Get cookies in middleware in http4s? - scala

I'm trying to write middleware that would extract specific cookie and store information in ContextRequest.
Here is my test code:
def cookie[F[_]: Sync](
logger: Logger[F]
): Kleisli[F, Request[F], ContextRequest[F, Option[Cookie]]] =
Kleisli { request: Request[F] =>
for {
_ <- logger.debug(s"finding cookie")
_ <- logger.debug(request.cookies.map(_.name).mkString(","))
} yield ContextRequest(none[Cookie], request)
}
Then I use it like this:
def httpApp: HttpApp[F] = cookie(logger).mapK(OptionT.liftK).andThen(routesWithCookieContext).orNotFound
The problem is: request doesn't have any cookies even so I see them in the Chrome dev tools and in the request's details in the logs. What I'm doing wrong and how to make it work?

Turned out it was the problem with a cookie content. I was using Circle's .asJson.noSpaces to convert case class into string and write it into cookie's value. But for some reason cookies with json in their value doesn't work.

Related

Lagom - Add header to response in service call composition

i want to write code which will refresh cookie (via set-cookie http header) in Lagom.
For clarification Cookie is an encoded string (for example AES).
Lets take lagom service call composition for authentication from Implementing services and edit it
def authenticated[Request, Response](
serviceCall: User => ServerServiceCall[Request, Response]
) = ServerServiceCall.composeAsync { requestHeader =>
//Get cookie from header and decode it
val cookie = decodeCookie(requestHeader)
//Get user based on cookie decode function
val userLookup = getUser(cookie)
userLookup.map {
case Some(user) =>
serviceCall(user)
case None => throw Forbidden("User must be authenticated")
}
}
It is possible to manipulate serviceCall(user) response headers?
I tried something like this:
serviceCall( employee ).handleResponseHeader { case (responseHeader, response) =>
responseHeader.withHeader("Set-Cookie",encodeCookie("NewCookieStringExample")) // Add header
response
}
But function handleResponseHeader requires only response[T] as result and header would not be changed because is immutable.
I know that i can pass cookie to serviceCall(user) and in every service call implementation return tuple with ResponseHeader and Response but this will impact all endpoints and will add much more code.
Use of HeaderFilter is possible too but this would decode and encode cookie twice in one request (in header filter and in authenticated service call composition )
Any tips?
You can return the modified Header and the Response as a Tuple:
serviceCall( employee ).handleResponseHeader((responseHeader, response) => {
val modifiedHeader = responseHeader.withHeader("Set-Cookie",encodeCookie("NewCookieStringExample")) // Add header
(modifiedHeader, response)
})
By the way, The provided example does not compile for me. composeAsync wants a Future[ServerServiceCall[...]].

Retrieve cookie value with Gatling

I'm kinda new to Gatling and I'd like to get the value from a cookie. I tried many ways to do so but I might misunderstand something.
At first I'm doing a post request to my auth API which create the cookie I want.
Then I've tried :
.exec {
session => println(session)
println(session.attributes)
// return a Some object whose value is of type CookieJar (with apparently private access)
println(session.attributes.get("gatling.http.cookies"))
/*
// Doesn't compile due to CookieJar being private
val value: CookieJar = session.attributes.get("gatling.http.cookies") match {
case None => None
case Some(cj: CookieJar) => cj
}
print(value)
*/
// return a GetCookieBuilder which doesn't seem really useful
println(getCookieValue(CookieKey("COOKIE_NAME")))
session
}
Do you have any idea about it ?
getCookieValue is a DSL component, not a method you can call in your own functions.
It's used as a scenario step to extract a cookie value from the internal CookieJar and copy it in the Session as a dedicated attribute.
exec(getCookieValue(CookieKey("COOKIE_NAME")))
.exec { session =>
println(session("COOKIE_NAME").as[String])
session
}

Verify X-Hub-Signature from Facebook

I'm something of a beginner with the Play Framework (2.5 and Scala in this case) - and I'm trying to learn by building a bot for Facebook messenger. However I've gotten stuck trying to verify the signature of the messages.
I've followed the Facebook documentation and created a webhook. Which handles POST requests usinggetRawMessages (see code below). This then tries to verify that the request is signed by Facebook using the verifyPayload function. However I can't seem to get the computed and the actual hashes to match up.
I've taken a lead from looking at this question: How to verify Instagram real-time API x-hub-signature in Java? which seems to be doing pretty much what I want, but for the Instagram equivalent. But I still can't seem to get it right.
val secret = "<facebooks secret token>"
def getRawMessages = Action (parse.raw) {
request =>
val xHubSignatureOption = request.headers.get("X-Hub-Signature")
try {
for {
signature <- xHubSignatureOption
rawBodyAsBytes <- request.body.asBytes()
} yield {
val rawBody = rawBodyAsBytes.toArray[Byte]
val incomingHash = signature.split("=").last
val verified = verifyPayload(rawBody, secret, incomingHash)
Logger.info(s"Was verified? $verified")
}
Ok("Test")
}
catch {
case _ => Ok("Test")
}
}
val HMAC_SHA1_ALGORITHM = "HmacSHA1"
def verifyPayload(payloadBytes: Array[Byte], secret: String, expected: String): Boolean = {
val secretKeySpec = new SecretKeySpec(secret.getBytes(StandardCharsets.UTF_8), HMAC_SHA1_ALGORITHM)
val mac = Mac.getInstance(HMAC_SHA1_ALGORITHM)
mac.init(secretKeySpec)
val result = mac.doFinal(payloadBytes)
val computedHash = Hex.encodeHex(result).mkString
Logger.info(s"Computed hash: $computedHash")
computedHash == expected
}
The Facebook webhook docs state:
The HTTP request will contain an X-Hub-Signature header which contains
the SHA1 signature of the request payload, using the app secret as the
key, and prefixed with sha1=. Your callback endpoint can verify this
signature to validate the integrity and origin of the payload
Please note that the calculation is made on the escaped unicode
version of the payload, with lower case hex digits. If you just
calculate against the decoded bytes, you will end up with a different
signature. For example, the string äöå should be escaped to
\u00e4\u00f6\u00e5.
I'm guessing that what I'm missing is getting the payload properly escaped to unicode, but I can't seem to find a way to do it. And the answer in the referenced question also appeared to just get the byte array without doing anything more with it (jsonRawBytes = jsonRaw.asBytes();).
Any help with how to proceed would be much appreciated.
Turns out I was using the wrong secret all along. Should anyone else make the same mistake, please note that it "App Secret" that is available on the application dashboard that you want. See the screenshot below.

Play Framework REST with basic authentication and SSL

I am new to this authentication area. I searched a lot but was not able to find a way to authenticate the REST calls made to the Play server. What are the various ways and best practice?
A very easy way is to use Action Composition. For a sample, take a look at this Gist provided by Guillaume Bort: https://gist.github.com/guillaumebort/2328236. If you want to use it in an async action, you can write something like:
def BasicSecured[A](username: String, password: String)(action: Action[A]): Action[A] = Action.async(action.parser) { request =>
request.headers.get("Authorization").flatMap { authorization =>
authorization.split(" ").drop(1).headOption.filter { encoded =>
new String(org.apache.commons.codec.binary.Base64.decodeBase64(encoded.getBytes)).split(":").toList match {
case u :: p :: Nil if u == username && password == p => true
case _ => false
}
}
}.map(_ => action(request)).getOrElse {
Future.successful(Unauthorized.withHeaders("WWW-Authenticate" -> """Basic realm="Secured Area""""))
}
}
SSL does not have anything to do with basic authentication. You can use HTTPS for API either directly or through a front-end HTTP server like ngnix. There are pretty good details in Play documentation on this subject.
basically, I have taken the answer from #centr and tried to make it a little more readable. See if you prefer this version of the same code. Tested thoroughly, works as expected.
def BasicSecured[A](username: String, password: String)(action: Action[A]): Action[A] = Action.async(action.parser) { request =>
val submittedCredentials: Option[List[String]] = for {
authHeader <- request.headers.get("Authorization")
parts <- authHeader.split(' ').drop(1).headOption
} yield new String(decodeBase64(parts.getBytes)).split(':').toList
submittedCredentials.collect {
case u :: p :: Nil if u == username && p == password => action(request)
}.getOrElse {
Future.successful(Unauthorized.withHeaders("WWW-Authenticate" -> """Basic realm="Secured Area""""))
}
}
If we are just talking about basic auth, you don't need any external module. Basically, you could implement it using action composition.
Here is a full example of it.
If you also need authorization, you could simply combine the previous example with Deadbolt. It will allow you to provide access to some group of clients and deny access to others.
SSL support does not have anything to do with the authentication. However, is explained in the Play Documentation
Read the following Readme/article: Securing Single Page Apps and REST Services and check out the corresponding sample application (same link).
It explains how to do what you're asking.
For Scala, Secure Social is probably the best estabilished solution. You will find plenty of documentation and examples at the given link.
You can also take a look at Play2-auth as another valid option.
You will find even more possibilities on Play 2 Modules list.
If you want/need to bake your own solution, it will probably still be useful to look into code of existing solutions for inspiration and ideas. Nevertheless, my general advice towards anything related with security is NOT to implement it yourself unless you really need it (and/or really know what you're doing).
BTW, there's absolutely nothing specific about REST here. You're essentially protecting your controllers methods, so it doesn't matter whether their invocation was triggered by a REST call or not.
A filter could be used as well. The following is based on Play 2.5.
import org.apache.commons.codec.binary.Base64
override def apply(nextFilter: RequestHeader => Future[Result])
(requestHeader: RequestHeader): Future[Result] = {
val auth = requestHeader.headers.get("Authorization")
val invalidResult = Future.successful(
Unauthorized.withHeaders("WWW-Authenticate" -> """Basic realm="Secured"""")
)
if (auth.isEmpty) {
invalidResult
}
else {
val credentials = new String(Base64.decodeBase64(auth.get.split(" ").drop(1).head.getBytes)).split(":")
if (credentials.length < 2) {
invalidResult
}
else {
for {
authVerify <- verify(credentials(0), credentials(1))
r <- {
if (authVerify) {
nextFilter(requestHeader).map { result: Result => result }
}
else {
invalidResult
}
}
} yield {
r
}
}
}
}
def verify(username: String, password: String): Future[Boolean]

Token based authentication in Play filter & passing objects along

I've written an API based on Play with Scala and I'm quite happy with the results. I'm in a stage where I'm looking at optimising and refactoring the code for the next version of the API and I had a few questions, the most pressing of which is authentication and the way I manage authentication.
The product I've written deals with businesses, so exposing Username + Password with each request, or maintaining sessions on the server side weren't the best options. So here's how authentication works for my application:
User authenticates with username/password.
Server returns a token associated with the user (stored as a column in the user table)
Each request made to the server from that point must contain a token.
Token is changed when a user logs out, and also periodically.
Now, my implementation of this is quite straightforward – I have several forms for all the API endpoints, each one of which expects a token against which it looks up the user and then evaluates if the user is allowed to make the change in the request, or get the data. So each of the forms in the authenticated realm are forms that need a token, and then several other parameters depending on the API endpoint.
What this causes is repetition. Each one of the forms that I'm using has to have a verification part based on the token. And its obviously not the briefest way to go about it. I keep needing to replicate the same kind of code over and over again.
I've been reading up about Play filters and have a few questions:
Is token based authentication using Play filters a good idea?
Can a filter not be applied for a certain request path?
If I look up a user based on the supplied token in a filter, can the looked up user object be passed on to the action so that we don't end up repeating the lookup for that request? (see example of how I'm approaching this situation.)
case class ItemDelete(usrToken: String, id: Long) {
var usr: User = null
var item: Item = null
}
val itemDeleteForm = Form(
mapping(
"token" -> nonEmptyText,
"id" -> longNumber
) (ItemDelete.apply)(ItemDelete.unapply)
verifying("unauthorized",
del => {
del.usr = User.authenticateByToken(del.usrToken)
del.usr match {
case null => false
case _ => true
}
}
)
verifying("no such item",
del => {
if (del.usr == null) false
Item.find.where
.eq("id", del.id)
.eq("companyId", del.usr.companyId) // reusing the 'usr' object, avoiding multiple db lookups
.findList.toList match {
case Nil => false
case List(item, _*) => {
del.item = item
true
}
}
}
)
)
Take a look at Action Composition, it allows you to inspect and transform a request on an action. If you use a Play Filter then it will be run on EVERY request made.
For example you can make a TokenAction which inspects the request and if a token has been found then refine the request to include the information based on the token, for example the user. And if no token has been found then return another result, like Unauthorized, Redirect or Forbidden.
I made a SessionRequest which has a user property with the optionally logged in user, it first looks up an existing session from the database and then takes the attached user and passes it to the request
A filter (WithUser) will then intercept the SessionRequest, if no user is available then redirect the user to the login page
// Request which optionally has a user
class SessionRequest[A](val user: Option[User], request: Request[A]) extends WrappedRequest[A](request)
object SessionAction extends ActionBuilder[SessionRequest] with ActionTransformer[Request, SessionRequest] {
def transform[A](request: Request[A]): Future[SessionRequest[A]] = Future.successful {
val optionalJsonRequest: Option[Request[AnyContent]] = request match {
case r: Request[AnyContent] => Some(r)
case _ => None
}
val result = {
// Check if token is in JSON request
for {
jsonRequest <- optionalJsonRequest
json <- jsonRequest.body.asJson
sessionToken <- (json \ "auth" \ "session").asOpt[String]
session <- SessionRepository.findByToken(sessionToken)
} yield session
} orElse {
// Else check if the token is in a cookie
for {
cookie <- request.cookies.get("sessionid")
sessionToken = cookie.value
session <- SessionRepository.findByToken(sessionToken)
} yield session
} orElse {
// Else check if its added in the header
for {
header <- request.headers.get("sessionid")
session <- SessionRepository.findByToken(header)
} yield session
}
result.map(x => new SessionRequest(x.user, request)).getOrElse(new SessionRequest(None, request))
}
}
// Redirect the request if there is no user attached to the request
object WithUser extends ActionFilter[SessionRequest] {
def filter[A](request: SessionRequest[A]): Future[Option[Result]] = Future.successful {
request.user.map(x => None).getOrElse(Some(Redirect("http://website/loginpage")))
}
}
You can then use it on a action
def index = (SessionAction andThen WithUser) { request =>
val user = request.user
Ok("Hello " + user.name)
}
I hope this will give you an idea on how to use Action Composition
The people at Stormpath has a sample Play application providing authentication via their Backend Service. Some of its code could be useful to you.
It uses username/password rather than tokens, but it should not be complex to modify that.
They have followed this Play Document:
https://www.playframework.com/documentation/2.0.8/ScalaSecurity.
The specific implementation for this is here:
https://github.com/stormpath/stormpath-play-sample/blob/dev/app/controllers/MainController.scala.
This Controller handles authentication operations and provides the isAuthenticated action via the Secured Trait (relying on play.api.mvc.Security). This operation checks if the user is
authenticated and redirects him to the login screen if he is not:
/**
* Action for authenticated users.
*/
def IsAuthenticated(f: => String => Request[AnyContent] => Future[SimpleResult]) =
Security.Authenticated(email, onUnauthorized) { user =>
Action.async { request =>
email(request).map { login =>
f(login)(request)
}.getOrElse(Future.successful(onUnauthorized(request)))
}
}
Then, each controller that needs authenticated operations must use the
Secured Trait:
object MyController extends Controller with Secured
And those operations are "wrapped" with the IsAuthenticated action:
def deleteItem(key: String) = IsAuthenticated { username => implicit request =>
val future = Future {
MyModel.deleteItem(request.session.get("id").get, key)
Ok
}
future.map(
status => status
)
}
Note that the deleteItem operation does not need a username, only the key. However, the authentication information is automatically obtained from the session. So, the business' API does not get polluted with security-specific parameters.
BTW, that application seems to have never been officially released so consider this code a proof of concept.