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, 6 insertions, 10 deletions

diff --git a/src/lib/libcrypto/dsa/dsa_lib.c b/src/lib/libcrypto/dsa/dsa_lib.c
index 8190d07348..d5fdd6e78e 100644
--- a/src/lib/libcrypto/dsa/dsa_lib.c
+++ b/src/lib/libcrypto/dsa/dsa_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsa_lib.c,v 1.28 2018/02/20 17:52:27 tb Exp $ */
+/* $OpenBSD: dsa_lib.c,v 1.29 2018/04/14 07:09:21 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -108,10 +108,8 @@ DSA_set_method(DSA *dsa, const DSA_METHOD *meth)
         if (mtmp->finish)
                 mtmp->finish(dsa);
 #ifndef OPENSSL_NO_ENGINE
-        if (dsa->engine) {
-                ENGINE_finish(dsa->engine);
-                dsa->engine = NULL;
-        }
+        ENGINE_finish(dsa->engine);
+        dsa->engine = NULL;
 #endif
         dsa->meth = meth;
         if (meth->init)
@@ -142,7 +140,7 @@ DSA_new_method(ENGINE *engine)
                 ret->engine = ENGINE_get_default_DSA();
         if (ret->engine) {
                 ret->meth = ENGINE_get_DSA(ret->engine);
-                if (!ret->meth) {
+                if (ret->meth == NULL) {
                         DSAerror(ERR_R_ENGINE_LIB);
                         ENGINE_finish(ret->engine);
                         free(ret);
@@ -170,8 +168,7 @@ DSA_new_method(ENGINE *engine)
         CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
         if (ret->meth->init != NULL && !ret->meth->init(ret)) {
 #ifndef OPENSSL_NO_ENGINE
-                if (ret->engine)
-                        ENGINE_finish(ret->engine);
+                ENGINE_finish(ret->engine);
 #endif
                 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, ret, &ret->ex_data);
                 free(ret);
@@ -196,8 +193,7 @@ DSA_free(DSA *r)
         if (r->meth->finish)
                 r->meth->finish(r);
 #ifndef OPENSSL_NO_ENGINE
-        if (r->engine)
-                ENGINE_finish(r->engine);
+        ENGINE_finish(r->engine);
 #endif
 
         CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DSA, r, &r->ex_data);