unless the server specifically requests a client cer-
tificate. Therefore merely including a client certificate on the command
line is no guarantee that the certificate works.
If there are problems verifying a server certificate, the -showcerts op-
tion can be used to show the whole chain.
Because this program has a lot of options and also because some of the
techniques used are rather old, the C source of s_client is rather hard
to read and not a model of how things should be done. A typical SSL
client program would be much simpler.
The -verify option should really exit if the server verification fails.
The -prexit option is a bit of a hack. We should really report informa-
tion whenever a session is renegotiated.
openssl s_server [-bugs] [-crlf] [-debug] [-hack] [-HTTP] [-msg] [-nbio]
[-nbio_test] [-no_dhe] [-no_ssl2] [-no_ssl3] [-no_tls1] [-no_tmp_rsa]
[-nocert] [-quiet] [-serverpref] [-ssl2] [-ssl3] [-state] [-tls1] [-WWW]
[-www] [-accept port] [-CAfile file] [-CApath directory] [-cert file]
[-cipher cipherlist] [-context id] [-dcert file] [-dhparam file]
[-dkey file] [-engine id] [-id_prefix arg] [-key keyfile]
[-rand file ...] [-Verify depth] [-verify depth]
The s_server command implements a generic SSL/TLS server which listens
for connections on a given port using SSL/TLS.
The options are as follows:
-accept port
The TCP port to listen on for connections. If not specified, 4433
is used.
-bugs
There are several known bugs in SSL and TLS implementations. Adding
this option enables various workarounds.
-CAfile file
A file containing trusted certificates to use during client authen-
tication and to use when attempting to build the server certificate
chain. The list is also used in the list of acceptable client CAs
passed to the client when a certificate is requested.
-CApath directory
The directory to use for client certificate verification. This
directory must be in "hash format"; see -verify for more informa-
tion. These are also used when building the server certificate
chain.
-cert file
The certificate to use; most server's cipher suites require the use
of a certificate and some require a certificate with a certain pub-
lic key type: for example the DSS cipher suites require a certifi-
cate containing a DSS (DSA) key. If not specified, the file
server.pem will be used.
-cipher cipherlist
This allows the cipher list used by the server to be modified. When
the client sends a list of supported ciphers, the first client ci-
pher also included in the server list is used. Because the client
specifies the preference order, the order of the server cipherlist
is irrelevant. See the CIPHERS section for more information.
-context id
Sets the SSL context ID. It can be given any string value. If this
option is not present, a default value will be used.
-crlf
This option translates a line feed from the terminal into CR+LF.
-dcert file, -dkey file
Specify an additional certificate and private key; these behave in
the same manner as the -cert and -key options except there is no
default if they are not specified (no additional certificate or key
is used). As noted above some cipher suites require a certificate
containing a key of a certain type. Some cipher suites need a cer-
tificate carrying an RSA key and some a DSS (DSA) key. By using RSA
and DSS certificates and keys, a server can support clients which
only support RSA or DSS cipher suites by using an appropriate cer-
tificate.
-debug
Print extensive debugging information including a hex dump of all
traffic.
-dhparam file
The DH parameter file to use. The ephemeral DH cipher suites gen-
erate keys using a set of DH parameters. If not specified, an at-
tempt is made to load the parameters from the server certificate
file. If this fails, a static set of parameters hard coded into the
s_server program will be used.
-engine id
Specifying an engine (by it's unique id string) will cause s_server
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be set
as the default for all available algorithms.
-hack
This option enables a further workaround for some early Netscape
SSL code (?).
-HTTP
Emulates a simple web server. Pages will be resolved relative to
the current directory; for example if the URL
https://myhost/page.html is requested, the file ./page.html will be
loaded. The files loaded are assumed to contain a complete and
correct HTTP response (lines that are part of the HTTP response
line and headers must end with CRLF).
-id_prefix arg
Generate SSL/TLS session IDs prefixed by arg. This is mostly useful
for testing any SSL/TLS code (e.g. proxies) that wish to deal with
multiple servers, when each of which might be generating a unique
range of session IDs (e.g. with a certain prefix).
-key keyfile
The private key to use. If not specified, the certificate file will
be used.
-msg Show all protocol messages with hex dump.
-nbio
Turns on non-blocking I/O.
-nbio_test
Tests non-blocking I/O.
-no_dhe
If this option is set, no DH parameters will be loaded, effectively
disabling the ephemeral DH cipher suites.
-no_ssl2 | -no_ssl3 | -no_tls1 | -ssl2 | -ssl3 | -tls1
These options disable the use of certain SSL or TLS protocols. By
default, the initial handshake uses a method which should be compa-
tible with all servers and permit them to use SSL v3, SSL v2, or
TLS as appropriate.
-no_tmp_rsa
Certain export cipher suites sometimes use a temporary RSA key;
this option disables temporary RSA key generation.
-nocert
If this option is set, no certificate is used. This restricts the
cipher suites available to the anonymous ones (currently just
anonymous DH).
-quiet
Inhibit printing of session and certificate information.
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified separated by a ':'.
-serverpref
Use server's cipher preferences.
-state
Prints out the SSL session states.
-WWW Emulates a simple web server. Pages will be resolved relative to
the current directory; for example if the URL
https://myhost/page.html is requested, the file ./page.html will be
loaded.
-www Sends a status message back to the client when it connects. This
includes lots of information about the ciphers used and various
session parameters. The output is in HTML format so this option
will normally be used with a web browser.
-Verify depth, -verify depth
The verify depth to use. This specifies the maximum length of the
client certificate chain and makes the server request a certificate
from the client. With the -Verify option, the client must supply a
certificate or an error occurs. With the -verify option, a certifi-
cate is requested but the client does not have to send one.
If a connection request is established with an SSL client and neither the
-www nor the -WWW option has been used, then normally any data received
from the client is displayed and any key presses will be sent to the
client.
Certain single letter commands are also recognized which perform special
operations: these are listed below.
P Send some plain text down the underlying TCP connection: this
should cause the client to disconnect due to a protocol violation.
Q End the current SSL connection and exit.
q End the current SSL connection, but still accept new connections.
R Renegotiate the SSL session and request a client certificate.
r Renegotiate the SSL session.
S Print out some session cache status information.
s_server can be used to debug SSL clients. To accept connections from a
web browser the command:
$ openssl s_server -accept 443 -www
can be used, for example.
Most web browsers (in particular Netscape and MSIE) only support RSA ci-
pher suites, so they cannot connect to servers which don't use a certifi-
cate carrying an RSA key or a version of OpenSSL with RSA disabled.
Although specifying an empty list of CAs when requesting a client certi-
ficate is strictly speaking a protocol violation, some SSL clients inter-
pret this to mean any CA is acceptable. This is useful for debugging pur-
poses.
The session parameters can printed out using the sess_id program.
Because this program has a lot of options and also because some of the
techniques used are rather old, the C source of s_server is rather hard
to read and not a model of how things should be done. A typical SSL
server program would be much simpler.
The output of common ciphers is wrong: it just gives the list of ciphers
that OpenSSL recognizes and the client supports.
There should be a way for the s_server program to print out details of
any unknown cipher suites a client says it supports.
openssl s_time [-bugs] [-nbio] [-new] [-reuse] [-ssl2] [-ssl3]
[-CAfile file] [-CApath directory] [-cert file] [-cipher cipherlist]
[-connect host:port] [-key keyfile] [-time seconds] [-verify depth]
[-www page]
The s_client command implements a generic SSL/TLS client which connects
to a remote host using SSL/TLS. It can request a page from the server and
includes the time to transfer the payload data in its timing measure-
ments. It measures the number of connections within a given timeframe,
the amount of data transferred (if any), and calculates the average time
spent for one connection.
The options are as follows:
-bugs There are several known bugs in SSL and TLS implementations. Ad-
ding this option enables various workarounds.
-CAfile file
A file containing trusted certificates to use during server au-
thentication and to use when attempting to build the client cer-
tificate chain.
-CApath directory
The directory to use for server certificate verification. This
directory must be in "hash format"; see verify for more informa-
tion. These are also used when building the client certificate
chain.
-cert file
The certificate to use, if one is requested by the server. The
default is not to use a certificate. The file is in PEM format.
-cipher cipherlist
This allows the cipher list sent by the client to be modified.
Although the server determines which cipher suite is used, it
should take the first supported cipher in the list sent by the
client. See the ciphers command for more information.
-connect host:port
This specifies the host and optional port to connect to.
-key keyfile
The private key to use. If not specified, the certificate file
will be used. The file is in PEM format.
-nbio Turns on non-blocking I/O.
-new Performs the timing test using a new session ID for each connec-
tion. If neither -new nor -reuse are specified, they are both on
by default and executed in sequence.
-reuse Performs the timing test using the same session ID; this can be
used as a test that session caching is working. If neither -new
nor -reuse are specified, they are both on by default and execut-
ed in sequence.
-ssl2 | -ssl3
These options disable the use of certain SSL or TLS protocols. By
default, the initial handshake uses a method which should be com-
patible with all servers and permit them to use SSL v3, SSL v2,
or TLS as appropriate. The timing program is not as rich in op-
tions to turn protocols on and off as the s_client program and
may not connect to all servers.
Unfortunately there are a lot of ancient and broken servers in
use which cannot handle this technique and will fail to connect.
Some servers only work if TLS is turned off with the -ssl3 op-
tion; others will only support SSL v2 and may need the -ssl2 op-
tion.
-time seconds
Specifies how long (in seconds) s_time should establish connec-
tions and optionally transfer payload data from a server. The de-
fault is 30 seconds. Server and client performance and the link
speed determine how many connections s_time can establish.
-verify depth
The verify depth to use. This specifies the maximum length of the
server certificate chain and turns on server certificate verifi-
cation. Currently the verify operation continues after errors, so
all the problems with a certificate chain can be seen. As a side
effect, the connection will never fail due to a server certifi-
cate verify failure.
-www page
This specifies the page to GET from the server. A value of '/'
gets the index.htm[l] page. If this parameter is not specified,
s_time will only perform the handshake to establish SSL connec-
tions but not transfer any payload data.
s_client can be used to measure the performance of an SSL connection. To
connect to an SSL HTTP server and get the default page the command
$ openssl s_time -connect servername:443 -www / -CApath yourdir \
-CAfile yourfile.pem -cipher commoncipher [-ssl3]
would typically be used (HTTPS uses port 443). "commoncipher" is a cipher
to which both client and server can agree; see the ciphers command for
details.
If the handshake fails, there are several possible causes: if it is noth-
ing obvious like no client certificate, the -bugs, -ssl2, and -ssl3 op-
tions can be tried in case it is a buggy server. In particular you should
play with these options before submitting a bug report to an OpenSSL
mailing list.
A frequent problem when attempting to get client certificates working is
that a web client complains it has no certificates or gives an empty list
to choose from. This is normally because the server is not sending the
clients certificate authority in its "acceptable CA list" when it re-
quests a certificate. By using s_client, the CA list can be viewed and
checked. However some servers only request client authentication after a
specific URL is requested. To obtain the list in this case, it is neces-
sary to use the -prexit option of s_client and send an HTTP request for
an appropriate page.
If a certificate is specified on the command line using the -cert option,
it will not be used unless the server specifically requests a client cer-
tificate. Therefore merely including a client certificate on the command
line is no guarantee that the certificate works.
Because this program does not have all the options of the s_client pro-
gram to turn protocols on and off, you may not be able to measure the
performance of all protocols with all servers.
The -verify option should really exit if the server verification fails.
openssl sess_id [-cert] [-noout] [-text] [-context ID] [-in file]
[-inform DER | PEM] [-out file] [-outform DER | PEM]
The sess_id program processes the encoded version of the SSL session
structure and optionally prints out SSL session details (for example the
SSL session master key) in human readable format. Since this is a diag-
nostic tool that needs some knowledge of the SSL protocol to use proper-
ly, most users will not need to use it.
The options are as follows:
-cert
If a certificate is present in the session, it will be output using
this option; if the -text option is also present, then it will be
printed out in text form.
-context ID
This option can set the session ID so the output session informa-
tion uses the supplied ID. The ID can be any string of characters.
This option won't normally be used.
-in file
This specifies the input file to read session information from, or
standard input by default.
-inform DER | PEM
This specifies the input format. The DER argument uses an ASN1 DER-
encoded format containing session details. The precise format can
vary from one version to the next. The PEM form is the default for-
mat: it consists of the DER format base64-encoded with additional
header and footer lines.
-noout
This option prevents output of the encoded version of the session.
-out file
This specifies the output file to write session information to, or
standard output if this option is not specified.
-outform DER | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-text
Prints out the various public or private key components in plain
text in addition to the encoded version.
Typical output:
SSL-Session:
Protocol : TLSv1
Cipher : 0016
Session-ID: 871E62626C554CE95488823752CBD5F3673A3EF3DCE9C67BD916C809914B40ED
Session-ID-ctx: 01000000
Master-Key: A7CEFC571974BE02CAC305269DC59F76EA9F0B180CB6642697A68251F2D2BB57E51DBBB4C7885573192AE9AEE220FACD
Key-Arg : None
Start Time: 948459261
Timeout : 300 (sec)
Verify return code 0 (ok)
These are described below in more detail.
Protocol This is the protocol in use: TLSv1, SSLv3, or SSLv2.
Cipher The cipher used is the actual raw SSL or TLS cipher
code; see the SSL or TLS specifications for more in-
formation.
Session-ID The SSL session ID in hex format.
Session-ID-ctx The session ID context in hex format.
Master-Key This is the SSL session master key.
Key-Arg The key argument; this is only used in SSL v2.
Start Time This is the session start time, represented as an
integer in standard UNIX format.
Timeout The timeout in seconds.
Verify return code This is the return code when an SSL client certifi-
cate is verified.
The PEM-encoded session format uses the header and footer lines:
-----BEGIN SSL SESSION PARAMETERS-----
-----END SSL SESSION PARAMETERS-----
Since the SSL session output contains the master key, it is possible to
read the contents of an encrypted session using this information. There-
fore appropriate security precautions should be taken if the information
is being output by a "real" application. This is, however, strongly
discouraged and should only be used for debugging purposes.
The cipher and start time should be printed out in human readable form.
openssl smime [-aes128 | -aes192 | -aes256 | -des | -des3 | -rc2-40 |
-rc2-64 | -rc2-128] [-binary] [-crl_check] [-crl_check_all] [-decrypt]
[-encrypt] [-noattr] [-nocerts] [-nochain] [-nodetach] [-nointern]
[-nosigs] [-noverify] [-pk7out] [-sign] [-text] [-verify] [-CAfile file]
[-CApath directory] [-certfile file] [-content file] [-engine id]
[-from addr] [-in file] [-inform DER | PEM | SMIME] [-inkey file]
[-keyform ENGINE | PEM] [-out file] [-outform DER | PEM | SMIME]
[-passin arg] [-rand file ...] [-recip file] [-signer file] [-subject s]
[-to addr] [cert.pem ...]
The smime command handles S/MIME mail. It can encrypt, decrypt, sign, and
verify S/MIME messages.
There are five operation options that set the type of operation to be
performed. The meaning of the other options varies according to the
operation type.
The five operation options are as follows:
-decrypt
Decrypt mail using the supplied certificate and private key. Ex-
pects an encrypted mail message in MIME format for the input file.
The decrypted mail is written to the output file.
-encrypt
Encrypt mail for the given recipient certificates. Input file is
the message to be encrypted. The output file is the encrypted mail
in MIME format.
-pk7out
Takes an input message and writes out a PEM-encoded PKCS#7 struc-
ture.
-sign
Sign mail using the supplied certificate and private key. Input
file is the message to be signed. The signed message in MIME format
is written to the output file.
-verify
Verify signed mail. Expects a signed mail message on input and out-
puts the signed data. Both clear text and opaque signing is sup-
ported.
The reamaining options are as follows:
-aes128 | -aes192 | -aes256 | -des | -des3 | -rc2-40 | -rc2-64 | -rc2-128
The encryption algorithm to use. 128-, 192-, or 256-bit AES, DES
(56 bits), triple DES (168 bits), or 40-, 64-, or 128-bit RC2,
respectively; if not specified, 40-bit RC2 is used. Only used with
-encrypt.
-binary
Normally, the input message is converted to "canonical" format
which is effectively using CR and LF as end of line - as required
by the S/MIME specification. When this option is present no trans-
lation occurs. This is useful when handling binary data which may
not be in MIME format.
-CAfile file
A file containing trusted CA certificates; only used with -verify.
-CApath directory
A directory containing trusted CA certificates; only used with
-verify. This directory must be a standard certificate directory:
that is, a hash of each subject name (using x509 -hash) should be
linked to each certificate.
cert.pem ...
One or more certificates of message recipients: used when encrypt-
ing a message.
-certfile file
Allows additional certificates to be specified. When signing, these
will be included with the message. When verifying, these will be
searched for the signers' certificates. The certificates should be
in PEM format.
-content file
This specifies a file containing the detached content. This is only
useful with the -verify command. This is only usable if the PKCS#7
structure is using the detached signature form where the content is
not included. This option will override any content if the input
format is S/MIME and it uses the multipart/signed MIME content
type.
-crl_check
Check revocation status of signer's certificate using CRLs.
-crl_check_all
Check revocation status of signer's certificate chain using CRLs.
-engine id
Specifying an engine (by it's unique id string) will cause smime to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-from addr, -subject s, -to addr
The relevant mail headers. These are included outside the signed
portion of a message so they may be included manually. When sign-
ing, many S/MIME mail clients check that the signer's certificate
email address matches the From: address.
-in file
The input message to be encrypted or signed or the MIME message to
be decrypted or verified.
-inform DER | PEM | SMIME
This specifies the input format for the PKCS#7 structure. The de-
fault is SMIME, which reads an S/MIME format message. PEM and DER
format change this to expect PEM and DER format PKCS#7 structures
instead. This currently only affects the input format of the PKCS#7
structure; if no PKCS#7 structure is being input (for example with
-encrypt or -sign), this option has no effect.
-inkey file
The private key to use when signing or decrypting. This must match
the corresponding certificate. If this option is not specified, the
private key must be included in the certificate file specified with
the -recip or -signer file.
-keyform ENGINE | PEM
Input private key format.
-noattr
Normally, when a message is signed a set of attributes are included
which include the signing time and supported symmetric algorithms.
With this option they are not included.
-nocerts
When signing a message, the signer's certificate is normally in-
cluded; with this option it is excluded. This will reduce the size
of the signed message but the verifier must have a copy of the
signer's certificate available locally (passed using the -certfile
option, for example).
-nochain
Do not do chain verification of signers' certificates: that is,
don't use the certificates in the signed message as untrusted CAs.
-nodetach
When signing a message use opaque signing: this form is more resis-
tant to translation by mail relays but it cannot be read by mail
agents that do not support S/MIME. Without this option cleartext
signing with the MIME type multipart/signed is used.
-nointern
When verifying a message, normally certificates (if any) included
in the message are searched for the signing certificate. With this
option, only the certificates specified in the -certfile option are
used. The supplied certificates can still be used as untrusted CAs
however.
-nosigs
Don't try to verify the signatures on the message.
-noverify
Do not verify the signer's certificate of a signed message.
-out file
The message text that has been decrypted or verified, or the output
MIME format message that has been signed or verified.
-outform DER | PEM | SMIME
This specifies the output format for the PKCS#7 structure. The de-
fault is SMIME, which writes an S/MIME format message. PEM and DER
format change this to write PEM and DER format PKCS#7 structures
instead. This currently only affects the output format of the
PKCS#7 structure; if no PKCS#7 structure is being output (for exam-
ple with -verify or -decrypt) this option has no effect.
-passin arg
The private key password source. For more information about the
format of arg, see the PASS PHRASE ARGUMENTS section above.
-rand file ...
A file or files containing random data used to seed the random
number generator, or an EGD socket (see RAND_egd(3)). Multiple
files can be specified separated by a ':'.
-recip file
The recipients certificate when decrypting a message. This certifi-
cate must match one of the recipients of the message or an error
occurs.
-signer file
The signer's certificate when signing a message. If a message is
being verified, the signer's certificates will be written to this
file if the verification was successful.
-text
This option adds plain text (text/plain) MIME headers to the sup-
plied message if encrypting or signing. If decrypting or verifying,
it strips off text headers: if the decrypted or verified message is
not of MIME type text/plain then an error occurs.
The MIME message must be sent without any blank lines between the headers
and the output. Some mail programs will automatically add a blank line.
Piping the mail directly to sendmail is one way to achieve the correct
format.
The supplied message to be signed or encrypted must include the necessary
MIME headers or many S/MIME clients won't display it properly (if at
all). You can use the -text option to automatically add plain text
headers.
A "signed and encrypted" message is one where a signed message is then
encrypted. This can be produced by encrypting an already signed message:
see the SMIME EXAMPLES section.
This version of the program only allows one signer per message, but it
will verify multiple signers on received messages. Some S/MIME clients
choke if a message contains multiple signers. It is possible to sign mes-
sages "in parallel" by signing an already signed message.
The options -encrypt and -decrypt reflect common usage in S/MIME clients.
Strictly speaking these process PKCS#7 enveloped data: PKCS#7 encrypted
data is used for other purposes.
0 The operation was completely successful.
1 An error occurred parsing the command options.
2 One of the input files could not be read.
3 An error occurred creating the PKCS#7 file or when reading the MIME
message.
4 An error occurred decrypting or verifying the message.
5 The message was verified correctly, but an error occurred writing
out the signer's certificates.
Create a cleartext signed message:
$ openssl smime -sign -in message.txt -text -out mail.msg \
-signer mycert.pem
Create an opaque signed message:
$ openssl smime -sign -in message.txt -text -out mail.msg \
-nodetach -signer mycert.pem
Create a signed message, include some additional certificates and read
the private key from another file:
$ openssl smime -sign -in in.txt -text -out mail.msg \
-signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
Send a signed message under UNIX directly to sendmail(8), including
headers:
$ openssl smime -sign -in in.txt -text -signer mycert.pem \
-from steve@openssl.org -to someone@somewhere \
-subject "Signed message" | sendmail someone@somewhere
Verify a message and extract the signer's certificate if successful:
$ openssl smime -verify -in mail.msg -signer user.pem \
-out signedtext.txt
Send encrypted mail using triple DES:
$ openssl smime -encrypt -in in.txt -from steve@openssl.org \
-to someone@somewhere -subject "Encrypted message" \
-des3 -out mail.msg user.pem
Sign and encrypt mail:
$ openssl smime -sign -in ml.txt -signer my.pem -text | \
openssl smime -encrypt -out mail.msg \
-from steve@openssl.org -to someone@somewhere \
-subject "Signed and Encrypted message" -des3 user.pem
Note: The encryption command does not include the -text option because
the message being encrypted already has MIME headers.
Decrypt mail:
$ openssl smime -decrypt -in mail.msg -recip mycert.pem \
-inkey key.pem"
The output from Netscape form signing is a PKCS#7 structure with the de-
tached signature format. You can use this program to verify the signature
by line wrapping the base64-encoded structure and surrounding it with:
-----BEGIN PKCS7-----
-----END PKCS7-----
and using the command:
$ openssl smime -verify -inform PEM -in signature.pem \
-content content.txt
Alternatively, you can base64 decode the signature and use:
$ openssl smime -verify -inform DER -in signature.der \
-content content.txt
The MIME parser isn't very clever: it seems to handle most messages that
I've thrown at it, but it may choke on others.
The code currently will only write out the signer's certificate to a
file: if the signer has a separate encryption certificate this must be
manually extracted. There should be some heuristic that determines the
correct encryption certificate.
Ideally, a database should be maintained of a certificate for each email
address.
The code doesn't currently take note of the permitted symmetric encryp-
tion algorithms as supplied in the SMIMECapabilities signed attribute.
This means the user has to manually include the correct encryption algo-
rithm. It should store the list of permitted ciphers in a database and
only use those.
No revocation checking is done on the signer's certificate.
The current code can only handle S/MIME v2 messages; the more complex
S/MIME v3 structures may cause parsing errors.
openssl speed [aes] [aes-128-cbc] [aes-192-cbc] [aes-256-cbc] [blowfish]
[bf-cbc] [cast] [cast-cbc] [des] [des-cbc] [des-ede3] [dsa] [dsa512]
[dsa1024] [dsa2048] [hmac] [md2] [md4] [md5] [rc2] [rc2-cbc] [rc4]
[rmd160] [rsa] [rsa512] [rsa1024] [rsa2048] [rsa4096] [sha1] [sha256]
[sha512] [-decrypt] [-elapsed] [-mr] [-engine id] [-evp e]
[-multi number]
The speed command is used to test the performance of cryptographic algo-
rithms.
[zero or more test algorithms]
If any options are given, speed tests those algorithms, otherwise
all of the above are tested.
-decrypt
Time decryption instead of encryption (only EVP).
-engine id
Specifying an engine (by it's unique id string) will cause speed to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-elapsed
Measure time in real time instead of CPU user time.
-evp e
Use EVP e.
-mr Produce machine readable output.
-multi number
Run number benchmarks in parallel.
openssl spkac [-noout] [-pubkey] [-verify] [-challenge string]
[-engine id] [-in file] [-key keyfile] [-out file] [-passin arg]
[-spkac spkacname] [-spksect section]
The spkac command processes Netscape signed public key and challenge
(SPKAC) files. It can print out their contents, verify the signature, and
produce its own SPKACs from a supplied private key.
The options are as follows:
-challenge string
Specifies the challenge string if an SPKAC is being created.
-engine id
Specifying an engine (by it's unique id string) will cause spkac to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-in file
This specifies the input file to read from, or standard input if
this option is not specified. Ignored if the -key option is used.
-key keyfile
Create an SPKAC file using the private key in keyfile. The -in,
-noout, -spksect, and -verify options are ignored if present.
-noout
Don't output the text version of the SPKAC (not used if an SPKAC is
being created).
-out file
Specifies the output file to write to, or standard output by de-
fault.
-passin arg
The input file password source. For more information about the for-
mat of arg, see the PASS PHRASE ARGUMENTS section above.
-pubkey
Output the public key of an SPKAC (not used if an SPKAC is being
created).
-spkac spkacname
Allows an alternative name for the variable containing the SPKAC.
The default is "SPKAC". This option affects both generated and in-
put SPKAC files.
-spksect section
Allows an alternative name for the section containing the SPKAC.
The default is the default section.
-verify
Verifies the digital signature on the supplied SPKAC.
Print out the contents of an SPKAC:
$ openssl spkac -in spkac.cnf
Verify the signature of an SPKAC:
$ openssl spkac -in spkac.cnf -noout -verify
Create an SPKAC using the challenge string "hello":
$ openssl spkac -key key.pem -challenge hello -out spkac.cnf
Example of an SPKAC, (long lines split up for clarity):
SPKAC=MIG5MGUwXDANBgkqhkiG9w0BAQEFAANLADBIAkEA1cCoq2Wa3Ixs47uI7F\
PVwHVIPDx5yso105Y6zpozam135a8R0CpoRvkkigIyXfcCjiVi5oWk+6FfPaD03u\
PFoQIDAQABFgVoZWxsbzANBgkqhkiG9w0BAQQFAANBAFpQtY/FojdwkJh1bEIYuc\
2EeM2KHTWPEepWYeawvHD0gQ3DngSC75YCWnnDdq+NQ3F+X4deMx9AaEglZtULwV\
4=
A created SPKAC with suitable DN components appended can be fed into the
ca utility.
SPKACs are typically generated by Netscape when a form is submitted con-
taining the KEYGEN tag as part of the certificate enrollment process.
The challenge string permits a primitive form of proof of possession of
private key. By checking the SPKAC signature and a random challenge
string, some guarantee is given that the user knows the private key
corresponding to the public key being certified. This is important in
some applications. Without this it is possible for a previous SPKAC to be
used in a "replay attack".
openssl verify [-crl_check] [-help] [-issuer_checks] [-verbose]
[-CAfile file] [-CApath directory] [-engine id] [-purpose purpose]
[-untrusted file] [-] [certificates]
The verify command verifies certificate chains.
The options are as follows:
-CApath directory
A directory of trusted certificates. The certificates should have
names of the form hash.0, or have symbolic links to them of this
form ("hash" is the hashed certificate subject name: see the -hash
option of the x509 utility). Under UNIX, the c_rehash script will
automatically create symbolic links to a directory of certificates.
-CAfile file
A file of trusted certificates. The file should contain multiple
certificates in PEM format, concatenated together.
-untrusted file
A file of untrusted certificates. The file should contain multiple
certificates.
-purpose purpose
The intended use for the certificate. Without this option no chain
verification will be done. Currently accepted uses are sslclient,
sslserver, nssslserver, smimesign, smimeencrypt, crlsign, any, and
ocsphelper. See the VERIFY OPERATION section for more information.
-help
Prints out a usage message.
-verbose
Print extra information about the operations being performed.
-issuer_checks
Print out diagnostics relating to searches for the issuer certifi-
cate of the current certificate. This shows why each candidate is-
suer certificate was rejected. However the presence of rejection
messages does not itself imply that anything is wrong: during the
normal verify process several rejections may take place.
-crl_check
Check revocation status of signer's certificate using CRLs.
-engine id
Specifying an engine (by it's unique id string) will cause verify
to attempt to obtain a functional reference to the specified en-
gine, thus initialising it if needed. The engine will then be set
as the default for all available algorithms.
- Marks the last option. All arguments following this are assumed to
be certificate files. This is useful if the first certificate
filename begins with a '-'.
certificates
One or more certificates to verify. If no certificate files are in-
cluded, an attempt is made to read a certificate from standard in-
put. They should all be in PEM format.
The verify program uses the same functions as the internal SSL and S/MIME
verification, therefore this description applies to these verify opera-
tions too.
There is one crucial difference between the verify operations performed
by the verify program: wherever possible an attempt is made to continue
after an error, whereas normally the verify operation would halt on the
first error. This allows all the problems with a certificate chain to be
determined.
The verify operation consists of a number of separate steps:
Firstly a certificate chain is built up starting from the supplied certi-
ficate and ending in the root CA. It is an error if the whole chain can-
not be built up. The chain is built up by looking up the issuer's certi-
ficate of the current certificate. If a certificate is found which is its
own issuer, it is assumed to be the root CA.
The process of "looking up the issuer's certificate" itself involves a
number of steps. In versions of OpenSSL before 0.9.5a the first certifi-
cate whose subject name matched the issuer of the current certificate was
assumed to be the issuer's certificate. In OpenSSL 0.9.6 and later all
certificates whose subject name matches the issuer name of the current
certificate are subject to further tests. The relevant authority key
identifier components of the current certificate (if present) must match
the subject key identifier (if present) and issuer and serial number of
the candidate issuer; in addition the keyUsage extension of the candidate
issuer (if present) must permit certificate signing.
The lookup first looks in the list of untrusted certificates and if no
match is found the remaining lookups are from the trusted certificates.
The root CA is always looked up in the trusted certificate list: if the
certificate to verify is a root certificate, then an exact match must be
found in the trusted list.
The second operation is to check every untrusted certificate's extensions
for consistency with the supplied purpose. If the -purpose option is not
included, then no checks are done. The supplied or "leaf" certificate
must have extensions compatible with the supplied purpose and all other
certificates must also be valid CA certificates. The precise extensions
required are described in more detail in the X509 CERTIFICATE EXTENSIONS
section below.
The third operation is to check the trust settings on the root CA. The
root CA should be trusted for the supplied purpose. For compatibility
with previous versions of SSLeay and OpenSSL, a certificate with no trust
settings is considered to be valid for all purposes.
The final operation is to check the validity of the certificate chain.
The validity period is checked against the current system time and the
notBefore and notAfter dates in the certificate. The certificate signa-
tures are also checked at this point.
If all operations complete successfully, the certificate is considered
valid. If any operation fails then the certificate is not valid.
When a verify operation fails, the output messages can be somewhat cryp-
tic. The general form of the error message is:
server.pem: /C=AU/ST=Queensland/O=CryptSoft Pty Ltd/CN=Test CA (1024-bit)
error 24 at 1 depth lookup:invalid CA certificate
The first line contains the name of the certificate being verified, fol-
lowed by the subject name of the certificate. The second line contains
the error number and the depth. The depth is the number of the certifi-
cate being verified when a problem was detected starting with zero for
the certificate being verified itself, then 1 for the CA that signed the
certificate and so on. Finally a text version of the error number is
presented.
An exhaustive list of the error codes and messages is shown below; this
also includes the name of the error code as defined in the header file
<openssl/x509_vfy.h>. Some of the error codes are defined but never re-
turned: these are described as "unused".
0 X509_V_OK: ok
The operation was successful.
2 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate
The issuer certificate could not be found: this occurs if the is-
suer certificate of an untrusted certificate cannot be found.
3 X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL
The CRL of a certificate could not be found. Unused.
4 X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt
certificate's signature
The certificate signature could not be decrypted. This means that
the actual signature value could not be determined rather than it
not matching the expected value. This is only meaningful for RSA
keys.
5 X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's
signature
The CRL signature could not be decrypted: this means that the actu-
al signature value could not be determined rather than it not
matching the expected value. Unused.
6 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode issuer
public key
The public key in the certificate SubjectPublicKeyInfo could not be
read.
7 X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure
The signature of the certificate is invalid.
8 X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure
The signature of the certificate is invalid. Unused.
9 X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid
The certificate is not yet valid: the notBefore date is after the
current time.
10 X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired
The certificate has expired; that is, the notAfter date is before
the current time.
11 X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid
The CRL is not yet valid. Unused.
12 X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired
The CRL has expired. Unused.
13 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in
certificate's notBefore field
The certificate notBefore field contains an invalid time.
14 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in
certificate's notAfter field
The certificate notAfter field contains an invalid time.
15 X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's las-
tUpdate field
The CRL lastUpdate field contains an invalid time. Unused.
16 X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nex-
tUpdate field
The CRL nextUpdate field contains an invalid time. Unused.
17 X509_V_ERR_OUT_OF_MEM: out of memory
An error occurred trying to allocate memory. This should never hap-
pen.
18 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate
The passed certificate is self-signed and the same certificate can-
not be found in the list of trusted certificates.
19 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in cer-
tificate chain
The certificate chain could be built up using the untrusted certi-
ficates but the root could not be found locally.
20 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local is-
suer certificate
The issuer certificate of a locally looked up certificate could not
be found. This normally means the list of trusted certificates is
not complete.
21 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the first
certificate
No signatures could be verified because the chain contains only one
certificate and it is not self-signed.
22 X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long
The certificate chain length is greater than the supplied maximum
depth. Unused.
23 X509_V_ERR_CERT_REVOKED: certificate revoked
The certificate has been revoked. Unused.
24 X509_V_ERR_INVALID_CA: invalid CA certificate
A CA certificate is invalid. Either it is not a CA or its exten-
sions are not consistent with the supplied purpose.
25 X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded
The basicConstraints pathlength parameter has been exceeded.
26 X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose
The supplied certificate cannot be used for the specified purpose.
27 X509_V_ERR_CERT_UNTRUSTED: certificate not trusted
The root CA is not marked as trusted for the specified purpose.
28 X509_V_ERR_CERT_REJECTED: certificate rejected
The root CA is marked to reject the specified purpose.
29 X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch
The current candidate issuer certificate was rejected because its
subject name did not match the issuer name of the current certifi-
cate. Only displayed when the -issuer_checks option is set.
30 X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier
mismatch
The current candidate issuer certificate was rejected because its
subject key identifier was present and did not match the authority
key identifier current certificate. Only displayed when the
-issuer_checks option is set.
31 X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial
number mismatch
The current candidate issuer certificate was rejected because its
issuer name and serial number were present and did not match the
authority key identifier of the current certificate. Only displayed
when the -issuer_checks option is set.
32 X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certificate
signing
The current candidate issuer certificate was rejected because its
keyUsage extension does not permit certificate signing.
50 X509_V_ERR_APPLICATION_VERIFICATION: application verification failure
An application specific error. Unused.
Although the issuer checks are a considerable improvement over the old
technique, they still suffer from limitations in the underlying
X509_LOOKUP API. One consequence of this is that trusted certificates
with matching subject name must either appear in a file (as specified by
the -CAfile option) or a directory (as specified by -CApath). If they oc-
cur in both, only the certificates in the file will be recognised.
Previous versions of OpenSSL assumed certificates with matching subject
name were identical and mishandled them.
openssl version [-abdfopv]
The version command is used to print out version information about
OpenSSL.
The options are as follows:
-a All information: this is the same as setting all the other flags.
-b The date the current version of OpenSSL was built.
-d OPENSSLDIR setting.
-f Compilation flags.
-o Option information: various options set when the library was built.
-p Platform setting.
-v The current OpenSSL version.
The output of openssl version -a would typically be used when sending in
a bug report.
The -d option was added in OpenSSL 0.9.7.
openssl x509 [-alias] [-C] [-CAcreateserial] [-clrext] [-clrreject]
[-clrtrust] [-dates] [-email] [-enddate] [-fingerprint] [-hash] [-issuer]
[-issuer_hash] [-issuer_hash_old] [-md2 | -md5 | -sha1] [-modulus]
[-noout] [-ocspid] [-pubkey] [-purpose] [-req] [-serial] [-startdate]
[-subject] [-subject_hash] [-subject_hash_old] [-text] [-trustout]
[-x509toreq] [-addreject arg] [-addtrust arg] [-CA file]
[-CAform DER | PEM] [-CAkey file] [-CAkeyform DER | PEM] [-CAserial file]
[-certopt option] [-checkend arg] [-days arg] [-engine id]
[-extensions section] [-extfile file] [-in file]
[-inform DER | NET | PEM] [-keyform DER | PEM] [-nameopt option]
[-out file] [-outform DER | NET | PEM] [-passin arg] [-set_serial n]
[-setalias arg] [-signkey file]
The x509 command is a multi-purpose certificate utility. It can be used
to display certificate information, convert certificates to various
forms, sign certificate requests like a "mini CA", or edit certificate
trust settings.
Since there are a large number of options, they are split up into various
sections.
X509 INPUT, OUTPUT, AND GENERAL PURPOSE OPTIONS
-engine id
Specifying an engine (by it's unique id string) will cause x509 to
attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the
default for all available algorithms.
-in file
This specifies the input file to read a certificate from, or stan-
dard input if this option is not specified.
-inform DER | NET | PEM
This specifies the input format. Normally, the command will expect
an X509 certificate, but this can change if other options such as
-req are present. The DER format is the DER encoding of the certi-
ficate and PEM is the base64 encoding of the DER encoding with
header and footer lines added. The NET option is an obscure
Netscape server format that is now obsolete.
-md2 | -md5 | -sha1
The digest to use. This affects any signing or display option that
uses a message digest, such as the -fingerprint, -signkey, and -CA
options. If not specified, MD5 is used. If the key being used to
sign with is a DSA key, this option has no effect: SHA1 is always
used with DSA keys.
-out file
This specifies the output file to write to, or standard output by
default.
-outform DER | NET | PEM
This specifies the output format; the options have the same meaning
as the -inform option.
-passin arg
The key password source. For more information about the format of
arg, see the PASS PHRASE ARGUMENTS section above.
Note: The -alias and -purpose options are also display options but are
described in the X509 TRUST SETTINGS section.
-C This outputs the certificate in the form of a C source file.
-certopt option
Customise the output format used with -text. The option argument
can be a single option or multiple options separated by commas. The
-certopt switch may also be used more than once to set multiple op-
tions. See the X509 TEXT OPTIONS section for more information.
-dates
Prints out the start and expiry dates of a certificate.
-email
Outputs the email address(es), if any.
-enddate
Prints out the expiry date of the certificate; that is, the
notAfter date.
-fingerprint
Prints out the digest of the DER-encoded version of the whole cer-
tificate (see DIGEST OPTIONS).
-hash
Outputs the "hash" of the certificate subject name. This is used in
OpenSSL to form an index to allow certificates in a directory to be
looked up by subject name.
-issuer
Outputs the issuer name.
-issuer_hash
Outputs the OpenSSL 1.x hash of the certificate issuer.
-issuer_hash_old
Outputs the OpenSSL 0.x hash of the certificate issuer.
-modulus
This option prints out the value of the modulus of the public key
contained in the certificate.
-nameopt option
Option which determines how the subject or issuer names are
displayed. The option argument can be a single option or multiple
options separated by commas. Alternatively, the -nameopt switch may
be used more than once to set multiple options. See the X509 NAME
OPTIONS section for more information.
-noout
This option prevents output of the encoded version of the request.
-ocspid
Print OCSP hash values for the subject name and public key.
-pubkey
Output the public key.
-serial
Outputs the certificate serial number.
-startdate
Prints out the start date of the certificate; that is, the
notBefore date.
-subject
Outputs the subject name.
-subject_hash
Outputs the OpenSSL 1.x hash of the certificate subject.
-subject_hash_old
Outputs the OpenSSL 0.x hash of the certificate subject. The -hash
option is currently aliased to this option, and is aliased to
-subject_hash in future OpenSSL versions.
-text
Prints out the certificate in text form. Full details are output
including the public key, signature algorithms, issuer and subject
names, serial number, any extensions present, and any trust set-
tings.
Please note these options are currently experimental and may well change.
A trusted certificate is an ordinary certificate which has several addi-
tional pieces of information attached to it such as the permitted and
prohibited uses of the certificate and an "alias".
Normally, when a certificate is being verified at least one certificate
must be "trusted". By default, a trusted certificate must be stored lo-
cally and must be a root CA: any certificate chain ending in this CA is
then usable for any purpose.
Trust settings currently are only used with a root CA. They allow a finer
control over the purposes the root CA can be used for. For example, a CA
may be trusted for an SSL client but not for SSL server use.
See the description of the verify utility for more information on the
meaning of trust settings.
Future versions of OpenSSL will recognize trust settings on any certifi-
cate: not just root CAs.
-addreject arg
Adds a prohibited use. It accepts the same values as the -addtrust
option.
-addtrust arg
Adds a trusted certificate use. Any object name can be used here,
but currently only clientAuth (SSL client use), serverAuth (SSL
server use), and emailProtection (S/MIME email) are used. Other
OpenSSL applications may define additional uses.
-alias
Outputs the certificate alias, if any.
-clrreject
Clears all the prohibited or rejected uses of the certificate.
-clrtrust
Clears all the permitted or trusted uses of the certificate.
-purpose
This option performs tests on the certificate extensions and out-
puts the results. For a more complete description, see the X509
CERTIFICATE EXTENSIONS section.
-setalias arg
Sets the alias of the certificate. This will allow the certificate
to be referred to using a nickname, for example "Steve's
Certificate".
-trustout
This causes x509 to output a trusted certificate. An ordinary or
trusted certificate can be input, but by default an ordinary certi-
ficate is output and any trust settings are discarded. With the
-trustout option a trusted certificate is output. A trusted certi-
ficate is automatically output if any trust settings are modified.
The x509 utility can be used to sign certificates and requests: it can
thus behave like a "mini CA".
-CA file
Specifies the CA certificate to be used for signing. When this op-
tion is present, x509 behaves like a "mini CA". The input file is
signed by the CA using this option; that is, its issuer name is set
to the subject name of the CA and it is digitally signed using the
CA's private key.
This option is normally combined with the -req option. Without the
-req option, the input is a certificate which must be self-signed.
-CAcreateserial
With this option the CA serial number file is created if it does
not exist: it will contain the serial number '02' and the certifi-
cate being signed will have '1' as its serial number. Normally, if
the -CA option is specified and the serial number file does not ex-
ist, it is an error.
-CAform DER | PEM
The format of the CA certificate file. The default is PEM.
-CAkey file
Sets the CA private key to sign a certificate with. If this option
is not specified, it is assumed that the CA private key is present
in the CA certificate file.
-CAkeyform DER | PEM
The format of the CA private key. The default is PEM.
-CAserial file
Sets the CA serial number file to use.
When the -CA option is used to sign a certificate, it uses a serial
number specified in a file. This file consists of one line contain-
ing an even number of hex digits with the serial number to use.
After each use the serial number is incremented and written out to
the file again.
The default filename consists of the CA certificate file base name
with .srl appended. For example, if the CA certificate file is
called mycacert.pem, it expects to find a serial number file called
mycacert.srl.
-checkend arg
Check whether the certificate expires in the next arg seconds. If
so, exit with return value 1; otherwise exit with return value 0.
-clrext
Delete any extensions from a certificate. This option is used when
a certificate is being created from another certificate (for exam-
ple with the -signkey or the -CA options). Normally, all extensions
are retained.
-days arg
Specifies the number of days to make a certificate valid for. The
default is 30 days.
-extensions section
The section to add certificate extensions from. If this option is
not specified, the extensions should either be contained in the un-
named (default) section or the default section should contain a
variable called "extensions" which contains the section to use.
-extfile file
File containing certificate extensions to use. If not specified, no
extensions are added to the certificate.
-keyform DER | PEM
Specifies the format (DER or PEM) of the private key file used in
the -signkey option.
-req By default, a certificate is expected on input. With this option a
certificate request is expected instead.
-set_serial n
Specifies the serial number to use. This option can be used with
either the -signkey or -CA options. If used in conjunction with the
-CA option, the serial number file (as specified by the -CAserial
or -CAcreateserial options) is not used.
The serial number can be decimal or hex (if preceded by '0x').
Negative serial numbers can also be specified but their use is not
recommended.
-signkey file
This option causes the input file to be self-signed using the sup-
plied private key.
If the input file is a certificate, it sets the issuer name to the
subject name (i.e. makes it self-signed), changes the public key to
the supplied value, and changes the start and end dates. The start
date is set to the current time and the end date is set to a value
determined by the -days option. Any certificate extensions are re-
tained unless the -clrext option is supplied.
If the input is a certificate request, a self-signed certificate is
created using the supplied private key using the subject name in
the request.
-x509toreq
Converts a certificate into a certificate request. The -signkey op-
tion is used to pass the required private key.
The -nameopt command line switch determines how the subject and issuer
names are displayed. If no -nameopt switch is present, the default
"oneline" format is used which is compatible with previous versions of
OpenSSL. Each option is described in detail below; all options can be
preceded by a '-' to turn the option off. Only compat, RFC2253, oneline,
and multiline will normally be used.
align
Align field values for a more readable output. Only usable with
sep_multiline.
compat
Use the old format. This is equivalent to specifying no name op-
tions at all.
dn_rev
Reverse the fields of the DN. This is required by RFC 2253. As a
side effect, this also reverses the order of multiple AVAs but this
is permissible.
dump_all
Dump all fields. This option, when used with dump_der, allows the
DER encoding of the structure to be unambiguously determined.
dump_der
When this option is set, any fields that need to be hexdumped will
be dumped using the DER encoding of the field. Otherwise just the
content octets will be displayed. Both options use the RFC 2253
#XXXX... format.
dump_nostr
Dump non-character string types (for example OCTET STRING); if this
option is not set, non-character string types will be displayed as
though each content octet represents a single character.
dump_unknown
Dump any field whose OID is not recognised by OpenSSL.
esc_2253
Escape the "special" characters required by RFC 2253 in a field
that is " ,+"<>;". Additionally, '#' is escaped at the beginning of
a string and a space character at the beginning or end of a string.
esc_ctrl
Escape control characters. That is, those with ASCII values less
than 0x20 (space) and the delete (0x7f) character. They are escaped
using the RFC 2253 \XX notation (where XX are two hex digits
representing the character value).
esc_msb
Escape characters with the MSB set; that is, with ASCII values
larger than 127.
multiline
A multiline format. It is equivalent to esc_ctrl, esc_msb,
sep_multiline, spc_eq, lname, and align.
no_type
This option does not attempt to interpret multibyte characters in
any way. That is, their content octets are merely dumped as though
one octet represents each character. This is useful for diagnostic
purposes but will result in rather odd looking output.
nofname, sname, lname, oid
These options alter how the field name is displayed. nofname does
not display the field at all. sname uses the "short name" form (CN
for commonName, for example). lname uses the long form. oid
represents the OID in numerical form and is useful for diagnostic
purpose.
oneline
A oneline format which is more readable than RFC2253. It is
equivalent to specifying the esc_2253, esc_ctrl, esc_msb, utf8,
dump_nostr, dump_der, use_quote, sep_comma_plus_spc, spc_eq, and
sname options.
RFC2253
Displays names compatible with RFC 2253; equivalent to esc_2253,
esc_ctrl, esc_msb, utf8, dump_nostr, dump_unknown, dump_der,
sep_comma_plus, dn_rev, and sname.
sep_comma_plus, sep_comma_plus_space, sep_semi_plus_space, sep_multiline
These options determine the field separators. The first character
is between RDNs and the second between multiple AVAs (multiple AVAs
are very rare and their use is discouraged). The options ending in
"space" additionally place a space after the separator to make it
more readable. The sep_multiline uses a linefeed character for the
RDN separator and a spaced '+' for the AVA separator. It also in-
dents the fields by four characters.
show_type
Show the type of the ASN1 character string. The type precedes the
field contents. For example "BMPSTRING: Hello World".
spc_eq
Places spaces round the '=' character which follows the field name.
use_quote
Escapes some characters by surrounding the whole string with '"'
characters. Without the option, all escaping is done with the '\'
character.
utf8 Convert all strings to UTF8 format first. This is required by RFC
2253. If you are lucky enough to have a UTF8 compatible terminal,
the use of this option (and not setting esc_msb) may result in the
correct display of multibyte (international) characters. If this
option is not present, multibyte characters larger than 0xff will
be represented using the format \UXXXX for 16 bits and \WXXXXXXXX
for 32 bits. Also, if this option is off, any UTF8Strings will be
converted to their character form first.
As well as customising the name output format, it is also possible to
customise the actual fields printed using the -certopt options when the
-text option is present. The default behaviour is to print all fields.
ca_default
The value used by the ca utility; equivalent to no_issuer,
no_pubkey, no_header, no_version, no_sigdump, and no_signame.
compatible
Use the old format. This is equivalent to specifying no output op-
tions at all.
ext_default
Retain default extension behaviour: attempt to print out unsupport-
ed certificate extensions.
ext_dump
Hex dump unsupported extensions.
ext_error
Print an error message for unsupported certificate extensions.
ext_parse
ASN1 parse unsupported extensions.
no_aux
Don't print out certificate trust information.
no_extensions
Don't print out any X509V3 extensions.
no_header
Don't print header information: that is, the lines saying
"Certificate" and "Data".
no_issuer
Don't print out the issuer name.
no_pubkey
Don't print out the public key.
no_serial
Don't print out the serial number.
no_sigdump
Don't give a hexadecimal dump of the certificate signature.
no_signame
Don't print out the signature algorithm used.
no_subject
Don't print out the subject name.
no_validity
Don't print the validity; that is, the notBefore and notAfter
fields.
no_version
Don't print out the version number.
Display the contents of a certificate:
$ openssl x509 -in cert.pem -noout -text
Display the certificate serial number:
$ openssl x509 -in cert.pem -noout -serial
Display the certificate subject name:
$ openssl x509 -in cert.pem -noout -subject
Display the certificate subject name in RFC 2253 form:
$ openssl x509 -in cert.pem -noout -subject -nameopt RFC2253
Display the certificate subject name in oneline form on a terminal sup-
porting UTF8:
$ openssl x509 -in cert.pem -noout -subject \
-nameopt oneline,esc_msb
Display the certificate MD5 fingerprint:
$ openssl x509 -in cert.pem -noout -fingerprint
Display the certificate SHA1 fingerprint:
$ openssl x509 -sha1 -in cert.pem -noout -fingerprint
Convert a certificate from PEM to DER format:
$ openssl x509 -in cert.pem -inform PEM -out cert.der -outform DER
Convert a certificate to a certificate request:
$ openssl x509 -x509toreq -in cert.pem -out req.pem \
-signkey key.pem
Convert a certificate request into a self-signed certificate using exten-
sions for a CA:
$ openssl x509 -req -in careq.pem -extfile openssl.cnf -extensions \
v3_ca -signkey key.pem -out cacert.pem
Sign a certificate request using the CA certificate above and add user
certificate extensions:
$ openssl x509 -req -in req.pem -extfile openssl.cnf -extensions \
v3_usr -CA cacert.pem -CAkey key.pem -CAcreateserial
Set a certificate to be trusted for SSL client use and set its alias to
"Steve's Class 1 CA":
$ openssl x509 -in cert.pem -addtrust clientAuth \
-setalias "Steve's Class 1 CA" -out trust.pem
The PEM format uses the header and footer lines:
-----BEGIN CERTIFICATE-----
-----END CERTIFICATE-----
It will also handle files containing:
-----BEGIN X509 CERTIFICATE-----
-----END X509 CERTIFICATE-----
Trusted certificates have the lines:
-----BEGIN TRUSTED CERTIFICATE-----
-----END TRUSTED CERTIFICATE-----
The conversion to UTF8 format used with the name options assumes that
T61Strings use the ISO 8859-1 character set. This is wrong, but Netscape
and MSIE do this, as do many certificates. So although this is incorrect
it is more likely to display the majority of certificates correctly.
The -fingerprint option takes the digest of the DER-encoded certificate.
This is commonly called a "fingerprint". Because of the nature of message
digests, the fingerprint of a certificate is unique to that certificate
and two certificates with the same fingerprint can be considered to be
the same.
The Netscape fingerprint uses MD5, whereas MSIE uses SHA1.
The -email option searches the subject name and the subject alternative
name extension. Only unique email addresses will be printed out: it will
not print the same address more than once.
The -purpose option checks the certificate extensions and determines what
the certificate can be used for. The actual checks done are rather com-
plex and include various hacks and workarounds to handle broken certifi-
cates and software.
The same code is used when verifying untrusted certificates in chains, so
this section is useful if a chain is rejected by the verify code.
The basicConstraints extension CA flag is used to determine whether the
certificate can be used as a CA. If the CA flag is true, it is a CA; if
the CA flag is false, it is not a CA. All CAs should have the CA flag set
to true.
If the basicConstraints extension is absent, then the certificate is con-
sidered to be a "possible CA"; other extensions are checked according to
the intended use of the certificate. A warning is given in this case be-
cause the certificate should really not be regarded as a CA: however, it
is allowed to be a CA to work around some broken software.
If the certificate is a V1 certificate (and thus has no extensions) and
it is self-signed, it is also assumed to be a CA but a warning is again
given: this is to work around the problem of Verisign roots which are V1
self-signed certificates.
If the keyUsage extension is present, then additional restraints are made
on the uses of the certificate. A CA certificate must have the
keyCertSign bit set if the keyUsage extension is present.
The extended key usage extension places additional restrictions on the
certificate uses. If this extension is present (whether critical or not),
the key can only be used for the purposes specified.
A complete description of each test is given below. The comments about
basicConstraints and keyUsage and V1 certificates above apply to all CA
certificates.
SSL Client
The extended key usage extension must be absent or include the "web
client authentication" OID. keyUsage must be absent or it must have
the digitalSignature bit set. Netscape certificate type must be ab-
sent or it must have the SSL client bit set.
SSL Client CA
The extended key usage extension must be absent or include the "web
client authentication" OID. Netscape certificate type must be ab-
sent or it must have the SSL CA bit set: this is used as a work
around if the basicConstraints extension is absent.
SSL Server
The extended key usage extension must be absent or include the "web
server authentication" and/or one of the SGC OIDs. keyUsage must be
absent or it must have the digitalSignature set, the
keyEncipherment set, or both bits set. Netscape certificate type
must be absent or have the SSL server bit set.
SSL Server CA
The extended key usage extension must be absent or include the "web
server authentication" and/or one of the SGC OIDs. Netscape certi-
ficate type must be absent or the SSL CA bit must be set: this is
used as a work around if the basicConstraints extension is absent.
Netscape SSL Server
For Netscape SSL clients to connect to an SSL server; it must have
the keyEncipherment bit set if the keyUsage extension is present.
This isn't always valid because some cipher suites use the key for
digital signing. Otherwise it is the same as a normal SSL server.
Common S/MIME Client Tests
The extended key usage extension must be absent or include the
"email protection" OID. Netscape certificate type must be absent or
should have the S/MIME bit set. If the S/MIME bit is not set in
Netscape certificate type, then the SSL client bit is tolerated as
an alternative but a warning is shown: this is because some Ver-
isign certificates don't set the S/MIME bit.
S/MIME Signing
In addition to the common S/MIME client tests, the digitalSignature
bit must be set if the keyUsage extension is present.
S/MIME Encryption
In addition to the common S/MIME tests, the keyEncipherment bit
must be set if the keyUsage extension is present.
S/MIME CA
The extended key usage extension must be absent or include the
"email protection" OID. Netscape certificate type must be absent or
must have the S/MIME CA bit set: this is used as a work around if
the basicConstraints extension is absent.
CRL Signing
The keyUsage extension must be absent or it must have the CRL sign-
ing bit set.
CRL Signing CA
The normal CA tests apply. Except in this case the basicConstraints
extension must be present.
Extensions in certificates are not transferred to certificate requests
and vice versa.
It is possible to produce invalid certificates or requests by specifying
the wrong private key or using inconsistent options in some cases: these
should be checked.
There should be options to explicitly set such things as start and end
dates, rather than an offset from the current time.
The code to implement the verify behaviour described in the X509 TRUST
SETTINGS is currently being developed. It thus describes the intended
behaviour rather than the current behaviour. It is hoped that it will
represent reality in OpenSSL 0.9.5 and later.
/etc/ssl/ Default config directory for openssl.
/etc/ssl/lib/ Unused.
/etc/ssl/private/ Default private key directory.
/etc/ssl/openssl.cnf Default configuration file for openssl.
/etc/ssl/x509v3.cnf Default configuration file for x509 certificates.
blowfish(3), crypto(3), des_crypt(3), dsa(3), ERR_error_string_n(3),
HMAC(3), md4(3), md5(3), RAND_egd(3), rsa(3), sha1(3), sha2(3), ssl(3),
des_modes(7), httpd(8), openssltool(8), sendmail(8), ssl(8), starttls(8),
vnconfig(8)
The SSL Protocol, Netscape Communications Corp., February 9 1995.
The SSL 3.0 Protocol, Netscape Communications Corp., November 18 1996.
The TLS Protocol Version 1.0, RFC 2246, January 1999.
LDAPv3 Distinguished Names, RFC 2253, December 1997.
PKCS #7: Cryptographic Message Syntax, RFC 2315, March 1998.
X.509 Certificate and CRL Profile, RFC 2459, January 1999.
Online Certificate Status Protocol - OCSP, RFC 2560, June 1999.
Cryptographic Message Syntax, RFC 2630, June 1999.
Advanced Encryption Standard (AES) Ciphersuites for Transport Layer
Security(TLS), RFC 3268, June 2002.
The openssl(1) document appeared in OpenSSL 0.9.2. The list-XXX-commands
pseudo-commands were added in OpenSSL 0.9.3; the no-XXX pseudo-commands
were added in OpenSSL 0.9.5a.
The openssl(1) manual page appeared in OpenBSD 3.3, after that what is
now the openssltool(1) manual page got rejected - but eventually made its
way into MirBSD.
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