NAME

       SSL_get_peer_signature_nid, SSL_get_peer_signature_type_nid, SSL_get_signature_nid,
       SSL_get_signature_type_nid - get TLS message signing types

SYNOPSIS

        #include <openssl/ssl.h>

        int SSL_get_peer_signature_nid(SSL *ssl, int *psig_nid);
        int SSL_get_peer_signature_type_nid(const SSL *ssl, int *psigtype_nid);
        int SSL_get_signature_nid(SSL *ssl, int *psig_nid);
        int SSL_get_signature_type_nid(const SSL *ssl, int *psigtype_nid);

DESCRIPTION

       SSL_get_peer_signature_nid() sets *psig_nid to the NID of the digest used by the peer to
       sign TLS messages. It is implemented as a macro.

       SSL_get_peer_signature_type_nid() sets *psigtype_nid to the signature type used by the
       peer to sign TLS messages. Currently the signature type is the NID of the public key type
       used for signing except for PSS signing where it is EVP_PKEY_RSA_PSS. To differentiate
       between rsa_pss_rsae_* and rsa_pss_pss_* signatures, it's necessary to check the type of
       public key in the peer's certificate.

       SSL_get_signature_nid() and SSL_get_signature_type_nid() return the equivalent information
       for the local end of the connection.

RETURN VALUES

       These functions return 1 for success and 0 for failure. There are several possible reasons
       for failure: the cipher suite has no signature (e.g. it uses RSA key exchange or is
       anonymous), the TLS version is below 1.2 or the functions were called too early, e.g.
       before the peer signed a message.

SEE ALSO

       ssl(7), SSL_get_peer_certificate(3),

COPYRIGHT

       Copyright 2017-2018 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 <https://www.openssl.org/source/license.html>.