make ENGINE_finish() succeed on NULL and simplify callers as in

OpenSSL commit 7c96dbcdab9 by Rich Salz.

This cleans up the caller side quite a bit and reduces the number of
lines enclosed in #ifndef OPENSSL_NO_ENGINE.  codesearch.debian.net
shows that almost nothing checks the return value of ENGINE_finish().
While there, replace a few nearby 'if (!ptr)' with 'if (ptr == NULL)'.

ok jsing, tested by & ok inoguchi

1 files changed, 2 insertions, 5 deletions

diff --git a/src/lib/libcrypto/evp/evp_enc.c b/src/lib/libcrypto/evp/evp_enc.c
index de7c690ca7..db2deb6905 100644
--- a/src/lib/libcrypto/evp/evp_enc.c
+++ b/src/lib/libcrypto/evp/evp_enc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: evp_enc.c,v 1.38 2018/02/17 16:54:08 jsing Exp $ */
+/* $OpenBSD: evp_enc.c,v 1.39 2018/04/14 07:09:21 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -577,10 +577,7 @@ EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
         }
         free(c->cipher_data);
 #ifndef OPENSSL_NO_ENGINE
-        if (c->engine)
-                /* The EVP_CIPHER we used belongs to an ENGINE, release the
-                 * functional reference we held for this reason. */
-                ENGINE_finish(c->engine);
+        ENGINE_finish(c->engine);
 #endif
         explicit_bzero(c, sizeof(EVP_CIPHER_CTX));
         return 1;