providers/proxy: send token request internally, with overwritten host header (#4675)

* send token request internally, with overwritten host header

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

* fix

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

---------

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

authentik/core/tasks.py

@@ -43,6 +43,7 @@ def clean_expired_models(self: MonitoredTask):
     amount = 0
     for session in AuthenticatedSession.objects.all():
         cache_key = f"{KEY_PREFIX}{session.session_key}"
+        value = None
         try:
             value = cache.get(cache_key)
         # pylint: disable=broad-except

authentik/policies/tests/test_engine.py

@@ -5,6 +5,7 @@ from django.test import TestCase
 from authentik.core.models import User
 from authentik.policies.dummy.models import DummyPolicy
 from authentik.policies.engine import PolicyEngine
+from authentik.policies.exceptions import PolicyEngineException
 from authentik.policies.expression.models import ExpressionPolicy
 from authentik.policies.models import Policy, PolicyBinding, PolicyBindingModel, PolicyEngineMode
 from authentik.policies.tests.test_process import clear_policy_cache
@@ -93,7 +94,7 @@ class TestPolicyEngine(TestCase):
         """Test invalid policy type"""
         pbm = PolicyBindingModel.objects.create()
         PolicyBinding.objects.create(target=pbm, policy=self.policy_wrong_type, order=0)
-        with self.assertRaises(TypeError):
+        with self.assertRaises(PolicyEngineException):
             engine = PolicyEngine(pbm, self.user)
             engine.build()
 

internal/outpost/proxyv2/application/application.go

@@ -46,6 +46,7 @@ type Application struct {
 	sessions             sessions.Store
 	proxyConfig          api.ProxyOutpostConfig
 	httpClient           *http.Client
+	publicHostHTTPClient *http.Client
 
 	log *log.Entry
 	mux *mux.Router
@@ -110,6 +111,7 @@ func NewApplication(p api.ProxyOutpostConfig, c *http.Client, server Server) (*A
 	}
 	mux := mux.NewRouter()
 
+	// Save cookie name, based on hashed client ID
 	h := sha256.New()
 	bs := string(h.Sum([]byte(*p.ClientId)))
 	sessionName := fmt.Sprintf("authentik_proxy_%s", bs[:8])
@@ -124,6 +126,7 @@ func NewApplication(p api.ProxyOutpostConfig, c *http.Client, server Server) (*A
 		tokenVerifier:        verifier,
 		proxyConfig:          p,
 		httpClient:           c,
+		publicHostHTTPClient: web.NewHostInterceptor(c, server.API().Outpost.Config["authentik_host"].(string)),
 		mux:                  mux,
 		errorTemplates:       templates.GetTemplates(),
 		ak:                   server.API(),

internal/outpost/proxyv2/application/endpoint.go

@@ -64,7 +64,6 @@ func GetOIDCEndpoint(p api.ProxyOutpostConfig, authentikHost string, embedded bo
 	ep.AuthURL = updateURL(authUrl, aku.Scheme, aku.Host)
 	ep.EndSessionEndpoint = updateURL(endUrl, aku.Scheme, aku.Host)
 	ep.JwksUri = updateURL(jwksUrl, aku.Scheme, aku.Host)
-	ep.TokenURL = updateURL(tokenUrl, aku.Scheme, aku.Host)
 	ep.Issuer = updateURL(ep.Issuer, aku.Scheme, aku.Host)
 	return ep
 }

internal/outpost/proxyv2/application/oauth_callback.go

@@ -24,7 +24,7 @@ func (a *Application) redeemCallback(savedState string, u *url.URL, c context.Co
 		return nil, fmt.Errorf("blank code")
 	}
 
-	ctx := context.WithValue(c, oauth2.HTTPClient, a.httpClient)
+	ctx := context.WithValue(c, oauth2.HTTPClient, a.publicHostHTTPClient)
 	// Verify state and errors.
 	oauth2Token, err := a.oauthConfig.Exchange(ctx, code)
 	if err != nil {

internal/utils/web/http_host_interceptor.go

@@ -0,0 +1,31 @@
+package web
+
+import (
+	"net/http"
+	"net/url"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type hostInterceptor struct {
+	inner http.RoundTripper
+	host  string
+}
+
+func (t hostInterceptor) RoundTrip(r *http.Request) (*http.Response, error) {
+	r.Host = t.host
+	return t.inner.RoundTrip(r)
+}
+
+func NewHostInterceptor(inner *http.Client, host string) *http.Client {
+	aku, err := url.Parse(host)
+	if err != nil {
+		log.WithField("host", host).WithError(err).Warn("failed to parse host")
+	}
+	return &http.Client{
+		Transport: hostInterceptor{
+			inner: inner.Transport,
+			host:  aku.Host,
+		},
+	}
+}