Updated: 2021/Apr/14


SSL_get_ciphers(3)                  OpenSSL                 SSL_get_ciphers(3)



NAME
       SSL_get1_supported_ciphers, SSL_get_client_ciphers, SSL_get_ciphers,
       SSL_CTX_get_ciphers, SSL_bytes_to_cipher_list, SSL_get_cipher_list,
       SSL_get_shared_ciphers - get list of available SSL_CIPHERs

LIBRARY
       libcrypto, -lcrypto

SYNOPSIS
        #include <openssl/ssl.h>

        STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *ssl);
        STACK_OF(SSL_CIPHER) *SSL_CTX_get_ciphers(const SSL_CTX *ctx);
        STACK_OF(SSL_CIPHER) *SSL_get1_supported_ciphers(SSL *s);
        STACK_OF(SSL_CIPHER) *SSL_get_client_ciphers(const SSL *ssl);
        int SSL_bytes_to_cipher_list(SSL *s, const unsigned char *bytes, size_t len,
                                     int isv2format, STACK_OF(SSL_CIPHER) **sk,
                                     STACK_OF(SSL_CIPHER) **scsvs);
        const char *SSL_get_cipher_list(const SSL *ssl, int priority);
        char *SSL_get_shared_ciphers(const SSL *s, char *buf, int size);

DESCRIPTION
       SSL_get_ciphers() returns the stack of available SSL_CIPHERs for ssl,
       sorted by preference. If ssl is NULL or no ciphers are available, NULL
       is returned.

       SSL_CTX_get_ciphers() returns the stack of available SSL_CIPHERs for
       ctx.

       SSL_get1_supported_ciphers() returns the stack of enabled SSL_CIPHERs
       for ssl as would be sent in a ClientHello (that is, sorted by
       preference).  The list depends on settings like the cipher list, the
       supported protocol versions, the security level, and the enabled
       signature algorithms.  SRP and PSK ciphers are only enabled if the
       appropriate callbacks or settings have been applied.  The list of
       ciphers that would be sent in a ClientHello can differ from the list of
       ciphers that would be acceptable when acting as a server.  For example,
       additional ciphers may be usable by a server if there is a gap in the
       list of supported protocols, and some ciphers may not be usable by a
       server if there is not a suitable certificate configured.  If ssl is
       NULL or no ciphers are available, NULL is returned.

       SSL_get_client_ciphers() returns the stack of available SSL_CIPHERs
       matching the list received from the client on ssl. If ssl is NULL, no
       ciphers are available, or ssl is not operating in server mode, NULL is
       returned.

       SSL_bytes_to_cipher_list() treats the supplied len octets in bytes as a
       wire-protocol cipher suite specification (in the three-octet-per-cipher
       SSLv2 wire format if isv2format is nonzero; otherwise the two-octet
       SSLv3/TLS wire format), and parses the cipher suites supported by the
       library into the returned stacks of SSL_CIPHER objects sk and
       Signalling Cipher-Suite Values scsvs.  Unsupported cipher suites are
       ignored.  Returns 1 on success and 0 on failure.

       SSL_get_cipher_list() returns a pointer to the name of the SSL_CIPHER
       listed for ssl with priority. If ssl is NULL, no ciphers are available,
       or there are less ciphers than priority available, NULL is returned.

       SSL_get_shared_ciphers() creates a colon separated and NUL terminated
       list of SSL_CIPHER names that are available in both the client and the
       server. buf is the buffer that should be populated with the list of
       names and size is the size of that buffer. A pointer to buf is returned
       on success or NULL on error. If the supplied buffer is not large enough
       to contain the complete list of names then a truncated list of names
       will be returned. Note that just because a ciphersuite is available
       (i.e. it is configured in the cipher list) and shared by both the
       client and the server it does not mean that it is enabled (see the
       description of SSL_get1_supported_ciphers() above). This function will
       return available shared ciphersuites whether or not they are enabled.
       This is a server side function only and must only be called after the
       completion of the initial handshake.

NOTES
       The details of the ciphers obtained by SSL_get_ciphers(),
       SSL_CTX_get_ciphers() SSL_get1_supported_ciphers() and
       SSL_get_client_ciphers() can be obtained using the
       SSL_CIPHER_get_name(3) family of functions.

       Call SSL_get_cipher_list() with priority starting from 0 to obtain the
       sorted list of available ciphers, until NULL is returned.

       Note: SSL_get_ciphers(), SSL_CTX_get_ciphers() and
       SSL_get_client_ciphers() return a pointer to an internal cipher stack,
       which will be freed later on when the SSL or SSL_SESSION object is
       freed.  Therefore, the calling code MUST NOT free the return value
       itself.

       The stack returned by SSL_get1_supported_ciphers() should be freed
       using sk_SSL_CIPHER_free().

       The stacks returned by SSL_bytes_to_cipher_list() should be freed using
       sk_SSL_CIPHER_free().

RETURN VALUES
       See DESCRIPTION

SEE ALSO
       ssl(7), SSL_CTX_set_cipher_list(3), SSL_CIPHER_get_name(3)

COPYRIGHT
       Copyright 2000-2018 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>.



1.1.1i                            2018-09-23                SSL_get_ciphers(3)