MirBSD manpage: SSL_CTX_get_max_cert_list(3), SSL_CTX_set_max_cert_list(3), SSL_get_max_cert_list(3), SSL_set_max_cert_list(3)

SSL_CTX_SET_MAX_CERT_LIST(3) OpenSSL SSL_CTX_SET_MAX_CERT_LIST(3)

NAME

     SSL_CTX_set_max_cert_list, SSL_CTX_get_max_cert_list,
     SSL_set_max_cert_list, SSL_get_max_cert_list, - manipulate
     allowed for the peer's certificate chain

SYNOPSIS

      #include <openssl/ssl.h>

      long SSL_CTX_set_max_cert_list(SSL_CTX *ctx, long size);
      long SSL_CTX_get_max_cert_list(SSL_CTX *ctx);

      long SSL_set_max_cert_list(SSL *ssl, long size);
      long SSL_get_max_cert_list(SSL *ctx);

DESCRIPTION

     SSL_CTX_set_max_cert_list() sets the maximum size allowed
     for the peer's certificate chain for all SSL objects created
     from ctx to be <size> bytes. The SSL objects inherit the
     setting valid for ctx at the time SSL_new(3) is being
     called.

     SSL_CTX_get_max_cert_list() returns the currently set max-
     imum size for ctx.

     SSL_set_max_cert_list() sets the maximum size allowed for
     the peer's certificate chain for ssl to be <size> bytes.
     This setting stays valid until a new value is set.

     SSL_get_max_cert_list() returns the currently set maximum
     size for ssl.

NOTES

     During the handshake process, the peer may send a certifi-
     cate chain. The TLS/SSL standard does not give any maximum
     size of the certificate chain. The OpenSSL library handles
     incoming data by a dynamically allocated buffer. In order to
     prevent this buffer from growing without bounds due to data
     received from a faulty or malicious peer, a maximum size for
     the certificate chain is set.

     The default value for the maximum certificate chain size is
     100kB (30kB on the 16bit DOS platform). This should be suf-
     ficient for usual certificate chains (OpenSSL's default max-
     imum chain length is 10, see SSL_CTX_set_verify(3), and cer-
     tificates without special extensions have a typical size of
     1-2kB).

     For special applications it can be necessary to extend the
     maximum certificate chain size allowed to be sent by the
     peer, see e.g. the work on "Internet X.509 Public Key
     Infrastructure Proxy Certificate Profile" and "TLS Delega-
     tion Protocol" at http://www.ietf.org/ and

MirBSD #10-current         2005-02-05                           1

SSL_CTX_SET_MAX_CERT_LIST(3) OpenSSL SSL_CTX_SET_MAX_CERT_LIST(3)

     http://www.globus.org/ .

     Under normal conditions it should never be necessary to set
     a value smaller than the default, as the buffer is handled
     dynamically and only uses the memory actually required by
     the data sent by the peer.

     If the maximum certificate chain size allowed is exceeded,
     the handshake will fail with a SSL_R_EXCESSIVE_MESSAGE_SIZE
     error.

RETURN VALUES

     SSL_CTX_set_max_cert_list() and SSL_set_max_cert_list()
     return the previously set value.

     SSL_CTX_get_max_cert_list() and SSL_get_max_cert_list()
     return the currently set value.

SEE ALSO

     ssl(3), SSL_new(3), SSL_CTX_set_verify(3)

HISTORY

     SSL*_set/get_max_cert_list() have been introduced in OpenSSL
     0.9.7.

MirBSD #10-current         2005-02-05                           2