MirOS Manual: keynote(3), kn_add_action(3), kn_add_assertion(3), kn_add_authorizer(3), kn_cleanup_action_environment(3), kn_close(3), kn_decode_base64(3), kn_decode_hex(3), kn_decode_key(3), kn_do_query(3), kn_encode_base64(3), kn_encode_hex(3), kn_encode_key(3), kn_free_key(3), kn_get_authorizer(3), kn_get_failed(3), kn_get_licensees(3), kn_get_string(3), kn_init(3), kn_keycompare(3), kn_query(3), kn_read_asserts(3), kn_remove_action(3), kn_remove_assertion(3), kn_remove_authorizer(3), kn_sign_assertion(3), kn_verify_assertion(3)

KEYNOTE(3)                 BSD Programmer's Manual                  KEYNOTE(3)

NAME

     keynote - a trust-management system library

SYNOPSIS

     #include <sys/types.h>
     #include <regex.h>
     #include <keynote.h>

     struct environment {
             char               *env_name;
             char               *env_value;
             int                 env_flags;
             regex_t             env_regex;
             struct environment *env_next;
     };

     struct keynote_deckey {
             int   dec_algorithm;
             void *dec_key;
     };

     struct keynote_binary {
             int   bn_len;
             char *bn_key;
     };

     struct keynote_keylist {
             int                     key_alg;
             void                   *key_key;
             char                   *key_stringkey;
             struct keynote_keylist *key_next;
     };

     extern int keynote_errno;

     int
     kn_init(void);

     int
     kn_add_assertion(int sessid, char *assertion, int len, int flags);

     int
     kn_remove_assertion(int sessid, int assertid);

     int
     kn_add_action(int sessid, char *name, char *value, int flags);

     int
     kn_remove_action(int sessid, char *name);

     int
     kn_add_authorizer(int sessid, char *principal);

     int
     kn_remove_authorizer(int sessid, char *principal);

     int
     kn_do_query(int sessid, char **returnvalues, int numvalues);

     int
     kn_get_failed(int sessid, int type, int seq);

     int
     kn_cleanup_action_environment(int sessid);
     int
     kn_close(int sessid);

     int
     kn_query(struct environment *env, char **returnvalues, int numvalues,
             char **trusted, int *trustedlen, int numtrusted,
             char **untrusted, int *untrustedlen, int numuntrusted,
             char **authorizers, int numauthauthorizers);

     char **
     kn_read_asserts(char *array, int arraylen, int *numassertions);

     int
     kn_keycompare(void *key1, void *key2, int algorithm);

     void *
     kn_get_authorizer(int sessid, int assertid, int *algorithm);

     struct keynote_keylist *
     kn_get_licensees(int sessid, int assertid);

     int
     kn_encode_base64(unsigned char const *src, unsigned int srclen,
             char *dst, unsigned int dstlen);

     int
     kn_decode_base64(char const *src, unsigned char *dst,
             unsigned int dstlen);

     int
     kn_encode_hex(unsigned char *src, char **dst, int srclen);

     int
     kn_decode_hex(char *src, char **dst);

     char *
     kn_encode_key(struct keynote_deckey *dc, int iencoding, int encoding,
             int keytype);

     int
     kn_decode_key(struct keynote_deckey *dc, char *key, int keytype);

     char *
     kn_sign_assertion(char *assertion, int len, char *key, char *algorithm,
             int vflag);

     int
     kn_verify_assertion(char *assertion, int len);

     void
     kn_free_key(struct keynote_deckey *);

     char *
     kn_get_string(char *);

     Link options: -lkeynote -lm -lcrypto

DESCRIPTION

     For more details on keynote, see RFC 2704.

     keynote_errno contains an error code if some library call failed. Failed
     calls return -1 (if their return value is integer), or NULL (if their re-
     turn value is a pointer) and set keynote_errno. The defined error codes
     are:

           ERROR_MEMORY    Some memory allocation or usage error was encoun-
                           tered.

           ERROR_SYNTAX    Some syntactic or logical error was encountered.

           ERROR_NOTFOUND  One of the arguments referred to a nonexistent
                           structure or entry.

     If no errors were encountered, keynote_errno will be set to 0. This vari-
     able should be reset to 0 if an error was encountered, prior to calling
     other library routines.

     The main interface to keynote is centered around the concept of a ses-
     sion. A session describes a collection of policies, assertions, action
     authorizers, return values, and action attributes that the keynote system
     uses to evaluate a query. Information is not shared between sessions.
     Policies, credentials, action authorizers, and action attributes can be
     added or deleted at any point during the lifetime of a session. Further-
     more, an application can discover which assertions failed to be evaluat-
     ed, and in what way, during a query.

     For those applications that only need to do a simple query, there exists
     a single call that takes as arguments all the necessary information and
     performs all the necessary steps. This is essentially a wrapper that
     calls the session API functions as necessary.

     Finally, there exist functions for doing ASCII to hexadecimal and Base64
     encoding (and vice versa), for encoding/decoding keys between ASCII and
     binary formats, and for signing and verifying assertions.

     The description of all keynote library functions follows.

     kn_init() creates a new keynote session, and performs any necessary ini-
     tializations. On success, this function returns the new session ID, which
     is used by all subsequent calls with a sessid argument. On failure, it
     returns -1 and sets keynote_errno to ERROR_MEMORY.

     kn_add_assertion() adds the assertion pointed to by the array assertion,
     of length len in the session identified by sessid. The first argument can
     be discarded after the call to this function. The following flags are de-
     fined:

           ASSERT_FLAG_LOCAL  Mark this assertion as ultimately trusted.
                              Trusted assertions need not be signed, and the
                              Authorizer and Licensees fields can have non-key
                              entries.

     At least one (trusted) assertion should have POLICY as the Authorizer. On
     success, this function will return an assertion ID which can be used to
     remove the assertion from the session, by using kn_remove_assertion(3).
     On failure, -1 is returned, and keynote_errno is set to ERROR_NOTFOUND if
     the session was not found, ERROR_SYNTAX if the assertion was syntactical-
     ly incorrect, or ERROR_MEMORY if necessary memory could not be allocated.

     kn_remove_assertion() removes the assertion identified by assertid from
     the session identified by sessid. On success, this function returns 0. On
     failure, it returns -1 and sets keynote_errno to ERROR_NOTFOUND.

     kn_add_action() inserts the variable name in the action environment of
     session sessid, with the value value. The same attribute may be added
     more than once, but only the last instance will be used (memory resources
     are consumed however).

     The flags specified are formed by or'ing the following values:

           ENVIRONMENT_FLAG_FUNC   In this case, value is a pointer to a func-
                                   tion that takes as argument a string and
                                   returns a string. This is used to implement
                                   callbacks for getting action attribute
                                   values. The argument passed to such a call-
                                   back function is a string identifying the
                                   action attribute whose value is requested,
                                   and should return a pointer to string con-
                                   taining that value (this pointer will not
                                   be freed by the library), the empty string
                                   if the value was not found, or a NULL to
                                   indicate an error (and may set
                                   keynote_errno appropriately). Prior to
                                   first use (currently, at the time the at-
                                   tribute is added to the session environ-
                                   ment), such functions are called with
                                   KEYNOTE_CALLBACK_INITIALIZE as the argument
                                   (defined in keynote.h) so that they can
                                   perform any special initializations. Furth-
                                   ermore, when the session is deleted, all
                                   such functions will be called with
                                   KEYNOTE_CALLBACK_CLEANUP to perform any
                                   special cleanup (such as free any allocated
                                   memory). A function may be called with ei-
                                   ther of these arguments more than once, if
                                   it has been defined as the callback func-
                                   tion for more than one attribute.

           ENVIRONMENT_FLAG_REGEX  In this case, name is a regular expression
                                   that may match more than one attribute. In
                                   case of conflict between a regular expres-
                                   sion and a "simple" attribute, the latter
                                   will be given priority. In case of conflict
                                   between two regular expression attributes,
                                   the one added later will be given priority.
                                   A callback function should never change the
                                   current keynote session,
                                   start/invoke/operate on another session, or
                                   call one of the session-API functions.

     The combination of the two flags may be used to specify callback func-
     tions that handle large sets of attributes (even to the extent of having
     one callback function handling all attribute references). This is partic-
     ularly useful when the action attribute set is particularly large.

     On success, kn_add_action(3) returns 0. On failure, it returns -1 and
     sets keynote_errno to ERROR_NOTFOUND if the session was not found,
     ERROR_SYNTAX if the name was invalid (e.g., started with an underscore
     character) or was NULL, or ERROR_MEMORY if necessary memory could not be
     allocated.

     kn_remove_action() removes action attribute name from the environment of
     session sessid. Notice that if more than one instances of name exist,
     only the one added last will be deleted. On success, this function re-
     turns 0. On failure, it returns -1 and keynote_errno is set to
     ERROR_NOTFOUND if the session or the attribute were not found, or
     ERROR_SYNTAX if the name was invalid. If the attribute value was a call-
     back, that function will be called with the define
     KEYNOTE_CALLBACK_CLEANUP as the argument.

     kn_add_authorizer() adds the principal pointed to by principal to the ac-
     tion authorizers list of session sessid. The principal is typically an
     ASCII-encoded key. On success, this function will return 0. On failure,
     it returns -1 and sets keynote_errno to ERROR_NOTFOUND if the session was
     not found, ERROR_SYNTAX if the encoding was invalid, or ERROR_MEMORY if
     necessary memory could not be allocated.

     kn_remove_authorizer() removes principal from the action authorizer list
     of session sessid. On success, this function returns 0. On failure, it
     returns -1 and sets keynote_errno to ERROR_NOTFOUND if the session was
     not found.

     kn_do_query() evaluates the request based on the assertions, action at-
     tributes, and action authorizers added to session sessid. returnvalues is
     an ordered array of strings that contain the return values. The lowest-
     ordered return value is contained in returnvalues[0], and the highest-
     ordered value is returnvalues[numvalues - 1]. If returnvalues is NULL,
     the returnvalues from the previous call to kn_do_query(3) will be used.
     The programmer SHOULD NOT free returnvalues after the call to
     kn_do_query(3) if this feature is used, as the array is not replicated
     internally. On success, this function returns an index into the
     returnvalues array. On failure, it returns -1 and sets keynote_errno to
     ERROR_NOTFOUND if the session was not found or the authorizers list was
     empty, ERROR_SYNTAX if no returnvalues have been specified, or
     ERROR_MEMORY if necessary memory could not be allocated.

     kn_get_failed() returns the assertion ID of the num'th assertion (start-
     ing from zero) in session sessid that was somehow invalid during evalua-
     tion. This function is typically called after kn_do_query(3) is used to
     evaluate a request. type specifies the type of failure the application is
     interested in. It can be set to:

           KEYNOTE_ERROR_ANY        to indicate interest in any error.

           KEYNOTE_ERROR_SYNTAX     for syntactic or semantic errors.

           KEYNOTE_ERROR_MEMORY     for memory-related problems.

           KEYNOTE_ERROR_SIGNATURE  if the assertion could not be cryptograph-
                                    ically verified.

     These values are defined in keynote.h. An application can then delete the
     offending assertion using kn_remove_assertion(3). For example, to remove
     all assertion whose signature failed, an application could do something
     like:

       while ((assertid = kn_get_failed(sessid, KEYNOTE_ERROR_SIGNATURE, 0)
              != -1)
         kn_remove_assertion(sessid, assertid);

     On success, kn_get_failed(3) returns an assertion ID. On failure, or when
     no assertion matching the given criteria is found, it returns -1 and set
     keynote_errno to ERROR_NOTFOUND.

     kn_cleanup_action_environment() removes all action attributes from the
     action environment of session sessid. It returns 0 on success.

     kn_close() closes session sessid and frees all related resources, delet-
     ing action attributes, action authorizers, and assertions. On success,
     this function returns 0. On failure, it returns -1 and sets keynote_errno
     to ERROR_NOTFOUND if the session was not found.

     kn_read_asserts() parses the string array of length arraylen and returns
     an array of pointers to strings containing copies of the assertions found
     in array. Both the array of pointers and the strings are allocated by
     kn_read_asserts() dynamically, and thus should be freed by the programmer
     when they are no longer needed. numassertions contains the number of
     assertions (and thus strings in the returned array) found in array. On
     failure, this function returns NULL and sets keynote_errno to
     ERROR_MEMORY if necessary memory could not be allocated, or ERROR_SYNTAX
     if array was NULL. Note that if there were no assertions found in array,
     a valid pointer will be returned, but numassertions will contain the
     value zero on return. The returned pointer should be freed by the pro-
     grammer.

     kn_keycompare() compares key1 and key2 (which must be of the same
     algorithm) and returns 1 if equal and 0 otherwise.

     kn_get_authorizer() returns the authorizer key (in binary format) for
     assertion assertid in session sessid. It also sets the algorithm argument
     to the algorithm of the authorizer key. On failure, kn_get_authorizer()
     returns NULL, and sets keynote_errno to ERROR_NOTFOUND.

     kn_get_licensees() returns the licensee key(s) for assertion assertid in
     session sessid. The keys are returned in a linked list of struct
     keynote_keylist structures. On failure, kn_get_licensees() returns NULL.
     and sets keynote_errno to ERROR_NOTFOUND.

     kn_query() takes as arguments a list of action attributes in env, a list
     of return values in returnvalues (the number of returnvalues is indicated
     by numvalues), a number (numtrusted) of locally-trusted assertions in
     trusted (the length of each assertion is given by the respective element
     of trustedlen), a number (numuntrusted) of assertions that need to be
     cryptographically verified in untrusted (the length of each assertion is
     given by the respective element of untrustedlen), and a number
     (numauthorizers) of action authorizers in authorizers. env is a linked
     list of struct environment structures. The env_name, env_value, and
     env_flags fields correspond to the name, value, and flags arguments to
     kn_add_assertion(3) respectively. env_regex is not used. On success, this
     function returns an index in returnvalues indicating the returned value
     to the query. On failure, it returns -1 and sets keynote_errno to the
     same values as kn_do_query(3), or to ERROR_MEMORY if a trusted or un-
     trusted assertion could not be added to the session due to lack of memory
     resources. Syntax errors in assertions will not be reported by
     kn_query().

     kn_encode_base64() converts the data of length srclen contained in src in
     Base64 encoding and stores them in dst which is of length dstlen. The ac-
     tual length of the encoding stored in dst is returned. dst should be long
     enough to also contain the trailing string terminator. If srclen is not a
     multiple of 4, or dst is not long enough to contain the encoded data,
     this function returns -1 and sets keynote_errno to ERROR_SYNTAX.

     kn_decode_base64() decodes the Base64-encoded data stored in src and
     stores the result in dst, which is of length dstlen. The actual length of
     the decoded data is returned on success. On failure, this function re-
     turns -1 and sets keynote_errno to ERROR_SYNTAX, denoting either an in-
     valid Base64 encoding or insufficient space in dst.

     kn_encode_hex() encodes in ASCII-hexadecimal format the data of length
     srclen contained in src. This function allocates a chunk of memory to
     store the result, which is returned in dst. Thus, this function should be
     used as follows:

       char *dst;

       kn_encode_hex(src, &dst, srclen);

     The length of the allocated buffer will be (2 * srclen + 1). On success,
     this function returns 0. On failure, it returns -1 and sets keynote_errno
     to ERROR_MEMORY if it failed to allocate enough memory, ERROR_SYNTAX if
     dst was NULL.

     kn_decode_hex() decodes the ASCII hex-encoded string in src and stores
     the result in a memory chunk allocated by the function. A pointer to that
     memory is stored in dst. The length of the allocated memory will be
     (strlen(src) / 2). On success, this function returns 0. On failure, it
     returns -1 and sets keynote_errno to ERROR_MEMORY if it could not allo-
     cate enough memory, or ERROR_SYNTAX if dst was NULL, or the length of src
     is not even.

     kn_encode_key() ASCII-encodes a cryptographic key. The binary representa-
     tion of the key is contained in dc. The field dec_key in that structure
     is a pointer to some cryptographic algorithm dependent information
     describing the key. In this implementation, this pointer should be a DSA
     * or RSA * for DSA or RSA keys respectively, as used in the SSL library,
     or a keynote_binary * for cryptographic keys whose algorithm keynote does
     not know about but the application wishes to include in the action au-
     thorizers (and thus need to be canonicalized). The field dec_algorithm
     describes the cryptographic algorithm, and may be one of
     KEYNOTE_ALGORITHM_DSA, KEYNOTE_ALGORITHM_RSA, or KEYNOTE_ALGORITHM_BINARY
     in this implementation.

     iencoding describes how the key should be binary-encoded. This implemen-
     tation supports INTERNAL_ENC_PKCS1 for RSA keys, INTERNAL_ENC_ASN1 for
     DSA keys, and INTERNAL_ENC_NONE for BINARY keys. encoding describes what
     ASCII encoding should be applied to the key. Valid values are
     ENCODING_HEX and ENCODING_BASE64, for hexadecimal and Base64 encoding
     respectively. keytype is one of KEYNOTE_PUBLIC_KEY or KEYNOTE_PRIVATE_KEY
     to indicate whether the key is public or private. Private keys have the
     string KEYNOTE_PRIVATE_KEY_PREFIX (defined in keynote.h) prefixed to the
     algorithm name. On success, this function returns a string containing the
     encoded key. On failure, it returns NULL and sets keynote_errno to
     ERROR_NOTFOUND if the dc argument was invalid, ERROR_MEMORY if it failed
     to allocate the necessary memory, or ERROR_SYNTAX if the key to be con-
     verted was invalid.

     kn_decode_key() decodes the ASCII-encoded string contained in key. The
     result is placed in dc, with dec_algorithm describing the algorithm (see
     kn_encode_key(3)), and dec_key pointing to an algorithm-dependent struc-
     ture. In this implementation, this is an SSLeay/OpenSSL-defined DSA * for
     DSA keys, RSA * for RSA and X509-based keys, and a keynote_binary * for
     BINARY keys. keytype takes the values KEYNOTE_PUBLIC_KEY or
     KEYNOTE_PRIVATE_KEY to specify a public or private key, where applicable.
     On success, this function returns 0. On failure, it returns -1 and sets
     keynote_errno to ERROR_MEMORY if necessary memory could not be allocated,
     or ERROR_SYNTAX if the key or the ASCII encoding was malformed.

     kn_sign_assertion() produces the cryptographic signature for the asser-
     tion of length len stored in assertion, using the ASCII-encoded crypto-
     graphic key contained in key. The type of signature to be produced is
     described by the string algorithm. Possible values for this string are
     SIG_RSA_SHA1_PKCS1_HEX, SIG_RSA_SHA1_PKCS1_BASE64, SIG_RSA_MD5_HEX and
     SIG_RSA_MD5_HEX for RSA keys, SIG_DSA_SHA1_HEX and SIG_DSA_SHA1_BASE64
     for DSA keys, SIG_X509_SHA1_HEX and SIG_X509_SHA1_BASE64 for X509-based
     keys. No other cryptographic signatures are currently supported by this
     implementation. If vflag is set to 1, then the generated signature will
     also be verified. On success, this function returns a string containing
     the ASCII-encoded signature, without modifying the assertion. On failure,
     it returns NULL and sets keynote_errno to ERROR_NOTFOUND if one of the
     arguments was NULL, ERROR_MEMORY if necessary memory could not be allo-
     cated, or ERROR_SYNTAX if the algorithm, the key, or the assertion (if
     signature verification was requested) was invalid.

     kn_verify_assertion() verifies the cryptographic signature on the asser-
     tion of length len contained in string assertion. On success, this func-
     tion returns SIGRESULT_TRUE if the signature could be verified, or
     SIGRESULT_FALSE otherwise. On failure, this function returns -1 and sets
     keynote_errno to ERROR_MEMORY if necessary memory could not be allocated,
     or ERROR_SYNTAX if the assertion contained a syntactic error, or the
     cryptographic algorithm was not supported.

     kn_free_key() frees a cryptographic key.

     kn_get_string() parses the argument, treating it as a keynote(4) (quoted)
     string. This is useful for parsing key files. On success, this function
     returns a pointer to the parsing result. The result is dynamically allo-
     cated and should be freed after use. On failure, NULL is returned.

FILES

     keynote.h
     libkeynote.a

SEE ALSO

     keynote(1), keynote(4), keynote(5)

     M. Blaze, J. Feigenbaum, and A. D. Keromytis, The KeyNote Trust-
     Management System, Version 2, RFC 2704, 1999.

     M. Blaze, J. Feigenbaum, and J. Lacy, "Decentralized Trust Management",
     IEEE Conference on Privacy and Security, 1996.

     M. Blaze, J. Feigenbaum, and M. Strauss, "Compliance-Checking in the
     PolicyMaker Trust Management System", Financial Crypto Conference, 1998.

AUTHORS

     Angelos D. Keromytis <angelos@dsl.cis.upenn.edu>

WEB PAGE

     http://www.cis.upenn.edu/~keynote

DIAGNOSTICS

     The return values of all the functions have been given along with the
     function description above.

BUGS

     None that we know of. If you find any, please report them to
           <keynote@research.att.com>

MirOS BSD #10-current           April 29, 1999                               7

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