Implemented login

app/controllers/authentication/SessionsController.scala

@@ -0,0 +1,43 @@
+package controllers.authentication
+
+import dao.{AuthTokensDAO, UsersDAO}
+import jakarta.inject.{Inject, Singleton}
+import models.AuthToken
+import play.api.libs.json.*
+import play.api.libs.functional.syntax.*
+import play.api.mvc.{AbstractController, ControllerComponents}
+
+import scala.concurrent.{ExecutionContext, Future}
+
+case class LoginData(username: String, password: String)
+implicit val loginDataReads: Reads[LoginData] = (
+  (JsPath \ "username").read[String] and
+    (JsPath \ "password").read[String]
+)(LoginData.apply)
+implicit val tokenWrites: Writes[AuthToken] = (token: AuthToken) => Json.obj(
+  "token" -> token.token,
+  "createdAt" -> token.createdAt,
+  "expiresAt" -> token.expiresAt
+)
+
+
+@Singleton
+class SessionsController @Inject()(controllerComponents: ControllerComponents, usersDAO: UsersDAO, authTokensDAO: AuthTokensDAO, implicit val ec: ExecutionContext) extends AbstractController(controllerComponents) {
+  def login() = Action.async(parse.json) { implicit request =>
+    val loginDataResult = request.body.validate[LoginData]
+    loginDataResult.fold(
+      errors => {
+        Future.successful(BadRequest(Json.obj("message" -> JsError.toJson(errors))))
+      },
+      loginData => {
+        usersDAO.authenticate(loginData.username, loginData.password).flatMap { userOption =>
+          userOption.fold(
+            Future.successful(UnprocessableEntity(Json.obj("message" -> "Invalid authentication")))
+          ){ user =>
+            authTokensDAO.createToken(user).map(token => Ok(Json.toJson(token)))
+          }
+        }
+      }
+    )
+  }
+}

app/dao/AuthTokensDAO.scala

@@ -0,0 +1,35 @@
+package dao
+
+import jakarta.inject.Inject
+import play.api.db.slick.{DatabaseConfigProvider, HasDatabaseConfigProvider}
+import slick.jdbc.PostgresProfile
+import slick.jdbc.PostgresProfile.api._
+
+import java.nio.ByteBuffer
+import java.security.SecureRandom
+import java.util.Base64
+import java.time.{Instant, Duration}
+
+import scala.concurrent.{ExecutionContext, Future}
+import models.AuthToken
+import schemas.AuthTokens
+
+class AuthTokensDAO @Inject()(protected val dbConfigProvider: DatabaseConfigProvider)(implicit val ec: ExecutionContext) extends HasDatabaseConfigProvider[PostgresProfile] {
+  private lazy val random = SecureRandom()
+  private lazy val base64 = Base64.getEncoder
+  private final lazy val tokenValidDuration = Duration.ofDays(30)
+
+  def createToken(user: models.User): Future[AuthToken] = {
+    val tokenRaw = ByteBuffer.allocate(10)
+    random.nextBytes(tokenRaw.array())
+    val token = AuthToken(
+      id = None,
+      userId = user.id.get,
+      token = base64.encodeToString(tokenRaw.array()),
+      createdAt = Instant.now,
+      expiresAt = Instant.now.plus(tokenValidDuration)
+    )
+
+    db.run((AuthTokens returning AuthTokens.map(_.id)) += token).map { tokenId => token.copy(id = Some(tokenId)) }
+  }
+}

app/dao/UsersDAO.scala

@@ -0,0 +1,31 @@
+package dao
+
+import de.mkammerer.argon2.Argon2Factory
+import execution.CryptoExecutionContext
+import jakarta.inject.Inject
+import play.api.db.slick.{DatabaseConfigProvider, HasDatabaseConfigProvider}
+import slick.jdbc.PostgresProfile
+import slick.jdbc.PostgresProfile.api.*
+
+import scala.concurrent.{ExecutionContext, Future}
+import models.User
+import schemas.Users
+
+class UsersDAO @Inject()(protected val dbConfigProvider: DatabaseConfigProvider, private val cryptoEC: CryptoExecutionContext)(implicit val ec: ExecutionContext)
+  extends HasDatabaseConfigProvider[PostgresProfile] {
+  private val argon2 = Argon2Factory.create()
+
+  def authenticate(username: String, password: String): Future[Option[User]] = {
+    val query = Users.filter(_.username === username).take(1).result.headOption
+
+    val userFuture = db.run(query)
+
+    userFuture.map { userOption =>
+      for {
+        user <- userOption
+        digest <- user.passwordDigest
+        if argon2.verify(digest, password.getBytes("UTF-8"))
+      } yield user
+    }(using cryptoEC)
+  }
+}

app/execution/CryptoExecutionContext.scala

@@ -0,0 +1,8 @@
+package execution
+
+import jakarta.inject.{Inject, Singleton}
+import org.apache.pekko.actor.ActorSystem
+import play.api.libs.concurrent.CustomExecutionContext
+
+@Singleton
+class CryptoExecutionContext @Inject()(system: ActorSystem) extends CustomExecutionContext(system, "pekko.actor.crypto-dispatcher")