/*
 * Copyright (C) 2020 The Android Open Source Project
 *
 * 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.android.encryptionrunner;

import androidx.annotation.NonNull;
import java.security.NoSuchAlgorithmException;
import java.security.SignatureException;

/** Represents a serializable encryption key. */
public interface Key {
  /** Returns a serialized encryption key. */
  @NonNull
  byte[] asBytes();

  /**
   * Encrypts data using this key.
   *
   * @param data the data to be encrypted
   * @return the encrypted data.
   */
  @NonNull
  byte[] encryptData(@NonNull byte[] data);

  /**
   * Decrypts data using this key.
   *
   * @param encryptedData The encrypted data.
   * @return decrypted data.
   * @throws SignatureException if encrypted data is not properly signed.
   */
  @NonNull
  byte[] decryptData(@NonNull byte[] encryptedData) throws SignatureException;

  /**
   * Returns a cryptographic digest of the key.
   *
   * @throws NoSuchAlgorithmException when a unique session can not be created.
   */
  @NonNull
  byte[] getUniqueSession() throws NoSuchAlgorithmException;
}