don't let BN_CTX_free(NULL) segfault

diff --git a/crypto/bn/bn_ctx.c b/crypto/bn/bn_ctx.c
index 7010193033f9e8a139b55fede7210efcbbcbc817..b3452f1a91e31081e18667e25c49790b5b5a876a 100644 (file)
--- a/crypto/bn/bn_ctx.c
+++ b/crypto/bn/bn_ctx.c
@@ -230,7 +230,10 @@ BN_CTX *BN_CTX_new(void)
 
 void BN_CTX_free(BN_CTX *ctx)
        {
+       if (ctx == NULL)
+               return;
 #ifdef BN_CTX_DEBUG
+       {
        BN_POOL_ITEM *pool = ctx->pool.head;
        fprintf(stderr,"BN_CTX_free, stack-size=%d, pool-bignums=%d\n",
                ctx->stack.size, ctx->pool.size);
@@ -242,6 +245,7 @@ void BN_CTX_free(BN_CTX *ctx)
                pool = pool->next;
        }
        fprintf(stderr,"\n");
+       }
 #endif
        BN_STACK_finish(&ctx->stack);
        BN_POOL_finish(&ctx->pool);