MD5総当たりjasypt版

md5jasypt.scala

import scala.collection.GenSeq
import org.jasypt.util.digest.Digester

object Main {
  val digester = new Digester("MD5")

  def main(args: Array[String]): Unit = {
    val salt = "hoge".getBytes("UTF8")
    val digest = digester.digest(salt ++ toBytes(567890))
    val single = timer { println(bruteForceSingle(salt, digest)) }
    val multi = timer { println(bruteForceMulti(salt, digest)) }
    println(s"SingleCore: $single")
    println(s"MultiCore: $multi")
  }

  def equals[T](xs: Array[T], ys: Array[T]): Boolean = {
    if(xs.size != ys.size) return false
    var i = 0
    while(i != xs.size) {
      if(xs(i) != ys(i)) return false
      i += 1
    }
    true
  }

  def toBytes(x: Int): Array[Byte] = {
    var value = x
    val b = new Array[Byte](4)
    var i = 3
    while(i != 0) {
      b(i) = value.byteValue
      value = value >>> 8
      i -= 1
    }
    b(0) = value.byteValue
    b
  }

  def bruteForceOne(salt: Array[Byte], digest: Array[Byte])(i: Int): Boolean = {
    val ary = salt ++ toBytes(i)
    val di = digester.digest(ary)
    equals(di, digest)
  }

  def bruteForceMulti(salt: Array[Byte], digest: Array[Byte]): GenSeq[Int] =
    (0 until 1000000).par.filter(bruteForceOne(salt, digest))

  def bruteForceSingle(salt: Array[Byte], digest: Array[Byte]): GenSeq[Int] =
    (0 until 1000000).filter(bruteForceOne(salt, digest))

  def timer(f: => Any): Long = {
    val start = System.currentTimeMillis
    f
    System.currentTimeMillis - start
  }
}

これ https://gist.github.com/ponkotuy/8931093 のjasyptを用いたバージョン。
手元環境の結果は

• Single - 343ms
• Multi - 414ms