SSL_CTX_set_cipher_list

SSL_CTX_set_cipher_list(3)	   OpenSSL	   SSL_CTX_set_cipher_list(3)



NAME
       SSL_CTX_set_cipher_list, SSL_set_cipher_list - choose list of avail-
       able 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 cre-
       ated from ctx.

       SSL_set_cipher_list() sets the list of ciphers only for ssl.

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 restric-
       tions 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 EDH need a certificate and key and additional DH-parame-
       ters (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-parame-
       ters (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 gener-
       ated and the handshake will fail.

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)



0.9.7a				  2001-07-23	   SSL_CTX_set_cipher_list(3)