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SSL_CTX_set1_sigalgs(3)             OpenSSL            SSL_CTX_set1_sigalgs(3)



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

LIBRARY
       libcrypto, -lcrypto

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() 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.

       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(), 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)

COPYRIGHT
       Copyright 2015-2018 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>.



3.0.12                            2023-05-07           SSL_CTX_set1_sigalgs(3)