Method createCipher

src/Encoder/BlockCipher.js:202–266

* Creates message cipher using given algorithm. * @protected * @param {string} name Algorithm name * @param {Uint8Array} message Message bytes * @return {Promise}

(name, mode, key, iv, padding, isEncode, message)

   * @return {Promise}
   */
  async createCipher (name, mode, key, iv, padding, isEncode, message) {
    const algorithm = BlockCipherEncoder.getAlgorithm(name)

    const { hasIV } = BlockCipherEncoder.getMode(mode)
    if (!hasIV) {
      iv = new Uint8Array([])
    }

    if (EnvUtil.isNode()) {
      const cipherName = algorithm.nodeAlgorithm + '-' + mode

      // Node v8.x - convert Uint8Array to Buffer - not needed for v10
      iv = global.Buffer.from(iv)
      message = global.Buffer.from(message)

      // Create message cipher using Node Crypto async
      return new Promise((resolve, reject) => {
        const cipher = isEncode
          ? nodeCrypto.createCipheriv(cipherName, key, iv)
          : nodeCrypto.createDecipheriv(cipherName, key, iv)

        cipher.setAutoPadding(padding)

        const resultBuffer = Buffer.concat([
          cipher.update(message),
          cipher.final()
        ])

        resolve(new Uint8Array(resultBuffer))
      })
    } else {
      const cipherName = algorithm.browserAlgorithm + '-' + mode

      // Get crypto subtle instance
      const crypto = window.crypto || window.msCrypto
      const cryptoSubtle = crypto.subtle || crypto.webkitSubtle

      // Create key instance
      const cryptoKey = await cryptoSubtle.importKey(
        'raw', key, { name: cipherName }, false, ['encrypt', 'decrypt'])

      // Create message cipher using Web Crypto API
      const algo = {
        name: cipherName,
        iv,
        counter: iv,
        length: algorithm.blockSize
      }

      let result = isEncode
        ? cryptoSubtle.encrypt(algo, cryptoKey, message)
        : cryptoSubtle.decrypt(algo, cryptoKey, message)

      // IE11 exception
      if (result.oncomplete !== undefined) {
        // Wrap IE11 CryptoOperation object in a promise
        result = new Promise((resolve, reject) => {
          result.oncomplete = resolve.bind(this, result.result)