From 24a2ffc6bb804a6c556ba19da9661190c8abd465 Mon Sep 17 00:00:00 2001
From: Kegan Dougal <kegan@matrix.org>
Date: Wed, 17 Aug 2016 16:13:16 +0100
Subject: [PATCH] Also apply base64 encoding to realm redirect paths and use
 URL-safe base64

---
 src/github.com/matrix-org/go-neb/api.go         | 16 +++++++++++++---
 src/github.com/matrix-org/go-neb/types/types.go |  5 +++--
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/src/github.com/matrix-org/go-neb/api.go b/src/github.com/matrix-org/go-neb/api.go
index c8356a0..ab75ee3 100644
--- a/src/github.com/matrix-org/go-neb/api.go
+++ b/src/github.com/matrix-org/go-neb/api.go
@@ -63,8 +63,18 @@ type realmRedirectHandler struct {
 
 func (rh *realmRedirectHandler) handle(w http.ResponseWriter, req *http.Request) {
 	segments := strings.Split(req.URL.Path, "/")
-	// last path segment is the realm ID which we will pass the incoming request to
-	realmID := segments[len(segments)-1]
+	// last path segment is the base64d realm ID which we will pass the incoming request to
+	base64realmID := segments[len(segments)-1]
+	bytesRealmID, err := base64.RawURLEncoding.DecodeString(base64realmID)
+	realmID := string(bytesRealmID)
+	if err != nil {
+		log.WithError(err).WithField("base64_realm_id", base64realmID).Print(
+			"Not a b64 encoded string",
+		)
+		w.WriteHeader(400)
+		return
+	}
+
 	realm, err := rh.db.LoadAuthRealm(realmID)
 	if err != nil {
 		log.WithError(err).WithField("realm_id", realmID).Print("Failed to load realm")
@@ -130,7 +140,7 @@ func (wh *webhookHandler) handle(w http.ResponseWriter, req *http.Request) {
 	// last path segment is the service ID which we will pass the incoming request to,
 	// but we've base64d it.
 	base64srvID := segments[len(segments)-1]
-	bytesSrvID, err := base64.StdEncoding.DecodeString(base64srvID)
+	bytesSrvID, err := base64.RawURLEncoding.DecodeString(base64srvID)
 	srvID := string(bytesSrvID)
 	if err != nil {
 		log.WithError(err).WithField("base64_service_id", base64srvID).Print(
diff --git a/src/github.com/matrix-org/go-neb/types/types.go b/src/github.com/matrix-org/go-neb/types/types.go
index e8b642a..d21db19 100644
--- a/src/github.com/matrix-org/go-neb/types/types.go
+++ b/src/github.com/matrix-org/go-neb/types/types.go
@@ -74,7 +74,7 @@ func CreateService(serviceID, serviceType string, serviceJSON []byte) (Service,
 		return nil, errors.New("Unknown service type: " + serviceType)
 	}
 
-	base64ServiceID := base64.StdEncoding.EncodeToString([]byte(serviceID))
+	base64ServiceID := base64.RawURLEncoding.EncodeToString([]byte(serviceID))
 	webhookEndpointURL := baseURL + "services/hooks/" + base64ServiceID
 	service := f(serviceID, webhookEndpointURL)
 	if err := json.Unmarshal(serviceJSON, service); err != nil {
@@ -109,7 +109,8 @@ func CreateAuthRealm(realmID, realmType string, realmJSON []byte) (AuthRealm, er
 	if f == nil {
 		return nil, errors.New("Unknown realm type: " + realmType)
 	}
-	redirectURL := baseURL + "realms/redirects/" + realmID
+	base64RealmID := base64.RawURLEncoding.EncodeToString([]byte(realmID))
+	redirectURL := baseURL + "realms/redirects/" + base64RealmID
 	r := f(realmID, redirectURL)
 	if err := json.Unmarshal(realmJSON, r); err != nil {
 		return nil, err