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 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

       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

       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.