On Thu, 14 Aug 2008, Michael Ströder wrote: ...
From my understanding this is what LDAP_OPT_X_TLS_CIPHER_SUITE is for, isn't it? It's directly passed to OpenSSL and can also be used to enable or disable SSLv2, SSLv3 and TLSv1 besides choosing the ciphers itself.
Nope. The cipher suite list and protocol versions supported are orthogonal: even if you include "!SSLv2" in your cipher suite, openssl will still send an SSLv2-compatible handshake. Ditto on the server side: when OpenSSL announced a vulnerability in the server SSLv2 handshake code, I looked at whether specifying "!SSLv2" in the cipher spec would protect the server as a workaround. Nope: only setting the SSL_OP_NO_SSLv2 option or using a SSLv3-only or TLSv1-only method would do it.
Apache HTTP server does it also that way. See: http://httpd.apache.org/docs/2.2/mod/mod_ssl.html#sslciphersuite
They also have the "SSLProtocol" directive, further down on that page.
Philip Guenther