pgsql: Fix low-risk potential denial of service against RADIUS login.

On 15 October 2010 16:03, Magnus Hagander <magnus@hagander.net> wrote:

Fix low-risk potential denial of service against RADIUS login.

Corrupt RADIUS responses were treated as errors and not ignored
(which the RFC2865 states they should be). This meant that a
user with unfiltered access to the network of the PostgreSQL
or RADIUS server could send a spoofed RADIUS response
to the PostgreSQL server causing it to reject a valid login,
provided the attacker could also guess (or brute-force) the
correct port number.

Fix is to simply retry the receive in a loop until the timeout
has expired or a valid (signed by the correct RADIUS server)
packet arrives.

Reported by Alan DeKok in bug #5687.

Branch
------
master

Details
-------
http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=0e7f7071e893bb171150e53271404b0819a40669

Modified Files
--------------
src/backend/libpq/auth.c |  220 ++++++++++++++++++++++++++--------------------
1 files changed, 126 insertions(+), 94 deletions(-)

Should this...

timeoutval = (endtime.tv_sec * 1000000 + endtime.tv_usec) -
(now.tv_sec * 1000000 + now.tv_usec);

be parenthesised a bit more? Given operator precedence, I'm assuming
this makes it...

timeoutval = ((endtime.tv_sec * 1000000) + endtime.tv_usec) -
((now.tv_sec * 1000000) + now.tv_usec);

--
Thom Brown
Twitter: @darkixion
IRC (freenode): dark_ixion
Registered Linux user: #516935