5 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
9 #include <openssl/ssl.h>
11 long SSL_CTX_set_max_cert_list(SSL_CTX *ctx, long size);
12 long SSL_CTX_get_max_cert_list(SSL_CTX *ctx);
14 long SSL_set_max_cert_list(SSL *ssl, long size);
15 long SSL_get_max_cert_list(SSL *ctx);
19 SSL_CTX_set_max_cert_list() sets the maximum size allowed for the peer's
20 certificate chain for all SSL objects created from B<ctx> to be <size> bytes.
21 The SSL objects inherit the setting valid for B<ctx> at the time
22 L<SSL_new(3)> is being called.
24 SSL_CTX_get_max_cert_list() returns the currently set maximum size for B<ctx>.
26 SSL_set_max_cert_list() sets the maximum size allowed for the peer's
27 certificate chain for B<ssl> to be <size> bytes. This setting stays valid
28 until a new value is set.
30 SSL_get_max_cert_list() returns the currently set maximum size for B<ssl>.
34 During the handshake process, the peer may send a certificate chain.
35 The TLS/SSL standard does not give any maximum size of the certificate chain.
36 The OpenSSL library handles incoming data by a dynamically allocated buffer.
37 In order to prevent this buffer from growing without bounds due to data
38 received from a faulty or malicious peer, a maximum size for the certificate
41 The default value for the maximum certificate chain size is 100kB (30kB
42 on the 16bit DOS platform). This should be sufficient for usual certificate
43 chains (OpenSSL's default maximum chain length is 10, see
44 L<SSL_CTX_set_verify(3)>, and certificates
45 without special extensions have a typical size of 1-2kB).
47 For special applications it can be necessary to extend the maximum certificate
48 chain size allowed to be sent by the peer, see e.g. the work on
49 "Internet X.509 Public Key Infrastructure Proxy Certificate Profile"
50 and "TLS Delegation Protocol" at http://www.ietf.org/ and
51 http://www.globus.org/ .
53 Under normal conditions it should never be necessary to set a value smaller
54 than the default, as the buffer is handled dynamically and only uses the
55 memory actually required by the data sent by the peer.
57 If the maximum certificate chain size allowed is exceeded, the handshake will
58 fail with a SSL_R_EXCESSIVE_MESSAGE_SIZE error.
62 SSL_CTX_set_max_cert_list() and SSL_set_max_cert_list() return the previously
65 SSL_CTX_get_max_cert_list() and SSL_get_max_cert_list() return the currently
70 L<ssl(3)>, L<SSL_new(3)>,
71 L<SSL_CTX_set_verify(3)>
75 Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.
77 Licensed under the OpenSSL license (the "License"). You may not use
78 this file except in compliance with the License. You can obtain a copy
79 in the file LICENSE in the source distribution or at
80 L<https://www.openssl.org/source/license.html>.