Merge pull request #396 from Opetushallitus/tor-xxxx-scala-cas-client…

…-uri-korjaus

Scala CAS Client URI -korjaus

parser/pom.xml

@@ -26,27 +26,13 @@
     <scala.version>2.12.16</scala.version>
     <scala.compat.version>2.12</scala.compat.version>
     <ch.qos.logback.contrib.version>0.1.5</ch.qos.logback.contrib.version>
-    <http4s.version>0.23.13</http4s.version>
+    <http4s.version>0.23.14</http4s.version>
     <org.json4s.version>4.0.6</org.json4s.version>
     <com.amazonaws.version>1.12.772</com.amazonaws.version>
     <spec2.version>4.16.1</spec2.version>
   </properties>
 
   <dependencies>
-
-    <!-- Internal dependencies -->
-    <dependency>
-      <groupId>fi.vm.sade</groupId>
-      <artifactId>scala-cas_2.12</artifactId>
-      <version>3.0.2-SNAPSHOT</version>
-      <exclusions>
-        <exclusion>
-          <groupId>org.http4s</groupId>
-          <artifactId>*</artifactId>
-        </exclusion>
-      </exclusions>
-    </dependency>
-
     <!-- https://mvnrepository.com/artifact/org.http4s/http4s-blaze-client -->
     <dependency>
       <groupId>org.http4s</groupId>
@@ -88,6 +74,12 @@
       <version>${scala.version}</version>
     </dependency>
 
+    <dependency>
+      <groupId>org.scala-lang.modules</groupId>
+      <artifactId>scala-xml_2.12</artifactId>
+      <version>2.0.1</version>
+    </dependency>
+
     <!-- https://mvnrepository.com/artifact/io.symphonia/lambda-logging -->
     <dependency>
       <groupId>io.symphonia</groupId>

parser/src/main/scala/fi/vm/sade/utils/cas/CasAuthenticatingClient.scala

@@ -0,0 +1,82 @@
+package fi.vm.sade.utils.cas
+
+import cats.effect.IO
+import cats.effect.kernel.Resource
+import cats.effect.std.Hotswap
+import fi.vm.sade.utils.cas.CasClient.SessionCookie
+import org.http4s.client.Client
+import org.http4s.{Request, Response, Status}
+import org.typelevel.ci.CIString
+
+
+/**
+ *  Middleware that handles CAS authentication automatically. Sessions are maintained by keeping
+ *  a central cache of session cookies per service url. If a session cookie is not found for requested service, it is obtained using
+ *  CasClient. Stale sessions are detected and refreshed automatically.
+ */
+object CasAuthenticatingClient extends Logging {
+  val DefaultSessionCookieName = "JSESSIONID"
+
+  private val sessions: collection.mutable.Map[CasParams, SessionCookie] = collection.mutable.Map.empty
+
+  def apply(
+             casClient: CasClient,
+             casParams: CasParams,
+             serviceClient: Client[IO],
+             clientCallerId: String,
+             sessionCookieName: String = DefaultSessionCookieName
+           ): Client[IO] = {
+    def openWithCasSession(request: Request[IO], hotswap: Hotswap[IO, Response[IO]]): IO[Response[IO]] = {
+      getCasSession(casParams).flatMap(requestWithCasSession(request, hotswap, retry = true))
+    }
+
+    def requestWithCasSession
+    (request: Request[IO], hotswap: Hotswap[IO, Response[IO]], retry: Boolean)
+    (sessionCookie: SessionCookie)
+    : IO[Response[IO]] = {
+      val fullRequest = FetchHelper.addDefaultHeaders(
+        request.addCookie(sessionCookieName, sessionCookie),
+        clientCallerId
+      )
+      // Hotswap use inspired by http4s Retry middleware:
+      hotswap.swap(serviceClient.run(fullRequest)).flatMap {
+        case r: Response[IO] if sessionExpired(r) && retry =>
+          logger.info("Session for " + casParams + " expired")
+          refreshSession(casParams).flatMap(requestWithCasSession(request, hotswap, retry = false))
+        case r: Response[IO] => IO.pure(r)
+      }
+    }
+
+    def isRedirectToLogin(resp: Response[IO]): Boolean =
+      resp.headers.get(CIString("Location")).exists(_.exists(header =>
+        header.value.contains("/cas/login") || header.value.contains("/cas-oppija/login")
+      ))
+
+    def sessionExpired(resp: Response[IO]): Boolean =
+      isRedirectToLogin(resp) || resp.status == Status.Unauthorized
+
+    def getCasSession(params: CasParams): IO[SessionCookie] = {
+      synchronized(sessions.get(params)) match {
+        case None =>
+          logger.debug(s"No existing $sessionCookieName found for " + params + ", creating new")
+          refreshSession(params)
+        case Some(session) =>
+          IO.pure(session)
+      }
+    }
+
+    def refreshSession(params: CasParams): IO[SessionCookie] = {
+      casClient.fetchCasSession(params, sessionCookieName).map { session =>
+        logger.debug("Storing new session for " + params)
+        synchronized(sessions.put(params, session))
+        session
+      }
+    }
+
+    Client { req =>
+      Hotswap.create[IO, Response[IO]].flatMap { hotswap =>
+        Resource.eval(openWithCasSession(req, hotswap))
+      }
+    }
+  }
+}