java_src/src/test/java/com/google/crypto/tink/prf/AesCmacPrfKeyManagerTest.java

// Copyright 2017 Google Inc.
//
// 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.prf;

import static com.google.common.truth.Truth.assertThat;
import static com.google.crypto.tink.testing.KeyTypeManagerTestUtil.testKeyTemplateCompatible;
import static org.junit.Assert.assertThrows;

import com.google.crypto.tink.KeyTemplate;
import com.google.crypto.tink.KeyTypeManager;
import com.google.crypto.tink.proto.AesCmacPrfKey;
import com.google.crypto.tink.proto.AesCmacPrfKeyFormat;
import com.google.crypto.tink.subtle.PrfAesCmac;
import com.google.crypto.tink.subtle.Random;
import com.google.protobuf.ByteString;
import com.google.protobuf.ExtensionRegistryLite;
import java.security.GeneralSecurityException;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/** Test for AesCmacPrfKeyManager. */
@RunWith(JUnit4.class)
public class AesCmacPrfKeyManagerTest {
  private final AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();
  private final KeyTypeManager.KeyFactory<AesCmacPrfKeyFormat, AesCmacPrfKey> factory =
      manager.keyFactory();

  @Test
  public void validateKeyFormat_empty() throws Exception {
    assertThrows(
        GeneralSecurityException.class,
        () ->
            new AesCmacPrfKeyManager()
                .keyFactory()
                .validateKeyFormat(AesCmacPrfKeyFormat.getDefaultInstance()));
  }

  private static AesCmacPrfKeyFormat makeAesCmacPrfKeyFormat(int keySize) {
    return AesCmacPrfKeyFormat.newBuilder().setKeySize(keySize).build();
  }

  @Test
  public void validateKeyFormat_valid() throws Exception {
    AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();
    manager.keyFactory().validateKeyFormat(makeAesCmacPrfKeyFormat(32));
  }

  @Test
  public void validateKeyFormat_notValid_throws() throws Exception {
    AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();
    assertThrows(
        GeneralSecurityException.class,
        () -> manager.keyFactory().validateKeyFormat(makeAesCmacPrfKeyFormat(31)));
    assertThrows(
        GeneralSecurityException.class,
        () -> manager.keyFactory().validateKeyFormat(makeAesCmacPrfKeyFormat(16)));
  }

  @Test
  public void createKey_valid() throws Exception {
    AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();
    manager.validateKey(manager.keyFactory().createKey(makeAesCmacPrfKeyFormat(32)));
  }

  @Test
  public void createKey_checkValues() throws Exception {
    AesCmacPrfKeyFormat keyFormat = makeAesCmacPrfKeyFormat(32);
    AesCmacPrfKey key = new AesCmacPrfKeyManager().keyFactory().createKey(keyFormat);
    assertThat(key.getKeyValue()).hasSize(keyFormat.getKeySize());
  }

  @Test
  public void createKey_multipleTimes() throws Exception {
    AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();
    AesCmacPrfKeyFormat keyFormat = makeAesCmacPrfKeyFormat(32);
    assertThat(manager.keyFactory().createKey(keyFormat).getKeyValue())
        .isNotEqualTo(manager.keyFactory().createKey(keyFormat).getKeyValue());
  }

  @Test
  public void validateKey_valid() throws Exception {
    AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();
    manager.validateKey(manager.keyFactory().createKey(makeAesCmacPrfKeyFormat(32)));
  }

  @Test
  public void validateKey_wrongVersion_throws() throws Exception {
    AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();
    AesCmacPrfKey validKey = manager.keyFactory().createKey(makeAesCmacPrfKeyFormat(32));
    assertThrows(
        GeneralSecurityException.class,
        () -> manager.validateKey(AesCmacPrfKey.newBuilder(validKey).setVersion(1).build()));
  }

  @Test
  public void validateKey_notValid_throws() throws Exception {
    AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();
    AesCmacPrfKey validKey = manager.keyFactory().createKey(makeAesCmacPrfKeyFormat(32));
    assertThrows(
        GeneralSecurityException.class,
        () ->
            manager.validateKey(
                AesCmacPrfKey.newBuilder(validKey)
                    .setKeyValue(ByteString.copyFrom(Random.randBytes(16)))
                    .build()));
    assertThrows(
        GeneralSecurityException.class,
        () ->
            manager.validateKey(
                AesCmacPrfKey.newBuilder(validKey)
                    .setKeyValue(ByteString.copyFrom(Random.randBytes(64)))
                    .build()));
  }

  @Test
  public void getPrimitive_works() throws Exception {
    AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();
    AesCmacPrfKey validKey = manager.keyFactory().createKey(makeAesCmacPrfKeyFormat(32));
    Prf managerPrf = manager.getPrimitive(validKey, Prf.class);
    Prf directPrf = new PrfAesCmac(validKey.getKeyValue().toByteArray());
    byte[] message = Random.randBytes(50);
    assertThat(managerPrf.compute(message, 16)).isEqualTo(directPrf.compute(message, 16));
  }

  @Test
  public void testAes256CmacTemplate() throws Exception {
    KeyTemplate template = AesCmacPrfKeyManager.aes256CmacTemplate();
    assertThat(template.getTypeUrl()).isEqualTo(new AesCmacPrfKeyManager().getKeyType());
    assertThat(template.getOutputPrefixType()).isEqualTo(KeyTemplate.OutputPrefixType.RAW);
    AesCmacPrfKeyFormat format =
        AesCmacPrfKeyFormat.parseFrom(
            template.getValue(), ExtensionRegistryLite.getEmptyRegistry());

    assertThat(format.getKeySize()).isEqualTo(32);
  }

  @Test
  public void testKeyTemplateAndManagerCompatibility() throws Exception {
    AesCmacPrfKeyManager manager = new AesCmacPrfKeyManager();

    testKeyTemplateCompatible(manager, AesCmacPrfKeyManager.aes256CmacTemplate());
  }

  @Test
  public void testKeyFormats() throws Exception {
    factory.validateKeyFormat(factory.keyFormats().get("AES256_CMAC_PRF").keyFormat);
    factory.validateKeyFormat(factory.keyFormats().get("AES_CMAC_PRF").keyFormat);
  }
}