SSL_CTX_set_cipher_list - choose list of available SSL_CIPHERs
#include <openssl/ssl.h> int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str); int SSL_set_cipher_list(SSL *ssl, const char *str);
OpenSSL SSL_CTX_set_cipher_list(3openssl)
NAME
SSL_CTX_set_cipher_list, SSL_set_cipher_list - choose list of available
SSL_CIPHERs
SYNOPSIS
#include <openssl/ssl.h>
int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str);
int SSL_set_cipher_list(SSL *ssl, const char *str);
DESCRIPTION
SSL_CTX_set_cipher_list() sets the list of available ciphers for ctx
using the control string str. The format of the string is described in
ciphers(1). The list of ciphers is inherited by all ssl objects created
from ctx.
SSL_set_cipher_list() sets the list of ciphers only for ssl.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+--------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------------+
|Availability | library/security/openssl |
+---------------+--------------------------+
|Stability | Pass-through uncommitted |
+---------------+--------------------------+
NOTES
The control string str should be universally usable and not depend on
details of the library configuration (ciphers compiled in). Thus no
syntax checking takes place. Items that are not recognized, because the
corresponding ciphers are not compiled in or because they are mistyped,
are simply ignored. Failure is only flagged if no ciphers could be
collected at all.
It should be noted, that inclusion of a cipher to be used into the list
is a necessary condition. On the client side, the inclusion into the
list is also sufficient. On the server side, additional restrictions
apply. All ciphers have additional requirements. ADH ciphers don't need
a certificate, but DH-parameters must have been set. All other ciphers
need a corresponding certificate and key.
A RSA cipher can only be chosen, when a RSA certificate is available.
RSA export ciphers with a keylength of 512 bits for the RSA key require
a temporary 512 bit RSA key, as typically the supplied key has a length
of 1024 bit (see SSL_CTX_set_tmp_rsa_callback(3)). RSA ciphers using
DHE need a certificate and key and additional DH-parameters (see
SSL_CTX_set_tmp_dh_callback(3)).
A DSA cipher can only be chosen, when a DSA certificate is available.
DSA ciphers always use DH key exchange and therefore need DH-parameters
(see SSL_CTX_set_tmp_dh_callback(3)).
When these conditions are not met for any cipher in the list (e.g. a
client only supports export RSA ciphers with a asymmetric key length of
512 bits and the server is not configured to use temporary RSA keys),
the "no shared cipher" (SSL_R_NO_SHARED_CIPHER) error is generated and
the handshake will fail.
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://www.openssl.org/source/openssl-1.0.2ze.tar.gz.
Further information about this software can be found on the open source
community website at https://www.openssl.org/.
RETURN VALUES
SSL_CTX_set_cipher_list() and SSL_set_cipher_list() return 1 if any
cipher could be selected and 0 on complete failure.
SEE ALSO
ssl(3), SSL_get_ciphers(3), SSL_CTX_use_certificate(3),
SSL_CTX_set_tmp_rsa_callback(3), SSL_CTX_set_tmp_dh_callback(3),
ciphers(1)
1.0.2ze 2022-06-28
SSL_CTX_set_cipher_list(3openssl)