text: /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   *
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   *
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   *
   * 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 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. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   *
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
   *
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.] */
  
  #include <memory>
  #include <string>
  #include <vector>
  
  #include <gtest/gtest.h>
  
  #include <openssl/digest.h>
  #include <openssl/hmac.h>
  
  #include "../test/file_test.h"
  #include "../test/test_util.h"
  
  
  static const EVP_MD *GetDigest(const std::string &name) {
    if (name == "MD5") {
      return EVP_md5();
    } else if (name == "SHA1") {
      return EVP_sha1();
    } else if (name == "SHA224") {
      return EVP_sha224();
    } else if (name == "SHA256") {
      return EVP_sha256();
    } else if (name == "SHA384") {
      return EVP_sha384();
    } else if (name == "SHA512") {
      return EVP_sha512();
    }
    return nullptr;
  }
  
  TEST(HMACTest, TestVectors) {
    FileTestGTest("crypto/hmac_extra/hmac_tests.txt", [](FileTest *t) {
      std::string digest_str;
      ASSERT_TRUE(t->GetAttribute(&digest_str, "HMAC"));
      const EVP_MD *digest = GetDigest(digest_str);
      ASSERT_TRUE(digest) << "Unknown digest: " << digest_str;
  
      std::vector<uint8_t> key, input, output;
      ASSERT_TRUE(t->GetBytes(&key, "Key"));
      ASSERT_TRUE(t->GetBytes(&input, "Input"));
      ASSERT_TRUE(t->GetBytes(&output, "Output"));
      ASSERT_EQ(EVP_MD_size(digest), output.size());
  
      // Test using the one-shot API.
      unsigned expected_mac_len = EVP_MD_size(digest);
      std::unique_ptr<uint8_t[]> mac(new uint8_t[expected_mac_len]);
      unsigned mac_len;
      ASSERT_TRUE(HMAC(digest, key.data(), key.size(), input.data(), input.size(),
                       mac.get(), &mac_len));
      EXPECT_EQ(Bytes(output), Bytes(mac.get(), mac_len));
  
      // Test using HMAC_CTX.
      bssl::ScopedHMAC_CTX ctx;
      ASSERT_TRUE(
          HMAC_Init_ex(ctx.get(), key.data(), key.size(), digest, nullptr));
      ASSERT_TRUE(HMAC_Update(ctx.get(), input.data(), input.size()));
      ASSERT_TRUE(HMAC_Final(ctx.get(), mac.get(), &mac_len));
      EXPECT_EQ(Bytes(output), Bytes(mac.get(), mac_len));
  
      // Test that an HMAC_CTX may be reset with the same key.
      ASSERT_TRUE(HMAC_Init_ex(ctx.get(), nullptr, 0, digest, nullptr));
      ASSERT_TRUE(HMAC_Update(ctx.get(), input.data(), input.size()));
      ASSERT_TRUE(HMAC_Final(ctx.get(), mac.get(), &mac_len));
      EXPECT_EQ(Bytes(output), Bytes(mac.get(), mac_len));
  
      // Test feeding the input in byte by byte.
      ASSERT_TRUE(HMAC_Init_ex(ctx.get(), nullptr, 0, nullptr, nullptr));
      for (size_t i = 0; i < input.size(); i++) {
        ASSERT_TRUE(HMAC_Update(ctx.get(), &input[i], 1));
      }
      ASSERT_TRUE(HMAC_Final(ctx.get(), mac.get(), &mac_len));
      EXPECT_EQ(Bytes(output), Bytes(mac.get(), mac_len));
    });
  }
  