Encode URLs properly (#728)

We were escaping the URL before performing any pattern matching on it.
This meant that if you sent data that URLdecoded to a "/", it would count as
a "/" in the URL, potentially causing a 404. This was causing some flaky tests
with some randomly-generated query parameters.

Now, we keep URLs encoded while doing the pattern matching, and only afterwards
do we URL decode each query parameter individually before passing them to their
respective handler functions.

github.com/gorilla/mux was also updated to v1.7.3 to fix a bug with URL encoding and subrouters.

11 files changed, 236 insertions, 45 deletions

diff --git a/appservice/routing/routing.go b/appservice/routing/routing.go
index f0b8461d..3c19c840 100644
--- a/appservice/routing/routing.go
+++ b/appservice/routing/routing.go
@@ -31,6 +31,10 @@ const pathPrefixApp = "/_matrix/app/r0"
 
 // Setup registers HTTP handlers with the given ServeMux. It also supplies the given http.Client
 // to clients which need to make outbound HTTP requests.
+//
+// Due to Setup being used to call many other functions, a gocyclo nolint is
+// applied:
+// nolint: gocyclo
 func Setup(
 	apiMux *mux.Router, cfg config.Dendrite, // nolint: unparam
 	queryAPI api.RoomserverQueryAPI, aliasAPI api.RoomserverAliasAPI, // nolint: unparam
diff --git a/clientapi/routing/joinroom.go b/clientapi/routing/joinroom.go
index c98688de..9c02a93c 100644
--- a/clientapi/routing/joinroom.go
+++ b/clientapi/routing/joinroom.go
@@ -86,7 +86,10 @@ func JoinRoomByIDOrAlias(
 	}
 	return util.JSONResponse{
 		Code: http.StatusBadRequest,
-		JSON: jsonerror.BadJSON("Invalid first character for room ID or alias"),
+		JSON: jsonerror.BadJSON(
+			fmt.Sprintf("Invalid first character '%s' for room ID or alias",
+				string([]rune(roomIDOrAlias)[0])), // Wrapping with []rune makes this call UTF-8 safe
+		),
 	}
 }
 
diff --git a/clientapi/routing/routing.go b/clientapi/routing/routing.go
index b0ced79e..8135e49a 100644
--- a/clientapi/routing/routing.go
+++ b/clientapi/routing/routing.go
@@ -41,6 +41,10 @@ const pathPrefixUnstable = "/_matrix/client/unstable"
 
 // Setup registers HTTP handlers with the given ServeMux. It also supplies the given http.Client
 // to clients which need to make outbound HTTP requests.
+//
+// Due to Setup being used to call many other functions, a gocyclo nolint is
+// applied:
+// nolint: gocyclo
 func Setup(
 	apiMux *mux.Router, cfg config.Dendrite,
 	producer *producers.RoomserverProducer,
@@ -90,7 +94,10 @@ func Setup(
 	).Methods(http.MethodPost, http.MethodOptions)
 	r0mux.Handle("/join/{roomIDOrAlias}",
 		common.MakeAuthAPI("join", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return JoinRoomByIDOrAlias(
 				req, device, vars["roomIDOrAlias"], cfg, federation, producer, queryAPI, aliasAPI, keyRing, accountDB,
 			)
@@ -98,19 +105,28 @@ func Setup(
 	).Methods(http.MethodPost, http.MethodOptions)
 	r0mux.Handle("/rooms/{roomID}/{membership:(?:join|kick|ban|unban|leave|invite)}",
 		common.MakeAuthAPI("membership", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return SendMembership(req, accountDB, device, vars["roomID"], vars["membership"], cfg, queryAPI, asAPI, producer)
 		}),
 	).Methods(http.MethodPost, http.MethodOptions)
 	r0mux.Handle("/rooms/{roomID}/send/{eventType}",
 		common.MakeAuthAPI("send_message", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return SendEvent(req, device, vars["roomID"], vars["eventType"], nil, nil, cfg, queryAPI, producer, nil)
 		}),
 	).Methods(http.MethodPost, http.MethodOptions)
 	r0mux.Handle("/rooms/{roomID}/send/{eventType}/{txnID}",
 		common.MakeAuthAPI("send_message", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			txnID := vars["txnID"]
 			return SendEvent(req, device, vars["roomID"], vars["eventType"], &txnID,
 				nil, cfg, queryAPI, producer, transactionsCache)
@@ -118,7 +134,10 @@ func Setup(
 	).Methods(http.MethodPut, http.MethodOptions)
 	r0mux.Handle("/rooms/{roomID}/state/{eventType:[^/]+/?}",
 		common.MakeAuthAPI("send_message", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			emptyString := ""
 			eventType := vars["eventType"]
 			// If there's a trailing slash, remove it
@@ -130,7 +149,10 @@ func Setup(
 	).Methods(http.MethodPut, http.MethodOptions)
 	r0mux.Handle("/rooms/{roomID}/state/{eventType}/{stateKey}",
 		common.MakeAuthAPI("send_message", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			stateKey := vars["stateKey"]
 			return SendEvent(req, device, vars["roomID"], vars["eventType"], nil, &stateKey, cfg, queryAPI, producer, nil)
 		}),
@@ -150,21 +172,30 @@ func Setup(
 
 	r0mux.Handle("/directory/room/{roomAlias}",
 		common.MakeExternalAPI("directory_room", func(req *http.Request) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return DirectoryRoom(req, vars["roomAlias"], federation, &cfg, aliasAPI)
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	r0mux.Handle("/directory/room/{roomAlias}",
 		common.MakeAuthAPI("directory_room", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return SetLocalAlias(req, device, vars["roomAlias"], &cfg, aliasAPI)
 		}),
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	r0mux.Handle("/directory/room/{roomAlias}",
 		common.MakeAuthAPI("directory_room", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return RemoveLocalAlias(req, device, vars["roomAlias"], aliasAPI)
 		}),
 	).Methods(http.MethodDelete, http.MethodOptions)
@@ -183,7 +214,10 @@ func Setup(
 
 	r0mux.Handle("/rooms/{roomID}/typing/{userID}",
 		common.MakeAuthAPI("rooms_typing", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return SendTyping(req, device, vars["roomID"], vars["userID"], accountDB, typingProducer)
 		}),
 	).Methods(http.MethodPut, http.MethodOptions)
@@ -223,14 +257,20 @@ func Setup(
 
 	r0mux.Handle("/user/{userId}/filter",
 		common.MakeAuthAPI("put_filter", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return PutFilter(req, device, accountDB, vars["userId"])
 		}),
 	).Methods(http.MethodPost, http.MethodOptions)
 
 	r0mux.Handle("/user/{userId}/filter/{filterId}",
 		common.MakeAuthAPI("get_filter", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetFilter(req, device, accountDB, vars["userId"], vars["filterId"])
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
@@ -239,21 +279,30 @@ func Setup(
 
 	r0mux.Handle("/profile/{userID}",
 		common.MakeExternalAPI("profile", func(req *http.Request) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetProfile(req, accountDB, vars["userID"], asAPI)
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	r0mux.Handle("/profile/{userID}/avatar_url",
 		common.MakeExternalAPI("profile_avatar_url", func(req *http.Request) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetAvatarURL(req, accountDB, vars["userID"], asAPI)
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	r0mux.Handle("/profile/{userID}/avatar_url",
 		common.MakeAuthAPI("profile_avatar_url", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return SetAvatarURL(req, accountDB, device, vars["userID"], userUpdateProducer, &cfg, producer, queryAPI)
 		}),
 	).Methods(http.MethodPut, http.MethodOptions)
@@ -262,14 +311,20 @@ func Setup(
 
 	r0mux.Handle("/profile/{userID}/displayname",
 		common.MakeExternalAPI("profile_displayname", func(req *http.Request) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetDisplayName(req, accountDB, vars["userID"], asAPI)
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	r0mux.Handle("/profile/{userID}/displayname",
 		common.MakeAuthAPI("profile_displayname", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return SetDisplayName(req, accountDB, device, vars["userID"], userUpdateProducer, &cfg, producer, queryAPI)
 		}),
 	).Methods(http.MethodPut, http.MethodOptions)
@@ -339,28 +394,40 @@ func Setup(
 
 	r0mux.Handle("/user/{userID}/account_data/{type}",
 		common.MakeAuthAPI("user_account_data", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return SaveAccountData(req, accountDB, device, vars["userID"], "", vars["type"], syncProducer)
 		}),
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	r0mux.Handle("/user/{userID}/rooms/{roomID}/account_data/{type}",
 		common.MakeAuthAPI("user_account_data", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return SaveAccountData(req, accountDB, device, vars["userID"], vars["roomID"], vars["type"], syncProducer)
 		}),
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	r0mux.Handle("/rooms/{roomID}/members",
 		common.MakeAuthAPI("rooms_members", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetMemberships(req, device, vars["roomID"], false, cfg, queryAPI)
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	r0mux.Handle("/rooms/{roomID}/joined_members",
 		common.MakeAuthAPI("rooms_members", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetMemberships(req, device, vars["roomID"], true, cfg, queryAPI)
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
@@ -380,14 +447,20 @@ func Setup(
 
 	r0mux.Handle("/devices/{deviceID}",
 		common.MakeAuthAPI("get_device", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetDeviceByID(req, deviceDB, device, vars["deviceID"])
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	r0mux.Handle("/devices/{deviceID}",
 		common.MakeAuthAPI("device_data", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return UpdateDeviceByID(req, deviceDB, device, vars["deviceID"])
 		}),
 	).Methods(http.MethodPut, http.MethodOptions)
diff --git a/common/basecomponent/base.go b/common/basecomponent/base.go
index d1f50754..6a20aca3 100644
--- a/common/basecomponent/base.go
+++ b/common/basecomponent/base.go
@@ -71,7 +71,7 @@ func NewBaseDendrite(cfg *config.Dendrite, componentName string) *BaseDendrite {
 		componentName: componentName,
 		tracerCloser:  closer,
 		Cfg:           cfg,
-		APIMux:        mux.NewRouter(),
+		APIMux:        mux.NewRouter().UseEncodedPath(),
 		KafkaConsumer: kafkaConsumer,
 		KafkaProducer: kafkaProducer,
 	}
diff --git a/common/routing.go b/common/routing.go
new file mode 100644
index 00000000..330912cd
--- /dev/null
+++ b/common/routing.go
@@ -0,0 +1,35 @@
+// Copyright 2019 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package common
+
+import (
+	"net/url"
+)
+
+// URLDecodeMapValues is a function that iterates through each of the items in a
+// map, URL decodes the value, and returns a new map with the decoded values
+// under the same key names
+func URLDecodeMapValues(vmap map[string]string) (map[string]string, error) {
+	decoded := make(map[string]string, len(vmap))
+	for key, value := range vmap {
+		decodedVal, err := url.QueryUnescape(value)
+		if err != nil {
+			return make(map[string]string), err
+		}
+		decoded[key] = decodedVal
+	}
+
+	return decoded, nil
+}
diff --git a/federationapi/routing/routing.go b/federationapi/routing/routing.go
index 035d54aa..16704e0b 100644
--- a/federationapi/routing/routing.go
+++ b/federationapi/routing/routing.go
@@ -35,6 +35,10 @@ const (
 )
 
 // Setup registers HTTP handlers with the given ServeMux.
+//
+// Due to Setup being used to call many other functions, a gocyclo nolint is
+// applied:
+// nolint: gocyclo
 func Setup(
 	apiMux *mux.Router,
 	cfg config.Dendrite,
@@ -64,7 +68,10 @@ func Setup(
 	v1fedmux.Handle("/send/{txnID}/", common.MakeFedAPI(
 		"federation_send", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return Send(
 				httpReq, request, gomatrixserverlib.TransactionID(vars["txnID"]),
 				cfg, query, producer, keys, federation,
@@ -75,7 +82,10 @@ func Setup(
 	v1fedmux.Handle("/invite/{roomID}/{eventID}", common.MakeFedAPI(
 		"federation_invite", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return Invite(
 				httpReq, request, vars["roomID"], vars["eventID"],
 				cfg, producer, keys,
@@ -92,7 +102,10 @@ func Setup(
 	v1fedmux.Handle("/exchange_third_party_invite/{roomID}", common.MakeFedAPI(
 		"exchange_third_party_invite", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return ExchangeThirdPartyInvite(
 				httpReq, request, vars["roomID"], query, cfg, federation, producer,
 			)
@@ -102,7 +115,10 @@ func Setup(
 	v1fedmux.Handle("/event/{eventID}", common.MakeFedAPI(
 		"federation_get_event", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetEvent(
 				httpReq.Context(), request, query, vars["eventID"],
 			)
@@ -112,7 +128,10 @@ func Setup(
 	v1fedmux.Handle("/state/{roomID}", common.MakeFedAPI(
 		"federation_get_event_auth", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetState(
 				httpReq.Context(), request, query, vars["roomID"],
 			)
@@ -122,7 +141,10 @@ func Setup(
 	v1fedmux.Handle("/state_ids/{roomID}", common.MakeFedAPI(
 		"federation_get_event_auth", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetStateIDs(
 				httpReq.Context(), request, query, vars["roomID"],
 			)
@@ -150,7 +172,10 @@ func Setup(
 	v1fedmux.Handle("/user/devices/{userID}", common.MakeFedAPI(
 		"federation_user_devices", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetUserDevices(
 				httpReq, deviceDB, vars["userID"],
 			)
@@ -160,7 +185,10 @@ func Setup(
 	v1fedmux.Handle("/make_join/{roomID}/{userID}", common.MakeFedAPI(
 		"federation_make_join", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			roomID := vars["roomID"]
 			userID := vars["userID"]
 			return MakeJoin(
@@ -172,7 +200,10 @@ func Setup(
 	v1fedmux.Handle("/send_join/{roomID}/{userID}", common.MakeFedAPI(
 		"federation_send_join", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			roomID := vars["roomID"]
 			userID := vars["userID"]
 			return SendJoin(
@@ -184,7 +215,10 @@ func Setup(
 	v1fedmux.Handle("/make_leave/{roomID}/{userID}", common.MakeFedAPI(
 		"federation_make_leave", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			roomID := vars["roomID"]
 			userID := vars["userID"]
 			return MakeLeave(
@@ -196,7 +230,10 @@ func Setup(
 	v1fedmux.Handle("/send_leave/{roomID}/{userID}", common.MakeFedAPI(
 		"federation_send_leave", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			roomID := vars["roomID"]
 			userID := vars["userID"]
 			return SendLeave(
@@ -215,7 +252,10 @@ func Setup(
 	v1fedmux.Handle("/get_missing_events/{roomID}", common.MakeFedAPI(
 		"federation_get_missing_events", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return GetMissingEvents(httpReq, request, query, vars["roomID"])
 		},
 	)).Methods(http.MethodPost)
@@ -223,7 +263,10 @@ func Setup(
 	v1fedmux.Handle("/backfill/{roomID}/", common.MakeFedAPI(
 		"federation_backfill", cfg.Matrix.ServerName, keys,
 		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest) util.JSONResponse {
-			vars := mux.Vars(httpReq)
+			vars, err := common.URLDecodeMapValues(mux.Vars(httpReq))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return Backfill(httpReq, request, query, vars["roomID"], cfg)
 		},
 	)).Methods(http.MethodGet)
diff --git a/go.mod b/go.mod
index 57490572..072d9ef3 100644
--- a/go.mod
+++ b/go.mod
@@ -16,7 +16,7 @@ require (
 	github.com/golang/snappy v0.0.0-20170119014723-7db9049039a0
 	github.com/google/shlex v0.0.0-20150127133951-6f45313302b9
 	github.com/gorilla/context v1.1.1
-	github.com/gorilla/mux v1.3.0
+	github.com/gorilla/mux v1.7.3
 	github.com/jaegertracing/jaeger-client-go v0.0.0-20170921145708-3ad49a1d839b
 	github.com/jaegertracing/jaeger-lib v0.0.0-20170920222118-21a3da6d66fe
 	github.com/klauspost/crc32 v0.0.0-20161016154125-cb6bfca970f6
diff --git a/go.sum b/go.sum
index 250b300b..ce3c07dd 100644
--- a/go.sum
+++ b/go.sum
@@ -10,6 +10,7 @@ github.com/codahale/hdrhistogram v0.0.0-20161010025455-3a0bb77429bd/go.mod h1:sE
 github.com/crossdock/crossdock-go v0.0.0-20160816171116-049aabb0122b/go.mod h1:v9FBN7gdVTpiD/+LZ7Po0UKvROyT87uLVxTHVky/dlQ=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/eapache/go-resiliency v0.0.0-20160104191539-b86b1ec0dd42 h1:f8ERmXYuaC+kCSv2w+y3rBK/oVu6If4DEm3jywJJ0hc=
 github.com/eapache/go-resiliency v0.0.0-20160104191539-b86b1ec0dd42/go.mod h1:kFI+JgMyC7bLPUVY133qvEBtVayf5mFgVsvEsIPBvNs=
@@ -27,6 +28,8 @@ github.com/google/shlex v0.0.0-20150127133951-6f45313302b9/go.mod h1:RpwtwJQFrIE
 github.com/gorilla/context v1.1.1/go.mod h1:kBGZzfjB9CEq2AlWe17Uuf7NDRt0dE0s8S51q0aT7Yg=
 github.com/gorilla/mux v1.3.0 h1:HwSEKGN6U5T2aAQTfu5pW8fiwjSp3IgwdRbkICydk/c=
 github.com/gorilla/mux v1.3.0/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
+github.com/gorilla/mux v1.7.3 h1:gnP5JzjVOuiZD07fKKToCAOjS0yOpj/qPETTXCCS6hw=
+github.com/gorilla/mux v1.7.3/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
 github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542/go.mod h1:Ow0tF8D4Kplbc8s8sSb3V2oUCygFHVp8gC3Dn6U4MNI=
 github.com/jaegertracing/jaeger-client-go v0.0.0-20170921145708-3ad49a1d839b/go.mod h1:HWG7INeOG1ZE17I/S8eeb+svquXmBS/hf1Obi6hJUyQ=
 github.com/jaegertracing/jaeger-lib v0.0.0-20170920222118-21a3da6d66fe/go.mod h1:VqeqQrZmZr9G4WdLw4ei9tAHU54iJRkfoFHvTTQn4jQ=
@@ -117,6 +120,7 @@ golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613 h1:MQ/ZZiDsUapFFiMS+vzwXk
 golang.org/x/crypto v0.0.0-20190131182504-b8fe1690c613/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/net v0.0.0-20170927055102-0a9397675ba3 h1:tTDpczhDVjW6WN3DinzKcw5juwkDTVn22I7MNlfxSXM=
 golang.org/x/net v0.0.0-20170927055102-0a9397675ba3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190301231341-16b79f2e4e95 h1:fY7Dsw114eJN4boqzVSbpVHO6rTdhq6/GnXeu+PKnzU=
 golang.org/x/net v0.0.0-20190301231341-16b79f2e4e95/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/sys v0.0.0-20171012164349-43eea11bc926 h1:PY6OU86NqbyZiOzaPnDw6oOjAGtYQqIua16z6y9QkwE=
 golang.org/x/sys v0.0.0-20171012164349-43eea11bc926/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -134,4 +138,6 @@ gopkg.in/macaroon.v2 v2.0.0/go.mod h1:+I6LnTMkm/uV5ew/0nsulNjL16SK4+C8yDmRUzHR17
 gopkg.in/macaroon.v2 v2.1.0/go.mod h1:OUb+TQP/OP0WOerC2Jp/3CwhIKyIa9kQjuc7H24e6/o=
 gopkg.in/yaml.v2 v2.0.0-20171116090243-287cf08546ab h1:yZ6iByf7GKeJ3gsd1Dr/xaj1DyJ//wxKX1Cdh8LhoAw=
 gopkg.in/yaml.v2 v2.0.0-20171116090243-287cf08546ab/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+
diff --git a/mediaapi/routing/routing.go b/mediaapi/routing/routing.go
index fb983ccc..5bcce177 100644
--- a/mediaapi/routing/routing.go
+++ b/mediaapi/routing/routing.go
@@ -34,6 +34,10 @@ import (
 const pathPrefixR0 = "/_matrix/media/r0"
 
 // Setup registers the media API HTTP handlers
+//
+// Due to Setup being used to call many other functions, a gocyclo nolint is
+// applied:
+// nolint: gocyclo
 func Setup(
 	apiMux *mux.Router,
 	cfg *config.Dendrite,
@@ -87,7 +91,7 @@ func makeDownloadAPI(
 		// Content-Type will be overridden in case of returning file data, else we respond with JSON-formatted errors
 		w.Header().Set("Content-Type", "application/json")
 
-		vars := mux.Vars(req)
+		vars, _ := common.URLDecodeMapValues(mux.Vars(req))
 		Download(
 			w,
 			req,
diff --git a/publicroomsapi/routing/routing.go b/publicroomsapi/routing/routing.go
index 6a4b79b7..3a1c9eb5 100644
--- a/publicroomsapi/routing/routing.go
+++ b/publicroomsapi/routing/routing.go
@@ -30,6 +30,10 @@ import (
 const pathPrefixR0 = "/_matrix/client/r0"
 
 // Setup configures the given mux with publicroomsapi server listeners
+//
+// Due to Setup being used to call many other functions, a gocyclo nolint is
+// applied:
+// nolint: gocyclo
 func Setup(apiMux *mux.Router, deviceDB *devices.Database, publicRoomsDB *storage.PublicRoomsServerDatabase) {
 	r0mux := apiMux.PathPrefix(pathPrefixR0).Subrouter()
 
@@ -41,14 +45,20 @@ func Setup(apiMux *mux.Router, deviceDB *devices.Database, publicRoomsDB *storag
 
 	r0mux.Handle("/directory/list/room/{roomID}",
 		common.MakeExternalAPI("directory_list", func(req *http.Request) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return directory.GetVisibility(req, publicRoomsDB, vars["roomID"])
 		}),
 	).Methods(http.MethodGet, http.MethodOptions)
 	// TODO: Add AS support
 	r0mux.Handle("/directory/list/room/{roomID}",
 		common.MakeAuthAPI("directory_list", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-			vars := mux.Vars(req)
+			vars, err := common.URLDecodeMapValues(mux.Vars(req))
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
 			return directory.SetVisibility(req, publicRoomsDB, vars["roomID"])
 		}),
 	).Methods(http.MethodPut, http.MethodOptions)
diff --git a/syncapi/routing/routing.go b/syncapi/routing/routing.go
index 93d939c3..cbdcfb6b 100644
--- a/syncapi/routing/routing.go
+++ b/syncapi/routing/routing.go
@@ -30,6 +30,10 @@ import (
 const pathPrefixR0 = "/_matrix/client/r0"
 
 // Setup configures the given mux with sync-server listeners
+//
+// Due to Setup being used to call many other functions, a gocyclo nolint is
+// applied:
+// nolint: gocyclo
 func Setup(apiMux *mux.Router, srp *sync.RequestPool, syncDB *storage.SyncServerDatabase, deviceDB *devices.Database) {
 	r0mux := apiMux.PathPrefix(pathPrefixR0).Subrouter()
 
@@ -45,17 +49,26 @@ func Setup(apiMux *mux.Router, srp *sync.RequestPool, syncDB *storage.SyncServer
 	})).Methods(http.MethodGet, http.MethodOptions)
 
 	r0mux.Handle("/rooms/{roomID}/state", common.MakeAuthAPI("room_state", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-		vars := mux.Vars(req)
+		vars, err := common.URLDecodeMapValues(mux.Vars(req))
+		if err != nil {
+			return util.ErrorResponse(err)
+		}
 		return OnIncomingStateRequest(req, syncDB, vars["roomID"])
 	})).Methods(http.MethodGet, http.MethodOptions)
 
 	r0mux.Handle("/rooms/{roomID}/state/{type}", common.MakeAuthAPI("room_state", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-		vars := mux.Vars(req)
+		vars, err := common.URLDecodeMapValues(mux.Vars(req))
+		if err != nil {
+			return util.ErrorResponse(err)
+		}
 		return OnIncomingStateTypeRequest(req, syncDB, vars["roomID"], vars["type"], "")
 	})).Methods(http.MethodGet, http.MethodOptions)
 
 	r0mux.Handle("/rooms/{roomID}/state/{type}/{stateKey}", common.MakeAuthAPI("room_state", authData, func(req *http.Request, device *authtypes.Device) util.JSONResponse {
-		vars := mux.Vars(req)
+		vars, err := common.URLDecodeMapValues(mux.Vars(req))
+		if err != nil {
+			return util.ErrorResponse(err)
+		}
 		return OnIncomingStateTypeRequest(req, syncDB, vars["roomID"], vars["type"], vars["stateKey"])
 	})).Methods(http.MethodGet, http.MethodOptions)
 }