Fix possible crash in X931 code.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3675)
(cherry picked from commit 5419dadd4bd1f7abbfa23326ca766d2c143f257c)

diff --git a/crypto/bn/bn_x931p.c b/crypto/bn/bn_x931p.c
index efa48bdf87724abd79a4ca7c6733cf9473b56e6a..f444af3feabd91802e4c797803a2c12ee13bf1ae 100644 (file)
--- a/crypto/bn/bn_x931p.c
+++ b/crypto/bn/bn_x931p.c
@@ -217,6 +217,8 @@ int BN_X931_generate_Xpq(BIGNUM *Xp, BIGNUM *Xq, int nbits, BN_CTX *ctx)
 
     BN_CTX_start(ctx);
     t = BN_CTX_get(ctx);
+    if (t == NULL)
+        goto err;
 
     for (i = 0; i < 1000; i++) {
         if (!BN_rand(Xq, nbits, 1, 0))
@@ -255,10 +257,12 @@ int BN_X931_generate_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
     int ret = 0;
 
     BN_CTX_start(ctx);
-    if (!Xp1)
+    if (Xp1 == NULL)
         Xp1 = BN_CTX_get(ctx);
-    if (!Xp2)
+    if (Xp2 == NULL)
         Xp2 = BN_CTX_get(ctx);
+    if (Xp1 == NULL || Xp2 == NULL)
+        goto error;
 
     if (!BN_rand(Xp1, 101, 0, 0))
         goto error;