// Copyright 2023 Google LLC
//
// 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.
//
////////////////////////////////////////////////////////////////////////////////

package com.google.crypto.tink.mac.internal;

import com.google.crypto.tink.AccessesPartialKey;
import com.google.crypto.tink.InsecureSecretKeyAccess;
import com.google.crypto.tink.mac.HmacKey;
import com.google.crypto.tink.mac.HmacParameters;
import com.google.crypto.tink.mac.HmacParameters.HashType;
import com.google.crypto.tink.mac.HmacParameters.Variant;
import com.google.crypto.tink.subtle.Hex;
import com.google.crypto.tink.util.SecretBytes;
import java.security.GeneralSecurityException;
import javax.annotation.Nullable;

/**
 * Test vector class, reusable test vectors, and convenience functions for testing Hmac
 * implementations.
 */
@AccessesPartialKey
public final class HmacTestUtil {

  // Test data from http://csrc.nist.gov/groups/STM/cavp/message-authentication.html#testing
  // and https://tools.ietf.org/html/rfc4231.
  @SuppressWarnings("MutablePublicArray") // This is an internal-only test utility. Our tests never
                                          // mutate this array.
  public static final HmacTestVector[] HMAC_TEST_VECTORS = {
    new HmacTestVector(
        Variant.NO_PREFIX,
        null,
        HashType.SHA1,
        "816aa4c3ee066310ac1e6666cf830c375355c3c8ba18cfe1f50a48c988b46272",
        "220248f5e6d7a49335b3f91374f18bb8b0ff5e8b9a5853f3cfb293855d78301d837a0a2eb9e4f056f06c08361"
            + "bd07180ee802651e69726c28910d2baef379606815dcbab01d0dc7acb0ba8e65a2928130da0522f2b2b3d05260"
            + "885cf1c64f14ca3145313c685b0274bf6a1cb38e4f99895c6a8cc72fbe0e52c01766fede78a1a",
        16,
        "17cb2e9e98b748b5ae0f7078ea5519e5"),
    new HmacTestVector(
        Variant.NO_PREFIX,
        null,
        HashType.SHA256,
        "6f35628d65813435534b5d67fbdb54cb33403d04e843103e6399f806cb5df95febbdd61236f33245",
        "752cff52e4b90768558e5369e75d97c69643509a5e5904e0a386cbe4d0970ef73f918f675945a9aefe26daea27"
            + "587e8dc909dd56fd0468805f834039b345f855cfe19c44b55af241fff3ffcd8045cd5c288e6c4e284c3720570b"
            + "58e4d47b8feeedc52fd1401f698a209fccfa3b4c0d9a797b046a2759f82a54c41ccd7b5f592b",
        16,
        "05d1243e6465ed9620c9aec1c351a186"),
    new HmacTestVector(
        Variant.NO_PREFIX,
        null,
        HashType.SHA384,
        "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b",
        "4869205468657265",
        48,
        "afd03944d84895626b0825f4ab46907f15f9dadbe4101ec682aa034c7cebc59cfaea9ea9076ede7f4af152e8b2fa9cb6"),
    new HmacTestVector(
        Variant.NO_PREFIX,
        null,
        HashType.SHA512,
        "726374c4b8df517510db9159b730f93431e0cd468d4f3821eab0edb93abd0fba46ab4f1ef35d54fec3d85fa89e"
            + "f72ff3d35f22cf5ab69e205c10afcdf4aaf11338dbb12073474fddb556e60b8ee52f91163ba314303ee0c910e6"
            + "4e87fbf302214edbe3f2",
        "ac939659dc5f668c9969c0530422e3417a462c8b665e8db25a883a625f7aa59b89c5ad0ece5712ca17442d1798"
            + "c6dea25d82c5db260cb59c75ae650be56569c1bd2d612cc57e71315917f116bbfa65a0aeb8af7840ee83d3e710"
            + "1c52cf652d2773531b7a6bdd690b846a741816c860819270522a5b0cdfa1d736c501c583d916",
        32,
        "bd3d2df6f9d284b421a43e5f9cb94bc4ff88a88243f1f0133bad0fb1791f6569"),
  };

  @SuppressWarnings("MutablePublicArray") // This is an internal-only test utility. Our tests never
                                          // mutate this array.
  public static final HmacTestVector[] PREFIXED_KEY_TYPES = {
    new HmacTestVector(
        Variant.LEGACY,
        1234,
        HashType.SHA1,
        "816aa4c3ee066310ac1e6666cf830c375355c3c8ba18cfe1f50a48c988b46272",
        "220248f5e6d7a49335b3f91374f18bb8b0ff5e8b9a5853f3cfb293855d78301d837a0a2eb9e4f056f06c08361"
            + "bd07180ee802651e69726c28910d2baef379606815dcbab01d0dc7acb0ba8e65a2928130da0522f2b2b3d05260"
            + "885cf1c64f14ca3145313c685b0274bf6a1cb38e4f99895c6a8cc72fbe0e52c01766fede78a1a",
        16,
        "00000004d20c2676610ded1bce1967ec654526ca7b"),
    new HmacTestVector(
        Variant.TINK,
        1234,
        HashType.SHA256,
        "6f35628d65813435534b5d67fbdb54cb33403d04e843103e6399f806cb5df95febbdd61236f33245",
        "752cff52e4b90768558e5369e75d97c69643509a5e5904e0a386cbe4d0970ef73f918f675945a9aefe26daea27"
            + "587e8dc909dd56fd0468805f834039b345f855cfe19c44b55af241fff3ffcd8045cd5c288e6c4e284c3720570b"
            + "58e4d47b8feeedc52fd1401f698a209fccfa3b4c0d9a797b046a2759f82a54c41ccd7b5f592b",
        16,
        "01000004d205d1243e6465ed9620c9aec1c351a186"),
    new HmacTestVector(
        Variant.CRUNCHY,
        1234,
        HashType.SHA384,
        "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b",
        "4869205468657265",
        48,
        "00000004d2afd03944d84895626b0825f4ab46907f15f9dadbe4101ec682aa034c7cebc59cfaea9ea9076ede7f4af152e8b2fa9cb6"),
    new HmacTestVector(
        Variant.TINK,
        1234,
        HashType.SHA512,
        "726374c4b8df517510db9159b730f93431e0cd468d4f3821eab0edb93abd0fba46ab4f1ef35d54fec3d85fa89e"
            + "f72ff3d35f22cf5ab69e205c10afcdf4aaf11338dbb12073474fddb556e60b8ee52f91163ba314303ee0c910e6"
            + "4e87fbf302214edbe3f2",
        "ac939659dc5f668c9969c0530422e3417a462c8b665e8db25a883a625f7aa59b89c5ad0ece5712ca17442d1798"
            + "c6dea25d82c5db260cb59c75ae650be56569c1bd2d612cc57e71315917f116bbfa65a0aeb8af7840ee83d3e710"
            + "1c52cf652d2773531b7a6bdd690b846a741816c860819270522a5b0cdfa1d736c501c583d916",
        32,
        "01000004d2bd3d2df6f9d284b421a43e5f9cb94bc4ff88a88243f1f0133bad0fb1791f6569"),
  };

  @SuppressWarnings("MutablePublicArray") // This is an internal-only test utility. Our tests never
                                          // mutate this array.
  public static final HmacTestVector[] CREATE_VERIFICATION_FAILS_FAST = {
    new HmacTestVector( // Wrong prefix.
        Variant.LEGACY,
        1234,
        HashType.SHA1,
        "816aa4c3ee066310ac1e6666cf830c375355c3c8ba18cfe1f50a48c988b46272",
        "220248f5e6d7a49335b3f91374f18bb8b0ff5e8b9a5853f3cfb293855d78301d837a0a2eb9e4f056f06c08361"
            + "bd07180ee802651e69726c28910d2baef379606815dcbab01d0dc7acb0ba8e65a2928130da0522f2b2b3d05260"
            + "885cf1c64f14ca3145313c685b0274bf6a1cb38e4f99895c6a8cc72fbe0e52c01766fede78a1a",
        16,
        "17cb2e9e98b748b5ae0f7078ea5519e5"),
    new HmacTestVector( // Wrong prefix.
        Variant.TINK,
        1234,
        HashType.SHA256,
        "6f35628d65813435534b5d67fbdb54cb33403d04e843103e6399f806cb5df95febbdd61236f33245",
        "752cff52e4b90768558e5369e75d97c69643509a5e5904e0a386cbe4d0970ef73f918f675945a9aefe26daea27"
            + "587e8dc909dd56fd0468805f834039b345f855cfe19c44b55af241fff3ffcd8045cd5c288e6c4e284c3720570b"
            + "58e4d47b8feeedc52fd1401f698a209fccfa3b4c0d9a797b046a2759f82a54c41ccd7b5f592b",
        16,
        "01075505d1243e6465ed9620c9aec1c351a186"),
    new HmacTestVector( // Tag too short.
        Variant.CRUNCHY,
        1234,
        HashType.SHA384,
        "0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b",
        "4869205468657265",
        16,
        "afd0"),
  };

  /**
   * Creates an {@link HmacParameters} object from the provided {@code keySizeBytes},
   * {@code fullTagSizeBytes}, {@code variant}, and {@code HashType}. This is a convenience method
   * that makes the tests code more concise and readable.
   */
  public static HmacParameters createHmacParameters(
      int keySizeBytes, int fullTagSizeBytes, Variant variant, HashType hashType) {
    try {
      return HmacParameters.builder()
          .setKeySizeBytes(keySizeBytes)
          .setTagSizeBytes(fullTagSizeBytes)
          .setVariant(variant)
          .setHashType(hashType)
          .build();
    } catch (GeneralSecurityException e) {
      throw new IllegalArgumentException("Incorrect parameters creation arguments", e);
    }
  }

  private static HmacKey createHmacKey(
      String key,
      int tagSizeBytes,
      Variant variant,
      @Nullable Integer idRequirement,
      HashType hashType) {
    try {
      return HmacKey.builder()
          .setKeyBytes(SecretBytes.copyFrom(Hex.decode(key), InsecureSecretKeyAccess.get()))
          .setParameters(
              createHmacParameters(
                  Hex.decode(key).length,
                  tagSizeBytes,
                  variant,
                  hashType))
          .setIdRequirement(idRequirement)
          .build();
    } catch (GeneralSecurityException e) {
      throw new IllegalArgumentException("Incorrect key creation arguments", e);
    }
  }

  /**
   * Represents a single Hmac test vector.
   */
  public static final class HmacTestVector {
    public final HmacKey key;
    public final byte[] message;
    public final byte[] tag;

    public HmacTestVector(
        Variant variant,
        @Nullable Integer id,
        HashType hashType,
        String key,
        String message,
        int tagSizeBytes,
        String tag) {
      this.key = createHmacKey(key, tagSizeBytes, variant, id, hashType);
      this.message = Hex.decode(message);
      this.tag = Hex.decode(tag);
    }
  }

  private HmacTestUtil() {}
}