From d741cf4cca0ad04d4300966011c30c4ab080aec1 Mon Sep 17 00:00:00 2001
From: Paul Bakker
Date: Mon, 28 Feb 2011 21:10:41 +0000
Subject: [PATCH] - Replaced function that fixes man-in-the-middle attack -
Added message to indicate inclusion of man-in-the-middle attack (Reported by
Larry Highsmith, Subreption LLC) - Released version 0.14.2
---
ChangeLog | 8 ++++-
include/polarssl/version.h | 8 ++---
library/dhm.c | 52 +++++++++++++---------------
tests/suites/test_suite_version.data | 4 +--
4 files changed, 38 insertions(+), 34 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 50b5a2b63546..79540c9907a8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
PolarSSL ChangeLog
-= Version 0.14.1 released on 2011-02-22
+= Version 0.14.2 released on 2011-02-28
+This release replaces version 0.14.1 which had possible copyright issues.
Bugfixes
* Corrected parsing of UTCTime dates before 1990 and
after 1950
@@ -13,6 +14,11 @@ Bugfixes
to negotiate anonymous connection (Fixes ticket #12,
found by Boris Krasnovskiy)
+Security fixes
+ * Fixed a possible Man-in-the-Middle attack on the
+ Diffie Hellman key exchange (thanks to Larry Highsmith,
+ Subreption LLC)
+
= Version 0.14.0 released on 2010-08-16
Features
* Added support for SSL_EDH_RSA_AES_128_SHA and
diff --git a/include/polarssl/version.h b/include/polarssl/version.h
index 294258d2718d..d13f01c83f31 100644
--- a/include/polarssl/version.h
+++ b/include/polarssl/version.h
@@ -36,16 +36,16 @@
*/
#define POLARSSL_VERSION_MAJOR 0
#define POLARSSL_VERSION_MINOR 14
-#define POLARSSL_VERSION_PATCH 1
+#define POLARSSL_VERSION_PATCH 2
/**
* The single version number has the following structure:
* MMNNPP00
* Major version | Minor version | Patch version
*/
-#define POLARSSL_VERSION_NUMBER 0x000E0100
-#define POLARSSL_VERSION_STRING "0.14.1"
-#define POLARSSL_VERSION_STRING_FULL "PolarSSL 0.14.1"
+#define POLARSSL_VERSION_NUMBER 0x000E0200
+#define POLARSSL_VERSION_STRING "0.14.2"
+#define POLARSSL_VERSION_STRING_FULL "PolarSSL 0.14.2"
#if defined(POLARSSL_VERSION_C)
diff --git a/library/dhm.c b/library/dhm.c
index b587fa6f079b..9b99a2b17078 100644
--- a/library/dhm.c
+++ b/library/dhm.c
@@ -63,34 +63,32 @@ static int dhm_read_bignum( mpi *X,
}
/*
- * Verify sanity of public value with regards to P
+ * Verify sanity of public parameter with regards to P
+ *
+ * Public parameter should be: 2 <= public_param <= P - 2
+ *
+ * For more information on the attack, see:
+ * http://www.cl.cam.ac.uk/~rja14/Papers/psandqs.pdf
+ * http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2005-2643
*/
-static int dhm_verifypub( const mpi *P, const mpi *pub_value )
+static int dhm_check_range( const mpi *public_param, const mpi *P )
{
- mpi X;
-
- mpi_init( &X, NULL );
- mpi_lset( &X, 1 );
-
- /* Check G^Y or G^X is valid */
- if( mpi_cmp_mpi( pub_value, &X ) <= 0 )
- {
- mpi_free( &X, NULL );
- return( POLARSSL_ERR_DHM_BAD_INPUT_DATA );
- }
+ mpi L, U;
+ int ret = POLARSSL_ERR_DHM_BAD_INPUT_DATA;
- /* Reset: x = P - 1 */
- mpi_sub_int( &X, P, 1 );
+ mpi_init( &L, &U, NULL );
+ mpi_lset( &L, 2 );
+ mpi_sub_int( &U, P, 2 );
- if( mpi_cmp_mpi( pub_value, &X ) >= 0 )
+ if( mpi_cmp_mpi( public_param, &L ) >= 0 &&
+ mpi_cmp_mpi( public_param, &U ) <= 0 )
{
- mpi_free( &X, NULL );
- return( POLARSSL_ERR_DHM_BAD_INPUT_DATA );
+ ret = 0;
}
- mpi_free( &X, NULL );
+ mpi_free( &L, &U, NULL );
- return( 0 );
+ return( ret );
}
/*
@@ -109,6 +107,9 @@ int dhm_read_params( dhm_context *ctx,
( ret = dhm_read_bignum( &ctx->GY, p, end ) ) != 0 )
return( ret );
+ if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
+ return( ret );
+
ctx->len = mpi_size( &ctx->P );
if( end - *p < 2 )
@@ -120,9 +121,6 @@ int dhm_read_params( dhm_context *ctx,
if( end != *p + n )
return( POLARSSL_ERR_DHM_BAD_INPUT_DATA );
- if( ( ret = dhm_verifypub( &ctx->P, &ctx->GY ) ) != 0 )
- return( ret );
-
return( 0 );
}
@@ -156,7 +154,7 @@ int dhm_make_params( dhm_context *ctx, int x_size,
MPI_CHK( mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X,
&ctx->P , &ctx->RP ) );
- if( ( ret = dhm_verifypub( &ctx->P, &ctx->GX ) ) != 0 )
+ if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 )
return( ret );
/*
@@ -235,8 +233,8 @@ int dhm_make_public( dhm_context *ctx, int x_size,
MPI_CHK( mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X,
&ctx->P , &ctx->RP ) );
- if( dhm_verifypub( &ctx->P, &ctx->GX ) != 0 )
- return( POLARSSL_ERR_DHM_MAKE_PUBLIC_FAILED );
+ if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 )
+ return( ret );
MPI_CHK( mpi_write_binary( &ctx->GX, output, olen ) );
@@ -262,7 +260,7 @@ int dhm_calc_secret( dhm_context *ctx,
MPI_CHK( mpi_exp_mod( &ctx->K, &ctx->GY, &ctx->X,
&ctx->P, &ctx->RP ) );
- if( ( ret = dhm_verifypub( &ctx->P, &ctx->GY ) ) != 0 )
+ if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
return( ret );
*olen = mpi_size( &ctx->K );
diff --git a/tests/suites/test_suite_version.data b/tests/suites/test_suite_version.data
index 25612502134d..b6c9ab6c21fa 100644
--- a/tests/suites/test_suite_version.data
+++ b/tests/suites/test_suite_version.data
@@ -1,5 +1,5 @@
Check compiletime library version
-check_compiletime_version:"0.14.1"
+check_compiletime_version:"0.14.2"
Check runtime library version
-check_runtime_version:"0.14.1"
+check_runtime_version:"0.14.2"