Merge branch 'main' of github.com:matrix-org/dendrite into s7evink/consent-tracking

Rename several variables

clientapi/auth/authtypes/logintypes.go

@@ -11,4 +11,5 @@ const (
 	LoginTypeRecaptcha          = "m.login.recaptcha"
 	LoginTypeApplicationService = "m.login.application_service"
 	LoginTypeToken              = "m.login.token"
+	LoginTypeTerms              = "m.login.terms"
 )

clientapi/jsonerror/jsonerror.go

@@ -29,6 +29,13 @@ type MatrixError struct {
 	Err     string `json:"error"`
 }
 
+// ConsentError is an error returned to users, who didn't accept  the
+// TOS of this server yet.
+type ConsentError struct {
+	MatrixError
+	ConsentURI string `json:"consent_uri"`
+}
+
 func (e MatrixError) Error() string {
 	return fmt.Sprintf("%s: %s", e.ErrCode, e.Err)
 }
@@ -207,3 +214,15 @@ func NotTrusted(serverName string) *MatrixError {
 		Err:     fmt.Sprintf("Untrusted server '%s'", serverName),
 	}
 }
+
+// ConsentNotGiven is an error returned to users, who didn't accept the
+// TOS of this server yet.
+func ConsentNotGiven(consentURI string, msg string) *ConsentError {
+	return &ConsentError{
+		MatrixError: MatrixError{
+			ErrCode: "M_CONSENT_NOT_GIVEN",
+			Err:     msg,
+		},
+		ConsentURI: consentURI,
+	}
+}

clientapi/routing/consent_tracking.go

@@ -0,0 +1,219 @@
+// Copyright 2022 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 routing
+
+import (
+	"bytes"
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"net/http"
+
+	appserviceAPI "github.com/matrix-org/dendrite/appservice/api"
+	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/setup/config"
+	userapi "github.com/matrix-org/dendrite/userapi/api"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
+)
+
+// The data used to populate the /consent request
+type constentTemplateData struct {
+	UserID       string
+	Version      string
+	UserHMAC     string
+	HasConsented bool
+	ReadOnly     bool
+}
+
+func writeHeaderAndText(w http.ResponseWriter, statusCode int) {
+	w.WriteHeader(statusCode)
+	_, _ = w.Write([]byte(http.StatusText(statusCode)))
+}
+
+func consent(writer http.ResponseWriter, req *http.Request, userAPI userapi.UserConsentPolicyAPI, cfg *config.ClientAPI) {
+	consentCfg := cfg.Matrix.UserConsentOptions
+
+	// The data used to populate the /consent request
+	data := constentTemplateData{
+		UserID:   req.FormValue("u"),
+		Version:  req.FormValue("v"),
+		UserHMAC: req.FormValue("h"),
+	}
+
+	switch req.Method {
+	case http.MethodGet:
+		// display the privacy policy without a form
+		data.ReadOnly = data.UserID == "" || data.UserHMAC == "" || data.Version == ""
+
+		// let's see if the user already consented to the current version
+		if !data.ReadOnly {
+			if ok, err := validHMAC(data.UserID, data.UserHMAC, consentCfg.FormSecret); err != nil || !ok {
+				writeHeaderAndText(writer, http.StatusForbidden)
+				return
+			}
+
+			res := &userapi.QueryPolicyVersionResponse{}
+			localpart, _, err := gomatrixserverlib.SplitID('@', data.UserID)
+			if err != nil {
+				logrus.WithError(err).Error("unable to split username")
+				writeHeaderAndText(writer, http.StatusInternalServerError)
+				return
+			}
+			if err = userAPI.QueryPolicyVersion(req.Context(), &userapi.QueryPolicyVersionRequest{
+				Localpart: localpart,
+			}, res); err != nil {
+				logrus.WithError(err).Error("unable query policy version")
+				writeHeaderAndText(writer, http.StatusInternalServerError)
+				return
+			}
+			data.HasConsented = res.PolicyVersion == consentCfg.Version
+		}
+
+		err := consentCfg.Templates.ExecuteTemplate(writer, consentCfg.Version+".gohtml", data)
+		if err != nil {
+			logrus.WithError(err).Error("unable to execute consent template")
+			writeHeaderAndText(writer, http.StatusInternalServerError)
+			return
+		}
+	case http.MethodPost:
+		ok, err := validHMAC(data.UserID, data.UserHMAC, consentCfg.FormSecret)
+		if err != nil || !ok {
+			if !ok {
+				writeHeaderAndText(writer, http.StatusForbidden)
+				return
+			}
+			writeHeaderAndText(writer, http.StatusInternalServerError)
+			return
+		}
+		localpart, _, err := gomatrixserverlib.SplitID('@', data.UserID)
+		if err != nil {
+			logrus.WithError(err).Error("unable to split username")
+			writeHeaderAndText(writer, http.StatusInternalServerError)
+			return
+		}
+		if err = userAPI.PerformUpdatePolicyVersion(
+			req.Context(),
+			&userapi.UpdatePolicyVersionRequest{
+				PolicyVersion: data.Version,
+				Localpart:     localpart,
+			},
+			&userapi.UpdatePolicyVersionResponse{},
+		); err != nil {
+			writeHeaderAndText(writer, http.StatusInternalServerError)
+			return
+		}
+		// display the privacy policy without a form
+		data.ReadOnly = false
+		data.HasConsented = true
+
+		err = consentCfg.Templates.ExecuteTemplate(writer, consentCfg.Version+".gohtml", data)
+		if err != nil {
+			logrus.WithError(err).Error("unable to print consent template")
+			writeHeaderAndText(writer, http.StatusInternalServerError)
+		}
+	}
+}
+
+func sendServerNoticeForConsent(userAPI userapi.ClientUserAPI, rsAPI api.ClientRoomserverAPI,
+	cfgNotices *config.ServerNotices,
+	cfgClient *config.ClientAPI,
+	senderDevice *userapi.Device,
+	asAPI appserviceAPI.AppServiceInternalAPI,
+) {
+	res := &userapi.QueryOutdatedPolicyResponse{}
+	if err := userAPI.QueryOutdatedPolicy(context.Background(), &userapi.QueryOutdatedPolicyRequest{
+		PolicyVersion: cfgClient.Matrix.UserConsentOptions.Version,
+	}, res); err != nil {
+		logrus.WithError(err).Error("unable to fetch users with outdated consent policy")
+		return
+	}
+
+	var (
+		consentOpts  = cfgClient.Matrix.UserConsentOptions
+		data         = make(map[string]string)
+		err          error
+		sentMessages int
+	)
+
+	if len(res.UserLocalparts) == 0 {
+		return
+	}
+
+	logrus.WithField("count", len(res.UserLocalparts)).Infof("Sending server notice to users who have not yet accepted the policy")
+
+	for _, localpart := range res.UserLocalparts {
+		if localpart == cfgClient.Matrix.ServerNotices.LocalPart {
+			continue
+		}
+		userID := fmt.Sprintf("@%s:%s", localpart, cfgClient.Matrix.ServerName)
+		data["ConsentURL"], err = consentOpts.ConsentURL(userID)
+		if err != nil {
+			logrus.WithError(err).WithField("userID", userID).Error("unable to construct consentURI")
+			continue
+		}
+		msgBody := &bytes.Buffer{}
+
+		if err = consentOpts.TextTemplates.ExecuteTemplate(msgBody, "serverNoticeTemplate", data); err != nil {
+			logrus.WithError(err).WithField("userID", userID).Error("unable to execute serverNoticeTemplate")
+			continue
+		}
+
+		req := sendServerNoticeRequest{
+			UserID: userID,
+			Content: struct {
+				MsgType string `json:"msgtype,omitempty"`
+				Body    string `json:"body,omitempty"`
+			}{
+				MsgType: consentOpts.ServerNoticeContent.MsgType,
+				Body:    msgBody.String(),
+			},
+		}
+		_, err = sendServerNotice(context.Background(), req, rsAPI, cfgNotices, cfgClient, senderDevice, asAPI, userAPI, nil, nil, nil)
+		if err != nil {
+			logrus.WithError(err).WithField("userID", userID).Error("failed to send server notice for consent to user")
+			continue
+		}
+		sentMessages++
+		res := &userapi.UpdatePolicyVersionResponse{}
+		if err = userAPI.PerformUpdatePolicyVersion(context.Background(), &userapi.UpdatePolicyVersionRequest{
+			PolicyVersion:      consentOpts.Version,
+			Localpart:          userID,
+			ServerNoticeUpdate: true,
+		}, res); err != nil {
+			logrus.WithError(err).WithField("userID", userID).Error("failed to update policy version")
+			continue
+		}
+	}
+	if sentMessages > 0 {
+		logrus.Infof("Sent messages to %d users", sentMessages)
+	}
+}
+
+func validHMAC(username, userHMAC, secret string) (bool, error) {
+	mac := hmac.New(sha256.New, []byte(secret))
+	_, err := mac.Write([]byte(username))
+	if err != nil {
+		return false, err
+	}
+	expectedMAC := mac.Sum(nil)
+	decoded, err := hex.DecodeString(userHMAC)
+	if err != nil {
+		return false, err
+	}
+	return hmac.Equal(decoded, expectedMAC), nil
+}

clientapi/routing/consent_tracking_test.go

@@ -0,0 +1,236 @@
+package routing
+
+import (
+	"context"
+	"fmt"
+	"html/template"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/matrix-org/dendrite/setup/config"
+	userapi "github.com/matrix-org/dendrite/userapi/api"
+)
+
+func Test_validHMAC(t *testing.T) {
+	type args struct {
+		username string
+		userHMAC string
+		secret   string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    bool
+		wantErr bool
+	}{
+		{
+			name:    "invalid hmac",
+			args:    args{},
+			wantErr: false,
+			want:    false,
+		},
+		// $ echo -n '@alice:localhost' | openssl sha256 -hmac 'helloWorld'
+		//(stdin)= 121c9bab767ed87a3136db0c3002144dfe414720aa328d235199082e4757541e
+		//
+		{
+			name: "valid hmac",
+			args: args{
+				username: "@alice:localhost",
+				userHMAC: "121c9bab767ed87a3136db0c3002144dfe414720aa328d235199082e4757541e",
+				secret:   "helloWorld",
+			},
+			want: true,
+		},
+		{
+			name: "invalid hmac",
+			args: args{
+				username: "@bob:localhost",
+				userHMAC: "121c9bab767ed87a3136db0c3002144dfe414720aa328d235199082e4757541e",
+				secret:   "helloWorld",
+			},
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := validHMAC(tt.args.username, tt.args.userHMAC, tt.args.secret)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("validHMAC() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("validHMAC() got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+type dummyAPI struct {
+	usersConsent map[string]string
+}
+
+func (d dummyAPI) QueryOutdatedPolicy(ctx context.Context, req *userapi.QueryOutdatedPolicyRequest, res *userapi.QueryOutdatedPolicyResponse) error {
+	return nil
+}
+
+func (d dummyAPI) PerformUpdatePolicyVersion(ctx context.Context, req *userapi.UpdatePolicyVersionRequest, res *userapi.UpdatePolicyVersionResponse) error {
+	d.usersConsent[req.Localpart] = req.PolicyVersion
+	return nil
+}
+
+func (d dummyAPI) QueryPolicyVersion(ctx context.Context, req *userapi.QueryPolicyVersionRequest, res *userapi.QueryPolicyVersionResponse) error {
+	res.PolicyVersion = "v2.0"
+	return nil
+}
+
+const dummyTemplate = `
+{{ if .HasConsented }}
+Consent given.
+{{ else }}
+WithoutForm
+	{{ if not .ReadOnly }}
+    With Form.
+    {{ end }}
+{{ end }}`
+
+func Test_consent(t *testing.T) {
+	type args struct {
+		username string
+		userHMAC string
+		version  string
+		method   string
+	}
+	tests := []struct {
+		name             string
+		args             args
+		wantRespCode     int
+		wantBodyContains string
+	}{
+		{
+			name: "not a userID, valid hmac",
+			args: args{
+				username: "notAuserID",
+				userHMAC: "7578bbface5ebb250a63935cebc05ca12060f58ebdbd271ecbc25e25a3da154d",
+				version:  "v1.0",
+				method:   http.MethodGet,
+			},
+			wantRespCode: http.StatusInternalServerError,
+		},
+
+		// $ echo -n '@alice:localhost' | openssl sha256 -hmac 'helloWorld'
+		//(stdin)= 121c9bab767ed87a3136db0c3002144dfe414720aa328d235199082e4757541e
+		//
+		{
+			name: "valid hmac for alice GET, not consented",
+			args: args{
+				username: "@alice:localhost",
+				userHMAC: "121c9bab767ed87a3136db0c3002144dfe414720aa328d235199082e4757541e",
+				version:  "v1.0",
+				method:   http.MethodGet,
+			},
+			wantRespCode:     http.StatusOK,
+			wantBodyContains: "With form",
+		},
+		{
+			name: "alice consents successfully",
+			args: args{
+				username: "@alice:localhost",
+				userHMAC: "121c9bab767ed87a3136db0c3002144dfe414720aa328d235199082e4757541e",
+				version:  "v1.0",
+				method:   http.MethodPost,
+			},
+			wantRespCode:     http.StatusOK,
+			wantBodyContains: "Consent given",
+		},
+		{
+			name: "valid hmac for alice GET, new version",
+			args: args{
+				username: "@alice:localhost",
+				userHMAC: "121c9bab767ed87a3136db0c3002144dfe414720aa328d235199082e4757541e",
+				version:  "v2.0",
+				method:   http.MethodGet,
+			},
+			wantRespCode:     http.StatusOK,
+			wantBodyContains: "With form",
+		},
+		{
+			name: "no hmac provided for alice, read only should be displayed",
+			args: args{
+				username: "@alice:localhost",
+				userHMAC: "",
+				version:  "v1.0",
+				method:   http.MethodGet,
+			},
+			wantRespCode:     http.StatusOK,
+			wantBodyContains: "WithoutForm",
+		},
+		{
+			name: "alice trying to get bobs status is forbidden",
+			args: args{
+				username: "@bob:localhost",
+				userHMAC: "121c9bab767ed87a3136db0c3002144dfe414720aa328d235199082e4757541e",
+				version:  "v1.0",
+				method:   http.MethodGet,
+			},
+			wantRespCode:     http.StatusForbidden,
+			wantBodyContains: "forbidden",
+		},
+		{
+			name: "alice trying to consent for bob is forbidden",
+			args: args{
+				username: "@bob:localhost",
+				userHMAC: "121c9bab767ed87a3136db0c3002144dfe414720aa328d235199082e4757541e",
+				version:  "v1.0",
+				method:   http.MethodPost,
+			},
+			wantRespCode:     http.StatusForbidden,
+			wantBodyContains: "forbidden",
+		},
+	}
+
+	userAPI := dummyAPI{
+		usersConsent: map[string]string{},
+	}
+	consentTemplates := template.Must(template.New("v1.0.gohtml").Parse(dummyTemplate))
+	consentTemplates = template.Must(consentTemplates.New("v2.0.gohtml").Parse(dummyTemplate))
+	userconsentOpts := config.UserConsentOptions{
+		FormSecret: "helloWorld",
+		Version:    "v1.0",
+		Templates:  consentTemplates,
+		BaseURL:    "http://localhost",
+	}
+	cfg := &config.ClientAPI{
+		Matrix: &config.Global{
+			UserConsentOptions: userconsentOpts,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			url := fmt.Sprintf("%s/consent?u=%s&v=%s&h=%s",
+				userconsentOpts.BaseURL, tt.args.username, tt.args.version, tt.args.userHMAC,
+			)
+
+			req := httptest.NewRequest(tt.args.method, url, nil)
+			w := httptest.NewRecorder()
+
+			consent(w, req, userAPI, cfg)
+
+			resp := w.Result()
+			body, err := ioutil.ReadAll(resp.Body)
+			if err != nil {
+				t.Fatalf("unable to read response body: %v", err)
+			}
+			defer resp.Body.Close()
+			if resp.StatusCode != tt.wantRespCode {
+				t.Fatalf("expected http %d, got %d", tt.wantRespCode, resp.StatusCode)
+			}
+
+			if !strings.Contains(strings.ToLower(string(body)), strings.ToLower(tt.wantBodyContains)) {
+				t.Fatalf("expected body to contain %s, but got %s", tt.wantBodyContains, string(body))
+			}
+		})
+	}
+}

clientapi/routing/register.go

@@ -31,13 +31,12 @@ import (
 
 	"github.com/matrix-org/dendrite/internal/eventutil"
 	"github.com/matrix-org/dendrite/setup/config"
-	"github.com/tidwall/gjson"
-
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/gomatrixserverlib/tokens"
 	"github.com/matrix-org/util"
 	"github.com/prometheus/client_golang/prometheus"
 	log "github.com/sirupsen/logrus"
+	"github.com/tidwall/gjson"
 
 	"github.com/matrix-org/dendrite/clientapi/auth"
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
@@ -721,6 +720,8 @@ func handleRegistrationFlow(
 	}
 
 	switch r.Auth.Type {
+	case authtypes.LoginTypeTerms:
+		sessions.addCompletedSessionStage(sessionID, authtypes.LoginTypeTerms)
 	case authtypes.LoginTypeRecaptcha:
 		// Check given captcha response
 		resErr := validateRecaptcha(cfg, r.Auth.Response, req.RemoteAddr)
@@ -788,11 +789,16 @@ func handleApplicationServiceRegistration(
 		return *err
 	}
 
+	policyVersion := ""
+	if cfg.Matrix.UserConsentOptions.Enabled {
+		policyVersion = cfg.Matrix.UserConsentOptions.Version
+	}
+
 	// If no error, application service was successfully validated.
 	// Don't need to worry about appending to registration stages as
 	// application service registration is entirely separate.
 	return completeRegistration(
-		req.Context(), userAPI, r.Username, "", appserviceID, req.RemoteAddr, req.UserAgent(), r.Auth.Session,
+		req.Context(), userAPI, r.Username, "", appserviceID, req.RemoteAddr, req.UserAgent(), r.Auth.Session, policyVersion,
 		r.InhibitLogin, r.InitialDisplayName, r.DeviceID, userapi.AccountTypeAppService,
 	)
 }
@@ -809,9 +815,13 @@ func checkAndCompleteFlow(
 	userAPI userapi.ClientUserAPI,
 ) util.JSONResponse {
 	if checkFlowCompleted(flow, cfg.Derived.Registration.Flows) {
+		policyVersion := ""
+		if cfg.Matrix.UserConsentOptions.Enabled {
+			policyVersion = cfg.Matrix.UserConsentOptions.Version
+		}
 		// This flow was completed, registration can continue
 		return completeRegistration(
-			req.Context(), userAPI, r.Username, r.Password, "", req.RemoteAddr, req.UserAgent(), sessionID,
+			req.Context(), userAPI, r.Username, r.Password, "", req.RemoteAddr, req.UserAgent(), sessionID, policyVersion,
 			r.InhibitLogin, r.InitialDisplayName, r.DeviceID, userapi.AccountTypeUser,
 		)
 	}
@@ -834,7 +844,7 @@ func checkAndCompleteFlow(
 func completeRegistration(
 	ctx context.Context,
 	userAPI userapi.ClientUserAPI,
-	username, password, appserviceID, ipAddr, userAgent, sessionID string,
+	username, password, appserviceID, ipAddr, userAgent, sessionID, policyVersion string,
 	inhibitLogin eventutil.WeakBoolean,
 	displayName, deviceID *string,
 	accType userapi.AccountType,
@@ -866,6 +876,7 @@ func completeRegistration(
 		Password:      password,
 		AccountType:   accType,
 		OnConflict:    userapi.ConflictAbort,
+		PolicyVersion: policyVersion,
 	}, &accRes)
 	if err != nil {
 		if _, ok := err.(*userapi.ErrorConflict); ok { // user already exists
@@ -1073,5 +1084,5 @@ func handleSharedSecretRegistration(userAPI userapi.ClientUserAPI, sr *SharedSec
 	if ssrr.Admin {
 		accType = userapi.AccountTypeAdmin
 	}
-	return completeRegistration(req.Context(), userAPI, ssrr.User, ssrr.Password, "", req.RemoteAddr, req.UserAgent(), "", false, &ssrr.User, &deviceID, accType)
+	return completeRegistration(req.Context(), userAPI, ssrr.User, ssrr.Password, "", req.RemoteAddr, req.UserAgent(), "", "", false, &ssrr.User, &deviceID, accType)
 }

clientapi/routing/room_tagging.go

@@ -15,6 +15,7 @@
 package routing
 
 import (
+	"context"
 	"encoding/json"
 	"net/http"
 
@@ -93,7 +94,7 @@ func PutTag(
 	}
 	tagContent.Tags[tag] = properties
 
-	if err = saveTagData(req, userID, roomID, userAPI, tagContent); err != nil {
+	if err = saveTagData(req.Context(), userID, roomID, userAPI, tagContent); err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("saveTagData failed")
 		return jsonerror.InternalServerError()
 	}
@@ -145,7 +146,7 @@ func DeleteTag(
 		}
 	}
 
-	if err = saveTagData(req, userID, roomID, userAPI, tagContent); err != nil {
+	if err = saveTagData(req.Context(), userID, roomID, userAPI, tagContent); err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("saveTagData failed")
 		return jsonerror.InternalServerError()
 	}
@@ -191,7 +192,7 @@ func obtainSavedTags(
 
 // saveTagData saves the provided tag data into the database
 func saveTagData(
-	req *http.Request,
+	context context.Context,
 	userID string,
 	roomID string,
 	userAPI api.ClientUserAPI,
@@ -208,5 +209,5 @@ func saveTagData(
 		AccountData: json.RawMessage(newTagData),
 	}
 	dataRes := api.InputAccountDataResponse{}
-	return userAPI.InputAccountData(req.Context(), &dataReq, &dataRes)
+	return userAPI.InputAccountData(context, &dataReq, &dataRes)
 }

clientapi/routing/routing.go

@@ -127,9 +127,13 @@ func Setup(
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	// server notifications
+	var (
+		serverNotificationSender *userapi.Device
+		err                      error
+	)
 	if cfg.Matrix.ServerNotices.Enabled {
 		logrus.Info("Enabling server notices at /_synapse/admin/v1/send_server_notice")
-		serverNotificationSender, err := getSenderDevice(context.Background(), userAPI, cfg)
+		serverNotificationSender, err = getSenderDevice(context.Background(), userAPI, cfg)
 		if err != nil {
 			logrus.WithError(err).Fatal("unable to get account for sending sending server notices")
 		}
@@ -177,13 +181,27 @@ func Setup(
 	// using ?: so the final regexp becomes what is below. We also need a trailing slash to stop 'v33333' matching.
 	// Note that 'apiversion' is chosen because it must not collide with a variable used in any of the routing!
 	v3mux := publicAPIMux.PathPrefix("/{apiversion:(?:r0|v3)}/").Subrouter()
-
 	unstableMux := publicAPIMux.PathPrefix("/unstable").Subrouter()
 
+	// NOTSPEC: consent tracking
+	if cfg.Matrix.UserConsentOptions.Enabled {
+		if !cfg.Matrix.ServerNotices.Enabled {
+			logrus.Warnf("Consent tracking is enabled, but server notes are not. No server notice will be sent to users")
+		} else {
+			// start a new go routine to send messages about consent
+			go sendServerNoticeForConsent(userAPI, rsAPI, &cfg.Matrix.ServerNotices, cfg, serverNotificationSender, asAPI)
+		}
+		publicAPIMux.HandleFunc("/consent", func(writer http.ResponseWriter, request *http.Request) {
+			consent(writer, request, userAPI, cfg)
+		}).Methods(http.MethodGet, http.MethodPost, http.MethodOptions)
+	}
+
+	consentRequiredCheck := httputil.WithConsentCheck(cfg.Matrix.UserConsentOptions, userAPI)
+
 	v3mux.Handle("/createRoom",
 		httputil.MakeAuthAPI("createRoom", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 			return CreateRoom(req, device, cfg, userAPI, rsAPI, asAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/join/{roomIDOrAlias}",
 		httputil.MakeAuthAPI(gomatrixserverlib.Join, userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -213,7 +231,7 @@ func Setup(
 				return PeekRoomByIDOrAlias(
 					req, device, rsAPI, vars["roomIDOrAlias"],
 				)
-			}),
+			}, consentRequiredCheck),
 		).Methods(http.MethodPost, http.MethodOptions)
 	}
 	v3mux.Handle("/joined_rooms",
@@ -258,7 +276,7 @@ func Setup(
 			return UnpeekRoomByID(
 				req, device, rsAPI, vars["roomID"],
 			)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/rooms/{roomID}/ban",
 		httputil.MakeAuthAPI("membership", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -267,7 +285,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return SendBan(req, userAPI, device, vars["roomID"], cfg, rsAPI, asAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/rooms/{roomID}/invite",
 		httputil.MakeAuthAPI("membership", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -279,7 +297,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return SendInvite(req, userAPI, device, vars["roomID"], cfg, rsAPI, asAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/rooms/{roomID}/kick",
 		httputil.MakeAuthAPI("membership", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -288,7 +306,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return SendKick(req, userAPI, device, vars["roomID"], cfg, rsAPI, asAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/rooms/{roomID}/unban",
 		httputil.MakeAuthAPI("membership", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -297,7 +315,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return SendUnban(req, userAPI, device, vars["roomID"], cfg, rsAPI, asAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/rooms/{roomID}/send/{eventType}",
 		httputil.MakeAuthAPI("send_message", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -317,7 +335,7 @@ func Setup(
 			txnID := vars["txnID"]
 			return SendEvent(req, device, vars["roomID"], vars["eventType"], &txnID,
 				nil, cfg, rsAPI, transactionsCache)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPut, http.MethodOptions)
 	v3mux.Handle("/rooms/{roomID}/event/{eventID}",
 		httputil.MakeAuthAPI("rooms_get_event", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -326,7 +344,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return GetEvent(req, device, vars["roomID"], vars["eventID"], cfg, rsAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	v3mux.Handle("/rooms/{roomID}/state", httputil.MakeAuthAPI("room_state", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -335,7 +353,7 @@ func Setup(
 			return util.ErrorResponse(err)
 		}
 		return OnIncomingStateRequest(req.Context(), device, rsAPI, vars["roomID"])
-	})).Methods(http.MethodGet, http.MethodOptions)
+	}, consentRequiredCheck)).Methods(http.MethodGet, http.MethodOptions)
 
 	v3mux.Handle("/rooms/{roomID}/aliases", httputil.MakeAuthAPI("aliases", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
@@ -343,7 +361,7 @@ func Setup(
 			return util.ErrorResponse(err)
 		}
 		return GetAliases(req, rsAPI, device, vars["roomID"])
-	})).Methods(http.MethodGet, http.MethodOptions)
+	}, consentRequiredCheck)).Methods(http.MethodGet, http.MethodOptions)
 
 	v3mux.Handle("/rooms/{roomID}/state/{type:[^/]+/?}", httputil.MakeAuthAPI("room_state", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
@@ -354,7 +372,7 @@ func Setup(
 		eventType := strings.TrimSuffix(vars["type"], "/")
 		eventFormat := req.URL.Query().Get("format") == "event"
 		return OnIncomingStateTypeRequest(req.Context(), device, rsAPI, vars["roomID"], eventType, "", eventFormat)
-	})).Methods(http.MethodGet, http.MethodOptions)
+	}, consentRequiredCheck)).Methods(http.MethodGet, http.MethodOptions)
 
 	v3mux.Handle("/rooms/{roomID}/state/{type}/{stateKey}", httputil.MakeAuthAPI("room_state", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
@@ -363,7 +381,7 @@ func Setup(
 		}
 		eventFormat := req.URL.Query().Get("format") == "event"
 		return OnIncomingStateTypeRequest(req.Context(), device, rsAPI, vars["roomID"], vars["type"], vars["stateKey"], eventFormat)
-	})).Methods(http.MethodGet, http.MethodOptions)
+	}, consentRequiredCheck)).Methods(http.MethodGet, http.MethodOptions)
 
 	v3mux.Handle("/rooms/{roomID}/state/{eventType:[^/]+/?}",
 		httputil.MakeAuthAPI("send_message", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -374,7 +392,7 @@ func Setup(
 			emptyString := ""
 			eventType := strings.TrimSuffix(vars["eventType"], "/")
 			return SendEvent(req, device, vars["roomID"], eventType, nil, &emptyString, cfg, rsAPI, nil)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	v3mux.Handle("/rooms/{roomID}/state/{eventType}/{stateKey}",
@@ -385,7 +403,7 @@ func Setup(
 			}
 			stateKey := vars["stateKey"]
 			return SendEvent(req, device, vars["roomID"], vars["eventType"], nil, &stateKey, cfg, rsAPI, nil)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	v3mux.Handle("/register", httputil.MakeExternalAPI("register", func(req *http.Request) util.JSONResponse {
@@ -487,7 +505,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return SendRedaction(req, device, vars["roomID"], vars["eventID"], cfg, rsAPI, nil, nil)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/rooms/{roomID}/redact/{eventID}/{txnId}",
 		httputil.MakeAuthAPI("rooms_redact", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -497,7 +515,7 @@ func Setup(
 			}
 			txnID := vars["txnId"]
 			return SendRedaction(req, device, vars["roomID"], vars["eventID"], cfg, rsAPI, &txnID, transactionsCache)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	v3mux.Handle("/sendToDevice/{eventType}/{txnID}",
@@ -508,7 +526,7 @@ func Setup(
 			}
 			txnID := vars["txnID"]
 			return SendToDevice(req, device, syncProducer, transactionsCache, vars["eventType"], &txnID)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	// This is only here because sytest refers to /unstable for this endpoint
@@ -522,7 +540,7 @@ func Setup(
 			}
 			txnID := vars["txnID"]
 			return SendToDevice(req, device, syncProducer, transactionsCache, vars["eventType"], &txnID)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	v3mux.Handle("/account/whoami",
@@ -531,7 +549,7 @@ func Setup(
 				return *r
 			}
 			return Whoami(req, device)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	v3mux.Handle("/account/password",
@@ -738,7 +756,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return SetAvatarURL(req, userAPI, device, vars["userID"], cfg, rsAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPut, http.MethodOptions)
 	// Browsers use the OPTIONS HTTP method to check if the CORS policy allows
 	// PUT requests, so we need to allow this method
@@ -763,7 +781,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return SetDisplayName(req, userAPI, device, vars["userID"], cfg, rsAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPut, http.MethodOptions)
 	// Browsers use the OPTIONS HTTP method to check if the CORS policy allows
 	// PUT requests, so we need to allow this method
@@ -771,19 +789,19 @@ func Setup(
 	v3mux.Handle("/account/3pid",
 		httputil.MakeAuthAPI("account_3pid", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 			return GetAssociated3PIDs(req, userAPI, device)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	v3mux.Handle("/account/3pid",
 		httputil.MakeAuthAPI("account_3pid", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 			return CheckAndSave3PIDAssociation(req, userAPI, device, cfg)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 
 	unstableMux.Handle("/account/3pid/delete",
 		httputil.MakeAuthAPI("account_3pid", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 			return Forget3PID(req, userAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 
 	v3mux.Handle("/{path:(?:account/3pid|register)}/email/requestToken",
@@ -798,7 +816,7 @@ func Setup(
 				return *r
 			}
 			return RequestTurnServer(req, device, cfg)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodGet, http.MethodOptions)
 
 	v3mux.Handle("/thirdparty/protocols",
@@ -868,7 +886,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return GetAdminWhois(req, userAPI, device, vars["userID"])
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodGet)
 
 	v3mux.Handle("/user/{userID}/openid/request_token",
@@ -881,7 +899,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return CreateOpenIDToken(req, userAPI, device, vars["userID"], cfg)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 
 	v3mux.Handle("/user_directory/search",
@@ -907,7 +925,7 @@ func Setup(
 				postContent.SearchString,
 				postContent.Limit,
 			)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 
 	v3mux.Handle("/rooms/{roomID}/members",
@@ -953,7 +971,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return SendForget(req, device, vars["roomID"], rsAPI)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 
 	v3mux.Handle("/rooms/{roomID}/upgrade",
@@ -1065,7 +1083,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return PutTag(req, userAPI, device, vars["userId"], vars["roomId"], vars["tag"], syncProducer)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPut, http.MethodOptions)
 
 	v3mux.Handle("/user/{userId}/rooms/{roomId}/tags/{tag}",
@@ -1075,7 +1093,7 @@ func Setup(
 				return util.ErrorResponse(err)
 			}
 			return DeleteTag(req, userAPI, device, vars["userId"], vars["roomId"], vars["tag"], syncProducer)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodDelete, http.MethodOptions)
 
 	v3mux.Handle("/capabilities",
@@ -1095,11 +1113,11 @@ func Setup(
 			return util.ErrorResponse(err)
 		}
 		return KeyBackupVersion(req, userAPI, device, vars["version"])
-	})
+	}, consentRequiredCheck)
 
 	getLatestBackupKeysVersion := httputil.MakeAuthAPI("get_latest_backup_keys_version", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		return KeyBackupVersion(req, userAPI, device, "")
-	})
+	}, consentRequiredCheck)
 
 	putBackupKeysVersion := httputil.MakeAuthAPI("put_backup_keys_version", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
@@ -1107,7 +1125,7 @@ func Setup(
 			return util.ErrorResponse(err)
 		}
 		return ModifyKeyBackupVersionAuthData(req, userAPI, device, vars["version"])
-	})
+	}, consentRequiredCheck)
 
 	deleteBackupKeysVersion := httputil.MakeAuthAPI("delete_backup_keys_version", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
@@ -1119,7 +1137,7 @@ func Setup(
 
 	postNewBackupKeysVersion := httputil.MakeAuthAPI("post_new_backup_keys_version", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		return CreateKeyBackupVersion(req, userAPI, device)
-	})
+	}, consentRequiredCheck)
 
 	v3mux.Handle("/room_keys/version/{version}", getBackupKeysVersion).Methods(http.MethodGet, http.MethodOptions)
 	v3mux.Handle("/room_keys/version", getLatestBackupKeysVersion).Methods(http.MethodGet, http.MethodOptions)
@@ -1150,7 +1168,7 @@ func Setup(
 			return *resErr
 		}
 		return UploadBackupKeys(req, userAPI, device, version, &reqBody)
-	})
+	}, consentRequiredCheck)
 
 	// Single room bulk session
 	putBackupKeysRoom := httputil.MakeAuthAPI("put_backup_keys_room", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -1182,7 +1200,7 @@ func Setup(
 		}
 		reqBody.Rooms[roomID] = body
 		return UploadBackupKeys(req, userAPI, device, version, &reqBody)
-	})
+	}, consentRequiredCheck)
 
 	// Single room, single session
 	putBackupKeysRoomSession := httputil.MakeAuthAPI("put_backup_keys_room_session", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -1215,7 +1233,7 @@ func Setup(
 		}
 		keyReq.Rooms[roomID].Sessions[sessionID] = reqBody
 		return UploadBackupKeys(req, userAPI, device, version, &keyReq)
-	})
+	}, consentRequiredCheck)
 
 	v3mux.Handle("/room_keys/keys", putBackupKeys).Methods(http.MethodPut)
 	v3mux.Handle("/room_keys/keys/{roomID}", putBackupKeysRoom).Methods(http.MethodPut)
@@ -1229,7 +1247,7 @@ func Setup(
 
 	getBackupKeys := httputil.MakeAuthAPI("get_backup_keys", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		return GetBackupKeys(req, userAPI, device, req.URL.Query().Get("version"), "", "")
-	})
+	}, consentRequiredCheck)
 
 	getBackupKeysRoom := httputil.MakeAuthAPI("get_backup_keys_room", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
@@ -1245,7 +1263,7 @@ func Setup(
 			return util.ErrorResponse(err)
 		}
 		return GetBackupKeys(req, userAPI, device, req.URL.Query().Get("version"), vars["roomID"], vars["sessionID"])
-	})
+	}, consentRequiredCheck)
 
 	v3mux.Handle("/room_keys/keys", getBackupKeys).Methods(http.MethodGet, http.MethodOptions)
 	v3mux.Handle("/room_keys/keys/{roomID}", getBackupKeysRoom).Methods(http.MethodGet, http.MethodOptions)
@@ -1261,11 +1279,11 @@ func Setup(
 
 	postDeviceSigningKeys := httputil.MakeAuthAPI("post_device_signing_keys", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		return UploadCrossSigningDeviceKeys(req, userInteractiveAuth, keyAPI, device, userAPI, cfg)
-	})
+	}, consentRequiredCheck)
 
 	postDeviceSigningSignatures := httputil.MakeAuthAPI("post_device_signing_signatures", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		return UploadCrossSigningDeviceSignatures(req, keyAPI, device)
-	})
+	}, consentRequiredCheck)
 
 	v3mux.Handle("/keys/device_signing/upload", postDeviceSigningKeys).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/keys/signatures/upload", postDeviceSigningSignatures).Methods(http.MethodPost, http.MethodOptions)
@@ -1277,12 +1295,12 @@ func Setup(
 	v3mux.Handle("/keys/upload/{deviceID}",
 		httputil.MakeAuthAPI("keys_upload", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 			return UploadKeys(req, keyAPI, device)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/keys/upload",
 		httputil.MakeAuthAPI("keys_upload", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 			return UploadKeys(req, keyAPI, device)
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/keys/query",
 		httputil.MakeAuthAPI("keys_query", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
@@ -1305,7 +1323,7 @@ func Setup(
 			}
 
 			return SetReceipt(req, syncProducer, device, vars["roomId"], vars["receiptType"], vars["eventId"])
-		}),
+		}, consentRequiredCheck),
 	).Methods(http.MethodPost, http.MethodOptions)
 	v3mux.Handle("/presence/{userId}/status",
 		httputil.MakeAuthAPI("set_presence", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {

clientapi/routing/server_notices.go

@@ -84,74 +84,66 @@ func SendServerNotice(
 	if resErr != nil {
 		return *resErr
 	}
+	res, _ := sendServerNotice(ctx, r, rsAPI, cfgNotices, cfgClient, senderDevice, asAPI, userAPI, txnID, device, txnCache)
+	return res
+}
+
+func sendServerNotice(
+	ctx context.Context,
+	serverNoticeRequest sendServerNoticeRequest,
+	rsAPI api.ClientRoomserverAPI,
+	cfgNotices *config.ServerNotices,
+	cfgClient *config.ClientAPI,
+	senderDevice *userapi.Device,
+	asAPI appserviceAPI.AppServiceInternalAPI,
+	userAPI userapi.ClientUserAPI,
+	txnID *string,
+	device *userapi.Device,
+	txnCache *transactions.Cache,
+) (util.JSONResponse, error) {
 
 	// check that all required fields are set
-	if !r.valid() {
+	if !serverNoticeRequest.valid() {
 		return util.JSONResponse{
 			Code: http.StatusBadRequest,
 			JSON: jsonerror.BadJSON("Invalid request"),
-		}
+		}, fmt.Errorf("Invalid JSON")
 	}
 
-	// get rooms for specified user
-	allUserRooms := []string{}
-	userRooms := api.QueryRoomsForUserResponse{}
-	// Get rooms the user is either joined, invited or has left.
-	for _, membership := range []string{"join", "invite", "leave"} {
-		if err := rsAPI.QueryRoomsForUser(ctx, &api.QueryRoomsForUserRequest{
-			UserID:         r.UserID,
-			WantMembership: membership,
-		}, &userRooms); err != nil {
-			return util.ErrorResponse(err)
+	qryServerNoticeRoom := &userapi.QueryServerNoticeRoomResponse{}
+	localpart, _, err := gomatrixserverlib.SplitID('@', serverNoticeRequest.UserID)
+	if err != nil {
+		return util.JSONResponse{
+			Code: http.StatusBadRequest,
+			JSON: jsonerror.BadJSON("Invalid request"),
+		}, err
 	}
-		allUserRooms = append(allUserRooms, userRooms.RoomIDs...)
+	err = userAPI.SelectServerNoticeRoomID(ctx, &userapi.QueryServerNoticeRoomRequest{Localpart: localpart}, qryServerNoticeRoom)
+	if err != nil {
+		return util.ErrorResponse(err), err
 	}
 
-	// get rooms of the sender
 	senderUserID := fmt.Sprintf("@%s:%s", cfgNotices.LocalPart, cfgClient.Matrix.ServerName)
-	senderRooms := api.QueryRoomsForUserResponse{}
-	if err := rsAPI.QueryRoomsForUser(ctx, &api.QueryRoomsForUserRequest{
-		UserID:         senderUserID,
-		WantMembership: "join",
-	}, &senderRooms); err != nil {
-		return util.ErrorResponse(err)
-	}
-
-	// check if we have rooms in common
-	commonRooms := []string{}
-	for _, userRoomID := range allUserRooms {
-		for _, senderRoomID := range senderRooms.RoomIDs {
-			if userRoomID == senderRoomID {
-				commonRooms = append(commonRooms, senderRoomID)
-			}
-		}
-	}
-
-	if len(commonRooms) > 1 {
-		return util.ErrorResponse(fmt.Errorf("expected to find one room, but got %d", len(commonRooms)))
-	}
-
-	var (
-		roomID      string
-		roomVersion = version.DefaultRoomVersion()
-	)
+	roomID := qryServerNoticeRoom.RoomID
+	roomVersion := version.DefaultRoomVersion()
 
 	// create a new room for the user
-	if len(commonRooms) == 0 {
+	if qryServerNoticeRoom.RoomID == "" {
+		var pl, cc []byte
 		powerLevelContent := eventutil.InitialPowerLevelsContent(senderUserID)
-		powerLevelContent.Users[r.UserID] = -10 // taken from Synapse
-		pl, err := json.Marshal(powerLevelContent)
+		powerLevelContent.Users[serverNoticeRequest.UserID] = -10 // taken from Synapse
+		pl, err = json.Marshal(powerLevelContent)
 		if err != nil {
-			return util.ErrorResponse(err)
+			return util.ErrorResponse(err), err
 		}
 		createContent := map[string]interface{}{}
 		createContent["m.federate"] = false
-		cc, err := json.Marshal(createContent)
+		cc, err = json.Marshal(createContent)
 		if err != nil {
-			return util.ErrorResponse(err)
+			return util.ErrorResponse(err), err
 		}
 		crReq := createRoomRequest{
-			Invite:                    []string{r.UserID},
+			Invite:                    []string{serverNoticeRequest.UserID},
 			Name:                      cfgNotices.RoomName,
 			Visibility:                "private",
 			Preset:                    presetPrivateChat,
@@ -166,36 +158,40 @@ func SendServerNotice(
 		switch data := roomRes.JSON.(type) {
 		case createRoomResponse:
 			roomID = data.RoomID
-
+			res := &userapi.UpdateServerNoticeRoomResponse{}
+			err = userAPI.UpdateServerNoticeRoomID(ctx, &userapi.UpdateServerNoticeRoomRequest{RoomID: roomID, Localpart: localpart}, res)
+			if err != nil {
+				util.GetLogger(ctx).WithError(err).Error("UpdateServerNoticeRoomID failed")
+				return jsonerror.InternalServerError(), err
+			}
 			// tag the room, so we can later check if the user tries to reject an invite
 			serverAlertTag := gomatrix.TagContent{Tags: map[string]gomatrix.TagProperties{
 				"m.server_notice": {
 					Order: 1.0,
 				},
 			}}
-			if err = saveTagData(req, r.UserID, roomID, userAPI, serverAlertTag); err != nil {
+			if err = saveTagData(ctx, serverNoticeRequest.UserID, roomID, userAPI, serverAlertTag); err != nil {
 				util.GetLogger(ctx).WithError(err).Error("saveTagData failed")
-				return jsonerror.InternalServerError()
+				return jsonerror.InternalServerError(), err
 			}
 
 		default:
 			// if we didn't get a createRoomResponse, we probably received an error, so return that.
-			return roomRes
+			return roomRes, fmt.Errorf("Unable to create room")
 		}
+
 	} else {
-		// we've found a room in common, check the membership
-		roomID = commonRooms[0]
-		membershipRes := api.QueryMembershipForUserResponse{}
-		err := rsAPI.QueryMembershipForUser(ctx, &api.QueryMembershipForUserRequest{UserID: r.UserID, RoomID: roomID}, &membershipRes)
+		res := &api.QueryMembershipForUserResponse{}
+		err = rsAPI.QueryMembershipForUser(ctx, &api.QueryMembershipForUserRequest{UserID: serverNoticeRequest.UserID, RoomID: roomID}, res)
 		if err != nil {
-			util.GetLogger(ctx).WithError(err).Error("unable to query membership for user")
-			return jsonerror.InternalServerError()
+			return util.ErrorResponse(err), err
 		}
-		if !membershipRes.IsInRoom {
 		// re-invite the user
-			res, err := sendInvite(ctx, userAPI, senderDevice, roomID, r.UserID, "Server notice room", cfgClient, rsAPI, asAPI, time.Now())
+		if res.Membership != gomatrixserverlib.Join {
+			var inviteRes util.JSONResponse
+			inviteRes, err = sendInvite(ctx, userAPI, senderDevice, roomID, serverNoticeRequest.UserID, "Server notice room", cfgClient, rsAPI, asAPI, time.Now())
 			if err != nil {
-				return res
+				return inviteRes, err
 			}
 		}
 	}
@@ -203,13 +199,13 @@ func SendServerNotice(
 	startedGeneratingEvent := time.Now()
 
 	request := map[string]interface{}{
-		"body":    r.Content.Body,
-		"msgtype": r.Content.MsgType,
+		"body":    serverNoticeRequest.Content.Body,
+		"msgtype": serverNoticeRequest.Content.MsgType,
 	}
 	e, resErr := generateSendEvent(ctx, request, senderDevice, roomID, "m.room.message", nil, cfgClient, rsAPI, time.Now())
 	if resErr != nil {
 		logrus.Errorf("failed to send message: %+v", resErr)
-		return *resErr
+		return *resErr, fmt.Errorf("Unable to send event")
 	}
 	timeToGenerateEvent := time.Since(startedGeneratingEvent)
 
@@ -224,7 +220,7 @@ func SendServerNotice(
 	// pass the new event to the roomserver and receive the correct event ID
 	// event ID in case of duplicate transaction is discarded
 	startedSubmittingEvent := time.Now()
-	if err := api.SendEvents(
+	if err = api.SendEvents(
 		ctx, rsAPI,
 		api.KindNew,
 		[]*gomatrixserverlib.HeaderedEvent{
@@ -236,7 +232,7 @@ func SendServerNotice(
 		false,
 	); err != nil {
 		util.GetLogger(ctx).WithError(err).Error("SendEvents failed")
-		return jsonerror.InternalServerError()
+		return jsonerror.InternalServerError(), err
 	}
 	util.GetLogger(ctx).WithFields(logrus.Fields{
 		"event_id":     e.EventID(),
@@ -259,7 +255,7 @@ func SendServerNotice(
 	sendEventDuration.With(prometheus.Labels{"action": "build"}).Observe(float64(timeToGenerateEvent.Milliseconds()))
 	sendEventDuration.With(prometheus.Labels{"action": "submit"}).Observe(float64(timeToSubmitEvent.Milliseconds()))
 
-	return res
+	return res, nil
 }
 
 func (r sendServerNoticeRequest) valid() (ok bool) {

cmd/create-account/main.go

@@ -146,7 +146,12 @@ func main() {
 		logrus.Fatalln("Username is already in use.")
 	}
 
-	_, err = accountDB.CreateAccount(context.Background(), *username, pass, "", accType)
+	policyVersion := ""
+	if cfg.Global.UserConsentOptions.Enabled {
+		policyVersion = cfg.Global.UserConsentOptions.Version
+	}
+
+	_, err = accountDB.CreateAccount(context.Background(), *username, pass, "", policyVersion, accType)
 	if err != nil {
 		logrus.Fatalln("Failed to create the account:", err.Error())
 	}

dendrite-sample.polylith.yaml

@@ -71,6 +71,35 @@ global:
     # appear in user clients.
     room_name: "Server Alerts"
 
+  # Consent tracking configuration
+  user_consent:
+    # If the user consent tracking is enabled or not
+    enabled: false
+    # The base URL this homeserver will serve clients on, e.g. https://matrix.org
+    base_url: http://localhost
+    # Randomly generated string (e.g. by using "pwgen -sy 32") to be used to calculate the HMAC
+    form_secret: "superSecretRandomlyGeneratedSecret"
+    # Require consent when user registers for the first time
+    require_at_registration: false
+    # The name to be shown to the user
+    policy_name: "Privacy policy"
+    # The directory to search for templates
+    template_dir: "./templates/privacy"
+    # The version of the policy. When loading templates, ".gohtml" template is added as a suffix
+    # e.g: ${template_dir}/1.0.gohtml needs to exist, if this is set to "1.0"
+    version: "1.0"
+    # Send a consent message to guest users
+    send_server_notice_to_guest: false
+    # Default message to send to users
+    server_notice_content:
+      msg_type: "m.text"
+      body: >-
+        Please give your consent to the privacy policy at {{ .ConsentURL }}.
+    # The error message to display if the user hasn't given their consent yet
+    block_events_error: >-
+      You can't send any messages until you consent to the privacy policy at
+      {{ .ConsentURL }}.
+
   # Configuration for NATS JetStream
   jetstream:
     # A list of NATS Server addresses to connect to. If none are specified, an

docs/templates/privacy/1.0.gohtml

@@ -0,0 +1,26 @@
+<!doctype html>
+<html lang="en">
+<head>
+    <title>Privacy policy</title>
+</head>
+<body>
+{{ if .HasConsented }}
+    <p>
+        You have already given your consent.
+    </p>
+{{ else }}
+    <p>
+        Please give your consent to keep using this homeserver.
+    </p>
+    {{ if not .ReadOnly }}
+        <!-- The variables used here are only provided when the 'u' param is given to the homeserver -->
+        <form method="post" action="consent">
+            <input type="hidden" name="v" value="{{ .Version }}"/>
+            <input type="hidden" name="u" value="{{ .UserID }}"/>
+            <input type="hidden" name="h" value="{{ .UserHMAC }}"/>
+            <input type="submit" value="I consent"/>
+        </form>
+    {{ end }}
+{{ end }}
+</body>
+</html>

internal/httputil/httpapi.go

@@ -15,6 +15,8 @@
 package httputil
 
 import (
+	"bytes"
+	"context"
 	"fmt"
 	"io"
 	"net/http"
@@ -25,9 +27,12 @@ import (
 
 	"github.com/getsentry/sentry-go"
 	"github.com/matrix-org/dendrite/clientapi/auth"
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/setup/config"
 	userapi "github.com/matrix-org/dendrite/userapi/api"
+	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
-	opentracing "github.com/opentracing/opentracing-go"
+	"github.com/opentracing/opentracing-go"
 	"github.com/opentracing/opentracing-go/ext"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
@@ -41,10 +46,24 @@ type BasicAuth struct {
 	Password string `yaml:"password"`
 }
 
+// AuthAPICheck is an option to MakeAuthAPI to add additional checks (e.g. WithConsentCheck) to verify
+// the user is allowed to do specific things.
+type AuthAPICheck func(ctx context.Context, device *userapi.Device) *util.JSONResponse
+
+// WithConsentCheck checks that a user has given his consent.
+func WithConsentCheck(options config.UserConsentOptions, api userapi.QueryPolicyVersionAPI) AuthAPICheck {
+	return func(ctx context.Context, device *userapi.Device) *util.JSONResponse {
+		if !options.Enabled {
+			return nil
+		}
+		return checkConsent(ctx, device.UserID, api, options)
+	}
+}
+
 // MakeAuthAPI turns a util.JSONRequestHandler function into an http.Handler which authenticates the request.
 func MakeAuthAPI(
 	metricsName string, userAPI userapi.QueryAcccessTokenAPI,
-	f func(*http.Request, *userapi.Device) util.JSONResponse,
+	f func(*http.Request, *userapi.Device) util.JSONResponse, checks ...AuthAPICheck,
 ) http.Handler {
 	h := func(req *http.Request) util.JSONResponse {
 		logger := util.GetLogger(req.Context())
@@ -72,6 +91,14 @@ func MakeAuthAPI(
 			}
 		}()
 
+		// apply additional checks, if any
+		for _, opt := range checks {
+			resp := opt(req.Context(), device)
+			if resp != nil {
+				return *resp
+			}
+		}
+
 		jsonRes := f(req, device)
 		// do not log 4xx as errors as they are client fails, not server fails
 		if hub != nil && jsonRes.Code >= 500 {
@@ -83,6 +110,53 @@ func MakeAuthAPI(
 	return MakeExternalAPI(metricsName, h)
 }
 
+func checkConsent(ctx context.Context, userID string, userAPI userapi.QueryPolicyVersionAPI, userConsentCfg config.UserConsentOptions) *util.JSONResponse {
+	localpart, _, err := gomatrixserverlib.SplitID('@', userID)
+	if err != nil {
+		return nil
+	}
+	// check which version of the policy the user accepted
+	res := &userapi.QueryPolicyVersionResponse{}
+	err = userAPI.QueryPolicyVersion(ctx, &userapi.QueryPolicyVersionRequest{
+		Localpart: localpart,
+	}, res)
+	if err != nil {
+		return &util.JSONResponse{
+			Code: http.StatusInternalServerError,
+			JSON: jsonerror.Unknown("unable to get policy version"),
+		}
+	}
+
+	// user hasn't accepted any policy, block access.
+	if userConsentCfg.Version != res.PolicyVersion {
+		uri, err := userConsentCfg.ConsentURL(userID)
+		if err != nil {
+			return &util.JSONResponse{
+				Code: http.StatusInternalServerError,
+				JSON: jsonerror.Unknown("unable to get consent URL"),
+			}
+		}
+		msg := &bytes.Buffer{}
+		c := struct {
+			ConsentURL string
+		}{
+			ConsentURL: uri,
+		}
+		if err = userConsentCfg.TextTemplates.ExecuteTemplate(msg, "blockEventsError", c); err != nil {
+			logrus.Infof("error consent message: %+v", err)
+			return &util.JSONResponse{
+				Code: http.StatusInternalServerError,
+				JSON: jsonerror.Unknown("unable to execute template"),
+			}
+		}
+		return &util.JSONResponse{
+			Code: http.StatusForbidden,
+			JSON: jsonerror.ConsentNotGiven(uri, msg.String()),
+		}
+	}
+	return nil
+}
+
 // MakeExternalAPI turns a util.JSONRequestHandler function into an http.Handler.
 // This is used for APIs that are called from the internet.
 func MakeExternalAPI(metricsName string, f func(*http.Request) util.JSONResponse) http.Handler {

mediaapi/routing/routing.go

@@ -59,15 +59,12 @@ func Setup(
 		PathToResult: map[string]*types.ThumbnailGenerationResult{},
 	}
 
-	uploadHandler := httputil.MakeAuthAPI(
-		"upload", userAPI,
-		func(req *http.Request, dev *userapi.Device) util.JSONResponse {
+	uploadHandler := httputil.MakeAuthAPI("upload", userAPI, func(req *http.Request, dev *userapi.Device) util.JSONResponse {
 		if r := rateLimits.Limit(req); r != nil {
 			return *r
 		}
 		return Upload(req, cfg, dev, db, activeThumbnailGeneration)
-		},
-	)
+	})
 
 	configHandler := httputil.MakeAuthAPI("config", userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
 		if r := rateLimits.Limit(req); r != nil {

setup/base/base.go

@@ -268,6 +268,7 @@ func (b *BaseDendrite) Close() error {
 func (b *BaseDendrite) DatabaseConnection(dbProperties *config.DatabaseOptions, writer sqlutil.Writer) (*sql.DB, sqlutil.Writer, error) {
 	if dbProperties.ConnectionString != "" || b == nil {
 		// Open a new database connection using the supplied config.
+		logrus.Infof("Open a new database connection using the supplied config.: %+v", dbProperties.ConnectionString)
 		db, err := sqlutil.Open(dbProperties, writer)
 		return db, writer, err
 	}

setup/config/config.go

@@ -265,6 +265,21 @@ func loadConfig(
 	return &c, nil
 }
 
+type Terms struct {
+	Policies Policies `json:"policies"`
+}
+type En struct {
+	Name string `json:"name"`
+	URL  string `json:"url"`
+}
+type PrivacyPolicy struct {
+	En      En     `json:"en"`
+	Version string `json:"version"`
+}
+type Policies struct {
+	PrivacyPolicy PrivacyPolicy `json:"privacy_policy"`
+}
+
 // Derive generates data that is derived from various values provided in
 // the config file.
 func (config *Dendrite) Derive() error {
@@ -275,13 +290,39 @@ func (config *Dendrite) Derive() error {
 	// TODO: Add email auth type
 	// TODO: Add MSISDN auth type
 
+	if config.Global.UserConsentOptions.Enabled && config.Global.UserConsentOptions.RequireAtRegistration {
+		uri := config.Global.UserConsentOptions.BaseURL + "/_matrix/client/consent?v=" + config.Global.UserConsentOptions.Version
+		config.Derived.Registration.Params[authtypes.LoginTypeTerms] = Terms{
+			Policies: Policies{
+				PrivacyPolicy: PrivacyPolicy{
+					En: En{
+						Name: config.Global.UserConsentOptions.PolicyName,
+						URL:  uri,
+					},
+					Version: config.Global.UserConsentOptions.Version,
+				},
+			},
+		}
+	}
 	if config.ClientAPI.RecaptchaEnabled {
 		config.Derived.Registration.Params[authtypes.LoginTypeRecaptcha] = map[string]string{"public_key": config.ClientAPI.RecaptchaPublicKey}
-		config.Derived.Registration.Flows = append(config.Derived.Registration.Flows,
-			authtypes.Flow{Stages: []authtypes.LoginType{authtypes.LoginTypeRecaptcha}})
-	} else {
-		config.Derived.Registration.Flows = append(config.Derived.Registration.Flows,
-			authtypes.Flow{Stages: []authtypes.LoginType{authtypes.LoginTypeDummy}})
+	}
+
+	if config.Derived.Registration.Flows == nil {
+		config.Derived.Registration.Flows = append(config.Derived.Registration.Flows, authtypes.Flow{
+			Stages: []authtypes.LoginType{authtypes.LoginTypeDummy},
+		})
+	}
+
+	// prepend each flow with LoginTypeTerms or LoginTypeRecaptcha
+	for i, flow := range config.Derived.Registration.Flows {
+		if config.Global.UserConsentOptions.Enabled && config.Global.UserConsentOptions.RequireAtRegistration {
+			flow.Stages = append([]authtypes.LoginType{authtypes.LoginTypeTerms}, flow.Stages...)
+		}
+		if config.ClientAPI.RecaptchaEnabled {
+			flow.Stages = append([]authtypes.LoginType{authtypes.LoginTypeRecaptcha}, flow.Stages...)
+		}
+		config.Derived.Registration.Flows[i] = flow
 	}
 
 	// Load application service configuration files

setup/config/config_global.go

@@ -1,7 +1,15 @@
 package config
 
 import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"html/template"
 	"math/rand"
+	"net/url"
+	"path/filepath"
+	textTemplate "text/template"
 	"time"
 
 	"github.com/matrix-org/gomatrixserverlib"
@@ -71,6 +79,9 @@ type Global struct {
 	// ServerNotices configuration used for sending server notices
 	ServerNotices ServerNotices `yaml:"server_notices"`
 
+	// Consent tracking options
+	UserConsentOptions UserConsentOptions `yaml:"user_consent"`
+
 	// ReportStats configures opt-in anonymous stats reporting.
 	ReportStats ReportStats `yaml:"report_stats"`
 }
@@ -88,6 +99,7 @@ func (c *Global) Defaults(generate bool) {
 	c.Metrics.Defaults(generate)
 	c.DNSCache.Defaults()
 	c.Sentry.Defaults()
+	c.UserConsentOptions.Defaults()
 	c.ServerNotices.Defaults(generate)
 	c.ReportStats.Defaults()
 }
@@ -100,6 +112,7 @@ func (c *Global) Verify(configErrs *ConfigErrors, isMonolith bool) {
 	c.Metrics.Verify(configErrs, isMonolith)
 	c.Sentry.Verify(configErrs, isMonolith)
 	c.DNSCache.Verify(configErrs, isMonolith)
+	c.UserConsentOptions.Verify(configErrs, isMonolith)
 	c.ServerNotices.Verify(configErrs, isMonolith)
 	c.ReportStats.Verify(configErrs, isMonolith)
 }
@@ -261,6 +274,102 @@ func (c *DNSCacheOptions) Verify(configErrs *ConfigErrors, isMonolith bool) {
 	checkPositive(configErrs, "cache_lifetime", int64(c.CacheLifetime))
 }
 
+// Consent tracking configuration
+// If either require_at_registration or send_server_notice_to_guest are true, consent
+// messages will be sent to the users.
+type UserConsentOptions struct {
+	// If consent tracking is enabled or not
+	Enabled bool `yaml:"enabled"`
+	// Randomly generated string to be used to calculate the HMAC
+	FormSecret string `yaml:"form_secret"`
+	// Require consent when user registers for the first time
+	RequireAtRegistration bool `yaml:"require_at_registration"`
+	// The name to be shown to the user
+	PolicyName string `yaml:"policy_name"`
+	// The directory to search for *.gohtml templates
+	TemplateDir string `yaml:"template_dir"`
+	// The version of the policy. When loading templates, ".gohtml" template is added as a suffix
+	// e.g: ${template_dir}/1.0.gohtml needs to exist, if this is set to 1.0
+	Version string `yaml:"version"`
+	// Send a consent message to guest users
+	SendServerNoticeToGuest bool `yaml:"send_server_notice_to_guest"`
+	// Default message to send to users
+	ServerNoticeContent struct {
+		MsgType string `yaml:"msg_type"`
+		Body    string `yaml:"body"`
+	} `yaml:"server_notice_content"`
+	// The error message to display if the user hasn't given their consent yet
+	BlockEventsError string `yaml:"block_events_error"`
+	// All loaded templates
+	Templates     *template.Template     `yaml:"-"`
+	TextTemplates *textTemplate.Template `yaml:"-"`
+	// The base URL this homeserver will serve clients on, e.g. https://matrix.org
+	BaseURL string `yaml:"base_url"`
+}
+
+func (c *UserConsentOptions) Defaults() {
+	c.Enabled = false
+	c.RequireAtRegistration = false
+	c.SendServerNoticeToGuest = false
+	c.PolicyName = "Privacy Policy"
+	c.Version = "1.0"
+	c.TemplateDir = "./templates/privacy"
+}
+
+func (c *UserConsentOptions) Verify(configErrors *ConfigErrors, isMonolith bool) {
+	if !c.Enabled {
+		return
+	}
+
+	checkNotEmpty(configErrors, "template_dir", c.TemplateDir)
+	checkNotEmpty(configErrors, "version", c.Version)
+	checkNotEmpty(configErrors, "policy_name", c.PolicyName)
+	checkNotEmpty(configErrors, "form_secret", c.FormSecret)
+	checkNotEmpty(configErrors, "base_url", c.BaseURL)
+	if len(*configErrors) > 0 {
+		return
+	}
+
+	p, err := filepath.Abs(c.TemplateDir)
+	if err != nil {
+		configErrors.Add("unable to get template directory")
+		return
+	}
+
+	c.TextTemplates = textTemplate.Must(textTemplate.New("blockEventsError").Parse(c.BlockEventsError))
+	c.TextTemplates = textTemplate.Must(c.TextTemplates.New("serverNoticeTemplate").Parse(c.ServerNoticeContent.Body))
+
+	// Read all defined *.gohtml templates
+	t, err := template.ParseGlob(filepath.Join(p, "*.gohtml"))
+	if err != nil || t == nil {
+		configErrors.Add(fmt.Sprintf("unable to read consent templates: %+v", err))
+		return
+	}
+	c.Templates = t
+	// Verify we've got a template for the defined version
+	versionTemplate := c.Templates.Lookup(c.Version + ".gohtml")
+	if versionTemplate == nil {
+		configErrors.Add(fmt.Sprintf("unable to load defined '%s' policy template", c.Version))
+	}
+}
+
+// ConsentURL constructs the URL shown to users to accept the TOS
+func (c *UserConsentOptions) ConsentURL(userID string) (string, error) {
+	mac := hmac.New(sha256.New, []byte(c.FormSecret))
+	_, err := mac.Write([]byte(userID))
+	if err != nil {
+		return "", err
+	}
+	userMAC := hex.EncodeToString(mac.Sum(nil))
+
+	params := url.Values{}
+	params.Add("u", userID)
+	params.Add("h", userMAC)
+	params.Add("v", c.Version)
+
+	return fmt.Sprintf("%s/_matrix/client/consent?%s", c.BaseURL, params.Encode()), nil
+}
+
 // PresenceOptions defines possible configurations for presence events.
 type PresenceOptions struct {
 	// Whether inbound presence events are allowed

setup/config/config_global_test.go

@@ -0,0 +1,115 @@
+package config
+
+import (
+	"testing"
+)
+
+func TestUserConsentOptions_Verify(t *testing.T) {
+	type args struct {
+		configErrors *ConfigErrors
+		isMonolith   bool
+	}
+	tests := []struct {
+		name    string
+		fields  UserConsentOptions
+		args    args
+		wantErr bool
+	}{
+		{
+			name: "template dir not set",
+			fields: UserConsentOptions{
+				RequireAtRegistration: true,
+			},
+			args: struct {
+				configErrors *ConfigErrors
+				isMonolith   bool
+			}{configErrors: &ConfigErrors{}, isMonolith: true},
+			wantErr: true,
+		},
+		{
+			name: "template dir set",
+			fields: UserConsentOptions{
+				RequireAtRegistration: true,
+				TemplateDir:           "testdata/privacy",
+			},
+			args: struct {
+				configErrors *ConfigErrors
+				isMonolith   bool
+			}{configErrors: &ConfigErrors{}, isMonolith: true},
+			wantErr: true,
+		},
+		{
+			name: "policy name not set",
+			fields: UserConsentOptions{
+				RequireAtRegistration: true,
+				TemplateDir:           "testdata/privacy",
+			},
+			args: struct {
+				configErrors *ConfigErrors
+				isMonolith   bool
+			}{configErrors: &ConfigErrors{}, isMonolith: true},
+			wantErr: true,
+		},
+		{
+			name: "policy name set",
+			fields: UserConsentOptions{
+				RequireAtRegistration: true,
+				TemplateDir:           "testdata/privacy",
+				PolicyName:            "Privacy policy",
+			},
+			args: struct {
+				configErrors *ConfigErrors
+				isMonolith   bool
+			}{configErrors: &ConfigErrors{}, isMonolith: true},
+			wantErr: true,
+		},
+		{
+			name: "version not set",
+			fields: UserConsentOptions{
+				RequireAtRegistration: true,
+				TemplateDir:           "testdata/privacy",
+			},
+			args: struct {
+				configErrors *ConfigErrors
+				isMonolith   bool
+			}{configErrors: &ConfigErrors{}, isMonolith: true},
+			wantErr: true,
+		},
+		{
+			name: "everyhing required set",
+			fields: UserConsentOptions{
+				RequireAtRegistration: true,
+				TemplateDir:           "./testdata/privacy",
+				Version:               "1.0",
+				PolicyName:            "Privacy policy",
+				FormSecret:            "helloWorld",
+				BaseURL:               "http://localhost",
+			},
+			args: struct {
+				configErrors *ConfigErrors
+				isMonolith   bool
+			}{configErrors: &ConfigErrors{}, isMonolith: true},
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := &UserConsentOptions{
+				Enabled:                 true,
+				BaseURL:                 tt.fields.BaseURL,
+				FormSecret:              tt.fields.FormSecret,
+				RequireAtRegistration:   tt.fields.RequireAtRegistration,
+				PolicyName:              tt.fields.PolicyName,
+				Version:                 tt.fields.Version,
+				TemplateDir:             tt.fields.TemplateDir,
+				SendServerNoticeToGuest: tt.fields.SendServerNoticeToGuest,
+				ServerNoticeContent:     tt.fields.ServerNoticeContent,
+				BlockEventsError:        tt.fields.BlockEventsError,
+			}
+			c.Verify(tt.args.configErrors, tt.args.isMonolith)
+			if !tt.wantErr && len(*tt.args.configErrors) > 0 {
+				t.Errorf("expected no errors, got '%+v'", tt.args.configErrors)
+			}
+		})
+	}
+}

setup/config/testdata/privacy/1.0.gohtml

@@ -0,0 +1,26 @@
+<!doctype html>
+<html lang="en">
+<head>
+    <title>Privacy policy</title>
+</head>
+<body>
+{{ if .HasConsented }}
+    <p>
+        You have already given your consent.
+    </p>
+{{ else }}
+    <p>
+        Please give your consent to keep using this homeserver.
+    </p>
+    {{ if not .ReadOnly }}
+        <!-- The variables used here are only provided when the 'u' param is given to the homeserver -->
+        <form method="post" action="consent">
+            <input type="hidden" name="v" value="{{ .Version }}"/>
+            <input type="hidden" name="u" value="{{ .UserID }}"/>
+            <input type="hidden" name="h" value="{{ .UserHMAC }}"/>
+            <input type="submit" value="I consent"/>
+        </form>
+    {{ end }}
+{{ end }}
+</body>
+</html>

setup/flags.go

@@ -44,7 +44,6 @@ func ParseFlags(monolith bool) *config.Dendrite {
 	}
 
 	cfg, err := config.Load(*configPath, monolith)
-
 	if err != nil {
 		logrus.Fatalf("Invalid config file: %s", err)
 	}

syncapi/routing/routing.go

@@ -93,6 +93,6 @@ func Setup(
 				vars["roomId"], vars["eventId"],
 				lazyLoadCache,
 			)
-		}),
+		}, httputil.WithConsentCheck(cfg.Matrix.UserConsentOptions, userAPI)),
 	).Methods(http.MethodGet, http.MethodOptions)
 }

userapi/api/api.go

@@ -66,6 +66,7 @@ type FederationUserAPI interface {
 // api functions required by the sync api
 type SyncUserAPI interface {
 	QueryAcccessTokenAPI
+	QueryPolicyVersionAPI
 	QueryAccountData(ctx context.Context, req *QueryAccountDataRequest, res *QueryAccountDataResponse) error
 	PerformLastSeenUpdate(ctx context.Context, req *PerformLastSeenUpdateRequest, res *PerformLastSeenUpdateResponse) error
 	PerformDeviceUpdate(ctx context.Context, req *PerformDeviceUpdateRequest, res *PerformDeviceUpdateResponse) error
@@ -78,6 +79,7 @@ type ClientUserAPI interface {
 	QueryAcccessTokenAPI
 	LoginTokenInternalAPI
 	UserLoginAPI
+	UserConsentPolicyAPI
 	QueryNumericLocalpart(ctx context.Context, res *QueryNumericLocalpartResponse) error
 	QueryDevices(ctx context.Context, req *QueryDevicesRequest, res *QueryDevicesResponse) error
 	QueryProfile(ctx context.Context, req *QueryProfileRequest, res *QueryProfileResponse) error
@@ -106,6 +108,18 @@ type ClientUserAPI interface {
 	QueryLocalpartForThreePID(ctx context.Context, req *QueryLocalpartForThreePIDRequest, res *QueryLocalpartForThreePIDResponse) error
 	PerformForgetThreePID(ctx context.Context, req *PerformForgetThreePIDRequest, res *struct{}) error
 	PerformSaveThreePIDAssociation(ctx context.Context, req *PerformSaveThreePIDAssociationRequest, res *struct{}) error
+	SelectServerNoticeRoomID(ctx context.Context, req *QueryServerNoticeRoomRequest, res *QueryServerNoticeRoomResponse) (err error)
+	UpdateServerNoticeRoomID(ctx context.Context, req *UpdateServerNoticeRoomRequest, res *UpdateServerNoticeRoomResponse) (err error)
+}
+
+type UserConsentPolicyAPI interface {
+	QueryPolicyVersionAPI
+	QueryOutdatedPolicy(ctx context.Context, req *QueryOutdatedPolicyRequest, res *QueryOutdatedPolicyResponse) error
+	PerformUpdatePolicyVersion(ctx context.Context, req *UpdatePolicyVersionRequest, res *UpdatePolicyVersionResponse) error
+}
+
+type QueryPolicyVersionAPI interface {
+	QueryPolicyVersion(ctx context.Context, req *QueryPolicyVersionRequest, res *QueryPolicyVersionResponse) error
 }
 
 // custom api functions required by pinecone / p2p demos
@@ -320,7 +334,7 @@ type QuerySearchProfilesResponse struct {
 type PerformAccountCreationRequest struct {
 	AccountType   AccountType // Required: whether this is a guest or user account
 	Localpart     string      // Required: The localpart for this account. Ignored if account type is guest.
-
+	PolicyVersion string      // optional: the privacy policy this account has accepted
 	AppServiceID  string      // optional: the application service ID (not user ID) creating this account, if any.
 	Password      string      // optional: if missing then this account will be a passwordless account
 	OnConflict    Conflict
@@ -412,6 +426,53 @@ type QueryOpenIDTokenResponse struct {
 	ExpiresAtMS int64
 }
 
+// QueryPolicyVersionRequest is the request for QueryPolicyVersionRequest
+type QueryPolicyVersionRequest struct {
+	Localpart string
+}
+
+// QueryPolicyVersionResponse is the response for QueryPolicyVersionRequest
+type QueryPolicyVersionResponse struct {
+	PolicyVersion string
+}
+
+// QueryOutdatedPolicyRequest is the request for QueryOutdatedPolicyRequest
+type QueryOutdatedPolicyRequest struct {
+	PolicyVersion string
+}
+
+// QueryOutdatedPolicyResponse is the response for QueryOutdatedPolicyRequest
+type QueryOutdatedPolicyResponse struct {
+	UserLocalparts []string
+}
+
+// UpdatePolicyVersionRequest is the request for UpdatePolicyVersionRequest
+type UpdatePolicyVersionRequest struct {
+	PolicyVersion, Localpart string
+	ServerNoticeUpdate       bool
+}
+
+// UpdatePolicyVersionResponse is the response for UpdatePolicyVersionRequest
+type UpdatePolicyVersionResponse struct{}
+
+// QueryServerNoticeRoomRequest is the request for QueryServerNoticeRoomRequest
+type QueryServerNoticeRoomRequest struct {
+	Localpart string
+}
+
+// QueryServerNoticeRoomResponse is the response for QueryServerNoticeRoomRequest
+type QueryServerNoticeRoomResponse struct {
+	RoomID string
+}
+
+// UpdateServerNoticeRoomRequest is the request for UpdateServerNoticeRoomRequest
+type UpdateServerNoticeRoomRequest struct {
+	Localpart, RoomID string
+}
+
+// UpdateServerNoticeRoomResponse is the response for UpdateServerNoticeRoomRequest
+type UpdateServerNoticeRoomResponse struct{}
+
 // Device represents a client's device (mobile, web, etc)
 type Device struct {
 	ID     string

userapi/api/api_trace.go

@@ -203,6 +203,36 @@ func (t *UserInternalAPITrace) PerformSaveThreePIDAssociation(ctx context.Contex
 	return err
 }
 
+func (t *UserInternalAPITrace) QueryPolicyVersion(ctx context.Context, req *QueryPolicyVersionRequest, res *QueryPolicyVersionResponse) error {
+	err := t.Impl.QueryPolicyVersion(ctx, req, res)
+	util.GetLogger(ctx).Infof("QueryPolicyVersion req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
+func (t *UserInternalAPITrace) QueryOutdatedPolicy(ctx context.Context, req *QueryOutdatedPolicyRequest, res *QueryOutdatedPolicyResponse) error {
+	err := t.Impl.QueryOutdatedPolicy(ctx, req, res)
+	util.GetLogger(ctx).Infof("QueryOutdatedPolicy req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
+func (t *UserInternalAPITrace) PerformUpdatePolicyVersion(ctx context.Context, req *UpdatePolicyVersionRequest, res *UpdatePolicyVersionResponse) error {
+	err := t.Impl.PerformUpdatePolicyVersion(ctx, req, res)
+	util.GetLogger(ctx).Infof("PerformUpdatePolicyVersion req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
+func (t *UserInternalAPITrace) SelectServerNoticeRoomID(ctx context.Context, req *QueryServerNoticeRoomRequest, res *QueryServerNoticeRoomResponse) error {
+	err := t.Impl.SelectServerNoticeRoomID(ctx, req, res)
+	util.GetLogger(ctx).Infof("SelectServerNoticeRoomID req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
+func (t *UserInternalAPITrace) UpdateServerNoticeRoomID(ctx context.Context, req *UpdateServerNoticeRoomRequest, res *UpdateServerNoticeRoomResponse) error {
+	err := t.Impl.UpdateServerNoticeRoomID(ctx, req, res)
+	util.GetLogger(ctx).Infof("UpdateServerNoticeRoomID req=%+v res=%+v", js(req), js(res))
+	return err
+}
+
 func js(thing interface{}) string {
 	b, err := json.Marshal(thing)
 	if err != nil {

userapi/internal/api.go

@@ -66,7 +66,7 @@ func (a *UserInternalAPI) InputAccountData(ctx context.Context, req *api.InputAc
 }
 
 func (a *UserInternalAPI) PerformAccountCreation(ctx context.Context, req *api.PerformAccountCreationRequest, res *api.PerformAccountCreationResponse) error {
-	acc, err := a.DB.CreateAccount(ctx, req.Localpart, req.Password, req.AppServiceID, req.AccountType)
+	acc, err := a.DB.CreateAccount(ctx, req.Localpart, req.Password, req.AppServiceID, req.PolicyVersion, req.AccountType)
 	if err != nil {
 		if errors.Is(err, sqlutil.ErrUserExists) { // This account already exists
 			switch req.OnConflict {
@@ -833,3 +833,60 @@ func (a *UserInternalAPI) PerformSaveThreePIDAssociation(ctx context.Context, re
 }
 
 const pushRulesAccountDataType = "m.push_rules"
+
+func (a *UserInternalAPI) QueryPolicyVersion(
+	ctx context.Context,
+	req *api.QueryPolicyVersionRequest,
+	res *api.QueryPolicyVersionResponse,
+) error {
+	var err error
+	res.PolicyVersion, err = a.DB.GetPrivacyPolicy(ctx, req.Localpart)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (a *UserInternalAPI) QueryOutdatedPolicy(
+	ctx context.Context,
+	req *api.QueryOutdatedPolicyRequest,
+	res *api.QueryOutdatedPolicyResponse,
+) error {
+	var err error
+	res.UserLocalparts, err = a.DB.GetOutdatedPolicy(ctx, req.PolicyVersion)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (a *UserInternalAPI) PerformUpdatePolicyVersion(
+	ctx context.Context,
+	req *api.UpdatePolicyVersionRequest,
+	res *api.UpdatePolicyVersionResponse,
+) error {
+	return a.DB.UpdatePolicyVersion(ctx, req.PolicyVersion, req.Localpart, req.ServerNoticeUpdate)
+}
+
+func (a *UserInternalAPI) SelectServerNoticeRoomID(
+	ctx context.Context,
+	req *api.QueryServerNoticeRoomRequest,
+	res *api.QueryServerNoticeRoomResponse,
+) (err error) {
+	roomID, err := a.DB.SelectServerNoticeRoomID(ctx, req.Localpart)
+	if err != nil {
+		return err
+	}
+	res.RoomID = roomID
+	return nil
+}
+
+func (a *UserInternalAPI) UpdateServerNoticeRoomID(
+	ctx context.Context,
+	req *api.UpdateServerNoticeRoomRequest,
+	res *api.UpdateServerNoticeRoomResponse,
+) (err error) {
+	return a.DB.UpdateServerNoticeRoomID(ctx, req.Localpart, req.RoomID)
+}

userapi/inthttp/client.go

@@ -44,6 +44,8 @@ const (
 	PerformSetDisplayNamePath          = "/userapi/performSetDisplayName"
 	PerformForgetThreePIDPath          = "/userapi/performForgetThreePID"
 	PerformSaveThreePIDAssociationPath = "/userapi/performSaveThreePIDAssociation"
+	PerformUpdatePolicyVersionPath     = "/userapi/performUpdatePolicyVersion"
+	PerformUpdateServerNoticeRoomPath  = "/userapi/performUpdateServerNoticeRoom"
 
 	QueryKeyBackupPath             = "/userapi/queryKeyBackup"
 	QueryProfilePath               = "/userapi/queryProfile"
@@ -61,6 +63,9 @@ const (
 	QueryAccountByPasswordPath     = "/userapi/queryAccountByPassword"
 	QueryLocalpartForThreePIDPath  = "/userapi/queryLocalpartForThreePID"
 	QueryThreePIDsForLocalpartPath = "/userapi/queryThreePIDsForLocalpart"
+	QueryPolicyVersionPath         = "/userapi/queryPolicyVersion"
+	QueryOutdatedPolicyUsersPath   = "/userapi/queryOutdatedPolicy"
+	QueryServerNoticeRoomPath      = "/userapi/queryServerNoticeRoom"
 )
 
 // NewUserAPIClient creates a UserInternalAPI implemented by talking to a HTTP POST API.
@@ -391,3 +396,43 @@ func (h *httpUserInternalAPI) PerformSaveThreePIDAssociation(ctx context.Context
 	apiURL := h.apiURL + PerformSaveThreePIDAssociationPath
 	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
 }
+
+func (h *httpUserInternalAPI) QueryOutdatedPolicy(ctx context.Context, req *api.QueryOutdatedPolicyRequest, res *api.QueryOutdatedPolicyResponse) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryOutdatedPolicy")
+	defer span.Finish()
+
+	apiURL := h.apiURL + QueryOutdatedPolicyUsersPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
+}
+
+func (h *httpUserInternalAPI) PerformUpdatePolicyVersion(ctx context.Context, req *api.UpdatePolicyVersionRequest, res *api.UpdatePolicyVersionResponse) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "PerformUpdatePolicyVersion")
+	defer span.Finish()
+
+	apiURL := h.apiURL + PerformUpdatePolicyVersionPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
+}
+
+func (h *httpUserInternalAPI) SelectServerNoticeRoomID(ctx context.Context, req *api.QueryServerNoticeRoomRequest, res *api.QueryServerNoticeRoomResponse) (err error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "SelectServerNoticeRoomID")
+	defer span.Finish()
+
+	apiURL := h.apiURL + QueryServerNoticeRoomPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
+}
+
+func (h *httpUserInternalAPI) QueryPolicyVersion(ctx context.Context, req *api.QueryPolicyVersionRequest, res *api.QueryPolicyVersionResponse) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "QueryPolicyVersion")
+	defer span.Finish()
+
+	apiURL := h.apiURL + QueryPolicyVersionPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
+}
+
+func (h *httpUserInternalAPI) UpdateServerNoticeRoomID(ctx context.Context, req *api.UpdateServerNoticeRoomRequest, res *api.UpdateServerNoticeRoomResponse) (err error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "UpdateServerNoticeRoomID")
+	defer span.Finish()
+
+	apiURL := h.apiURL + PerformUpdateServerNoticeRoomPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, req, res)
+}

userapi/inthttp/server.go

@@ -457,4 +457,74 @@ func AddRoutes(internalAPIMux *mux.Router, s api.UserInternalAPI) {
 			return util.JSONResponse{Code: http.StatusOK, JSON: &struct{}{}}
 		}),
 	)
+	internalAPIMux.Handle(QueryPolicyVersionPath,
+		httputil.MakeInternalAPI("queryPolicyVersion", func(req *http.Request) util.JSONResponse {
+			request := api.QueryPolicyVersionRequest{}
+			response := api.QueryPolicyVersionResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			err := s.QueryPolicyVersion(req.Context(), &request, &response)
+			if err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
+	internalAPIMux.Handle(QueryOutdatedPolicyUsersPath,
+		httputil.MakeInternalAPI("queryOutdatedPolicyUsers", func(req *http.Request) util.JSONResponse {
+			request := api.QueryOutdatedPolicyRequest{}
+			response := api.QueryOutdatedPolicyResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			err := s.QueryOutdatedPolicy(req.Context(), &request, &response)
+			if err != nil {
+				return util.JSONResponse{Code: http.StatusBadRequest, JSON: &response}
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
+	internalAPIMux.Handle(PerformUpdatePolicyVersionPath,
+		httputil.MakeInternalAPI("performUpdatePolicyVersionPath", func(req *http.Request) util.JSONResponse {
+			request := api.UpdatePolicyVersionRequest{}
+			response := api.UpdatePolicyVersionResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			err := s.PerformUpdatePolicyVersion(req.Context(), &request, &response)
+			if err != nil {
+				return util.JSONResponse{Code: http.StatusBadRequest, JSON: &response}
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
+	internalAPIMux.Handle(QueryServerNoticeRoomPath,
+		httputil.MakeInternalAPI("queryServerNoticeRoom", func(req *http.Request) util.JSONResponse {
+			request := api.QueryServerNoticeRoomRequest{}
+			response := api.QueryServerNoticeRoomResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			err := s.SelectServerNoticeRoomID(req.Context(), &request, &response)
+			if err != nil {
+				return util.JSONResponse{Code: http.StatusBadRequest, JSON: &response}
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
+	internalAPIMux.Handle(PerformUpdateServerNoticeRoomPath,
+		httputil.MakeInternalAPI("performUpdateServerNoticeRoom", func(req *http.Request) util.JSONResponse {
+			request := api.UpdateServerNoticeRoomRequest{}
+			response := api.UpdateServerNoticeRoomResponse{}
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			err := s.UpdateServerNoticeRoomID(req.Context(), &request, &response)
+			if err != nil {
+				return util.JSONResponse{Code: http.StatusBadRequest, JSON: &response}
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
 }

userapi/storage/interface.go

@@ -36,7 +36,7 @@ type Account interface {
 	// CreateAccount makes a new account with the given login name and password, and creates an empty profile
 	// for this account. If no password is supplied, the account will be a passwordless account. If the
 	// account already exists, it will return nil, ErrUserExists.
-	CreateAccount(ctx context.Context, localpart string, plaintextPassword string, appserviceID string, accountType api.AccountType) (*api.Account, error)
+	CreateAccount(ctx context.Context, localpart string, plaintextPassword string, appserviceID string, policyVersion string, accountType api.AccountType) (*api.Account, error)
 	GetAccountByPassword(ctx context.Context, localpart, plaintextPassword string) (*api.Account, error)
 	GetNewNumericLocalpart(ctx context.Context) (int64, error)
 	CheckAccountAvailability(ctx context.Context, localpart string) (bool, error)
@@ -126,9 +126,18 @@ type Notification interface {
 	DeleteOldNotifications(ctx context.Context) error
 }
 
+type ConsentTracking interface {
+	GetPrivacyPolicy(ctx context.Context, localpart string) (policyVersion string, err error)
+	GetOutdatedPolicy(ctx context.Context, policyVersion string) (userIDs []string, err error)
+	UpdatePolicyVersion(ctx context.Context, policyVersion, localpart string, serverNotice bool) error
+	SelectServerNoticeRoomID(ctx context.Context, localpart string) (roomID string, err error)
+	UpdateServerNoticeRoomID(ctx context.Context, localpart, roomID string) (err error)
+}
+
 type Database interface {
 	Account
 	AccountData
+	ConsentTracking
 	Device
 	KeyBackup
 	LoginToken

userapi/storage/postgres/accounts_table.go

@@ -19,6 +19,7 @@ import (
 	"database/sql"
 	"time"
 
+	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/gomatrixserverlib"
 
 	"github.com/matrix-org/dendrite/clientapi/userutil"
@@ -43,14 +44,19 @@ CREATE TABLE IF NOT EXISTS account_accounts (
     -- If the account is currently active
     is_deactivated BOOLEAN DEFAULT FALSE,
 	-- The account_type (user = 1, guest = 2, admin = 3, appservice = 4)
-	account_type SMALLINT NOT NULL
+	account_type SMALLINT NOT NULL,
+	-- The policy version this user has accepted
+	policy_version TEXT,
+   -- The policy version the user received from the server notices room
+	policy_version_sent TEXT,
+	server_notice_room_id TEXT
     -- TODO:
     -- upgraded_ts, devices, any email reset stuff?
 );
 `
 
 const insertAccountSQL = "" +
-	"INSERT INTO account_accounts(localpart, created_ts, password_hash, appservice_id, account_type) VALUES ($1, $2, $3, $4, $5)"
+	"INSERT INTO account_accounts(localpart, created_ts, password_hash, appservice_id, account_type, policy_version) VALUES ($1, $2, $3, $4, $5, $6)"
 
 const updatePasswordSQL = "" +
 	"UPDATE account_accounts SET password_hash = $1 WHERE localpart = $2"
@@ -67,6 +73,24 @@ const selectPasswordHashSQL = "" +
 const selectNewNumericLocalpartSQL = "" +
 	"SELECT COALESCE(MAX(localpart::integer), 0) FROM account_accounts WHERE localpart ~ '^[0-9]*$'"
 
+const selectPrivacyPolicySQL = "" +
+	"SELECT policy_version FROM account_accounts WHERE localpart = $1"
+
+const batchSelectPrivacyPolicySQL = "" +
+	"SELECT localpart FROM account_accounts WHERE (policy_version IS NULL OR policy_version <> $1) AND (policy_version_sent IS NULL OR policy_version_sent <> $1)"
+
+const updatePolicyVersionSQL = "" +
+	"UPDATE account_accounts SET policy_version = $1 WHERE localpart = $2"
+
+const updatePolicyVersionServerNoticeSQL = "" +
+	"UPDATE account_accounts SET policy_version_sent = $1 WHERE localpart = $2"
+
+const selectServerNoticeRoomSQL = "" +
+	"SELECT server_notice_room_id FROM account_accounts WHERE localpart = $1"
+
+const updateServerNoticeRoomSQL = "" +
+	"UPDATE account_accounts SET server_notice_room_id = $1 WHERE localpart = $2"
+
 type accountsStatements struct {
 	insertAccountStmt                   *sql.Stmt
 	updatePasswordStmt                  *sql.Stmt
@@ -74,6 +98,12 @@ type accountsStatements struct {
 	selectAccountByLocalpartStmt        *sql.Stmt
 	selectPasswordHashStmt              *sql.Stmt
 	selectNewNumericLocalpartStmt       *sql.Stmt
+	selectPrivacyPolicyStmt             *sql.Stmt
+	batchSelectPrivacyPolicyStmt        *sql.Stmt
+	updatePolicyVersionStmt             *sql.Stmt
+	updatePolicyVersionServerNoticeStmt *sql.Stmt
+	selectServerNoticeRoomStmt          *sql.Stmt
+	updateServerNoticeRoomStmt          *sql.Stmt
 	serverName                          gomatrixserverlib.ServerName
 }
 
@@ -92,6 +122,12 @@ func NewPostgresAccountsTable(db *sql.DB, serverName gomatrixserverlib.ServerNam
 		{&s.selectAccountByLocalpartStmt, selectAccountByLocalpartSQL},
 		{&s.selectPasswordHashStmt, selectPasswordHashSQL},
 		{&s.selectNewNumericLocalpartStmt, selectNewNumericLocalpartSQL},
+		{&s.selectPrivacyPolicyStmt, selectPrivacyPolicySQL},
+		{&s.batchSelectPrivacyPolicyStmt, batchSelectPrivacyPolicySQL},
+		{&s.updatePolicyVersionStmt, updatePolicyVersionSQL},
+		{&s.updatePolicyVersionServerNoticeStmt, updatePolicyVersionServerNoticeSQL},
+		{&s.selectServerNoticeRoomStmt, selectServerNoticeRoomSQL},
+		{&s.updateServerNoticeRoomStmt, updateServerNoticeRoomSQL},
 	}.Prepare(db)
 }
 
@@ -99,16 +135,16 @@ func NewPostgresAccountsTable(db *sql.DB, serverName gomatrixserverlib.ServerNam
 // this account will be passwordless. Returns an error if this account already exists. Returns the account
 // on success.
 func (s *accountsStatements) InsertAccount(
-	ctx context.Context, txn *sql.Tx, localpart, hash, appserviceID string, accountType api.AccountType,
+	ctx context.Context, txn *sql.Tx, localpart, hash, appserviceID, policyVersion string, accountType api.AccountType,
 ) (*api.Account, error) {
 	createdTimeMS := time.Now().UnixNano() / 1000000
 	stmt := sqlutil.TxStmt(txn, s.insertAccountStmt)
 
 	var err error
 	if accountType != api.AccountTypeAppService {
-		_, err = stmt.ExecContext(ctx, localpart, createdTimeMS, hash, nil, accountType)
+		_, err = stmt.ExecContext(ctx, localpart, createdTimeMS, hash, nil, accountType, policyVersion)
 	} else {
-		_, err = stmt.ExecContext(ctx, localpart, createdTimeMS, hash, appserviceID, accountType)
+		_, err = stmt.ExecContext(ctx, localpart, createdTimeMS, hash, appserviceID, accountType, policyVersion)
 	}
 	if err != nil {
 		return nil, err
@@ -178,3 +214,71 @@ func (s *accountsStatements) SelectNewNumericLocalpart(
 	err = stmt.QueryRowContext(ctx).Scan(&id)
 	return id + 1, err
 }
+
+// selectPrivacyPolicy gets the current privacy policy a specific user accepted
+func (s *accountsStatements) SelectPrivacyPolicy(
+	ctx context.Context, txn *sql.Tx, localPart string,
+) (policy string, err error) {
+	var policyNull sql.NullString
+	stmt := sqlutil.TxStmt(txn, s.selectPrivacyPolicyStmt)
+	err = stmt.QueryRowContext(ctx, localPart).Scan(&policyNull)
+	return policyNull.String, err
+}
+
+// batchSelectPrivacyPolicy queries all users which didn't accept the current policy version
+func (s *accountsStatements) BatchSelectPrivacyPolicy(
+	ctx context.Context, txn *sql.Tx, policyVersion string,
+) (userIDs []string, err error) {
+	stmt := sqlutil.TxStmt(txn, s.batchSelectPrivacyPolicyStmt)
+	rows, err := stmt.QueryContext(ctx, policyVersion)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "BatchSelectPrivacyPolicy: rows.close() failed")
+	for rows.Next() {
+		var userID string
+		if err := rows.Scan(&userID); err != nil {
+			return userIDs, err
+		}
+		userIDs = append(userIDs, userID)
+	}
+	return userIDs, rows.Err()
+}
+
+// updatePolicyVersion sets the policy_version for a specific user
+func (s *accountsStatements) UpdatePolicyVersion(
+	ctx context.Context, txn *sql.Tx, policyVersion, localpart string, serverNotice bool,
+) (err error) {
+	stmt := s.updatePolicyVersionStmt
+	if serverNotice {
+		stmt = s.updatePolicyVersionServerNoticeStmt
+	}
+	stmt = sqlutil.TxStmt(txn, stmt)
+	_, err = stmt.ExecContext(ctx, policyVersion, localpart)
+	return err
+}
+
+// SelectServerNoticeRoomID queries the server notice room ID.
+func (s *accountsStatements) SelectServerNoticeRoomID(
+	ctx context.Context, txn *sql.Tx, localpart string,
+) (roomID string, err error) {
+	stmt := sqlutil.TxStmt(txn, s.selectServerNoticeRoomStmt)
+
+	roomIDNull := sql.NullString{}
+	row := stmt.QueryRowContext(ctx, localpart)
+	err = row.Scan(&roomIDNull)
+	if err != nil && err != sql.ErrNoRows {
+		return "", err
+	}
+	// roomIDNull.String is either the roomID or an empty string
+	return roomIDNull.String, nil
+}
+
+// UpdateServerNoticeRoomID sets the server notice room ID.
+func (s *accountsStatements) UpdateServerNoticeRoomID(
+	ctx context.Context, txn *sql.Tx, localpart, roomID string,
+) (err error) {
+	stmt := sqlutil.TxStmt(txn, s.updateServerNoticeRoomStmt)
+	_, err = stmt.ExecContext(ctx, roomID, localpart)
+	return
+}

userapi/storage/postgres/deltas/20200929203058_is_active.go

@@ -12,6 +12,7 @@ import (
 func LoadFromGoose() {
 	goose.AddMigration(UpIsActive, DownIsActive)
 	goose.AddMigration(UpAddAccountType, DownAddAccountType)
+	goose.AddMigration(UpAddPolicyVersion, DownAddPolicyVersion)
 }
 
 func LoadIsActive(m *sqlutil.Migrations) {

userapi/storage/postgres/deltas/2022043014375800_add_policy_version.go

@@ -0,0 +1,45 @@
+package deltas
+
+import (
+	"database/sql"
+	"fmt"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+)
+
+func LoadAddPolicyVersion(m *sqlutil.Migrations) {
+	m.AddMigration(UpAddPolicyVersion, DownAddPolicyVersion)
+}
+
+func UpAddPolicyVersion(tx *sql.Tx) error {
+	_, err := tx.Exec("ALTER TABLE account_accounts ADD COLUMN IF NOT EXISTS policy_version TEXT;")
+	if err != nil {
+		return fmt.Errorf("failed to execute upgrade: %w", err)
+	}
+	_, err = tx.Exec("ALTER TABLE account_accounts ADD COLUMN IF NOT EXISTS policy_version_sent TEXT;")
+	if err != nil {
+		return fmt.Errorf("failed to execute upgrade: %w", err)
+	}
+	_, err = tx.Exec("ALTER TABLE account_accounts ADD COLUMN IF NOT EXISTS server_notice_room_id TEXT;")
+	if err != nil {
+		return fmt.Errorf("failed to execute upgrade: %w", err)
+	}
+
+	return nil
+}
+
+func DownAddPolicyVersion(tx *sql.Tx) error {
+	_, err := tx.Exec("ALTER TABLE account_accounts DROP COLUMN policy_version;")
+	if err != nil {
+		return fmt.Errorf("failed to execute downgrade: %w", err)
+	}
+	_, err = tx.Exec("ALTER TABLE account_accounts DROP COLUMN policy_version_sent;")
+	if err != nil {
+		return fmt.Errorf("failed to execute downgrade: %w", err)
+	}
+	_, err = tx.Exec("ALTER TABLE account_accounts DROP COLUMN server_notice_room_id;")
+	if err != nil {
+		return fmt.Errorf("failed to execute downgrade: %w", err)
+	}
+	return nil
+}

userapi/storage/postgres/storage.go

@@ -46,6 +46,7 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 	deltas.LoadIsActive(m)
 	//deltas.LoadLastSeenTSIP(m)
 	deltas.LoadAddAccountType(m)
+	deltas.LoadAddPolicyVersion(m)
 	if err = m.RunDeltas(db, dbProperties); err != nil {
 		return nil, err
 	}

userapi/storage/shared/storage.go

@@ -28,6 +28,7 @@ import (
 
 	"github.com/matrix-org/dendrite/userapi/types"
 	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
 	"golang.org/x/crypto/bcrypt"
 
 	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
@@ -125,7 +126,7 @@ func (d *Database) SetPassword(
 // for this account. If no password is supplied, the account will be a passwordless account. If the
 // account already exists, it will return nil, ErrUserExists.
 func (d *Database) CreateAccount(
-	ctx context.Context, localpart, plaintextPassword, appserviceID string, accountType api.AccountType,
+	ctx context.Context, localpart, plaintextPassword, appserviceID, policyVersion string, accountType api.AccountType,
 ) (acc *api.Account, err error) {
 	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		// For guest accounts, we create a new numeric local part
@@ -139,7 +140,7 @@ func (d *Database) CreateAccount(
 			plaintextPassword = ""
 			appserviceID = ""
 		}
-		acc, err = d.createAccount(ctx, txn, localpart, plaintextPassword, appserviceID, accountType)
+		acc, err = d.createAccount(ctx, txn, localpart, plaintextPassword, appserviceID, policyVersion, accountType)
 		return err
 	})
 	return
@@ -148,7 +149,7 @@ func (d *Database) CreateAccount(
 // WARNING! This function assumes that the relevant mutexes have already
 // been taken out by the caller (e.g. CreateAccount or CreateGuestAccount).
 func (d *Database) createAccount(
-	ctx context.Context, txn *sql.Tx, localpart, plaintextPassword, appserviceID string, accountType api.AccountType,
+	ctx context.Context, txn *sql.Tx, localpart, plaintextPassword, appserviceID, policyVersion string, accountType api.AccountType,
 ) (*api.Account, error) {
 	var err error
 	var account *api.Account
@@ -160,7 +161,8 @@ func (d *Database) createAccount(
 			return nil, err
 		}
 	}
-	if account, err = d.Accounts.InsertAccount(ctx, txn, localpart, hash, appserviceID, accountType); err != nil {
+	if account, err = d.Accounts.InsertAccount(ctx, txn, localpart, hash, appserviceID, policyVersion, accountType); err != nil {
+		logrus.WithError(err).Error("d.Accounts.InsertAccount error")
 		return nil, sqlutil.ErrUserExists
 	}
 	if err = d.Profiles.InsertProfile(ctx, txn, localpart); err != nil {
@@ -763,3 +765,42 @@ func (d *Database) RemovePushers(
 func (d *Database) UserStatistics(ctx context.Context) (*types.UserStatistics, *types.DatabaseEngine, error) {
 	return d.Stats.UserStatistics(ctx, nil)
 }
+
+// GetPrivacyPolicy returns the accepted privacy policy version, if any.
+func (d *Database) GetPrivacyPolicy(ctx context.Context, localpart string) (policyVersion string, err error) {
+	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		policyVersion, err = d.Accounts.SelectPrivacyPolicy(ctx, txn, localpart)
+		return err
+	})
+	return
+}
+
+// GetOutdatedPolicy queries all users which didn't accept the current policy version
+func (d *Database) GetOutdatedPolicy(ctx context.Context, policyVersion string) (userIDs []string, err error) {
+	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		userIDs, err = d.Accounts.BatchSelectPrivacyPolicy(ctx, txn, policyVersion)
+		return err
+	})
+	return
+}
+
+// UpdatePolicyVersion sets the accepted policy_version for a user.
+func (d *Database) UpdatePolicyVersion(ctx context.Context, policyVersion, localpart string, serverNotice bool) (err error) {
+	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		return d.Accounts.UpdatePolicyVersion(ctx, txn, policyVersion, localpart, serverNotice)
+	})
+	return
+}
+
+// SelectServerNoticeRoomID returns the server notice room, if one is set.
+func (d *Database) SelectServerNoticeRoomID(ctx context.Context, localpart string) (roomID string, err error) {
+	return d.Accounts.SelectServerNoticeRoomID(ctx, nil, localpart)
+}
+
+// UpdateServerNoticeRoomID updates the server notice room
+func (d *Database) UpdateServerNoticeRoomID(ctx context.Context, localpart, roomID string) (err error) {
+	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		return d.Accounts.UpdateServerNoticeRoomID(ctx, txn, localpart, roomID)
+	})
+	return
+}

userapi/storage/sqlite3/accounts_table.go

@@ -19,6 +19,7 @@ import (
 	"database/sql"
 	"time"
 
+	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/gomatrixserverlib"
 
 	"github.com/matrix-org/dendrite/clientapi/userutil"
@@ -43,14 +44,19 @@ CREATE TABLE IF NOT EXISTS account_accounts (
     -- If the account is currently active
     is_deactivated BOOLEAN DEFAULT 0,
 	-- The account_type (user = 1, guest = 2, admin = 3, appservice = 4)
-	account_type INTEGER NOT NULL
+	account_type INTEGER NOT NULL,
+	-- The policy version this user has accepted
+	policy_version TEXT,
+    -- The policy version the user received from the server notices room
+	policy_version_sent TEXT,
+	server_notice_room_id TEXT
     -- TODO:
     -- upgraded_ts, devices, any email reset stuff?
 );
 `
 
 const insertAccountSQL = "" +
-	"INSERT INTO account_accounts(localpart, created_ts, password_hash, appservice_id, account_type) VALUES ($1, $2, $3, $4, $5)"
+	"INSERT INTO account_accounts(localpart, created_ts, password_hash, appservice_id, account_type, policy_version) VALUES ($1, $2, $3, $4, $5, $6)"
 
 const updatePasswordSQL = "" +
 	"UPDATE account_accounts SET password_hash = $1 WHERE localpart = $2"
@@ -67,6 +73,24 @@ const selectPasswordHashSQL = "" +
 const selectNewNumericLocalpartSQL = "" +
 	"SELECT COALESCE(MAX(CAST(localpart AS INT)), 0) FROM account_accounts WHERE CAST(localpart AS INT) <> 0"
 
+const selectPrivacyPolicySQL = "" +
+	"SELECT policy_version FROM account_accounts WHERE localpart = $1"
+
+const batchSelectPrivacyPolicySQL = "" +
+	"SELECT localpart FROM account_accounts WHERE (policy_version IS NULL OR policy_version <> $1) AND (policy_version_sent IS NULL OR policy_version_sent <> $2)"
+
+const updatePolicyVersionSQL = "" +
+	"UPDATE account_accounts SET policy_version = $1 WHERE localpart = $2"
+
+const updatePolicyVersionServerNoticeSQL = "" +
+	"UPDATE account_accounts SET policy_version_sent = $1 WHERE localpart = $2"
+
+const selectServerNoticeRoomSQL = "" +
+	"SELECT server_notice_room_id FROM account_accounts WHERE localpart = $1"
+
+const updateServerNoticeRoomSQL = "" +
+	"UPDATE account_accounts SET server_notice_room_id = $1 WHERE localpart = $2"
+
 type accountsStatements struct {
 	db                                  *sql.DB
 	insertAccountStmt                   *sql.Stmt
@@ -75,6 +99,12 @@ type accountsStatements struct {
 	selectAccountByLocalpartStmt        *sql.Stmt
 	selectPasswordHashStmt              *sql.Stmt
 	selectNewNumericLocalpartStmt       *sql.Stmt
+	selectPrivacyPolicyStmt             *sql.Stmt
+	batchSelectPrivacyPolicyStmt        *sql.Stmt
+	updatePolicyVersionStmt             *sql.Stmt
+	updatePolicyVersionServerNoticeStmt *sql.Stmt
+	selectServerNoticeRoomStmt          *sql.Stmt
+	updateServerNoticeRoomStmt          *sql.Stmt
 	serverName                          gomatrixserverlib.ServerName
 }
 
@@ -94,6 +124,12 @@ func NewSQLiteAccountsTable(db *sql.DB, serverName gomatrixserverlib.ServerName)
 		{&s.selectAccountByLocalpartStmt, selectAccountByLocalpartSQL},
 		{&s.selectPasswordHashStmt, selectPasswordHashSQL},
 		{&s.selectNewNumericLocalpartStmt, selectNewNumericLocalpartSQL},
+		{&s.selectPrivacyPolicyStmt, selectPrivacyPolicySQL},
+		{&s.batchSelectPrivacyPolicyStmt, batchSelectPrivacyPolicySQL},
+		{&s.updatePolicyVersionStmt, updatePolicyVersionSQL},
+		{&s.updatePolicyVersionServerNoticeStmt, updatePolicyVersionServerNoticeSQL},
+		{&s.selectServerNoticeRoomStmt, selectServerNoticeRoomSQL},
+		{&s.updateServerNoticeRoomStmt, updateServerNoticeRoomSQL},
 	}.Prepare(db)
 }
 
@@ -101,16 +137,16 @@ func NewSQLiteAccountsTable(db *sql.DB, serverName gomatrixserverlib.ServerName)
 // this account will be passwordless. Returns an error if this account already exists. Returns the account
 // on success.
 func (s *accountsStatements) InsertAccount(
-	ctx context.Context, txn *sql.Tx, localpart, hash, appserviceID string, accountType api.AccountType,
+	ctx context.Context, txn *sql.Tx, localpart, hash, appserviceID, policyVersion string, accountType api.AccountType,
 ) (*api.Account, error) {
 	createdTimeMS := time.Now().UnixNano() / 1000000
-	stmt := s.insertAccountStmt
+	stmt := sqlutil.TxStmt(txn, s.insertAccountStmt)
 
 	var err error
 	if accountType != api.AccountTypeAppService {
-		_, err = sqlutil.TxStmt(txn, stmt).ExecContext(ctx, localpart, createdTimeMS, hash, nil, accountType)
+		_, err = stmt.ExecContext(ctx, localpart, createdTimeMS, hash, nil, accountType, policyVersion)
 	} else {
-		_, err = sqlutil.TxStmt(txn, stmt).ExecContext(ctx, localpart, createdTimeMS, hash, appserviceID, accountType)
+		_, err = stmt.ExecContext(ctx, localpart, createdTimeMS, hash, appserviceID, accountType, policyVersion)
 	}
 	if err != nil {
 		return nil, err
@@ -183,3 +219,72 @@ func (s *accountsStatements) SelectNewNumericLocalpart(
 	}
 	return id + 1, err
 }
+
+// selectPrivacyPolicy gets the current privacy policy a specific user accepted
+
+func (s *accountsStatements) SelectPrivacyPolicy(
+	ctx context.Context, txn *sql.Tx, localPart string,
+) (policy string, err error) {
+	var policyNull sql.NullString
+	stmt := sqlutil.TxStmt(txn, s.selectPrivacyPolicyStmt)
+	err = stmt.QueryRowContext(ctx, localPart).Scan(&policyNull)
+	return policyNull.String, err
+}
+
+// batchSelectPrivacyPolicy queries all users which didn't accept the current policy version
+func (s *accountsStatements) BatchSelectPrivacyPolicy(
+	ctx context.Context, txn *sql.Tx, policyVersion string,
+) (userIDs []string, err error) {
+	stmt := sqlutil.TxStmt(txn, s.batchSelectPrivacyPolicyStmt)
+	rows, err := stmt.QueryContext(ctx, policyVersion, policyVersion)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "BatchSelectPrivacyPolicy: rows.close() failed")
+	for rows.Next() {
+		var userID string
+		if err := rows.Scan(&userID); err != nil {
+			return userIDs, err
+		}
+		userIDs = append(userIDs, userID)
+	}
+	return userIDs, rows.Err()
+}
+
+// updatePolicyVersion sets the policy_version for a specific user
+func (s *accountsStatements) UpdatePolicyVersion(
+	ctx context.Context, txn *sql.Tx, policyVersion, localpart string, serverNotice bool,
+) (err error) {
+	stmt := s.updatePolicyVersionStmt
+	if serverNotice {
+		stmt = s.updatePolicyVersionServerNoticeStmt
+	}
+	stmt = sqlutil.TxStmt(txn, stmt)
+	_, err = stmt.ExecContext(ctx, policyVersion, localpart)
+	return err
+}
+
+// SelectServerNoticeRoomID queries the server notice room ID.
+func (s *accountsStatements) SelectServerNoticeRoomID(
+	ctx context.Context, txn *sql.Tx, localpart string,
+) (roomID string, err error) {
+	stmt := sqlutil.TxStmt(txn, s.selectServerNoticeRoomStmt)
+
+	roomIDNull := sql.NullString{}
+	row := stmt.QueryRowContext(ctx, localpart)
+	err = row.Scan(&roomIDNull)
+	if err != nil && err != sql.ErrNoRows {
+		return "", err
+	}
+	// roomIDNull.String is either the roomID or an empty string
+	return roomIDNull.String, nil
+}
+
+// UpdateServerNoticeRoomID sets the server notice room ID.
+func (s *accountsStatements) UpdateServerNoticeRoomID(
+	ctx context.Context, txn *sql.Tx, localpart, roomID string,
+) (err error) {
+	stmt := sqlutil.TxStmt(txn, s.updateServerNoticeRoomStmt)
+	_, err = stmt.ExecContext(ctx, roomID, localpart)
+	return
+}

userapi/storage/sqlite3/deltas/20200929203058_is_active.go

@@ -12,6 +12,7 @@ import (
 func LoadFromGoose() {
 	goose.AddMigration(UpIsActive, DownIsActive)
 	goose.AddMigration(UpAddAccountType, DownAddAccountType)
+	goose.AddMigration(UpAddPolicyVersion, DownAddPolicyVersion)
 }
 
 func LoadIsActive(m *sqlutil.Migrations) {

userapi/storage/sqlite3/deltas/2022021012490600_add_account_type.go

@@ -4,15 +4,9 @@ import (
 	"database/sql"
 	"fmt"
 
-	"github.com/pressly/goose"
-
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 )
 
-func init() {
-	goose.AddMigration(UpAddAccountType, DownAddAccountType)
-}
-
 func LoadAddAccountType(m *sqlutil.Migrations) {
 	m.AddMigration(UpAddAccountType, DownAddAccountType)
 }

userapi/storage/sqlite3/deltas/2022043014375800_add_policy_version.go

@@ -0,0 +1,44 @@
+package deltas
+
+import (
+	"database/sql"
+	"fmt"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+)
+
+func LoadAddPolicyVersion(m *sqlutil.Migrations) {
+	m.AddMigration(UpAddPolicyVersion, DownAddPolicyVersion)
+}
+
+func UpAddPolicyVersion(tx *sql.Tx) error {
+	_, err := tx.Exec("ALTER TABLE account_accounts ADD COLUMN policy_version TEXT;")
+	if err != nil {
+		return fmt.Errorf("failed to execute upgrade: %w", err)
+	}
+	_, err = tx.Exec("ALTER TABLE account_accounts ADD COLUMN policy_version_sent TEXT;")
+	if err != nil {
+		return fmt.Errorf("failed to execute upgrade: %w", err)
+	}
+	_, err = tx.Exec("ALTER TABLE account_accounts ADD COLUMN server_notice_room_id TEXT;")
+	if err != nil {
+		return fmt.Errorf("failed to execute upgrade: %w", err)
+	}
+	return nil
+}
+
+func DownAddPolicyVersion(tx *sql.Tx) error {
+	_, err := tx.Exec("ALTER TABLE account_accounts DROP COLUMN policy_version;")
+	if err != nil {
+		return fmt.Errorf("failed to execute downgrade: %w", err)
+	}
+	_, err = tx.Exec("ALTER TABLE account_accounts DROP COLUMN policy_version_sent;")
+	if err != nil {
+		return fmt.Errorf("failed to execute downgrade: %w", err)
+	}
+	_, err = tx.Exec("ALTER TABLE account_accounts DROP COLUMN server_notice_room_id;")
+	if err != nil {
+		return fmt.Errorf("failed to execute downgrade: %w", err)
+	}
+	return nil
+}

userapi/storage/sqlite3/storage.go

@@ -18,11 +18,10 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/matrix-org/gomatrixserverlib"
-
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/setup/base"
 	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/gomatrixserverlib"
 
 	"github.com/matrix-org/dendrite/userapi/storage/shared"
 	"github.com/matrix-org/dendrite/userapi/storage/sqlite3/deltas"
@@ -47,6 +46,7 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 	deltas.LoadIsActive(m)
 	//deltas.LoadLastSeenTSIP(m)
 	deltas.LoadAddAccountType(m)
+	deltas.LoadAddPolicyVersion(m)
 	if err = m.RunDeltas(db, dbProperties); err != nil {
 		return nil, err
 	}

userapi/storage/storage_test.go

@@ -78,7 +78,7 @@ func Test_Accounts(t *testing.T) {
 		aliceLocalpart, _, err := gomatrixserverlib.SplitID('@', alice.ID)
 		assert.NoError(t, err)
 
-		accAlice, err := db.CreateAccount(ctx, aliceLocalpart, "testing", "", api.AccountTypeAdmin)
+		accAlice, err := db.CreateAccount(ctx, aliceLocalpart, "testing", "", "v1.0", api.AccountTypeAdmin)
 		assert.NoError(t, err, "failed to create account")
 		// verify the newly create account is the same as returned by CreateAccount
 		var accGet *api.Account
@@ -102,7 +102,7 @@ func Test_Accounts(t *testing.T) {
 		first, err := db.GetNewNumericLocalpart(ctx)
 		assert.NoError(t, err, "failed to get new numeric localpart")
 		// Create a new account to verify the numeric localpart is updated
-		_, err = db.CreateAccount(ctx, "", "testing", "", api.AccountTypeGuest)
+		_, err = db.CreateAccount(ctx, "", "testing", "", "v1.0", api.AccountTypeGuest)
 		assert.NoError(t, err, "failed to create account")
 		second, err := db.GetNewNumericLocalpart(ctx)
 		assert.NoError(t, err)
@@ -350,7 +350,7 @@ func Test_Profile(t *testing.T) {
 		defer close()
 
 		// create account, which also creates a profile
-		_, err = db.CreateAccount(ctx, aliceLocalpart, "testing", "", api.AccountTypeAdmin)
+		_, err = db.CreateAccount(ctx, aliceLocalpart, "testing", "", "v1.0", api.AccountTypeAdmin)
 		assert.NoError(t, err, "failed to create account")
 
 		gotProfile, err := db.GetProfileByLocalpart(ctx, aliceLocalpart)

userapi/storage/tables/interface.go

@@ -32,12 +32,18 @@ type AccountDataTable interface {
 }
 
 type AccountsTable interface {
-	InsertAccount(ctx context.Context, txn *sql.Tx, localpart, hash, appserviceID string, accountType api.AccountType) (*api.Account, error)
+	InsertAccount(ctx context.Context, txn *sql.Tx, localpart, hash, appserviceID, policyVersion string, accountType api.AccountType) (*api.Account, error)
 	UpdatePassword(ctx context.Context, localpart, passwordHash string) (err error)
 	DeactivateAccount(ctx context.Context, localpart string) (err error)
 	SelectPasswordHash(ctx context.Context, localpart string) (hash string, err error)
 	SelectAccountByLocalpart(ctx context.Context, localpart string) (*api.Account, error)
 	SelectNewNumericLocalpart(ctx context.Context, txn *sql.Tx) (id int64, err error)
+
+	SelectPrivacyPolicy(ctx context.Context, txn *sql.Tx, localPart string) (policy string, err error)
+	BatchSelectPrivacyPolicy(ctx context.Context, txn *sql.Tx, policyVersion string) (userIDs []string, err error)
+	UpdatePolicyVersion(ctx context.Context, txn *sql.Tx, policyVersion, localpart string, serverNotice bool) (err error)
+	SelectServerNoticeRoomID(ctx context.Context, txn *sql.Tx, localpart string) (roomID string, err error)
+	UpdateServerNoticeRoomID(ctx context.Context, txn *sql.Tx, localpart, roomID string) (err error)
 }
 
 type DevicesTable interface {

userapi/storage/tables/stats_table_test.go

@@ -88,7 +88,7 @@ func mustMakeAccountAndDevice(
 		appServiceID = util.RandomString(16)
 	}
 
-	_, err := accDB.InsertAccount(ctx, nil, localpart, "", appServiceID, accType)
+	_, err := accDB.InsertAccount(ctx, nil, localpart, "", "", appServiceID, accType)
 	if err != nil {
 		t.Fatalf("unable to create account: %v", err)
 	}

userapi/userapi_test.go

@@ -75,7 +75,7 @@ func TestQueryProfile(t *testing.T) {
 	// only one DBType, since userapi.AddInternalRoutes complains about multiple prometheus counters added
 	userAPI, accountDB, close := MustMakeInternalAPI(t, apiTestOpts{}, test.DBTypeSQLite)
 	defer close()
-	_, err := accountDB.CreateAccount(context.TODO(), "alice", "foobar", "", api.AccountTypeUser)
+	_, err := accountDB.CreateAccount(context.TODO(), "alice", "foobar", "", "", api.AccountTypeUser)
 	if err != nil {
 		t.Fatalf("failed to make account: %s", err)
 	}
@@ -154,7 +154,7 @@ func TestLoginToken(t *testing.T) {
 		test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
 			userAPI, accountDB, close := MustMakeInternalAPI(t, apiTestOpts{}, dbType)
 			defer close()
-			_, err := accountDB.CreateAccount(ctx, "auser", "apassword", "", api.AccountTypeUser)
+			_, err := accountDB.CreateAccount(ctx, "auser", "apassword", "", "", api.AccountTypeUser)
 			if err != nil {
 				t.Fatalf("failed to make account: %s", err)
 			}