BigIP 11.6 HF4 + SSL ciphers

I trust you read: https://support.f5.com/kb/en-us/solutions/public/13000/100/sol13171.html

If you have disabled RC4, and SSLv3(protocol) and DES, and even SHA1 based ciphers, I'm not at all surprised that older android clients won't be able to connect.

I think SSL Labs shows you the oldest version of android that works, and if anything newer than 2.3 would work, I personally wouldn't worry too much. Same for Windows XP -- no need to worry about an OS that it's vendor no longer supports.

By the way, it seems like you disabled everything except perhaps: ECDHE+AES-GCM.

That will break a lot of software out there.

Not all ciphers are considered weak.

I think disabling SSLv3, MD5 and RC4 should be enough to get you A+ rating.

Also, you should not adhere too strongly to SSLLabs rating.

You should only be concerned about the score based on how much strength you want, vs how much older software you wish to support. RC4 and SSLv3 are generally safe to disable, as most software in the last 10 or so years should be able to do fine without these.

Also, if you don't order the ciphers by Speed (@speed), then the LTM will always choose the strongest Cipher presented by the client that it also supports. I believe that if you order them by speed, then the LTM chooses the fastest Cipher that the client also supports, and not necessarily the strongest. This doesn't seem like what you want.

This is working for us to get an A+ on SSLLabs and 'is using a modern cipher suite' in chrome 44. Of course HSTS must be enabled to get the A+.

!LOW:!SSLv3:!MD5:!RC4-SHA:!DHE:!EXPORT:ECDHE+AES-GCM:ECDHE:RSA+AES:RSA+3DES

Here's the rational and process:

For reference, here's the DEFAULT for 11.6:

!LOW:!SSLv3:!MD5:!RC4-SHA:!EXPORT:DHE+AES-GCM:DHE+AES:DHE+3DES:AES-GCM+RSA:RSA+AES:RSA+3DES:ECDHE+AES-GCM:ECDHE+AES:ECDHE-RSA-DES-CBC3-SHA

1) Starting with the exclude list from the 11.6 DEFAULT:

!LOW:!SSLv3:!MD5:!RC4-SHA:!EXPORT

2) Get rid of the DHE too since SSLLabs sees them as weak and there are other ciphers to support older browsers:

!LOW:!SSLv3:!MD5:!RC4-SHA:!DHE

3) Prioritize the elliptic curve diffie-helman cipher that chrome likes:

!LOW:!SSLv3:!MD5:!RC4-SHA:!DHE:!EXPORT:ECDHE+AES-GCM

4) Prioritize all other elliptic curve diffie-helman ciphers so clients prefer forward secrecy ciphers:

!LOW:!SSLv3:!MD5:!RC4-SHA:!DHE:!EXPORT:ECDHE+AES-GCM:ECDHE

5) Include other old ciphers from the DEFAULT to handle old Java and android browsers:

!LOW:!SSLv3:!MD5:!RC4-SHA:!DHE:!EXPORT:ECDHE+AES-GCM:ECDHE:RSA+AES

6) Include other old ciphers from the DEFAULT to handle IE8/XP:

!LOW:!SSLv3:!MD5:!RC4-SHA:!DHE:!EXPORT:ECDHE+AES-GCM:ECDHE:RSA+AES:RSA+3DES

This is excellent!

I'm using 11.6 HF5 and this cipher gave me an A in SSLLABS but an obsolete cipher suite in Chrome :

DEFAULT:!DHE:@SPEED

Whereas this cipher gave me an A- in SSLLABS (better than A) and a modern cipher suite in Chrome :

DEFAULT:!SHA1:!DHE:@SPEED

Problem with this last configuration is that lots of devices are becoming uncompatible (IE8-10 + Win 7 for example) ...

Watch out, this is only applicable on 11.6 because "DEFAULT" is different from one version to another, cf. this doc : https://support.f5.com/kb/en-us/solutions/public/13000/100/sol13171.html

I'm wondering if there is a way to please Chrome AND SSLLAB without excluding all the browsers that need SHA1 ?

This is an OLD discussion I know. I stumbled upon it by accident and thought to share my 2 cents.

ECDHE:DEFAULT:!DHE