//===- llvm/unittest/Support/SHA256Test.cpp - SHA256 tests
//----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements unit tests for the SHA256 functions.
//
//===----------------------------------------------------------------------===//

#include "llvm/Support/SHA256.h"
#include "llvm/ADT/ArrayRef.h"
#include "gtest/gtest.h"

using namespace llvm;

namespace {

static std::string toHex(ArrayRef<uint8_t> Input) {
  static const char *const LUT = "0123456789abcdef";
  size_t Length = Input.size();

  std::string Output;
  Output.reserve(2 * Length);
  for (size_t i = 0; i < Length; ++i) {
    const unsigned char c = Input[i];
    Output.push_back(LUT[c >> 4]);
    Output.push_back(LUT[c & 15]);
  }
  return Output;
}

/// Tests an arbitrary set of bytes passed as \p Input.
void TestSHA256Sum(ArrayRef<uint8_t> Input, StringRef Final) {
  SHA256 Hash;
  Hash.update(Input);
  auto hash = Hash.final();
  auto hashStr = toHex(hash);
  EXPECT_EQ(hashStr, Final);
}

using KV = std::pair<const char *, const char *>;

TEST(SHA256Test, SHA256) {
  std::array<KV, 5> testvectors{
      KV{"",
         "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"},
      KV{"a",
         "ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb"},
      KV{"abc",
         "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"},
      KV{"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
         "248d6a61d20638b8e5c026930c3e6039a33ce45964ff2167f6ecedd419db06c1"},
      KV{"abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklm"
         "nopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
         "cf5b16a778af8380036ce59e7b0492370b249b11e8f07a51afac45037afee9d1"}};

  for (auto input_expected : testvectors) {
    auto str = std::get<0>(input_expected);
    auto expected = std::get<1>(input_expected);
    TestSHA256Sum({reinterpret_cast<const uint8_t *>(str), strlen(str)},
                  expected);
  }

  std::string rep(1000, 'a');
  SHA256 Hash;
  for (int i = 0; i < 1000; ++i) {
    Hash.update({reinterpret_cast<const uint8_t *>(rep.data()), rep.size()});
  }
  auto hash = Hash.final();
  auto hashStr = toHex(hash);
  EXPECT_EQ(hashStr,
            "cdc76e5c9914fb9281a1c7e284d73e67f1809a48a497200e046d39ccc7112cd0");
}

} // namespace