NAME
SSL_get_shared_ciphers —
ciphers supported by both client and
server
SYNOPSIS
#include
<openssl/ssl.h>
char *
SSL_get_shared_ciphers(const SSL
*ssl, char *buf, int
len);
DESCRIPTION
If ssl contains a session in server mode,SSL_get_shared_ciphers()
puts as many names of ciphers that are supported by both the client and the
server into the buffer buf as the buffer is long enough
to contain. Names are separated by colons. At most len
bytes are written to buf including the terminating NUL
character.
RETURN VALUES
SSL_get_shared_ciphers() returns
buf on success or NULL on
failure. The following situations cause failure:
- SSL_is_server(3) is false, i.e., ssl is not set to server mode.
- SSL_get_ciphers(3) is
NULLor empty, i.e., no ciphers are available for use by the server. - SSL_get_session(3) is
NULL, i.e., ssl contains no session. - SSL_get_client_ciphers(3) is
NULLor empty, i.e., ssl contains no information about ciphers supported by the client, or the client does not support any ciphers. - The len argument is less than 2.
SEE ALSO
HISTORY
SSL_get_shared_ciphers() first appeared in
SSLeay 0.4.5b and has been available since OpenBSD
2.4.
BUGS
If the list is too long to fit into len bytes, it is silently truncated after the last cipher name that fits, and all following ciphers are skipped. If the buffer is very short such that even the first cipher name does not fit, an empty string is returned even when some shared ciphers are actually available.
There is no easy way to find out how much space is required for buf or whether the supplied space was sufficient.