*** empty log message ***

1 files changed, 29 insertions, 13 deletions

diff --git a/lib/gnutls_dh.c b/lib/gnutls_dh.c
index dd308ad440..bce4157e8f 100644
--- a/lib/gnutls_dh.c
+++ b/lib/gnutls_dh.c
@@ -4,19 +4,20 @@
  * This file is part of GNUTLS.
  *           someday was part of gsti
  *
- * GNUTLS is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ *  The GNUTLS library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public   
+ *  License as published by the Free Software Foundation; either 
+ *  version 2.1 of the License, or (at your option) any later version.
  *
- * GNUTLS is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of 
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
  *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 
 #include <gnutls_int.h>
@@ -39,6 +40,7 @@
 	_gnutls_mpi_release(g);
 */
 
+#define MAX_BITS 12000
 
 /* returns the public value (X), and the secret (ret_x).
  */
@@ -50,6 +52,11 @@ GNUTLS_MPI gnutls_calc_dh_secret(GNUTLS_MPI * ret_x, GNUTLS_MPI g, GNUTLS_MPI pr
 	 * prime/2
 	 */
 
+	if (x_size > MAX_BITS || x_size <= 0) {
+		gnutls_assert();
+		return NULL;
+	}
+
 	x = _gnutls_mpi_new(x_size);
 	if (x == NULL) {
 		gnutls_assert();
@@ -59,9 +66,10 @@ GNUTLS_MPI gnutls_calc_dh_secret(GNUTLS_MPI * ret_x, GNUTLS_MPI g, GNUTLS_MPI pr
 		return NULL;
 	}
 
-	/* x_size-7 is there to overcome a bug in libgcrypt
+	/* (x_size/8)*8 is there to overcome a bug in libgcrypt
+	 * which does not really check the bits given but the bytes.
 	 */
-	_gnutls_mpi_randomize(x, x_size-7, GCRY_STRONG_RANDOM);
+	_gnutls_mpi_randomize(x, (x_size/8)*8, GCRY_STRONG_RANDOM);
 
 	e = _gnutls_mpi_alloc_like(prime);
 	if (e == NULL) {
@@ -72,6 +80,7 @@ GNUTLS_MPI gnutls_calc_dh_secret(GNUTLS_MPI * ret_x, GNUTLS_MPI g, GNUTLS_MPI pr
 		_gnutls_mpi_release( &x);
 		return NULL;
 	}
+
 	_gnutls_mpi_powm(e, g, x, prime);
 
 	if (ret_x)
@@ -85,6 +94,13 @@ GNUTLS_MPI gnutls_calc_dh_secret(GNUTLS_MPI * ret_x, GNUTLS_MPI g, GNUTLS_MPI pr
 GNUTLS_MPI gnutls_calc_dh_key(GNUTLS_MPI f, GNUTLS_MPI x, GNUTLS_MPI prime)
 {
 	GNUTLS_MPI k;
+	int bits;
+	
+	bits = _gnutls_mpi_get_nbits(prime);
+	if (bits <= 0 || bits > MAX_BITS) {
+		gnutls_assert();
+		return NULL;
+	}
 
 	k = _gnutls_mpi_alloc_like(prime);
 	if (k == NULL)