Desk.com integration in scala

DeskDotCom.scala

// Desk.com integration based on http://dev.desk.com/guides/sso/
// License: Public domain

import scala.util.parsing.json.JSONObject
import org.apache.commons.codec.binary.Base64

import java.util.Arrays
import java.text.DateFormat
import java.text.SimpleDateFormat
import java.util.Date
import java.net.URLEncoder

import java.security.MessageDigest
import java.security.SecureRandom

import javax.crypto.Cipher
import javax.crypto.Mac
import javax.crypto.spec.IvParameterSpec
import javax.crypto.spec.SecretKeySpec

/**
  Create redirect URL for Desk.com "Private Access / Multipass SSO"
  Usage:

  val desk = new DeskDotCom("yoursite", "xxxx")
  val url  = desk.loginURL("test123", "john@example.com", "John Smith", "co12", "Example Inc")
  redirect(url) // the url format returned: "https://yoursite.desk.com/..."

  If you're using custom fields, they have to be created first in the admin console:
  https://yoursite.desk.com/admin/case-management/customer-settings/custom-fields
  Name=CompanyID key=companyid Type=Text
  Name=Company   key=company   Type=text
*/
class DeskDotCom(siteKeyOrig: String, apiKey:String) {
  protected val siteKey: String = siteKeyOrig.toLowerCase

  def loginURL(custUid:String, custEmail:String, custName:String, custCompanyID:String="", custCompanyName:String=""): String = {
    val salted: String    = apiKey + siteKey
    val md: MessageDigest = MessageDigest.getInstance("SHA1")
    md.update(salted.getBytes("utf-8"))

    val digest: Array[Byte]  = md.digest()
    val key: SecretKeySpec   = new SecretKeySpec(Arrays.copyOfRange(digest, 0, 16), "AES")
    val iv: Array[Byte]      = new Array[Byte](16)
    val random: SecureRandom = new SecureRandom()
    random.nextBytes(iv)

    val df: DateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mmZ")
    var userMap: Map[String, String] = Map()
    userMap += ("uid"-> custUid)
    userMap += ("expires" -> df.format(new Date(new Date().getTime() + 300000)))
    userMap += ("customer_email" -> custEmail)
    userMap += ("customer_name"  -> custName)
    if (!custCompanyID.isEmpty)   userMap += ("customer_custom_companyid"-> custCompanyID)
    if (!custCompanyName.isEmpty) userMap += ("customer_custom_company"  -> custCompanyName)
    
    val data = JSONObject( userMap ).toString()
    val aes  = Cipher.getInstance("AES/CBC/PKCS5Padding")
    val ivSpec   = new IvParameterSpec(iv)
    aes.init(Cipher.ENCRYPT_MODE, key, ivSpec)

    val encrypted: Array[Byte] = aes.doFinal(data.getBytes("utf-8"))
    val combined:  Array[Byte] = new Array(iv.length + encrypted.length)
    System.arraycopy(iv, 0, combined, 0, iv.length)
    System.arraycopy(encrypted, 0, combined, iv.length, encrypted.length)

    val multipass: Array[Byte]   = Base64.encodeBase64(combined)
    val apiKeyEnc: SecretKeySpec = new SecretKeySpec(apiKey.getBytes("utf-8"), "HmacSHA1")
    val hmac: Mac                = Mac.getInstance("HmacSHA1")
    hmac.init(apiKeyEnc)
    
    val rawHmac:   Array[Byte] = hmac.doFinal(multipass)
    val signature: Array[Byte] = Base64.encodeBase64(rawHmac)

    val encodeType = "UTF-8"
    val multipassString = URLEncoder.encode(new String(multipass), encodeType)
    val signatureString = URLEncoder.encode(new String(signature), encodeType)
    
    val url = "https://" + siteKey +
              ".desk.com/customer/authentication/multipass/callback?multipass=" +
              multipassString + "&signature=" + signatureString
    return url
  }
  
}