Scala AES 256 encryption

commons-codec-1.10.jar

crypto.scala

import javax.crypto.{KeyGenerator, Cipher}
import javax.crypto.spec.SecretKeySpec

import org.apache.commons.codec.binary.Base64

trait Encryption {
  def encrypt(dataBytes: Array[Byte], secret: String): Array[Byte]
  def decrypt(codeBytes: Array[Byte], secret: String): Array[Byte]
}

class JavaCryptoEncryption(algorithm: String) extends Encryption {
  private def decodeBase64(string: String) = Base64.decodeBase64(string)
  private def cipher(mode: Int, b64secret: String): Cipher = {
    val encipher = Cipher.getInstance(algorithm + "/ECB/PKCS5Padding")
    encipher.init(mode, new SecretKeySpec(decodeBase64(b64secret), algorithm))
    encipher
  }

  def encrypt(bytes: Array[Byte], b64secret: String): Array[Byte] = {
    val encoder = cipher(Cipher.ENCRYPT_MODE, b64secret)
    encoder.doFinal(bytes)
  }

  def decrypt(bytes: Array[Byte], b64secret: String): Array[Byte] = {
    val decoder = cipher(Cipher.DECRYPT_MODE, b64secret)
    decoder.doFinal(bytes)
  }
}

object DES extends JavaCryptoEncryption("DES")
object AES extends JavaCryptoEncryption("AES")

object crypto {
  def main(args: Array[String]) {
    def encodeBase64(bytes: Array[Byte]) = Base64.encodeBase64String(bytes)
    def generateKey(algorithm: String, size: Int): Array[Byte] = {
      val generator = KeyGenerator.getInstance(algorithm)
      generator.init(size)
      generator.generateKey().getEncoded
    }
    val string = args(0)
    println(s"JAVA_HOME=${System.getProperty("java.home")}")

    // For 256 to work, see http://stackoverflow.com/questions/6481627/java-security-illegal-key-size-or-default-parameters
    val genKey = encodeBase64(generateKey("AES", 256))
    println(s"genKey: $genKey")
    println(s"string: `$string`")
    val encrypted = AES.encrypt(string.getBytes("UTF-8"), genKey)
    println(s"encrypted: ${encodeBase64(encrypted)}")
    val decrypted = AES.decrypt(encrypted, genKey)
    println(s"decrypted: ${new String(decrypted, "UTF-8")}")
  }
}

enable-256.sh

# http://stackoverflow.com/questions/6481627/java-security-illegal-key-size-or-default-parameters

# maybe doesn't need to be set... but I needed to set it on my machine
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre

# Download the "Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 8 Download":
# http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html
# then, copy the JAR files into your JAVA installation:
cp *.jar $JAVA_HOME/lib/security

run.sh

#!/bin/bash

rm *.class
scalac -classpath .:commons-codec-1.10.jar crypto.scala
scala -classpath .:commons-codec-1.10.jar crypto "my string"