NAME
SSL_get_ciphers,
SSL_CTX_get_ciphers,
SSL_get1_supported_ciphers,
SSL_get_client_ciphers,
SSL_get_cipher_list —
get lists of available
SSL_CIPHERs
SYNOPSIS
/* -lssl -lcrypto */
#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
*ssl);
STACK_OF(SSL_CIPHER) *
SSL_get_client_ciphers(const
SSL *ssl);
const char *
SSL_get_cipher_list(const
SSL *ssl, int
priority);
DESCRIPTION
SSL_get_ciphers()
returns the stack of available SSL_CIPHERs for
ssl, sorted by preference.
SSL_CTX_get_ciphers()
returns the stack of available SSL_CIPHERs for
ctx.
SSL_get1_supported_ciphers()
returns a stack of enabled SSL_CIPHERs for
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.
SSL_get_client_ciphers()
returns the stack of available SSL_CIPHERs matching
the list received from the client on ssl.
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.
SSL_get_cipher_list()
is deprecated — use SSL_get_ciphers() instead
— and badly misnamed; it does not return a list but the name of one
element of the return value of SSL_get_ciphers(),
with the index given by the 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 NULL is returned.
RETURN VALUES
SSL_get_ciphers() returns an internal
pointer to a list of ciphers or NULL if
ssl is NULL or if no ciphers
are available. The returned pointer may not only become invalid when
ssl is destroyed or when
SSL_set_cipher_list(3) is called on it, but also when the
SSL_CTX object in use by ssl at
the time of the call is freed or when
SSL_CTX_set_cipher_list(3) is called on that context
object.
SSL_CTX_get_ciphers() returns an internal
pointer to a list of ciphers or NULL if
ctx is NULL or if no ciphers
are available. The returned pointer becomes invalid when
ctx is destroyed or when
SSL_CTX_set_cipher_list(3) is called on it.
SSL_get1_supported_ciphers() returns a
newly allocated list of ciphers or NULL if
ssl is 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
sk_SSL_CIPHER_free().
SSL_get_client_ciphers() returns an
internal pointer to a list of ciphers or NULL if
ssl is NULL, has no active
session, or is not operating in server mode. The returned pointer becomes
invalid when the SSL_SESSION object is destroyed, even
if the ssl object remains valid. It may also become
invalid in other circumstances, for example when processing a new
ClientHello.
SSL_get_cipher_list() returns an internal
pointer to a string or NULL if
ssl is NULL, if no ciphers are
available, or if priority is greater than or equal to
the number of available ciphers.
SEE ALSO
HISTORY
SSL_get_cipher_list() first appeared in
SSLeay 0.5.2. SSL_get_ciphers() first appeared in
SSLeay 0.8.0. Both functions have been available since
OpenBSD 2.4.
SSL_CTX_get_ciphers() first appeared in
OpenSSL 1.1.0 and has been available since OpenBSD
6.3.
SSL_get1_supported_ciphers() and
SSL_get_client_ciphers() first appeared in OpenSSL
1.1.0 and has been available since OpenBSD 6.5.