Date: Fri, 30 Aug 2013 17:14:55 +0400 From: Slawa Olhovchenkov <slw@zxy.spb.ru> To: Dag-Erling Sm??rgrav <des@des.no> Cc: freebsd-security@FreeBSD.org Subject: Re: OpenSSH, PAM and kerberos Message-ID: <20130830131455.GW3796@zxy.spb.ru> In-Reply-To: <86sixrwdcv.fsf@nine.des.no> References: <20130829004844.GA70584@zxy.spb.ru> <86d2ovy64p.fsf@nine.des.no> <20130830100926.GU3796@zxy.spb.ru> <20130830103009.GV3796@zxy.spb.ru> <86sixrwdcv.fsf@nine.des.no>
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On Fri, Aug 30, 2013 at 02:51:44PM +0200, Dag-Erling Sm??rgrav wrote: > Slawa Olhovchenkov <slw@zxy.spb.ru> writes: > > Dag-Erling Sm??rgrav <des@des.no> writes: > > > PAM authentication in OpenSSH was broken for non-trivial cases when > > > privilege separation was implemented. Fixing it properly would be > > > very difficult. > > Same behaviour with 'UsePrivilegeSeparation no'. This issuse not in > > privilege separation, this is because PAM authentication use pthread > > emulation throw fork(). > > Please don't tell me how the code works. I wrote it - or rather, I > wrote a version that worked, before the OpenSSH developers implemented > privilege separation and had to break the PAM integration code to make > it fit. Even if you #define UNSUPPORTED_POSIX_THREADS_HACK to use > threads instead of a subprocess, OpenSSH will still call pam_start() > twice and lose the data stored in the authentication phase before > running the session phase. Hmmm, now I try to compile sshd with UNSUPPORTED_POSIX_THREADS_HACK and it works (/tmp/krb5cc_NNNN created, kerberosied login to other host working w/o entering password). And I see only one record in log file (debug1: PAM: initializing for "slw") What I missed? PS: UsePrivilegeSeparation yes > (this is technically an abuse of the PAM API; I should probably add a > few lines to the OpenPAM dispatcher so it logs an error every time an > application tries to open a session without first authenticating) > > DES > -- > Dag-Erling Sm??rgrav - des@des.no
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