X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_gcd.c;h=0091ea4e08a67cf1daedf50beb5fa8278fe05000;hp=22f80939d61eaa4361fa7db7692f7ec9df1fd563;hb=83cf7abf8e9abbd4d0b68c63dc1cb43374aafe63;hpb=26a7d938c9bf932a55cb5e4e02abb48fe395c5cd

diff --git a/crypto/bn/bn_gcd.c b/crypto/bn/bn_gcd.c
index 22f80939d6..0091ea4e08 100644
--- a/crypto/bn/bn_gcd.c
+++ b/crypto/bn/bn_gcd.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -140,7 +140,14 @@ BIGNUM *int_bn_mod_inverse(BIGNUM *in,
     BIGNUM *ret = NULL;
     int sign;
 
-    if (pnoinv)
+    /* This is invalid input so we don't worry about constant time here */
+    if (BN_abs_is_word(n, 1) || BN_is_zero(n)) {
+        if (pnoinv != NULL)
+            *pnoinv = 1;
+        return NULL;
+    }
+
+    if (pnoinv != NULL)
         *pnoinv = 0;
 
     if ((BN_get_flags(a, BN_FLG_CONSTTIME) != 0)