Fix RT 3193

[oweals/openssl.git] / doc / ssl / SSL_CTX_set_cipher_list.pod

diff --git a/doc/ssl/SSL_CTX_set_cipher_list.pod b/doc/ssl/SSL_CTX_set_cipher_list.pod
index 0fec5682965cf1f1bc2d5539c8a44c1375128a2c..8b41917334b7bf95c654a23c7224eba48491372c 100644 (file)
--- a/doc/ssl/SSL_CTX_set_cipher_list.pod
+++ b/doc/ssl/SSL_CTX_set_cipher_list.pod
@@ -31,20 +31,22 @@ 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.
+also sufficient unless the security level excludes it. 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
 L<SSL_CTX_set_tmp_rsa_callback(3)|SSL_CTX_set_tmp_rsa_callback(3)>).
-RSA ciphers using EDH need a certificate and key and additional DH-parameters.
+RSA ciphers using DHE need a certificate and key and additional DH-parameters
+(see L<SSL_CTX_set_tmp_dh_callback(3)|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.
+DSA ciphers always use DH key exchange and therefore need DH-parameters
+(see L<SSL_CTX_set_tmp_dh_callback(3)|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
@@ -52,6 +54,10 @@ 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.
 
+If the cipher list does not contain any SSLv2 cipher suites (this is the
+default) then SSLv2 is effectively disabled and neither clients nor servers
+will attempt to use SSLv2.
+
 =head1 RETURN VALUES
 
 SSL_CTX_set_cipher_list() and SSL_set_cipher_list() return 1 if any cipher