[ https://issues.apache.org/jira/browse/TS-3136?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14594017#comment-14594017 ]
Susan Hinrichs commented on TS-3136: ------------------------------------ I ran an experiment to estimate the impact of DHE on our traffic set. I set up 2048 bit dhparams file and inserted the DHE params ciphers right in front of the non PFS ciphers. The following cipher percentages changed |_.Cipher|_.6/19 list w/o DHE %|_.6/19 list with DHE %| |DHE-RSA-AES128-SHA|0|4.12| |AES128-SHA|5.78|0| |AES256-SHA|0|1.28| These don't all add up to equal exchanges. The other ciphers had small shifts one way or the other. Even with DHE there are still a small percentage of CBC ciphers that sneak through. I did these test in series, so these aren't the end-all be-all numbers. I just wanted to get some idea on the scale of the impact. So broadly speaking by introducing DHE most of the non-PFS ciphers get shifted over to DHE. However, I would still argue that we should not include DHE in the default cipher list. Most of the major sites do not offer DHE. We've had a major ATS deployer experience an increase in SSL errors that went away when DHE was removed. If you don't install a good DHParam, the DHE protocol can be hacked. Therefore, for a default stance, I think an ATS deployment will operate more securely and with less stability risk if DHE is not included in the cipher_suites list. > Change default TLS cipher suites > -------------------------------- > > Key: TS-3136 > URL: https://issues.apache.org/jira/browse/TS-3136 > Project: Traffic Server > Issue Type: Improvement > Components: Security, SSL > Reporter: Leif Hedstrom > Assignee: Susan Hinrichs > Labels: compatibility > Fix For: 6.0.0 > > > In TS-3135 [~i.galic] suggested: > {quote} > also, recommendations for a safer ciphersuite: > SSLCipherSuite > ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-AES256-SHA:ECDHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES256-GCM-SHA384:AES128-GCM-SHA256:AES256-SHA256:AES128-SHA256:AES256-SHA:AES128-SHA:DES-CBC3-SHA:HIGH:!aNULL:!eNULL:!EXPORT:!DES:!MD5:!PSK:!RC4 > > from https://cipherli.st/ > {quote} > [~jacksontj] had responded with: > {quote} > [~i.galic] That cipher quite is geared towards security, but doesn't support > quite a few older clients. I'd recommend we use the suite from mozilla > (https://wiki.mozilla.org/Security/Server_Side_TLS#Recommended_Server_Configurations) > which is a good mix of security and compatibility: > {code} > ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA > {code} > {quote} -- This message was sent by Atlassian JIRA (v6.3.4#6332)