From: Giuseppe D'Angelo <dangelog@gmail.com>
Date: Sat, 24 Mar 2012 08:50:02 +0000 (+0000)
Subject: QHash security fix (2/2): enable QHash random seed
X-Git-Tag: 071012110112~1235^2^2~34
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c01eaa438200edc9a3bbcd8ae1e8ded058bea268;p=profile%2Fivi%2Fqtbase.git

QHash security fix (2/2): enable QHash random seed

Algorithmic complexity attacks against hash tables have been known
since 2003 (cf. [1, 2]), and they have been left unpatched for years
until the 2011 attacks [3] against many libraries /
(reference) implementations of programming languages.

This patch makes qHash use the QHash seed introduced in the
previous commits, thus truly randomizing bucketing in QHash.

[1] http://www.cs.rice.edu/~scrosby/hash/CrosbyWallach_UsenixSec2003.pdf
[2] http://perldoc.perl.org/perlsec.html#Algorithmic-Complexity-Attacks
[3] http://www.ocert.org/advisories/ocert-2011-003.html

Task-number: QTBUG-23529
Change-Id: Ibee9cf6aa820af5d777fcde478647665c728052a
Reviewed-by: Jason McDonald <jason.mcdonald@nokia.com>
---

diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h
index e318872..fe6a8df 100644
--- a/src/corelib/tools/qhash.h
+++ b/src/corelib/tools/qhash.h
@@ -874,7 +874,7 @@ Q_OUTOFLINE_TEMPLATE typename QHash<Key, T>::Node **QHash<Key, T>::findNode(cons
     uint h = 0;
 
     if (d->numBuckets || ahp) {
-        h = qHash(akey, 0);
+        h = qHash(akey, d->seed);
         if (ahp)
             *ahp = h;
     }