SSL_CTX_set_options() and SSL_set_options() affect the (external)
protocol behaviour of the SSL library. The (internal) behaviour of
the API can be changed by using the similar
-L<SSL_CTX_set_modes(3)|SSL_CTX_set_modes(3)> and SSL_set_modes() functions.
+L<SSL_CTX_set_mode(3)|SSL_CTX_set_mode(3)> and SSL_set_mode() functions.
During a handshake, the option settings of the SSL object are used. When
a new SSL object is created from a context using SSL_new(), the current
=item SSL_OP_MSIE_SSLV2_RSA_PADDING
-...
+As of OpenSSL 0.9.7h and 0.9.8a, this option has no effect.
=item SSL_OP_SSLEAY_080_CLIENT_DH_BUG
...
+=item SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
+
+Disables a countermeasure against a SSL 3.0/TLS 1.0 protocol
+vulnerability affecting CBC ciphers, which cannot be handled by some
+broken SSL implementations. This option has no effect for connections
+using other ciphers.
+
=item SSL_OP_ALL
All of the above bug workarounds.
=back
-It is save and recommended to use SSL_OP_ALL to enable the bug workaround
-options.
+It is usually safe to use B<SSL_OP_ALL> to enable the bug workaround
+options if compatibility with somewhat broken implementations is
+desired.
The following B<modifying> options are available:
the DH parameters were not generated using "strong" primes
(e.g. when using DSA-parameters, see L<dhparam(1)|dhparam(1)>).
If "strong" primes were used, it is not strictly necessary to generate
-a new DH key during each handshake but it is also recommendet.
-SSL_OP_SINGLE_DH_USE should therefore be enabled whenever
+a new DH key during each handshake but it is also recommended.
+B<SSL_OP_SINGLE_DH_USE> should therefore be enabled whenever
temporary/ephemeral DH parameters are used.
=item SSL_OP_EPHEMERAL_RSA
preferences. When not set, the SSL server will always follow the clients
preferences. When set, the SSLv3/TLSv1 server will choose following its
own preferences. Because of the different protocol, for SSLv2 the server
-will send his list of preferences to the client and the client chooses.
+will send its list of preferences to the client and the client chooses.
=item SSL_OP_PKCS1_CHECK_1
=item SSL_OP_NETSCAPE_CA_DN_BUG
If we accept a netscape connection, demand a client cert, have a
-non-self-sighed CA which does not have it's CA in netscape, and the
+non-self-signed CA which does not have its CA in netscape, and the
browser has a cert, it will crash/hang. Works for 3.x and 4.xbeta
=item SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG
Do not use the TLSv1 protocol.
+=item SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
+
+When performing renegotiation as a server, always start a new session
+(i.e., session resumption requests are only accepted in the initial
+handshake). This option is not needed for clients.
+
+=item SSL_OP_NO_TICKET
+
+Normally clients and servers will, where possible, transparently make use
+of RFC4507bis tickets for stateless session resumption.
+
+If this option is set this functionality is disabled and tickets will
+not be used by clients or servers.
+
=back
=head1 RETURN VALUES
=head1 HISTORY
-SSL_OP_CIPHER_SERVER_PREFERENCE has been added in OpenSSL 0.9.7.
+B<SSL_OP_CIPHER_SERVER_PREFERENCE> and
+B<SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION> have been added in
+OpenSSL 0.9.7.
+
+B<SSL_OP_TLS_ROLLBACK_BUG> has been added in OpenSSL 0.9.6 and was automatically
+enabled with B<SSL_OP_ALL>. As of 0.9.7, it is no longer included in B<SSL_OP_ALL>
+and must be explicitly set.
-SSL_OP_TLS_ROLLBACK_BUG has been added in OpenSSL 0.9.6 and was automatically
-enabled with SSL_OP_ALL. As of 0.9.7 it is no longer included in SSL_OP_ALL
-and must be explicitely set.
+B<SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS> has been added in OpenSSL 0.9.6e.
+Versions up to OpenSSL 0.9.6c do not include the countermeasure that
+can be disabled with this option (in OpenSSL 0.9.6d, it was always
+enabled).
=cut
projects / oweals / openssl.git / blobdiff