Cyberoam firewall blocks obfs2/3 bridge addresses
User(s) reported that his University uses Cyberoam firewall[0] and he/she can't establish any Tor connections since then. So I gave him the PT bundle with four working bridges one obfs2 and three obfs3, later he replied back with a log that shows that the firewall blocked all the bridges[1]
isis said that it could be an sslmitm[2][3]. But according to sysrqb there is no ssl handshake to mitm. so something else was used.
UPDATE:
I received another ticket complaining about Cyberoam, I pointed the user to normal TBB with normal bridges and it didn't work. Next I gave him PT bundle with 4 unpublished bridges and again he can't connect.
I asked him to send me the debug log (see attached: VidaliaLog1.txt).
[0]: Help desk tickets related to Cyberoam #13271 (moved) #14345 #13563 (closed) #13786 (moved) [1]: Log attached. [2]: https://blog.torproject.org/blog/security-vulnerability-found-cyberoam-dpi-devices-cve-2012-3372 [3]: http://blogs.law.harvard.edu/herdict/2012/07/11/cyberoam-fixes-flaw-threatening-tor-users/