Fix a missing NULL check in dsa_builtin_paramgen

We should check the last BN_CTX_get() call to ensure that it isn't NULL before we try and use any of the allocated BIGNUMs. Issue reported by Shi Lei. Reviewed-by: Richard Levitte <levitte@openssl.org> (cherry picked from commit 1ff7425)
openssl · Sep 21, 2016 · 6bdd263 · 6bdd263
1 parent cade326
commit 6bdd263
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/crypto/dsa/dsa_gen.c b/crypto/dsa/dsa_gen.c
@@ -100,6 +100,9 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
     p = BN_CTX_get(ctx);
     test = BN_CTX_get(ctx);
 
+    if (test == NULL)
+        goto err;
+
     if (!BN_lshift(test, BN_value_one(), bits - 1))
         goto err;