Ravelry crypto

gistfile1.scala

object Crypto {
  /** Sign a request as a user */
  def sign(url: String, params: Map[String, String], token: String, secret: String): String = {
    val paramsToSign = params ++ commonParams ++ Map("auth_token" -> token)
    finalsign(url, paramsToSign, secret)
  }

  /** Sign a request as Ballero */
  def appsign(url: String, params: Map[String, String]): String = {
    val paramsToSign = params ++ commonParams
    finalsign(url, paramsToSign, Keys.secret)
  }

  private def finalsign(url: String, params: Map[String, String], secret: String): String = {
    val proveMe = "%s?%s".format(url, params.keySet.toList.sorted
      .map { name => (name, params(name)) }
      .map { case (name, value) => "%s=%s".format(encode(name), encode(value)) }.mkString("&")
    )

    val hmac256 = new HmacSha256
    val signature = Base64.encode(hmac256.create(secret, proveMe))
    "%s&signature=%s".format(proveMe, encode(signature))
  }

  private def commonParams: Map[String, String] =
    Map("access_key" -> Keys.key, "timestamp" -> iso8601)

  /** Gets an ISO8601 formatted timestamp. */
  private def iso8601: String = {
    val now = new Date()
    val sdf: SimpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.000Z")
    sdf.format( now )
  }

  private def encode(str: String): String = java.net.URLEncoder.encode(str, "UTF-8")
}