Use /admin/v1/register in create-account (#2484)

* Get all account data on CompleteSync

* Revert "Get all account data on CompleteSync"

This reverts commit 44a3e566d8fb940b0b757aea9b8408fa19ea9f54.

* Use /_synapse/admin/v1/register to create account

* Linting

* Linter again :)

* Update docs

* Use HTTP API to reset password, add option to User API `PerformPasswordUpdate` to invalidate sessions

* Fix routing name

* Tell me more about what went wrong

* Deprecate the `-reset-password` flag, document the new API

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

cmd/create-account/main.go

@@ -15,20 +15,26 @@
 package main
 
 import (
-	"context"
+	"bytes"
+	"crypto/hmac"
+	"crypto/sha1"
+	"encoding/hex"
+	"encoding/json"
 	"flag"
 	"fmt"
 	"io"
+	"net/http"
 	"os"
 	"regexp"
 	"strings"
+	"time"
+
+	"github.com/tidwall/gjson"
 
-	"github.com/matrix-org/dendrite/setup"
-	"github.com/matrix-org/dendrite/setup/base"
-	"github.com/matrix-org/dendrite/userapi/api"
-	"github.com/matrix-org/dendrite/userapi/storage"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/term"
+
+	"github.com/matrix-org/dendrite/setup"
 )
 
 const usage = `Usage: %s
@@ -58,12 +64,17 @@ var (
 	password           = flag.String("password", "", "The password to associate with the account")
 	pwdFile            = flag.String("passwordfile", "", "The file to use for the password (e.g. for automated account creation)")
 	pwdStdin           = flag.Bool("passwordstdin", false, "Reads the password from stdin")
-	pwdLess            = flag.Bool("passwordless", false, "Create a passwordless account, e.g. if only an accesstoken is required")
 	isAdmin            = flag.Bool("admin", false, "Create an admin account")
 	resetPassword      = flag.Bool("reset-password", false, "Resets the password for the given username")
+	serverURL          = flag.String("url", "https://localhost:8448", "The URL to connect to.")
 	validUsernameRegex = regexp.MustCompile(`^[0-9a-z_\-=./]+$`)
 )
 
+var cl = http.Client{
+	Timeout:   time.Second * 10,
+	Transport: http.DefaultTransport,
+}
+
 func main() {
 	name := os.Args[0]
 	flag.Usage = func() {
@@ -72,15 +83,15 @@ func main() {
 	}
 	cfg := setup.ParseFlags(true)
 
+	if *resetPassword {
+		logrus.Fatalf("The reset-password flag has been replaced by the POST /_dendrite/admin/resetPassword/{localpart} admin API.")
+	}
+
 	if *username == "" {
 		flag.Usage()
 		os.Exit(1)
 	}
 
-	if *pwdLess && *resetPassword {
-		logrus.Fatalf("Can not reset to an empty password, unable to login afterwards.")
-	}
-
 	if !validUsernameRegex.MatchString(*username) {
 		logrus.Warn("Username can only contain characters a-z, 0-9, or '_-./='")
 		os.Exit(1)
@@ -90,67 +101,94 @@ func main() {
 		logrus.Fatalf("Username can not be longer than 255 characters: %s", fmt.Sprintf("@%s:%s", *username, cfg.Global.ServerName))
 	}
 
-	var pass string
-	var err error
-	if !*pwdLess {
-		pass, err = getPassword(*password, *pwdFile, *pwdStdin, os.Stdin)
-		if err != nil {
-			logrus.Fatalln(err)
-		}
-	}
-
-	// avoid warning about open registration
-	cfg.ClientAPI.RegistrationDisabled = true
-
-	b := base.NewBaseDendrite(cfg, "")
-	defer b.Close() // nolint: errcheck
-
-	accountDB, err := storage.NewUserAPIDatabase(
-		b,
-		&cfg.UserAPI.AccountDatabase,
-		cfg.Global.ServerName,
-		cfg.UserAPI.BCryptCost,
-		cfg.UserAPI.OpenIDTokenLifetimeMS,
-		0, // TODO
-		cfg.Global.ServerNotices.LocalPart,
-	)
+	pass, err := getPassword(*password, *pwdFile, *pwdStdin, os.Stdin)
 	if err != nil {
-		logrus.WithError(err).Fatalln("Failed to connect to the database")
+		logrus.Fatalln(err)
 	}
 
-	accType := api.AccountTypeUser
-	if *isAdmin {
-		accType = api.AccountTypeAdmin
-	}
-
-	available, err := accountDB.CheckAccountAvailability(context.Background(), *username)
-	if err != nil {
-		logrus.Fatalln("Unable check username existence.")
-	}
-	if *resetPassword {
-		if available {
-			logrus.Fatalln("Username could not be found.")
-		}
-		err = accountDB.SetPassword(context.Background(), *username, pass)
-		if err != nil {
-			logrus.Fatalf("Failed to update password for user %s: %s", *username, err.Error())
-		}
-		if _, err = accountDB.RemoveAllDevices(context.Background(), *username, ""); err != nil {
-			logrus.Fatalf("Failed to remove all devices: %s", err.Error())
-		}
-		logrus.Infof("Updated password for user %s and invalidated all logins\n", *username)
-		return
-	}
-	if !available {
-		logrus.Fatalln("Username is already in use.")
-	}
-
-	_, err = accountDB.CreateAccount(context.Background(), *username, pass, "", accType)
+	accessToken, err := sharedSecretRegister(cfg.ClientAPI.RegistrationSharedSecret, *serverURL, *username, pass, *isAdmin)
 	if err != nil {
 		logrus.Fatalln("Failed to create the account:", err.Error())
 	}
 
-	logrus.Infoln("Created account", *username)
+	logrus.Infof("Created account: %s (AccessToken: %s)", *username, accessToken)
+}
+
+type sharedSecretRegistrationRequest struct {
+	User     string `json:"username"`
+	Password string `json:"password"`
+	Nonce    string `json:"nonce"`
+	MacStr   string `json:"mac"`
+	Admin    bool   `json:"admin"`
+}
+
+func sharedSecretRegister(sharedSecret, serverURL, localpart, password string, admin bool) (accesToken string, err error) {
+	registerURL := fmt.Sprintf("%s/_synapse/admin/v1/register", serverURL)
+	nonceReq, err := http.NewRequest(http.MethodGet, registerURL, nil)
+	if err != nil {
+		return "", fmt.Errorf("unable to create http request: %w", err)
+	}
+	nonceResp, err := cl.Do(nonceReq)
+	if err != nil {
+		return "", fmt.Errorf("unable to get nonce: %w", err)
+	}
+	body, err := io.ReadAll(nonceResp.Body)
+	if err != nil {
+		return "", fmt.Errorf("failed to read response body: %w", err)
+	}
+	defer nonceResp.Body.Close() // nolint: errcheck
+
+	nonce := gjson.GetBytes(body, "nonce").Str
+
+	adminStr := "notadmin"
+	if admin {
+		adminStr = "admin"
+	}
+	reg := sharedSecretRegistrationRequest{
+		User:     localpart,
+		Password: password,
+		Nonce:    nonce,
+		Admin:    admin,
+	}
+	macStr, err := getRegisterMac(sharedSecret, nonce, localpart, password, adminStr)
+	if err != nil {
+		return "", err
+	}
+	reg.MacStr = macStr
+
+	js, err := json.Marshal(reg)
+	if err != nil {
+		return "", fmt.Errorf("unable to marshal json: %w", err)
+	}
+	registerReq, err := http.NewRequest(http.MethodPost, registerURL, bytes.NewBuffer(js))
+	if err != nil {
+		return "", fmt.Errorf("unable to create http request: %w", err)
+
+	}
+	regResp, err := cl.Do(registerReq)
+	if err != nil {
+		return "", fmt.Errorf("unable to create account: %w", err)
+	}
+	defer regResp.Body.Close() // nolint: errcheck
+	if regResp.StatusCode < 200 || regResp.StatusCode >= 300 {
+		body, _ = io.ReadAll(regResp.Body)
+		return "", fmt.Errorf(gjson.GetBytes(body, "error").Str)
+	}
+	r, _ := io.ReadAll(regResp.Body)
+
+	return gjson.GetBytes(r, "access_token").Str, nil
+}
+
+func getRegisterMac(sharedSecret, nonce, localpart, password, adminStr string) (string, error) {
+	joined := strings.Join([]string{nonce, localpart, password, adminStr}, "\x00")
+	mac := hmac.New(sha1.New, []byte(sharedSecret))
+	_, err := mac.Write([]byte(joined))
+	if err != nil {
+		return "", fmt.Errorf("unable to construct mac: %w", err)
+	}
+	regMac := mac.Sum(nil)
+
+	return hex.EncodeToString(regMac), nil
 }
 
 func getPassword(password, pwdFile string, pwdStdin bool, r io.Reader) (string, error) {