tests: add sha256sum unit test

tests/unit_tests/CMakeLists.txt

@@ -53,6 +53,7 @@ set(unit_tests_sources
   mul_div.cpp
   parse_amount.cpp
   serialization.cpp
+  sha256.cpp
   slow_memmem.cpp
   test_tx_utils.cpp
   test_peerlist.cpp

tests/unit_tests/sha256.cpp

@@ -0,0 +1,45 @@
+// Copyright (c) 2017, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "gtest/gtest.h"
+
+#include "string_tools.h"
+#include "common/util.h"
+
+static bool check(const std::string &data, const char *expected_hash_hex)
+{
+  crypto::hash hash, expected_hash;
+  if (!epee::string_tools::hex_to_pod(expected_hash_hex, expected_hash))
+    return false;
+  return tools::sha256sum((const uint8_t*)data.data(), data.size(), hash) && hash == expected_hash;
+}
+
+TEST(sha256, empty) { ASSERT_TRUE(check(std::string(), "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")); }
+TEST(sha256, small) { ASSERT_TRUE(check("0123456789", "84d89877f0d4041efb6bf91a16f0248f2fd573e6af05c19f96bedb9f882f7882")); }
+TEST(sha256, large) { ASSERT_TRUE(check(std::string(65536*256, 0), "080acf35a507ac9849cfcba47dc2ad83e01b75663a516279c8b9d243b719643e")); }
+