I've set up a list of ciphers that excludes SSLv2 ciphers (and other weak ones) in the hope of preventing SSLv2 connections:
ssl_cipher_list = TLSv1+HIGH : !SSLv2 : RC4+MEDIUM : !aNULL : !eNULL : !3DES : @STRENGTH However, this doesn't prevent the SSLv2 connection being allowed as our Nessus scans show and I'm tasked with trying to plug that "hole". I see Dovecot2 had the following change a year or so ago, in file src/login-common/ssl-proxy-openssl.c: - SSL_CTX_set_options(ssl_ctx, SSL_OP_ALL); + SSL_CTX_set_options(ssl_ctx, SSL_OP_ALL | SSL_OP_NO_SSLv2); I tried making the same change to dovecot1's src tree on our test system and it seems to have the desired effect; however I am very hesitant about putting this into our production system without seeking advice here first :-) Have I missed anything that's obviously bad about doing this please? Thanks again, Steve Platt
