text: /*
   * pkcs7.pad
   * https://github.com/brightcove/pkcs7
   *
   * Copyright (c) 2014 Brightcove
   * Licensed under the apache2 license.
   */
  
  let PADDING;
  
  /**
   * Returns a new Uint8Array that is padded with PKCS#7 padding.
   * @param plaintext {Uint8Array} the input bytes before encryption
   * @return {Uint8Array} the padded bytes
   * @see http://tools.ietf.org/html/rfc5652
   */
  export default function pad(plaintext) {
    const padding = PADDING[(plaintext.byteLength % 16) || 0];
    const result = new Uint8Array(plaintext.byteLength + padding.length);
  
    result.set(plaintext);
    result.set(padding, plaintext.byteLength);
  
    return result;
  }
  
  // pre-define the padding values
  PADDING = [
    [16, 16, 16, 16,
     16, 16, 16, 16,
     16, 16, 16, 16,
     16, 16, 16, 16],
  
    [15, 15, 15, 15,
     15, 15, 15, 15,
     15, 15, 15, 15,
     15, 15, 15],
  
    [14, 14, 14, 14,
     14, 14, 14, 14,
     14, 14, 14, 14,
     14, 14],
  
    [13, 13, 13, 13,
     13, 13, 13, 13,
     13, 13, 13, 13,
     13],
  
    [12, 12, 12, 12,
     12, 12, 12, 12,
     12, 12, 12, 12],
  
    [11, 11, 11, 11,
     11, 11, 11, 11,
     11, 11, 11],
  
    [10, 10, 10, 10,
     10, 10, 10, 10,
     10, 10],
  
    [9, 9, 9, 9,
     9, 9, 9, 9,
     9],
  
    [8, 8, 8, 8,
     8, 8, 8, 8],
  
    [7, 7, 7, 7,
     7, 7, 7],
  
    [6, 6, 6, 6,
     6, 6],
  
    [5, 5, 5, 5,
     5],
  
    [4, 4, 4, 4],
  
    [3, 3, 3],
  
    [2, 2],
  
    [1]
  ];
  