NAME
SSLCTXsetcipherlist, SSLsetcipherlist - choose list of available
SSLCIPHERsSYNOPSIS
#include
int SSLCTXsetcipherlist(SSLCTX *ctx, const char *str); int SSLsetcipherlist(SSL *ssl, const char *str);DESCRIPTION
SSLCTXsetcipherlist() sets the list of available ciphers for ccttxx using the control string ssttrr. The format of the string is described in ciphers(1). The list of ciphers is inherited by all ssssll objects created from ccttxx. SSLsetcipherlist() sets the list of ciphers only for ssssll. NNOOTTEESS The control string ssttrr 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 needa 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 SSLCTXsettmprsacallback(3)). RSA ciphers usingEDH need a certificate and key and additional DH-parameters (see
SSLCTXsettmpdhcallback(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 SSLCTXsettmpdhcallback(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" (SSLRNOSHAREDCIPHER) error is generated and the handshake will fail.RETURN VALUES
SSLCTXsetcipherlist() and SSLsetcipherlist() return 1 if any cipher could be selected and 0 on complete failure.SEE ALSO
ssl(3), SSLgetciphers(3), SSLCTXusecertificate(3), SSLCTXsettmprsacallback(3), SSLCTXsettmpdhcallback(3), ciphers(1)0.9.7l 2001-07-23 SSLCTXsetcipherlist(3)