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TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (DHE-RSA-AES256-GCM-SHA384) and TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 not work with Firefox 50.0

  • 5 replies
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  • Last reply by davidfr

davidfr
davidfr
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Hello, First, thanks for Firefox and all you work ! Ciphers TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (DHE-RSA-AES256-GCM-SHA384) and TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 (DHE-RSA-AES256-SHA256) not work with Firefox 50.0 and Firefox 53 Nithly. But they are in the wiki : https://wiki.mozilla.org/Security/Server_Side_TLS in "Intermediate compatibility (default)" Are they supported ? Thanks a lot. David

Hello, First, thanks for Firefox and all you work ! Ciphers TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (DHE-RSA-AES256-GCM-SHA384) and TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 (DHE-RSA-AES256-SHA256) not work with Firefox 50.0 and Firefox 53 Nithly. But they are in the wiki : https://wiki.mozilla.org/Security/Server_Side_TLS in "Intermediate compatibility (default)" Are they supported ? Thanks a lot. David

All Replies (5)

John99
John99
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This is not something I understand & would need to research further, so if this reply does not help you get an answer by bumping the post I suggest you try in another Mozilla forum

If the subject is not on topic there hopefully they will be able to say where you can get an answer.

cor-el
cor-el
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  • Top 10 Contributor
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Note that your System Details list shows an old Firefox 35 version.

  • User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:35.0) Gecko/20100101 Firefox/35.0

You can see the supported ciphers as security.ssl3.* prefs on the about:config page.

davidfr
davidfr Question owner
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cor-el a écrit

Note that your System Details list shows an old Firefox 35 version.
  • User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:35.0) Gecko/20100101 Firefox/35.0
You can see the supported ciphers as security.ssl3.* prefs on the about:config page.

Hello ! Thanks for your reply. My useragent is fixed by an extention, so the version is false. I'm on firefox 50, my about:config juste have : security.ssl3.dhe_rsa_aes_128_sha : yes security.ssl3.dhe_rsa_aes_256_sha : yes not SHA384 or SHA256

Do you have it on you firefox version ?

Thanks a lot

Thanks John99, I will see it.

Have a good day

cor-el
cor-el
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You need to set prefs that that are involved with the Logjam vulnerability to false to disable cipher suites in case they are currently enabled (true).

  • security.ssl3.dhe_rsa_aes_128_sha
  • security.ssl3.dhe_rsa_aes_256_sha

These shouldn't be enabled.

davidfr
davidfr Question owner
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cor-el a écrit

You need to set prefs that that are involved with the Logjam vulnerability to false to disable cipher suites in case they are currently enabled (true).
  • security.ssl3.dhe_rsa_aes_128_sha
  • security.ssl3.dhe_rsa_aes_256_sha
These shouldn't be enabled.

Thanks for your reply but my question is can we use (regardles of this security problem) TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 and TLS_DHE_RSA_WITH_AES_256_CBC_SHA256.

My servers are not vulnerable to Logjam and I want to use this. But it seam that firefox not support it. Do you have information on this point ?

What is you recommandation ? The use of ecdhe_rsa_aes_256_gcm_sha384 ?

Thanks