.\" $OpenBSD: SSL_get_ciphers.3,v 1.11 2020/09/16 07:25:15 schwarze Exp $ .\" full merge up to: OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100 .\" selective merge up to: OpenSSL 83cf7abf May 29 13:07:08 2018 +0100 .\" .\" This file is a derived work. .\" The changes are covered by the following Copyright and license: .\" .\" Copyright (c) 2020 Ingo Schwarze .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. 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IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: September 16 2020 $ .Dt SSL_GET_CIPHERS 3 .Os .Sh NAME .Nm SSL_get_ciphers , .Nm SSL_CTX_get_ciphers , .Nm SSL_get1_supported_ciphers , .Nm SSL_get_client_ciphers , .Nm SSL_get_cipher_list .Nd get lists of available SSL_CIPHERs .Sh SYNOPSIS .In openssl/ssl.h .Ft STACK_OF(SSL_CIPHER) * .Fn SSL_get_ciphers "const SSL *ssl" .Ft STACK_OF(SSL_CIPHER) * .Fn SSL_CTX_get_ciphers "const SSL_CTX *ctx" .Ft STACK_OF(SSL_CIPHER) * .Fn SSL_get1_supported_ciphers "SSL *ssl" .Ft STACK_OF(SSL_CIPHER) * .Fn SSL_get_client_ciphers "const SSL *ssl" .Ft const char * .Fn SSL_get_cipher_list "const SSL *ssl" "int priority" .Sh DESCRIPTION .Fn SSL_get_ciphers returns the stack of available .Vt SSL_CIPHER Ns s for .Fa ssl , sorted by preference. .Pp .Fn SSL_CTX_get_ciphers returns the stack of available .Vt SSL_CIPHER Ns s for .Fa ctx . .Pp .Fn SSL_get1_supported_ciphers returns a stack of enabled .Vt SSL_CIPHER Ns s for .Fa ssl as it would be sent in a ClientHello, sorted by preference. The list depends on settings like the cipher list, the supported protocol versions, the security level, and the enabled signature algorithms. 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. .Pp .Fn SSL_get_client_ciphers returns the stack of available .Vt SSL_CIPHER Ns s matching the list received from the client on .Fa ssl . .Pp The details of the ciphers obtained by .Fn SSL_get_ciphers , .Fn SSL_CTX_get_ciphers , .Fn SSL_get1_supported_ciphers , and .Fn SSL_get_client_ciphers can be obtained using the .Xr SSL_CIPHER_get_name 3 family of functions. .Pp .Fn SSL_get_cipher_list is deprecated \(em use .Fn SSL_get_ciphers instead \(em and badly misnamed; it does not return a list but the name of one element of the return value of .Fn SSL_get_ciphers , with the index given by the .Fa priority argument. Passing 0 selects the cipher with the highest priority. To iterate over all available ciphers in decreasing priority, repeatedly increment the argument by 1 until .Dv NULL is returned. .Sh RETURN VALUES .Fn SSL_get_ciphers returns an internal pointer to a list of ciphers or .Dv NULL if .Fa ssl is .Dv NULL or if no ciphers are available. The returned pointer may not only become invalid when .Fa ssl is destroyed or when .Xr SSL_set_cipher_list 3 is called on it, but also when the .Vt SSL_CTX object in use by .Fa ssl at the time of the call is freed or when .Xr SSL_CTX_set_cipher_list 3 is called on that context object. .Pp .Fn SSL_CTX_get_ciphers returns an internal pointer to a list of ciphers or .Dv NULL if .Fa ctx is .Dv NULL or if no ciphers are available. The returned pointer becomes invalid when .Fa ctx is destroyed or when .Xr SSL_CTX_set_cipher_list 3 is called on it. .Pp .Fn SSL_get1_supported_ciphers returns a newly allocated list of ciphers or .Dv NULL if .Fa ssl is .Dv NULL , if no ciphers are available, or if an error occurs. When the returned pointer is no longer needed, the caller is responsible for freeing it using .Fn sk_SSL_CIPHER_free . .Pp .Fn SSL_get_client_ciphers returns an internal pointer to a list of ciphers or .Dv NULL if .Fa ssl is .Dv NULL , has no active session, or is not operating in server mode. The returned pointer becomes invalid when the .Vt SSL_SESSION object is destroyed, even if the .Fa ssl object remains valid. It may also become invalid in other circumstances, for example when processing a new ClientHello. .Pp .Fn SSL_get_cipher_list returns an internal pointer to a string or .Dv NULL if .Fa ssl is .Dv NULL , if no ciphers are available, or if .Fa priority is greater than or equal to the number of available ciphers. .Sh SEE ALSO .Xr ssl 3 , .Xr SSL_CIPHER_get_name 3 , .Xr SSL_CTX_set_cipher_list 3 .Sh HISTORY .Fn SSL_get_cipher_list first appeared in SSLeay 0.5.2. .Fn SSL_get_ciphers first appeared in SSLeay 0.8.0. Both functions have been available since .Ox 2.4 . .Pp .Fn SSL_CTX_get_ciphers first appeared in OpenSSL 1.1.0 and has been available since .Ox 6.3 . .Pp .Fn SSL_get1_supported_ciphers and .Fn SSL_get_client_ciphers first appeared in OpenSSL 1.1.0 and has been available since .Ox 6.5 .