Manual Pages for UNIX Operating System command usage for man SSL_CTX_set_cipher_list

OpenSSL                         SSL_CTX_set_cipher_list(3openssl)



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     SSL_CTX_set_cipher_list, SSL_set_cipher_list - choose list
     of available SSL_CIPHERs

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      #include 

      int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str);
      int SSL_set_cipher_list(SSL *ssl, const char *str);


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     SSL_CTX_set_cipher_list() sets the list of available ciphers
     for ccccttttxxxx using the control string ssssttttrrrr. The format of the
     string is described in ciphers(1). The list of ciphers is
     inherited by all ssssssssllll objects created from ccccttttxxxx.

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

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     The control string ssssttttrrrr 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 EDH
     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



23/Jul/2001            Last change: 0.9.8o                      1






OpenSSL                         SSL_CTX_set_cipher_list(3openssl)



     configured to use temporary RSA keys), the "no shared
     cipher" (SSL_R_NO_SHARED_CIPHER) error is generated and the
     handshake will fail.

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     SSL_CTX_set_cipher_list() and SSL_set_cipher_list() return 1
     if any cipher could be selected and 0 on complete failure.

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     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)











































23/Jul/2001            Last change: 0.9.8o                      2