Ensure that bn_expand()/bn_wexpand() fail on negative sizes.

ok tb@

1 files changed, 7 insertions, 1 deletions

diff --git a/src/lib/libcrypto/bn/bn_lib.c b/src/lib/libcrypto/bn/bn_lib.c
index 7c85e7ad08..15bbdf1273 100644
--- a/src/lib/libcrypto/bn/bn_lib.c
+++ b/src/lib/libcrypto/bn/bn_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_lib.c,v 1.58 2022/11/23 03:00:12 jsing Exp $ */
+/* $OpenBSD: bn_lib.c,v 1.59 2022/11/23 03:04:52 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -377,6 +377,9 @@ bn_expand2(BIGNUM *b, int words)
 BIGNUM *
 bn_expand(BIGNUM *a, int bits)
 {
+        if (bits < 0)
+                return (NULL);
+
         if (bits > (INT_MAX - BN_BITS2 + 1))
                 return (NULL);
 
@@ -389,6 +392,9 @@ bn_expand(BIGNUM *a, int bits)
 BIGNUM *
 bn_wexpand(BIGNUM *a, int words)
 {
+        if (words < 0)
+                return NULL;
+
         if (words <= a->dmax)
                 return a;