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post.scala

def verifyToken(token: String): Future[Option[AccessToken]] = {
  val tokenVerifier = RSATokenVerifier.create(token).realmUrl(keycloakDeployment.getRealmInfoUrl)
  for {
    publicKey <- publicKeys.map(_.get(tokenVerifier.getHeader.getKeyId))
  } yield publicKey match {
    case Some(publicKey) =>
      val token = tokenVerifier.publicKey(publicKey).verify().getToken
      Some(token)
    case None =>
      log.warning(s"no public key found for id ${tokenVerifier.getHeader.getKeyId}")
      None
  }
}