Relanding Porting of HKDF changes from server.

crypto/hkdf_unittest.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "crypto/hkdf.h"
+
+#include <string>
+
+#include "base/strings/string_number_conversions.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using crypto::HKDF;
+
+namespace test {
+namespace {
+
+struct HKDFTest {
+  const char* key_hex;
+  const char* salt_hex;
+  const char* info_hex;
+  const char* output_hex;
+};
+
+// These test cases are taken from
+// https://tools.ietf.org/html/rfc5869#appendix-A.
+static const HKDFTest kHKDFTests[] = {{
+    "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b",
+    "000102030405060708090a0b0c",
+    "f0f1f2f3f4f5f6f7f8f9",
+    "3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5"
+    "b887185865",
+  }, {
+    "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f2021222324"
+    "25262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f40414243444546474849"
+    "4a4b4c4d4e4f",
+    "606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f8081828384"
+    "85868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9"
+    "aaabacadaeaf",
+    "b0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4"
+    "d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9"
+    "fafbfcfdfeff",
+    "b11e398dc80327a1c8e7f78c596a49344f012eda2d4efad8a050cc4c19afa97c59045a99ca"
+    "c7827271cb41c65e590e09da3275600c2f09b8367793a9aca3db71cc30c58179ec3e87c14c"
+    "01d5c1f3434f1d87",
+  }, {
+    "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b",
+    "",
+    "",
+    "8da4e775a563c18f715f802a063c5a31b8a11f5c5ee1879ec3454e5f3c738d2d9d201395fa"
+    "a4b61a96c8",
+  },
+};
+
+TEST(HKDFTest, HKDFConstruct) {
+  for (size_t i = 0; i < arraysize(kHKDFTests); i++) {
+    const HKDFTest& test(kHKDFTests[i]);
+    SCOPED_TRACE(i);
+
+    std::vector<uint8> data;
+    EXPECT_TRUE(base::HexStringToBytes(test.key_hex, &data));
+    const std::string key(reinterpret_cast<char *>(&data[0]), data.size());
+
+    data.clear();
+    // |salt_hex| could be optional.
+    std::string salt_hex(test.salt_hex);
+    if (!salt_hex.empty())
+      EXPECT_TRUE(base::HexStringToBytes(salt_hex, &data));
+    const std::string salt(reinterpret_cast<char *>(&data[0]), data.size());

[Ryan Sleevi, 2013/02/23 00:19:19]

std::string salt(test.salt_hex);
if (!salt_hex.empty()) {
  ASSERT_TRUE(..., &data);
  salt->assign(....);
}

[ramant (doing other things), 2013/02/23 00:37:33]

Done.

+
+    data.clear();
+    // |info_hex| could be optional.
+    std::string info_hex(test.info_hex);
+    if (!info_hex.empty())
+      EXPECT_TRUE(base::HexStringToBytes(info_hex, &data));
+    const std::string info(reinterpret_cast<char *>(&data[0]), data.size());
+
+    data.clear();
+    EXPECT_TRUE(base::HexStringToBytes(test.output_hex, &data));
+    const std::string expected(reinterpret_cast<char *>(&data[0]), data.size());
+
+    // We set the key_length to the length of the expected output and then take
+    // the result from the first key, which is the client write key.
+    HKDF hkdf(key, salt, info, expected.size(), 0);
+
+    ASSERT_EQ(expected.size(), hkdf.client_write_key().size());
+    EXPECT_EQ(0, memcmp(expected.data(), hkdf.client_write_key().data(),
+                        expected.size()));
+  }
+}
+
+}  // namespace
+}  // namespace test