Method performEncode

src/Encoder/NihilistCipher.js:90–124

* Performs encode on given content. * @protected * @param {Chain} content * @return {number[]|string|Uint8Array|Chain} Encoded content

(content)

   * @return {number[]|string|Uint8Array|Chain} Encoded content
   */
  async performEncode (content) {
    const key = this.getSettingValue('key')
    const separator = this.getSettingValue('separator')

    // Translate both plaintext and key using the Polybius square
    const plaintextPolybius = await this._polybiusSquare.encode(
      content.getString().replace(/j/gi, 'i'))
    const keyPolybius = await this._polybiusSquare.encode(key)

    const contentLength = plaintextPolybius.getLength() / 2
    const keyLength = key.getLength()

    const values = new Array(contentLength)
    let plaintextValue, keyIndex, keyValue

    for (let i = 0; i < contentLength; i++) {
      // Compose plaintext number
      plaintextValue = parseInt(
        plaintextPolybius.getCharAt(i * 2) +
        plaintextPolybius.getCharAt(i * 2 + 1)
      )

      // Compose key number
      keyIndex = MathUtil.mod(i, keyLength) * 2
      keyValue = parseInt(
        keyPolybius.getCharAt(keyIndex) +
        keyPolybius.getCharAt(keyIndex + 1)
      )

      // Add plaintext and key values together
      values[i] = plaintextValue + keyValue
    }

    return Chain.join(values, separator)
  }

  /**
   * Performs decode on given content.