=pod =head1 NAME SSL_CIPHER_get_name, SSL_CIPHER_standard_name, OPENSSL_cipher_name, SSL_CIPHER_get_bits, SSL_CIPHER_get_version, SSL_CIPHER_description, SSL_CIPHER_get_cipher_nid, SSL_CIPHER_get_digest_nid, SSL_CIPHER_get_handshake_digest, SSL_CIPHER_get_kx_nid, SSL_CIPHER_get_auth_nid, SSL_CIPHER_get_prf_nid, SSL_CIPHER_is_aead, SSL_CIPHER_find, SSL_CIPHER_get_id, SSL_CIPHER_get_protocol_id - get SSL_CIPHER properties =head1 SYNOPSIS #include const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher); const char *SSL_CIPHER_standard_name(const SSL_CIPHER *cipher); const char *OPENSSL_cipher_name(const char *stdname); int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher, int *alg_bits); char *SSL_CIPHER_get_version(const SSL_CIPHER *cipher); char *SSL_CIPHER_description(const SSL_CIPHER *cipher, char *buf, int size); int SSL_CIPHER_get_cipher_nid(const SSL_CIPHER *c); int SSL_CIPHER_get_digest_nid(const SSL_CIPHER *c); const EVP_MD *SSL_CIPHER_get_handshake_digest(const SSL_CIPHER *c); int SSL_CIPHER_get_kx_nid(const SSL_CIPHER *c); int SSL_CIPHER_get_auth_nid(const SSL_CIPHER *c); int SSL_CIPHER_get_prf_nid(const SSL_CIPHER *c); int SSL_CIPHER_is_aead(const SSL_CIPHER *c); const SSL_CIPHER *SSL_CIPHER_find(SSL *ssl, const unsigned char *ptr); uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *c); uint32_t SSL_CIPHER_get_protocol_id(const SSL_CIPHER *c); =head1 DESCRIPTION SSL_CIPHER_get_name() returns a pointer to the name of B. If the B is NULL, it returns "(NONE)". SSL_CIPHER_standard_name() returns a pointer to the standard RFC name of B. If the B is NULL, it returns "(NONE)". If the B has no standard name, it returns B. If B was defined in both SSLv3 and TLS, it returns the TLS name. OPENSSL_cipher_name() returns a pointer to the OpenSSL name of B. If the B is NULL, or B has no corresponding OpenSSL name, it returns "(NONE)". Where both exist, B should be the TLS name rather than the SSLv3 name. SSL_CIPHER_get_bits() returns the number of secret bits used for B. If B is NULL, 0 is returned. SSL_CIPHER_get_version() returns string which indicates the SSL/TLS protocol version that first defined the cipher. It returns "(NONE)" if B is NULL. SSL_CIPHER_get_cipher_nid() returns the cipher NID corresponding to B. If there is no cipher (e.g. for cipher suites with no encryption) then B is returned. SSL_CIPHER_get_digest_nid() returns the digest NID corresponding to the MAC used by B during record encryption/decryption. If there is no digest (e.g. for AEAD cipher suites) then B is returned. SSL_CIPHER_get_handshake_digest() returns an EVP_MD for the digest used during the SSL/TLS handshake when using the SSL_CIPHER B. Note that this may be different to the digest used to calculate the MAC for encrypted records. SSL_CIPHER_get_kx_nid() returns the key exchange NID corresponding to the method used by B. If there is no key exchange, then B is returned. If any appropriate key exchange algorithm can be used (as in the case of TLS 1.3 cipher suites) B is returned. Examples (not comprehensive): NID_kx_rsa NID_kx_ecdhe NID_kx_dhe NID_kx_psk SSL_CIPHER_get_auth_nid() returns the authentication NID corresponding to the method used by B. If there is no authentication, then B is returned. If any appropriate authentication algorithm can be used (as in the case of TLS 1.3 cipher suites) B is returned. Examples (not comprehensive): NID_auth_rsa NID_auth_ecdsa NID_auth_psk SSL_CIPHER_get_prf_nid() retuns the pseudo-random function NID for B. If B is a pre-TLS-1.2 cipher, it returns B but note these ciphers use SHA-256 in TLS 1.2. Other return values may be treated uniformly in all applicable versions. Examples (not comprehensive): NID_md5_sha1 NID_sha256 NID_sha384 SSL_CIPHER_is_aead() returns 1 if the cipher B is AEAD (e.g. GCM or ChaCha20/Poly1305), and 0 if it is not AEAD. SSL_CIPHER_find() returns a B structure which has the cipher ID stored in B. The B parameter is a two element array of B, which stores the two-byte TLS cipher ID (as allocated by IANA) in network byte order. This parameter is usually retrieved from a TLS packet by using functions like L. SSL_CIPHER_find() returns NULL if an error occurs or the indicated cipher is not found. SSL_CIPHER_get_id() returns the OpenSSL-specific ID of the given cipher B. That ID is not the same as the IANA-specific ID. SSL_CIPHER_get_protocol_id() returns the two-byte ID used in the TLS protocol of the given cipher B. SSL_CIPHER_description() returns a textual description of the cipher used into the buffer B of length B provided. If B is provided, it must be at least 128 bytes, otherwise a buffer will be allocated using OPENSSL_malloc(). If the provided buffer is too small, or the allocation fails, B is returned. The string returned by SSL_CIPHER_description() consists of several fields separated by whitespace: =over 4 =item Textual representation of the cipher name. =item The minimum protocol version that the ciphersuite supports, such as B. Note that this is not always the same as the protocol version in which the ciphersuite was first defined because some ciphersuites are backwards compatible with earlier protocol versions. =item Kx= Key exchange method such as B, B, etc. =item Au= Authentication method such as B, B, etc.. None is the representation of anonymous ciphers. =item Enc= Encryption method, with number of secret bits, such as B. =item Mac= Message digest, such as B. =back Some examples for the output of SSL_CIPHER_description(): ECDHE-RSA-AES256-GCM-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256) Mac=AEAD RSA-PSK-AES256-CBC-SHA384 TLSv1.0 Kx=RSAPSK Au=RSA Enc=AES(256) Mac=SHA384 =head1 RETURN VALUES SSL_CIPHER_get_name(), SSL_CIPHER_standard_name(), OPENSSL_cipher_name(), SSL_CIPHER_get_version() and SSL_CIPHER_description() return the corresponding value in a null-terminated string for a specific cipher or "(NONE)" if the cipher is not found. SSL_CIPHER_get_bits() returns a positive integer representing the number of secret bits or 0 if an error occurred. SSL_CIPHER_get_cipher_nid(), SSL_CIPHER_get_digest_nid(), SSL_CIPHER_get_kx_nid() and SSL_CIPHER_get_auth_nid() return the NID value or B if an error occurred. SSL_CIPHER_get_handshake_digest() returns a valid B structure or NULL if an error occurred. SSL_CIPHER_is_aead() returns 1 if the cipher is AEAD or 0 otherwise. SSL_CIPHER_find() returns a valid B structure or NULL if an error occurred. SSL_CIPHER_get_id() returns a 4-byte integer representing the OpenSSL-specific ID. SSL_CIPHER_get_protocol_id() returns a 2-byte integer representing the TLS protocol-specific ID. =head1 SEE ALSO L, L, L, L =head1 HISTORY The SSL_CIPHER_get_version() function was updated to always return the correct protocol string in OpenSSL 1.1.0. The SSL_CIPHER_description() function was changed to return B on error, rather than a fixed string, in OpenSSL 1.1.0. The SSL_CIPHER_get_handshake_digest() function was added in OpenSSL 1.1.1. The SSL_CIPHER_standard_name() function was globally available in OpenSSL 1.1.1. Before OpenSSL 1.1.1, tracing (B argument to Configure) was required to enable this function. The OPENSSL_cipher_name() function was added in OpenSSL 1.1.1. The SSL_CIPHER_get_prf_nid() function was added in OpenSSL 3.0.0. =head1 COPYRIGHT Copyright 2000-2019 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 L. =cut