From 152a689cf93f2bac78c1b0d6ee24c86640ae0f34 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Bodo=20M=C3=B6ller?= <bodo@openssl.org>
Date: Sun, 3 Dec 2000 09:39:04 +0000
Subject: [PATCH] Don't allow BIGNUMs to become so large that computations with
 dmax might overflow.

---
 crypto/bn/bn.h     | 1 +
 crypto/bn/bn_err.c | 1 +
 crypto/bn/bn_lib.c | 6 ++++++
 3 files changed, 8 insertions(+)

diff --git a/crypto/bn/bn.h b/crypto/bn/bn.h
index 3d5c91adb9..a5b6ed9d4c 100644
--- a/crypto/bn/bn.h
+++ b/crypto/bn/bn.h
@@ -541,6 +541,7 @@ int BN_bntest_rand(BIGNUM *rnd, int bits, int top,int bottom);
 #define BN_R_NOT_INITIALIZED				 107
 #define BN_R_NO_INVERSE					 108
 #define BN_R_P_IS_NOT_PRIME				 112
+#define BN_R_TOO_LARGE					 114
 #define BN_R_TOO_MANY_ITERATIONS			 113
 #define BN_R_TOO_MANY_TEMPORARY_VARIABLES		 109
 
diff --git a/crypto/bn/bn_err.c b/crypto/bn/bn_err.c
index afb9320322..2bb311f95c 100644
--- a/crypto/bn/bn_err.c
+++ b/crypto/bn/bn_err.c
@@ -105,6 +105,7 @@ static ERR_STRING_DATA BN_str_reasons[]=
 {BN_R_NOT_INITIALIZED                    ,"not initialized"},
 {BN_R_NO_INVERSE                         ,"no inverse"},
 {BN_R_P_IS_NOT_PRIME                     ,"p is not prime"},
+{BN_R_TOO_LARGE                          ,"too large"},
 {BN_R_TOO_MANY_ITERATIONS                ,"too many iterations"},
 {BN_R_TOO_MANY_TEMPORARY_VARIABLES       ,"too many temporary variables"},
 {0,NULL}
diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c
index 050e02bd3a..096bcf1835 100644
--- a/crypto/bn/bn_lib.c
+++ b/crypto/bn/bn_lib.c
@@ -312,6 +312,12 @@ static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
 	const BN_ULONG *B;
 	int i;
 
+	if (words > (INT_MAX/(4*BN_BITS2)))
+		{
+		BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_TOO_LARGE);
+		return NULL;
+		}
+
 	bn_check_top(b);	
 	if (BN_get_flags(b,BN_FLG_STATIC_DATA))
 		{
-- 
2.25.1