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

        #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);

       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

       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.

       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 16-bit 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 and .

       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.

       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.

       ssl(7), SSL_new(3), SSL_CTX_set_verify(3)

       Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (the "License").  You may not use this
       file except in compliance with the License.  You can obtain a copy in the
       file LICENSE in the source distribution or at

1.1.1j                             2021-02-16       SSL_CTX_SET_MAX_CERT_LIST(3)