package ixee.cryptopals.utils.crypto

import javax.crypto.Cipher

class CBCCipher(cipher: Cipher, init: Seq[Byte]) {
  var state: Seq[Byte] = init
  var leftover: Seq[Byte] = Seq()

  def enc(data: Seq[Byte]): Seq[Byte] = {
    (blocks, leftover) = blockized(leftover append data)
    blocks.map(encBlock).reduce(_ append _)
  }

  def encBlock(data: Seq[Byte]): Seq[Byte] = {
    state = cipher.doFinal((data xor state).toArray)
    state
  }

  def blockized(data: Seq[Byte])(size: Int): (Seq[Seq[Byte]], Seq[Byte]) =
    data.splitAt(data.length - (data.length % size))
}