outposts/proxy: fix potential empty redirect, add tests

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

#2141

internal/outpost/proxyv2/application/mode_forward_nginx_test.go

@@ -71,7 +71,7 @@ func TestForwardHandleNginx_Single_Claims(t *testing.T) {
 	}
 
 	rr = httptest.NewRecorder()
-	a.forwardHandleTraefik(rr, req)
+	a.forwardHandleNginx(rr, req)
 
 	h := rr.Result().Header
 

internal/outpost/proxyv2/application/mode_proxy.go

@@ -79,5 +79,6 @@ func (a *Application) proxyModifyRequest(u *url.URL) func(req *http.Request) {
 }
 
 func (a *Application) proxyModifyResponse(res *http.Response) error {
+	res.Header.Set("X-Powered-By", "authentik_proxy2")
 	return nil
 }

internal/outpost/proxyv2/application/utils.go

@@ -26,21 +26,14 @@ func (a *Application) redirectToStart(rw http.ResponseWriter, r *http.Request) {
 	if err == nil {
 		a.log.WithError(err).Warning("failed to decode session")
 	}
-	redirectUrl := r.URL.String()
-	// simple way to copy the URL
-	u, _ := url.Parse(redirectUrl)
-	// In proxy and forward_single mode we only have one URL that we route on
-	// if we somehow got here without that URL, make sure we're at least redirected back to it
-	if a.Mode() == api.PROXYMODE_PROXY || a.Mode() == api.PROXYMODE_FORWARD_SINGLE {
-		u.Host = a.proxyConfig.ExternalHost
-	}
+	redirectUrl := urlJoin(a.proxyConfig.ExternalHost, r.URL.Path)
 	if a.Mode() == api.PROXYMODE_FORWARD_DOMAIN {
 		dom := strings.TrimPrefix(*a.proxyConfig.CookieDomain, ".")
 		// In forward_domain we only check that the current URL's host
 		// ends with the cookie domain (remove the leading period if set)
 		if !strings.HasSuffix(r.URL.Hostname(), dom) {
 			a.log.WithField("url", r.URL.String()).WithField("cd", dom).Warning("Invalid redirect found")
-			redirectUrl = ""
+			redirectUrl = a.proxyConfig.ExternalHost
 		}
 	}
 	s.Values[constants.SessionRedirect] = redirectUrl

internal/outpost/proxyv2/application/utils_test.go

@@ -0,0 +1,81 @@
+package application
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"goauthentik.io/api"
+	"goauthentik.io/internal/outpost/proxyv2/constants"
+)
+
+func TestRedirectToStart_Proxy(t *testing.T) {
+	a := newTestApplication()
+	a.proxyConfig.Mode = api.PROXYMODE_PROXY.Ptr()
+	a.proxyConfig.ExternalHost = "https://test.goauthentik.io"
+	req, _ := http.NewRequest("GET", "/foo/bar/baz", nil)
+
+	rr := httptest.NewRecorder()
+	a.redirectToStart(rr, req)
+
+	assert.Equal(t, http.StatusFound, rr.Code)
+	loc, _ := rr.Result().Location()
+	assert.Equal(t, "https://test.goauthentik.io/akprox/start", loc.String())
+
+	s, _ := a.sessions.Get(req, constants.SeesionName)
+	assert.Equal(t, "https://test.goauthentik.io/foo/bar/baz", s.Values[constants.SessionRedirect])
+}
+
+func TestRedirectToStart_Forward(t *testing.T) {
+	a := newTestApplication()
+	a.proxyConfig.Mode = api.PROXYMODE_FORWARD_SINGLE.Ptr()
+	a.proxyConfig.ExternalHost = "https://test.goauthentik.io"
+	req, _ := http.NewRequest("GET", "/foo/bar/baz", nil)
+
+	rr := httptest.NewRecorder()
+	a.redirectToStart(rr, req)
+
+	assert.Equal(t, http.StatusFound, rr.Code)
+	loc, _ := rr.Result().Location()
+	assert.Equal(t, "https://test.goauthentik.io/akprox/start", loc.String())
+
+	s, _ := a.sessions.Get(req, constants.SeesionName)
+	assert.Equal(t, "https://test.goauthentik.io/foo/bar/baz", s.Values[constants.SessionRedirect])
+}
+
+func TestRedirectToStart_Forward_Domain_Invalid(t *testing.T) {
+	a := newTestApplication()
+	a.proxyConfig.CookieDomain = api.PtrString("foo")
+	a.proxyConfig.Mode = api.PROXYMODE_FORWARD_DOMAIN.Ptr()
+	a.proxyConfig.ExternalHost = "https://test.goauthentik.io"
+	req, _ := http.NewRequest("GET", "/foo/bar/baz", nil)
+
+	rr := httptest.NewRecorder()
+	a.redirectToStart(rr, req)
+
+	assert.Equal(t, http.StatusFound, rr.Code)
+	loc, _ := rr.Result().Location()
+	assert.Equal(t, "https://test.goauthentik.io/akprox/start", loc.String())
+
+	s, _ := a.sessions.Get(req, constants.SeesionName)
+	assert.Equal(t, "https://test.goauthentik.io", s.Values[constants.SessionRedirect])
+}
+
+func TestRedirectToStart_Forward_Domain(t *testing.T) {
+	a := newTestApplication()
+	a.proxyConfig.CookieDomain = api.PtrString("goauthentik.io")
+	a.proxyConfig.Mode = api.PROXYMODE_FORWARD_DOMAIN.Ptr()
+	a.proxyConfig.ExternalHost = "https://test.goauthentik.io"
+	req, _ := http.NewRequest("GET", "/foo/bar/baz", nil)
+
+	rr := httptest.NewRecorder()
+	a.redirectToStart(rr, req)
+
+	assert.Equal(t, http.StatusFound, rr.Code)
+	loc, _ := rr.Result().Location()
+	assert.Equal(t, "https://test.goauthentik.io/akprox/start", loc.String())
+
+	s, _ := a.sessions.Get(req, constants.SeesionName)
+	assert.Equal(t, "https://test.goauthentik.io", s.Values[constants.SessionRedirect])
+}