text: // Copyright 2012 The Closure Library Authors. All Rights Reserved.
  //
  // 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.
  
  /**
   * @fileoverview Interface definition of a block cipher. A block cipher is a
   * pair of algorithms that implement encryption and decryption of input bytes.
   *
   * @see http://en.wikipedia.org/wiki/Block_cipher
   *
   * @author nnaze@google.com (Nathan Naze)
   */
  
  goog.provide('goog.crypt.BlockCipher');
  
  
  
  /**
   * Interface definition for a block cipher.
   * @interface
   */
  goog.crypt.BlockCipher = function() {};
  
  
  /**
   * Encrypt a plaintext block.  The implementation may expect (and assert)
   * a particular block length.
   * @param {!Array<number>} input Plaintext array of input bytes.
   * @return {!Array<number>} Encrypted ciphertext array of bytes.  Should be the
   *     same length as input.
   */
  goog.crypt.BlockCipher.prototype.encrypt;
  
  
  /**
   * Decrypt a plaintext block.  The implementation may expect (and assert)
   * a particular block length.
   * @param {!Array<number>} input Ciphertext. Array of input bytes.
   * @return {!Array<number>} Decrypted plaintext array of bytes.  Should be the
   *     same length as input.
   */
  goog.crypt.BlockCipher.prototype.decrypt;
  