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In scanning some sites that have been secured with the InCommon certificates available through ITS, I'm noticing some poor grades and potential problems due to using SHA1. There could be some real problems with SHA1 certificates coming down the pipeline very soon... Chrome could be marking them as insecure as early as Q1 of 2015, if the certificate expires in 2017 (e.g., a 3-year cert bought this calendar year). Actually, it looks like the InCommon certificate itself only uses SHA1, so they have a bigger fish to fry there, but perhaps if one of their large customers starts putting pressure on them to get it fixed, they could make some traction. Anyone from ITS able to comment on what the plan is to get us certificates that meet the new requirements? Carl Bussema III Information Technologist Michigan State University Outreach & Engagement Phone: (517) 353-8977 • Fax: (517) 432-9541 [log in to unmask] On Thu, Oct 16, 2014 at 11:27 AM, Kim Geiger <[log in to unmask]> wrote: > Thank you for this, David. > > -- > Kim Geiger > WKAR Radio & Television, WKAR.org > East Lansing, Michigan > 517-884-4766 > > > >>> On 10/16/2014 at 11:10 AM, David Graff <[log in to unmask]> wrote: > > Since crypto as a whole is under a lot of scrutiny with heartbleed and > now > > the Poodle attack, here's what we've done to mitigate things. > > > > Disable SSL3 in IE, enable TLS 1.1/1.2 > > > > This one is easy. In the Advanced Settings tab of IE, scroll to the > bottom > > and uncheck SSL 2/3 if either are enabled, and make sure TLS 1.0/1.1/1.2 > are > > all enabled (1.1/1.2 typically are not). The IE Group Policy Object also > > allows you to configure and lock this down easily. This is the MS > recommend > > mitigation until they patch out SSL3. > > > > Other Browsers > > > > I haven't found a way to disable SSL3 in Chrome, but considering their > rapid > > update cycle they will probably patch it out for you. In Firefox, go to > > about:config and change the value on security.tls.version.min from 0 to > 1. > > This will bump up the minimum protocol to TLS 1.0, disabling SSL3. This > > change will likely come in a patch in the next few days as well. No idea > > about Safari. > > > > Disable SSL3 in SCHANNEL, enable TLS 1.1/1.2 > > > > Unfortunately there isn't a built-in group policy object to do it, so the > > attached SSL-TLS Config.reg file will do it for you. It disables SSL3 > (along > > with SSL2, and PCT1 if they were enabled somehow) as well as enabling TLS > > 1.1/1.2 if they are supported on the OS. XP/2003 only supports TLS1.0, > but > > it will ignore the reg keys for the protocols it doesn't have and is > safe to > > do across the board. > > > > Install Server 2003 AES Hotfix > > > > http://support.microsoft.com/kb/948963 > > > > If you still have any 2003 systems kicking around, install this hotfix to > > add support for some basic AES ciphers in addition to the RC4 (bad) and > 3DES > > (okay) ones that it comes with. It won't apply to XP, but nobody is still > > using any of those systems at this point, right? ;) > > > > Define SCHANNEL SSL Cipher Suite Order > > > > Policies\Admin Templates\Network\SSL Configuration Settings\SSL Cipher > Suite > > Order > > > > This one needs to be done through GPO, might be possible to do through a > > registry merge but I'm not sure where they keys live. Use the attached > > schannel config.txt file to define which cipher suites should be used, in > > order of preference. The first ones use elliptic curve key exchange > which is > > very good, but only supported on newer devices. The last three on the > list > > > (TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_3DES > > _EDE_CBC_SHA) > > are your legacy suites to support old devices. Android 2.3 , Java 6, and > > Server 2003 clients with the mentioned hotfix will use the first two AES > > suites, XP systems or 2003 systems without the AES hotfix will use the > 3DES > > suite which is still secure at this point. If you don't have any 2003/XP > > systems on your network, you can probably drop 3DES. > > > > With all that done, your HTTPS IIS websites should be validating like > this: > > > > > https://www.ssllabs.com/ssltest/analyze.html?d=ipf.msu.edu&hideResults=on > > > > Which is about as good as you can get it for now without cutting off > Android > > 2.3 devices, which there are still a good number of floating around. >