1=pod 2 3=head1 NAME 4 5SSL_get0_peer_signature_name, SSL_get_peer_signature_nid, 6SSL_get_peer_signature_type_nid, SSL_get0_signature_name, 7SSL_get_signature_nid, SSL_get_signature_type_nid - 8get TLS message signing types 9 10=head1 SYNOPSIS 11 12 #include <openssl/ssl.h> 13 14 int SSL_get0_peer_signature_name(const SSL *ssl, const char **sigalg); 15 int SSL_get_peer_signature_nid(SSL *ssl, int *psig_nid); 16 int SSL_get_peer_signature_type_nid(const SSL *ssl, int *psigtype_nid); 17 int SSL_get0_signature_name(SSL *ssl, const char **sigalg); 18 int SSL_get_signature_nid(SSL *ssl, int *psig_nid); 19 int SSL_get_signature_type_nid(const SSL *ssl, int *psigtype_nid); 20 21=head1 DESCRIPTION 22 23SSL_get0_peer_signature_name() sets I<*sigalg> to the IANA name of the 24L<signature scheme|https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-signaturescheme> 25used by the peer to sign the TLS handshake. 26The caller must not free the returned pointer. 27The returned string should be copied if it is to be retained beyond the 28lifetime of the SSL connection. 29 30SSL_get_peer_signature_nid() sets B<*psig_nid> to the NID of the digest used 31by the peer to sign TLS messages. It is implemented as a macro. 32 33SSL_get_peer_signature_type_nid() sets B<*psigtype_nid> to the signature 34type used by the peer to sign TLS messages. Currently the signature type 35is the NID of the public key type used for signing except for PSS signing 36where it is B<EVP_PKEY_RSA_PSS>. To differentiate between 37B<rsa_pss_rsae_*> and B<rsa_pss_pss_*> signatures, it's necessary to check 38the type of public key in the peer's certificate. 39 40SSL_get0_signature_name(), SSL_get_signature_nid() and 41SSL_get_signature_type_nid() return the equivalent information for the local 42end of the connection. 43 44=head1 RETURN VALUES 45 46These functions return 1 for success and 0 for failure. There are several 47possible reasons for failure: the peer or local end is a client and did not 48sign the handshake (did not use a client certificate), the cipher suite has no 49signature (e.g. it uses RSA key exchange or is anonymous), the TLS version is 50below 1.2 or the functions were called too early, e.g. before the peer signed a 51message. 52 53=head1 SEE ALSO 54 55L<ssl(7)>, L<SSL_get_peer_certificate(3)>, 56 57=head1 HISTORY 58 59The SSL_get0_peer_signature_name() and SSL_get0_signature_name() functions were 60added in OpenSSL 3.5. 61 62=head1 COPYRIGHT 63 64Copyright 2017-2025 The OpenSSL Project Authors. All Rights Reserved. 65 66Licensed under the Apache License 2.0 (the "License"). You may not use 67this file except in compliance with the License. You can obtain a copy 68in the file LICENSE in the source distribution or at 69L<https://www.openssl.org/source/license.html>. 70 71=cut 72