commit f173e0ac74404221ce74b5039a8817d3ac148e55
author Manuel Pégourié-Gonnard <mpg@elzevir.fr> Sat Nov 17 12:42:51 2012 +0100
committer Paul Bakker <p.j.bakker@polarssl.org> Wed Jan 16 12:52:17 2013 +0100
tree 8eedbe28024666e18554584ebad80b7a5bd0219e
parent d8ee8440a787b3d1b1a0c74fdce3152d7c026b7b

Fixed segfault in mpi_shift_r(), Fixed memory leak in test_suite_mpi
(cherry picked from commit e44ec108bea03837fa72714ca33e6dc557c1189b)

ChangeLog

diff --git a/ChangeLog b/ChangeLog
index c82a783..60e0f77 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -10,6 +10,8 @@
    * Prevent reading over buffer boundaries on X509 certificate parsing
    * mpi_exp_mod() now correctly handles negative base numbers (Closes ticket
      #52)
+   * Fixed possible segfault in mpi_shift_r() (found by Manuel
+     Pégourié-Gonnard)
 
 Security
    * Fixed potential memory zeroization on miscrafted RSA key (found by Eloi

library/bignum.c

diff --git a/library/bignum.c b/library/bignum.c
index 4518d4a..acaba6a 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -609,6 +609,9 @@
     v0 = count /  biL;
     v1 = count & (biL - 1);
 
+    if( v0 > X->n || ( v0 == X->n && v1 > 0 ) )
+        return mpi_lset( X, 0 );
+
     /*
      * shift by count / limb_size
      */

tests/suites/test_suite_mpi.data

diff --git a/tests/suites/test_suite_mpi.data b/tests/suites/test_suite_mpi.data
index a5a5cf9..ae618f1 100644
--- a/tests/suites/test_suite_mpi.data
+++ b/tests/suites/test_suite_mpi.data
@@ -300,6 +300,18 @@
 Test mpi_shift_r #2
 mpi_shift_r:10:"120815570979701484704906977000760567182871429114712069861589084706550626575967516787438008593490722779337547394120718248995900363209947025063336882559539208430319216688889117222633155838468458047056355241515415159736436403445579777425189969":45:10:"3433785053053426415343295076376096153094051405637175942660777670498379921354157795219578264137985649407981651226029903483433269093721578004287291678324982297860947730012217028349628999378309630601971640587504883789518896817457"
 
+Test mpi_shift_r #4
+mpi_shift_r:16:"FFFFFFFFFFFFFFFF":63:16:"01"
+
+Test mpi_shift_r #4
+mpi_shift_r:16:"FFFFFFFFFFFFFFFF":64:16:"00"
+
+Test mpi_shift_r #6
+mpi_shift_r:16:"FFFFFFFFFFFFFFFF":65:16:"00"
+
+Test mpi_shift_r #7
+mpi_shift_r:16:"FFFFFFFFFFFFFFFF":128:16:"00"
+
 Base test mpi_mul_mpi #1
 mpi_mul_mpi:10:"5":10:"7":10:"35"
 

tests/suites/test_suite_mpi.function

diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index 1b328c4..596b7df 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -162,7 +162,7 @@
     TEST_ASSERT( mpi_set_bit( &X, {pos}, {val} ) == 0 );
     TEST_ASSERT( mpi_cmp_mpi( &X, &Y ) == 0 );
 
-    mpi_free( &X );
+    mpi_free( &X ); mpi_free( &Y );
 }
 END_CASE