=over 4
-=item SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG
-
-...
-
-=item SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER
-
-...
-
=item SSL_OP_SAFARI_ECDHE_ECDSA_BUG
Don't prefer ECDHE-ECDSA ciphers when the client appears to be Safari on OS X.
OS X 10.8..10.8.3 has broken support for ECDHE-ECDSA ciphers.
-=item SSL_OP_SSLEAY_080_CLIENT_DH_BUG
-
-...
-
-=item SSL_OP_TLS_D5_BUG
-
-...
-
=item SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
Disables a countermeasure against a SSL 3.0/TLS 1.0 protocol
=item SSL_OP_ALL
-All of the above bug workarounds.
+All of the above bug workarounds plus B<SSL_OP_LEGACY_SERVER_CONNECT> as
+mentioned below.
=back
same SSLv3.1=TLSv1 announcement. Some clients step down to SSLv3 with respect
to the server's answer and violate the version rollback protection.)
-=item SSL_OP_SINGLE_DH_USE
-
-Always create a new key when using temporary/ephemeral DH parameters
-(see L<SSL_CTX_set_tmp_dh_callback(3)>).
-This option must be used to prevent small subgroup attacks, when
-the DH parameters were not generated using "strong" primes
-(e.g. when using DSA-parameters, see L<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 recommended.
-B<SSL_OP_SINGLE_DH_USE> should therefore be enabled whenever
-temporary/ephemeral DH parameters are used.
-
-=item SSL_OP_EPHEMERAL_RSA
-
-This option is no longer implemented and is treated as no op.
-
=item SSL_OP_CIPHER_SERVER_PREFERENCE
When choosing a cipher, use the server's preferences instead of the client
preferences. When set, the SSL/TLS server will choose following its
own preferences.
-=item SSL_OP_PKCS1_CHECK_1
-
-...
-
-=item SSL_OP_PKCS1_CHECK_2
-
-...
-
-
=item SSL_OP_NO_SSLv3, SSL_OP_NO_TLSv1, SSL_OP_NO_TLSv1_1,
-SSL_OP_NO_TLSv1_2, SSL_OP_NO_DTLSv1, SSL_OP_NO_DTLSv1_2
+SSL_OP_NO_TLSv1_2, SSL_OP_NO_TLSv1_3, SSL_OP_NO_DTLSv1, SSL_OP_NO_DTLSv1_2
-These options turn off the SSLv3, TLSv1, TLSv1.1 or TLSv1.2 protocol
+These options turn off the SSLv3, TLSv1, TLSv1.1, TLSv1.2 or TLSv1.3 protocol
versions with TLS or the DTLSv1, DTLSv1.2 versions with DTLS,
respectively.
As of OpenSSL 1.1.0, these options are deprecated, use
(i.e., session resumption requests are only accepted in the initial
handshake). This option is not needed for clients.
-=item SSL_OP_NO_TICKET
+=item SSL_OP_NO_COMPRESSION
+
+Do not use compression even if it is supported.
-Normally clients and servers will, where possible, transparently make use
-of RFC4507bis tickets for stateless session resumption.
+=item SSL_OP_NO_QUERY_MTU
-If this option is set this functionality is disabled and tickets will
-not be used by clients or servers.
+Do not query the MTU. Only affects DTLS connections.
+
+=item SSL_OP_COOKIE_EXCHANGE
+
+Turn on Cookie Exchange as described in RFC4347 Section 4.2.1. Only affects
+DTLS connections.
+
+=item SSL_OP_NO_TICKET
+
+SSL/TLS supports two mechanisms for resuming sessions: session ids and stateless
+session tickets.
+
+When using session ids a copy of the session information is
+cached on the server and a unique id is sent to the client. When the client
+wishes to resume it provides the unique id so that the server can retrieve the
+session information from its cache.
+
+When using stateless session tickets the server uses a session ticket encryption
+key to encrypt the session information. This encrypted data is sent to the
+client as a "ticket". When the client wishes to resume it sends the encrypted
+data back to the server. The server uses its key to decrypt the data and resume
+the session. In this way the server can operate statelessly - no session
+information needs to be cached locally.
+
+The TLSv1.3 protocol only supports tickets and does not directly support session
+ids. However OpenSSL allows two modes of ticket operation in TLSv1.3: stateful
+and stateless. Stateless tickets work the same way as in TLSv1.2 and below.
+Stateful tickets mimic the session id behaviour available in TLSv1.2 and below.
+The session information is cached on the server and the session id is wrapped up
+in a ticket and sent back to the client. When the client wishes to resume, it
+presents a ticket in the same way as for stateless tickets. The server can then
+extract the session id from the ticket and retrieve the session information from
+its cache.
+
+By default OpenSSL will use stateless tickets. The SSL_OP_NO_TICKET option will
+cause stateless tickets to not be issued. In TLSv1.2 and below this means no
+ticket gets sent to the client at all. In TLSv1.3 a stateful ticket will be
+sent. This is a server-side option only.
+
+In TLSv1.3 it is possible to suppress all tickets (stateful and stateless) from
+being sent by calling L<SSL_CTX_set_num_tickets(3)> or
+L<SSL_set_num_tickets(3)>.
=item SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
If this option is set, Encrypt-then-MAC is disabled. Clients will not
propose, and servers will not accept the extension.
+=item SSL_OP_NO_RENEGOTIATION
+
+Disable all renegotiation in TLSv1.2 and earlier. Do not send HelloRequest
+messages, and ignore renegotiation requests via ClientHello.
+
+=item SSL_OP_ALLOW_NO_DHE_KEX
+
+In TLSv1.3 allow a non-(ec)dhe based key exchange mode on resumption. This means
+that there will be no forward secrecy for the resumed session.
+
+=item SSL_OP_PRIORITIZE_CHACHA
+
+When SSL_OP_CIPHER_SERVER_PREFERENCE is set, temporarily reprioritize
+ChaCha20-Poly1305 ciphers to the top of the server cipher list if a
+ChaCha20-Poly1305 cipher is at the top of the client cipher list. This helps
+those clients (e.g. mobile) use ChaCha20-Poly1305 if that cipher is anywhere
+in the server cipher list; but still allows other clients to use AES and other
+ciphers. Requires B<SSL_OP_CIPHER_SERVER_PREFERENCE>.
+
+=item SSL_OP_ENABLE_MIDDLEBOX_COMPAT
+
+If set then dummy Change Cipher Spec (CCS) messages are sent in TLSv1.3. This
+has the effect of making TLSv1.3 look more like TLSv1.2 so that middleboxes that
+do not understand TLSv1.3 will not drop the connection. Regardless of whether
+this option is set or not CCS messages received from the peer will always be
+ignored in TLSv1.3. This option is set by default. To switch it off use
+SSL_clear_options(). A future version of OpenSSL may not set this by default.
+
+=item SSL_OP_NO_ANTI_REPLAY
+
+By default, when a server is configured for early data (i.e., max_early_data > 0),
+OpenSSL will switch on replay protection. See L<SSL_read_early_data(3)> for a
+description of the replay protection feature. Anti-replay measures are required
+to comply with the TLSv1.3 specification. Some applications may be able to
+mitigate the replay risks in other ways and in such cases the built in OpenSSL
+functionality is not required. Those applications can turn this feature off by
+setting this option. This is a server-side opton only. It is ignored by
+clients.
+
+=back
+
+The following options no longer have any effect but their identifiers are
+retained for compatibility purposes:
+
+=over 4
+
+=item SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
+
+=item SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER
+
+=item SSL_OP_SSLEAY_080_CLIENT_DH_BUG
+
+=item SSL_OP_TLS_D5_BUG
+
+=item SSL_OP_TLS_BLOCK_PADDING_BUG
+
+=item SSL_OP_MSIE_SSLV2_RSA_PADDING
+
+=item SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG
+
+=item SSL_OP_MICROSOFT_SESS_ID_BUG
+
+=item SSL_OP_NETSCAPE_CHALLENGE_BUG
+
+=item SSL_OP_PKCS1_CHECK_1
+
+=item SSL_OP_PKCS1_CHECK_2
+
+=item SSL_OP_SINGLE_DH_USE
+
+=item SSL_OP_SINGLE_ECDH_USE
+
+=item SSL_OP_EPHEMERAL_RSA
+
=back
=head1 SECURE RENEGOTIATION
=head1 SEE ALSO
-L<ssl(3)>, L<SSL_new(3)>, L<SSL_clear(3)>,
+L<ssl(7)>, L<SSL_new(3)>, L<SSL_clear(3)>,
L<SSL_CTX_set_tmp_dh_callback(3)>,
L<SSL_CTX_set_min_proto_version(3)>,
L<dhparam(1)>
The attempt to always try to use secure renegotiation was added in
Openssl 0.9.8m.
+B<SSL_OP_PRIORITIZE_CHACHA> and B<SSL_OP_NO_RENEGOTIATION> were added in
+OpenSSL 1.1.1.
+
=head1 COPYRIGHT
-Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
projects / openssl.git / blobdiff