oss-sec mailing list archives

Re: Apache 2.4 mod_ssl SSLSessionTickets -- others vulnerable?


From: Mark Felder <feld () feld me>
Date: Wed, 04 Feb 2015 12:09:35 -0600



On Wed, Feb 4, 2015, at 11:59, Reed Loden wrote:
... or you could do something like what Twitter did [0] and write your
own
scripts to generate new session ticket keys regularly and store them only
in a tmpfs or /dev/shm type environment.

agl also talks about this problem on his blog [1] a while ago.

As for your earlier question, nginx has the same issue here [2]. Really
all
comes down to OpenSSL not making it easy to do better.

~reed

[0] https://blog.twitter.com/2013/forward-secrecy-at-twitter
[1] https://www.imperialviolet.org/2013/06/27/botchingpfs.html
[2]
http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key


Okay, so the failure is two-pronged: the current limitations in OpenSSL
with regards to managing session ticket keys, and the use of session
tickets when PFS cipher is negotiated.


Thanks for all the details, guys.


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