Add platform detection logic for SecureRandom (#676)

* Add CMake platform detection logic for SecureRandom

Now only builds secure_random_arc4random.cc if available.

Remove firebase/firestore/base/port.h. Nothing else was in that
directory.

* Add a SecureRandom implementation that uses OpenSSL

This is usable on Linux, Windows, and Android

* Properly check return from RAND_bytes

1 files changed, 0 insertions, 33 deletions

diff --git a/Firestore/core/src/firebase/firestore/base/port.h b/Firestore/core/src/firebase/firestore/base/port.h
deleted file mode 100644
index 5e3959d..0000000
--- a/Firestore/core/src/firebase/firestore/base/port.h
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright 2017 Google
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_BASE_PORT_H_
-#define FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_BASE_PORT_H_
-
-#if defined(__APPLE__)
-// On Apple platforms we support building via CocoaPods without CMake. When
-// building this way we can't test the presence of features so predefine all
-// the platform-support feature macros to their expected values.
-
-// All supported Apple platforms have arc4random(3).
-#define HAVE_ARC4RANDOM 1
-
-#else
-
-#error "Unknown platform."
-#endif  // defined(__APPLE__)
-
-#endif  // FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_BASE_PORT_H_