LocalLB::SSLOption¶

Members¶

Member

Value

Description

SSL_OPTION_MICROSOFT_SESSION_ID_BUG

0

When talking SSLv2, if session-id reuse is performed, the session-id passed back in the server-finished message is different from the one decided upon. This option is ignored for client-side SSL.

SSL_OPTION_NETSCAPE_CHALLENGE_BUG

1

Netscape-Commerce/1.12, when talking SSLv2, accepts a 32 byte challenge but then appears to only use 16 bytes when generating the encryption keys. Using 16 bytes is ok but it should be ok to use 32. According to the SSLv3 spec, one should use 32 bytes for the challenge when operating in SSLv2/v3 compatibility mode, but as mentioned above, this breaks this server so 16 bytes is the way to go. This option is ignored for client-side SSL.

SSL_OPTION_NETSCAPE_REUSE_CIPHER_CHANGE_BUG

2

First a connection is established with RC4-MD5. If it is then resumed, we end up using DES-CBC3-SHA. It should be RC4-MD5 according to 7.6.1.3. Netscape-Enterprise/2.01 (https://merchant.netscape.com) has this bug. It only really shows up when connecting via SSLv2/v3 then reconnecting via SSLv3. The cipher list changes…. NEW INFORMATION: Try connecting with a cipher list of just DES-CBC-SHA:RC4-MD5. For some weird reason, each new connection uses RC4-MD5, but a re-connect tries to use DES-CBC-SHA. So netscape, when doing a re-connect, always takes the first cipher in the cipher list.

SSL_OPTION_SSLREF2_REUSE_CERT_TYPE_BUG

3

Slow a non-zero certificate type during SSL resume handshakes as a workaround for a bug in Netscape’s SSLv2 reference implementation. This option is ignored for client-side SSL.

SSL_OPTION_MICROSOFT_BIG_SSLV3_BUFFER

4

Enable a workaround for communicating with older Microsoft applications that use non-standard SSL record sizes.

SSL_OPTION_MSIE_SSL_V2_RSA_PADDING

5

Enable a workaround for communicating with older Microsoft applications that use non-standard RSA key padding. This option is ignored for server-side SSL.

SSL_OPTION_SSLEAY_080_CLIENT_DH_BUG

6

Enable a workaround for communicating with older SSLeay-based applications that specify an incorrect Diffee-Hellman public value length. This option is ignored for server-side SSL.

SSL_OPTION_TLS_D5_BUG

7

Workaround for communicating with older TLSv1-enabled applications that specify an incorrect encrypted RSA key length. This option is ignored for server-side SSL.

SSL_OPTION_TLS_BLOCK_PADDING_BUG

8

Enable a workaround for communicating with older TLSv1-enabled applications that use incorrect block padding.

SSL_OPTION_DONT_INSERT_EMPTY_FRAGMENTS

9

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.

SSL_OPTION_ALL_BUGFIXES

10

All of the above bug workarounds. It is usually safe to use ALL_BUGFIXES to enable the bug workaround options if compatibility with somewhat broken implementations is desired.

SSL_OPTION_PASSIVE_CLOSE

11

For servessl profiles only, this specifies that the SSL filter will forestall TCP half-closes by waiting for the connection shutdown from the server. This is a workaround for HTTP/1.0 and HTTP/0.9 clients which sent an HTTP request followed by a FIN, which would cause immediate teardown for serverssl-only proxies. Instead of closing immediately, the proxy will wait for the server to close.

SSL_OPTION_NO_SESSION_RESUMPTION_ON_RENEGOTIATION

12

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 ignored for server-side SSL.

SSL_OPTION_SINGLE_DH_USE

13

Always create a new key when using temporary/ephemeral DH parameters (see 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 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. SSL_OP_SINGLE_DH_USE should therefore be enabled whenever temporary/ephemeral DH parameters are used.

SSL_OPTION_EPHEMERAL_RSA

14

Always use ephemeral (temporary) RSA key when doing RSA operations (see SSL_CTX_set_tmp_rsa_callback(3)). According to the specifications this is only done when a RSA key can only be used for signature operations (namely under export ciphers with restricted RSA keylength). By setting this option, ephemeral RSA keys are always used. This option breaks compatibility with the SSL/TLS specifications and may lead to interoperability problems with clients and should therefore never be used. Ciphers with EDH (ephemeral Diffie-Hellman) key exchange should be used instead.

SSL_OPTION_CIPHER_SERVER_PREFERENCE

15

When choosing a cipher, use the server’s preferences instead of the client 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.

SSL_OPTION_TLS_ROLLBACK_BUG

16

Disable version rollback attack detection. During the client key exchange, the client must send the same information about acceptable SSL/TLS protocol levels as during the first hello. Some clients violate this rule by adapting to the server’s answer. (Example: the client sends a SSLv2 hello and accepts up to SSLv3.1=TLSv1, the server only understands up to SSLv3. In this case the client must still use the same SSLv3.1=TLSv1 announcement. Some clients step down to SSLv3 with respect to the server’s answer and violate the version rollback protection.)

SSL_OPTION_NO_SSL_V2

17

Do not use the SSLv2 protocol.

SSL_OPTION_NO_SSL_V3

18

Do not use the SSLv3 protocol.

SSL_OPTION_NO_TLS_V1

19

Do not use the TLSv1 protocol.

SSL_OPTION_PKCS1_CHECK_1

20

These debugging options deliberately manipulate the PKCS1 padding used by SSL clients in an attempt to detect vulnerability to particular SSL server vulnerabilities. These options are not recommended for normal use. These options are ignored for client-side SSL.

SSL_OPTION_PKCS1_CHECK_2

21

These debugging options deliberately manipulate the PKCS1 padding used by SSL clients in an attempt to detect vulnerability to particular SSL server vulnerabilities. These options are not recommended for normal use. These options are ignored for client-side SSL.

SSL_OPTION_NETSCAPE_CA_DN_BUG

22

If we accept a netscape connection, demand a client cert, have a 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

SSL_OPTION_NETSCAPE_DEMO_CIPHER_CHANGE_BUG

23

This debugging option deliberately manipulates the SSL server session resumption behavior to mimic that of certain Netscape servers (see the NETSCAPE_REUSE_CIPHER_CHANGE_BUG description above). This option is not recommended for normal use. This option is ignored for server-side SSL.

See Also¶

Sample Code¶

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