Preferred SSLCipherSuite for mod_ssl

SSLCipherSuite DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:HIGH:!3DES:!ECDH:!SRP:!aNULL:!CAMELLIA:!PSK:!EXPORT:!eNULL

Provides:

DHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(128) Mac=AEAD
DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(256) Mac=AEAD
DHE-RSA-AES128-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA256
DHE-RSA-AES256-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA256
DHE-RSA-AES128-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA1
DHE-RSA-AES256-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA1
AES128-GCM-SHA256       TLSv1.2 Kx=RSA      Au=RSA  Enc=AESGCM(128) Mac=AEAD
AES256-GCM-SHA384       TLSv1.2 Kx=RSA      Au=RSA  Enc=AESGCM(256) Mac=AEAD
AES128-SHA256           TLSv1.2 Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA256
AES256-SHA256           TLSv1.2 Kx=RSA      Au=RSA  Enc=AES(256)  Mac=SHA256
AES128-SHA              SSLv3 Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA1
AES256-SHA              SSLv3 Kx=RSA      Au=RSA  Enc=AES(256)  Mac=SHA1
DHE-DSS-AES256-GCM-SHA384 TLSv1.2 Kx=DH       Au=DSS  Enc=AESGCM(256) Mac=AEAD
DHE-DSS-AES256-SHA256   TLSv1.2 Kx=DH       Au=DSS  Enc=AES(256)  Mac=SHA256
DHE-DSS-AES256-SHA      SSLv3 Kx=DH       Au=DSS  Enc=AES(256)  Mac=SHA1
DHE-DSS-AES128-GCM-SHA256 TLSv1.2 Kx=DH       Au=DSS  Enc=AESGCM(128) Mac=AEAD
DHE-DSS-AES128-SHA256   TLSv1.2 Kx=DH       Au=DSS  Enc=AES(128)  Mac=SHA256
DHE-DSS-AES128-SHA      SSLv3 Kx=DH       Au=DSS  Enc=AES(128)  Mac=SHA1

This is a modification of the ciphersuite list from http://www.matthewgkeller.com/blog/2014/01/09/ecdhe-vs-dhe-in-the-new-world-order/comment-page-1/

Primarily we are looking to remove elliptical curve ciphers in favor of discrete log methods (Schneier, 2013) due to the uncertainty of NSA compromization of ECC. We also try to prioritize the remaining available ciphers by preferring GCM mode over CBC mode.

1. AES128 has better key schedule than AES256 (Schneier, 2013).
2. We support "SSLv3" ciphers because in OpenSSL, TLSv1.0 ciphers are classified as SSLv3 ciphers.