Appservice Login (2nd attempt) (#3078)

Rebase of #2936 as @vijfhoek wrote he got no time to work on this, and I
kind of needed it for my experiments.
I checked the tests, and it is working with my example code (i.e.
impersonating, registering, creating channel, invite people, write
messages).
I'm not a huge `go` pro, and still learning, but I tried to fix and/or
integrate the changes as best as possible with the current `main` branch
changes.
If there is anything left, let me know and I'll try to figure it out.

Signed-off-by: `Kuhn Christopher <kuhnchris+git@kuhnchris.eu>`

---------

Signed-off-by: Sijmen <me@sijman.nl>
Signed-off-by: Sijmen Schoon <me@sijman.nl>
Co-authored-by: Sijmen Schoon <me@sijman.nl>
Co-authored-by: Sijmen Schoon <me@vijf.life>
Co-authored-by: Till <2353100+S7evinK@users.noreply.github.com>

clientapi/routing/login.go

@@ -19,6 +19,7 @@ import (
 	"net/http"
 
 	"github.com/matrix-org/dendrite/clientapi/auth"
+	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
 	"github.com/matrix-org/dendrite/clientapi/userutil"
 	"github.com/matrix-org/dendrite/setup/config"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
@@ -40,28 +41,25 @@ type flow struct {
 	Type string `json:"type"`
 }
 
-func passwordLogin() flows {
-	f := flows{}
-	s := flow{
-		Type: "m.login.password",
-	}
-	f.Flows = append(f.Flows, s)
-	return f
-}
-
 // Login implements GET and POST /login
 func Login(
 	req *http.Request, userAPI userapi.ClientUserAPI,
 	cfg *config.ClientAPI,
 ) util.JSONResponse {
 	if req.Method == http.MethodGet {
-		// TODO: support other forms of login other than password, depending on config options
+		loginFlows := []flow{{Type: authtypes.LoginTypePassword}}
+		if len(cfg.Derived.ApplicationServices) > 0 {
+			loginFlows = append(loginFlows, flow{Type: authtypes.LoginTypeApplicationService})
+		}
+		// TODO: support other forms of login, depending on config options
 		return util.JSONResponse{
 			Code: http.StatusOK,
-			JSON: passwordLogin(),
+			JSON: flows{
+				Flows: loginFlows,
+			},
 		}
 	} else if req.Method == http.MethodPost {
-		login, cleanup, authErr := auth.LoginFromJSONReader(req.Context(), req.Body, userAPI, userAPI, cfg)
+		login, cleanup, authErr := auth.LoginFromJSONReader(req, userAPI, userAPI, cfg)
 		if authErr != nil {
 			return *authErr
 		}

clientapi/routing/login_test.go

@@ -114,6 +114,44 @@ func TestLogin(t *testing.T) {
 
 		ctx := context.Background()
 
+		// Inject a dummy application service, so we have a "m.login.application_service"
+		// in the login flows
+		as := &config.ApplicationService{}
+		cfg.AppServiceAPI.Derived.ApplicationServices = []config.ApplicationService{*as}
+
+		t.Run("Supported log-in flows are returned", func(t *testing.T) {
+			req := test.NewRequest(t, http.MethodGet, "/_matrix/client/v3/login")
+			rec := httptest.NewRecorder()
+			routers.Client.ServeHTTP(rec, req)
+			if rec.Code != http.StatusOK {
+				t.Fatalf("failed to get log-in flows: %s", rec.Body.String())
+			}
+
+			t.Logf("response: %s", rec.Body.String())
+			resp := flows{}
+			if err := json.Unmarshal(rec.Body.Bytes(), &resp); err != nil {
+				t.Fatal(err)
+			}
+
+			appServiceFound := false
+			passwordFound := false
+			for _, flow := range resp.Flows {
+				if flow.Type == "m.login.password" {
+					passwordFound = true
+				} else if flow.Type == "m.login.application_service" {
+					appServiceFound = true
+				} else {
+					t.Fatalf("got unknown login flow: %s", flow.Type)
+				}
+			}
+			if !appServiceFound {
+				t.Fatal("m.login.application_service missing from login flows")
+			}
+			if !passwordFound {
+				t.Fatal("m.login.password missing from login flows")
+			}
+		})
+
 		for _, tc := range testCases {
 			t.Run(tc.name, func(t *testing.T) {
 				req := test.NewRequest(t, http.MethodPost, "/_matrix/client/v3/login", test.WithJSONBody(t, map[string]interface{}{

clientapi/routing/receipt.go

@@ -23,13 +23,12 @@ import (
 	"github.com/matrix-org/dendrite/clientapi/producers"
 	"github.com/matrix-org/gomatrixserverlib/spec"
 
-	"github.com/matrix-org/dendrite/userapi/api"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
 	"github.com/matrix-org/util"
 	"github.com/sirupsen/logrus"
 )
 
-func SetReceipt(req *http.Request, userAPI api.ClientUserAPI, syncProducer *producers.SyncAPIProducer, device *userapi.Device, roomID, receiptType, eventID string) util.JSONResponse {
+func SetReceipt(req *http.Request, userAPI userapi.ClientUserAPI, syncProducer *producers.SyncAPIProducer, device *userapi.Device, roomID, receiptType, eventID string) util.JSONResponse {
 	timestamp := spec.AsTimestamp(time.Now())
 	logrus.WithFields(logrus.Fields{
 		"roomID":      roomID,
@@ -54,13 +53,13 @@ func SetReceipt(req *http.Request, userAPI api.ClientUserAPI, syncProducer *prod
 			}
 		}
 
-		dataReq := api.InputAccountDataRequest{
+		dataReq := userapi.InputAccountDataRequest{
 			UserID:      device.UserID,
 			DataType:    "m.fully_read",
 			RoomID:      roomID,
 			AccountData: data,
 		}
-		dataRes := api.InputAccountDataResponse{}
+		dataRes := userapi.InputAccountDataResponse{}
 		if err := userAPI.InputAccountData(req.Context(), &dataReq, &dataRes); err != nil {
 			util.GetLogger(req.Context()).WithError(err).Error("userAPI.InputAccountData failed")
 			return util.ErrorResponse(err)

clientapi/routing/register.go

@@ -647,6 +647,16 @@ func handleGuestRegistration(
 	}
 }
 
+// localpartMatchesExclusiveNamespaces will check if a given username matches any
+// application service's exclusive users namespace
+func localpartMatchesExclusiveNamespaces(
+	cfg *config.ClientAPI,
+	localpart string,
+) bool {
+	userID := userutil.MakeUserID(localpart, cfg.Matrix.ServerName)
+	return cfg.Derived.ExclusiveApplicationServicesUsernameRegexp.MatchString(userID)
+}
+
 // handleRegistrationFlow will direct and complete registration flow stages
 // that the client has requested.
 // nolint: gocyclo
@@ -695,7 +705,7 @@ func handleRegistrationFlow(
 	// If an access token is provided, ignore this check this is an appservice
 	// request and we will validate in validateApplicationService
 	if len(cfg.Derived.ApplicationServices) != 0 &&
-		UsernameMatchesExclusiveNamespaces(cfg, r.Username) {
+		localpartMatchesExclusiveNamespaces(cfg, r.Username) {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: spec.ASExclusive("This username is reserved by an application service."),
@@ -772,7 +782,7 @@ func handleApplicationServiceRegistration(
 
 	// Check application service register user request is valid.
 	// The application service's ID is returned if so.
-	appserviceID, err := validateApplicationService(
+	appserviceID, err := internal.ValidateApplicationServiceRequest(
 		cfg, r.Username, accessToken,
 	)
 	if err != nil {

clientapi/routing/sendevent.go

@@ -224,7 +224,7 @@ func SendEvent(
 		req.Context(), rsAPI,
 		api.KindNew,
 		[]*types.HeaderedEvent{
-			&types.HeaderedEvent{PDU: e},
+			{PDU: e},
 		},
 		device.UserDomain(),
 		domain,