runtime-node-crypto/lib/cipher.js

A Node compatible Crypto module for runtimejs

'use strict';

var ba = require('browserify-aes');
var base64 = require('base64-js');
var cjs = require('crypto-js');

class Cipher {
  constructor(cipher, key) {
    this._cipher = cipher;
    this._key = key;
    this._cont = '';
    this._handle = (cipher.substr(0, 3) === 'aes') ? new ba.Cipher(cipher, key) : null;
  }
  update(cont, enc) {
    if (this._handle !== null) {
      this._handle.update(cont, enc);
      return this;
    } else {
      if (enc !== 'base64') {
        cont = new Buffer(cont, enc).toString('utf8');
        this._cont += cont;
        return this;
      }
      this._cont += base64.toByteArray(cont).toString('utf8');
      return this;
    }
    return this;
  }
  setAutoPadding(padd) {
    // do nothing, padding is always off.
    // TODO: add padding option.
  }
  final(enc) {
    if (this._handle !== null) {
      return this._handle.final(enc);
    } else {
      var cipherString = cjs.RC4.encrypt(this._cont, this._key);
      var buffer = new Buffer(String(cipherString), 'binary');

      if (enc) {
        if (enc !== 'base64') {
          return buffer.toString(enc);
        }
        return base64.fromByteArray(buffer);
      } else {
        return buffer;
      }
    }
  }
}

class Cipheriv extends Cipher {
  constructor(cipher, key, iv) {
    super(cipher, key);
    this._key = key + iv;
  }
}

class Decipher extends Cipher {
  constructor(cipher, key) {
    super(cipher, key);
  }
  final(enc) {
    if (this._handle !== null) {
      return this._handle.final(enc);
    } else {
      var cipherString = cjs.RC4.decrypt(this._cont, this._key);
      var buffer = new Buffer(String(cipherString), 'hex');

      if (enc) {
        if (enc !== 'base64') {
          return buffer.toString(enc);
        }
        return base64.fromByteArray(buffer);
      } else {
        return buffer;
      }
    }
  }
}

class Decipheriv extends Decipher {
  constructor(cipher, key, iv) {
    super(cipher, key);
    this._key = key + iv;
  }
}

module.exports = {};
module.exports.Cipher = Cipher;
module.exports.Cipheriv = Cipheriv;
module.exports.Decipher = Decipher;
module.exports.Decipheriv = Decipheriv;