NAME    [Toc]    [Back]

       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    [Toc]    [Back]

        #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    [Toc]    [Back]

       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 maximum
 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    [Toc]    [Back]

       During the handshake process, the peer may send a certificate
 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
       sufficient for usual certificate chains (OpenSSL's default
       maximum chain length is 10, see SSL_CTX_set_verify(3), and
       certificates 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 Delegation
 Protocol" at http://www.ietf.org/ and
       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    [Toc]    [Back]

       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    [Toc]    [Back]

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

HISTORY    [Toc]    [Back]

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


OpenBSD 3.6                 2002-05-14                          2