SSL_CTX_SET1_SIGALGS(3ossl) OpenSSL SSL_CTX_SET1_SIGALGS(3ossl)
NAME
SSL_CTX_set1_sigalgs, SSL_set1_sigalgs, SSL_CTX_set1_sigalgs_list,
SSL_set1_sigalgs_list, SSL_CTX_set1_client_sigalgs,
SSL_set1_client_sigalgs, SSL_CTX_set1_client_sigalgs_list,
SSL_set1_client_sigalgs_list - set supported signature algorithms
SYNOPSIS
#include <openssl/ssl.h>
long SSL_CTX_set1_sigalgs(SSL_CTX *ctx, const int *slist, long slistlen);
long SSL_set1_sigalgs(SSL *ssl, const int *slist, long slistlen);
long SSL_CTX_set1_sigalgs_list(SSL_CTX *ctx, const char *str);
long SSL_set1_sigalgs_list(SSL *ssl, const char *str);
long SSL_CTX_set1_client_sigalgs(SSL_CTX *ctx, const int *slist, long slistlen);
long SSL_set1_client_sigalgs(SSL *ssl, const int *slist, long slistlen);
long SSL_CTX_set1_client_sigalgs_list(SSL_CTX *ctx, const char *str);
long SSL_set1_client_sigalgs_list(SSL *ssl, const char *str);
DESCRIPTION
SSL_CTX_set1_sigalgs(3) and SSL_set1_sigalgs() set the supported
signature algorithms for ctx or ssl. The array slist of length slistlen
must consist of pairs of NIDs corresponding to digest and public key
algorithms.
SSL_CTX_set1_sigalgs_list() and SSL_set1_sigalgs_list() set the
supported signature algorithms for ctx or ssl. The str parameter must
be a null terminated string consisting of a colon separated list of
elements, where each element is either a combination of a public key
algorithm and a digest separated by +, or a TLS 1.3-style named
SignatureScheme such as rsa_pss_pss_sha256. If a list entry is preceded
with the "?" character, it will be ignored if an implementation is
missing.
SSL_CTX_set1_client_sigalgs(), SSL_set1_client_sigalgs(),
SSL_CTX_set1_client_sigalgs_list() and SSL_set1_client_sigalgs_list()
set signature algorithms related to client authentication, otherwise
they are identical to SSL_CTX_set1_sigalgs(3), SSL_set1_sigalgs(),
SSL_CTX_set1_sigalgs_list() and SSL_set1_sigalgs_list().
All these functions are implemented as macros. The signature algorithm
parameter (integer array or string) is not freed: the application
should free it, if necessary.
NOTES
If an application wishes to allow the setting of signature algorithms
as one of many user configurable options it should consider using the
more flexible SSL_CONF API instead.
The signature algorithms set by a client are used directly in the
supported signature algorithm in the client hello message.
The supported signature algorithms set by a server are not sent to the
client but are used to determine the set of shared signature algorithms
and (if server preferences are set with
SSL_OP_CIPHER_SERVER_PREFERENCE) their order.
The client authentication signature algorithms set by a server are sent
in a certificate request message if client authentication is enabled,
otherwise they are unused.
Similarly client authentication signature algorithms set by a client
are used to determined the set of client authentication shared
signature algorithms.
Signature algorithms will neither be advertised nor used if the
security level prohibits them (for example SHA1 if the security level
is 4 or more).
Currently the NID_md5, NID_sha1, NID_sha224, NID_sha256, NID_sha384 and
NID_sha512 digest NIDs are supported and the public key algorithm NIDs
EVP_PKEY_RSA, EVP_PKEY_RSA_PSS, EVP_PKEY_DSA and EVP_PKEY_EC.
The short or long name values for digests can be used in a string (for
example "MD5", "SHA1", "SHA224", "SHA256", "SHA384", "SHA512") and the
public key algorithm strings "RSA", "RSA-PSS", "DSA" or "ECDSA".
The TLS 1.3 signature scheme names (such as "rsa_pss_pss_sha256") can
also be used with the _list forms of the API.
The use of MD5 as a digest is strongly discouraged due to security
weaknesses.
RETURN VALUES
All these functions return 1 for success and 0 for failure.
EXAMPLES
Set supported signature algorithms to SHA256 with ECDSA and SHA256 with
RSA using an array:
const int slist[] = {NID_sha256, EVP_PKEY_EC, NID_sha256, EVP_PKEY_RSA};
SSL_CTX_set1_sigalgs(ctx, slist, 4);
Set supported signature algorithms to SHA256 with ECDSA and SHA256 with
RSA using a string:
SSL_CTX_set1_sigalgs_list(ctx, "ECDSA+SHA256:RSA+SHA256");
SEE ALSO
ssl(7), SSL_get_shared_sigalgs(3), SSL_CONF_CTX_new(3)
HISTORY
Support for ignoring unknown signature algorithms in
SSL_CTX_set1_sigalgs_list(), SSL_set1_sigalgs_list(),
SSL_CTX_set1_client_sigalgs_list() and SSL_set1_client_sigalgs_list()
was added in OpenSSL 3.3.
COPYRIGHT
Copyright 2015-2024 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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
<https://www.openssl.org/source/license.html>.
3.3.2 2024-09-04 SSL_CTX_SET1_SIGALGS(3ossl)
openssl 3.3.2 - Generated Tue Sep 24 13:51:39 CDT 2024