Make bcrypt cost configurable
MODIFY
cmd/create-account/main.go
cmd/create-account/main.go
@@ -24,6 +24,7 @@ import (
"github.com/matrix-org/dendrite/setup/config"
"github.com/matrix-org/dendrite/userapi/storage/accounts"
"github.com/sirupsen/logrus"
+ "golang.org/x/crypto/bcrypt"
)
const usage = `Usage: %s
@@ -57,7 +58,7 @@ func main() {
accountDB, err := accounts.NewDatabase(&config.DatabaseOptions{
ConnectionString: cfg.UserAPI.AccountDatabase.ConnectionString,
- }, cfg.Global.ServerName)
+ }, cfg.Global.ServerName, bcrypt.DefaultCost)
if err != nil {
logrus.Fatalln("Failed to connect to the database:", err.Error())
}

MODIFY
cmd/generate-config/main.go
cmd/generate-config/main.go
@@ -5,6 +5,7 @@ import (
"fmt"
"github.com/matrix-org/dendrite/setup/config"
+ "golang.org/x/crypto/bcrypt"
"gopkg.in/yaml.v2"
)
@@ -68,6 +69,7 @@ func main() {
cfg.Logging[0].Level = "trace"
// don't hit matrix.org when running tests!!!
cfg.SigningKeyServer.KeyPerspectives = config.KeyPerspectives{}
+ cfg.UserAPI.BCryptCost = bcrypt.MinCost
}
j, err := yaml.Marshal(cfg)

MODIFY
dendrite-config.yaml
dendrite-config.yaml
@@ -340,6 +340,13 @@ sync_api:
# Configuration for the User API.
user_api:
+ # The cost when hashing passwords on registration/login. Default: 10. Min: 4, Max: 31
+ # See https://pkg.go.dev/golang.org/x/crypto/bcrypt for more information.
+ # Setting this lower makes registration/login consume less CPU resources at the cost of security
+ # should the database be compromised. Setting this higher makes registration/login consume more
+ # CPU resources but makes it harder to brute force password hashes.
+ # This value can be low if performing tests or on embedded Dendrite instances (e.g WASM builds)
+ # bcrypt_cost: 10
internal_api:
listen: http://localhost:7781
connect: http://localhost:7781

MODIFY
setup/base.go
setup/base.go
@@ -263,7 +263,7 @@ func (b *BaseDendrite) KeyServerHTTPClient() keyserverAPI.KeyInternalAPI {
// CreateAccountsDB creates a new instance of the accounts database. Should only
// be called once per component.
func (b *BaseDendrite) CreateAccountsDB() accounts.Database {
- db, err := accounts.NewDatabase(&b.Cfg.UserAPI.AccountDatabase, b.Cfg.Global.ServerName)
+ db, err := accounts.NewDatabase(&b.Cfg.UserAPI.AccountDatabase, b.Cfg.Global.ServerName, b.Cfg.UserAPI.BCryptCost)
if err != nil {
logrus.WithError(err).Panicf("failed to connect to accounts db")
}

MODIFY
setup/config/config_userapi.go
setup/config/config_userapi.go
package config
+import "golang.org/x/crypto/bcrypt"
+
type UserAPI struct {
Matrix *Global `yaml:"-"`
InternalAPI InternalAPIOptions `yaml:"internal_api"`
+ // The cost when hashing passwords.
+ BCryptCost int `yaml:"bcrypt_cost"`
+
// The Account database stores the login details and account information
// for local users. It is accessed by the UserAPI.
AccountDatabase DatabaseOptions `yaml:"account_database"`
@@ -20,6 +25,7 @@ func (c *UserAPI) Defaults() {
c.DeviceDatabase.Defaults(10)
c.AccountDatabase.ConnectionString = "file:userapi_accounts.db"
c.DeviceDatabase.ConnectionString = "file:userapi_devices.db"
+ c.BCryptCost = bcrypt.DefaultCost
}
func (c *UserAPI) Verify(configErrs *ConfigErrors, isMonolith bool) {

MODIFY
userapi/storage/accounts/postgres/storage.go
userapi/storage/accounts/postgres/storage.go
@@ -44,10 +44,11 @@ type Database struct {
accountDatas accountDataStatements
threepids threepidStatements
serverName gomatrixserverlib.ServerName
+ bcryptCost int
}
// NewDatabase creates a new accounts and profiles database
-func NewDatabase(dbProperties *config.DatabaseOptions, serverName gomatrixserverlib.ServerName) (*Database, error) {
+func NewDatabase(dbProperties *config.DatabaseOptions, serverName gomatrixserverlib.ServerName, bcryptCost int) (*Database, error) {
db, err := sqlutil.Open(dbProperties)
if err != nil {
return nil, err
@@ -56,6 +57,7 @@ func NewDatabase(dbProperties *config.DatabaseOptions, serverName gomatrixserver
serverName: serverName,
db: db,
writer: sqlutil.NewDummyWriter(),
+ bcryptCost: bcryptCost,
}
// Create tables before executing migrations so we don't fail if the table is missing,
@@ -131,7 +133,7 @@ func (d *Database) SetDisplayName(
func (d *Database) SetPassword(
ctx context.Context, localpart, plaintextPassword string,
) error {
- hash, err := hashPassword(plaintextPassword)
+ hash, err := d.hashPassword(plaintextPassword)
if err != nil {
return err
}
@@ -175,7 +177,7 @@ func (d *Database) createAccount(
// Generate a password hash if this is not a password-less user
hash := ""
if plaintextPassword != "" {
- hash, err = hashPassword(plaintextPassword)
+ hash, err = d.hashPassword(plaintextPassword)
if err != nil {
return nil, err
}
@@ -246,8 +248,8 @@ func (d *Database) GetNewNumericLocalpart(
return d.accounts.selectNewNumericLocalpart(ctx, nil)
}
-func hashPassword(plaintext string) (hash string, err error) {
- hashBytes, err := bcrypt.GenerateFromPassword([]byte(plaintext), bcrypt.DefaultCost)
+func (d *Database) hashPassword(plaintext string) (hash string, err error) {
+ hashBytes, err := bcrypt.GenerateFromPassword([]byte(plaintext), d.bcryptCost)
return string(hashBytes), err
}

MODIFY
userapi/storage/accounts/sqlite3/storage.go
userapi/storage/accounts/sqlite3/storage.go
@@ -42,6 +42,7 @@ type Database struct {
accountDatas accountDataStatements
threepids threepidStatements
serverName gomatrixserverlib.ServerName
+ bcryptCost int
accountsMu sync.Mutex
profilesMu sync.Mutex
@@ -50,7 +51,7 @@ type Database struct {
}
// NewDatabase creates a new accounts and profiles database
-func NewDatabase(dbProperties *config.DatabaseOptions, serverName gomatrixserverlib.ServerName) (*Database, error) {
+func NewDatabase(dbProperties *config.DatabaseOptions, serverName gomatrixserverlib.ServerName, bcryptCost int) (*Database, error) {
db, err := sqlutil.Open(dbProperties)
if err != nil {
return nil, err
@@ -59,6 +60,7 @@ func NewDatabase(dbProperties *config.DatabaseOptions, serverName gomatrixserver
serverName: serverName,
db: db,
writer: sqlutil.NewExclusiveWriter(),
+ bcryptCost: bcryptCost,
}
// Create tables before executing migrations so we don't fail if the table is missing,
@@ -143,7 +145,7 @@ func (d *Database) SetDisplayName(
func (d *Database) SetPassword(
ctx context.Context, localpart, plaintextPassword string,
) error {
- hash, err := hashPassword(plaintextPassword)
+ hash, err := d.hashPassword(plaintextPassword)
if err != nil {
return err
}
@@ -208,7 +210,7 @@ func (d *Database) createAccount(
// Generate a password hash if this is not a password-less user
hash := ""
if plaintextPassword != "" {
- hash, err = hashPassword(plaintextPassword)
+ hash, err = d.hashPassword(plaintextPassword)
if err != nil {
return nil, err
}
@@ -278,8 +280,8 @@ func (d *Database) GetNewNumericLocalpart(
return d.accounts.selectNewNumericLocalpart(ctx, nil)
}
-func hashPassword(plaintext string) (hash string, err error) {
- hashBytes, err := bcrypt.GenerateFromPassword([]byte(plaintext), bcrypt.DefaultCost)
+func (d *Database) hashPassword(plaintext string) (hash string, err error) {
+ hashBytes, err := bcrypt.GenerateFromPassword([]byte(plaintext), d.bcryptCost)
return string(hashBytes), err
}

MODIFY
userapi/storage/accounts/storage.go
userapi/storage/accounts/storage.go
@@ -27,12 +27,12 @@ import (
// NewDatabase opens a new Postgres or Sqlite database (based on dataSourceName scheme)
// and sets postgres connection parameters
-func NewDatabase(dbProperties *config.DatabaseOptions, serverName gomatrixserverlib.ServerName) (Database, error) {
+func NewDatabase(dbProperties *config.DatabaseOptions, serverName gomatrixserverlib.ServerName, bcryptCost int) (Database, error) {
switch {
case dbProperties.ConnectionString.IsSQLite():
- return sqlite3.NewDatabase(dbProperties, serverName)
+ return sqlite3.NewDatabase(dbProperties, serverName, bcryptCost)
case dbProperties.ConnectionString.IsPostgres():
- return postgres.NewDatabase(dbProperties, serverName)
+ return postgres.NewDatabase(dbProperties, serverName, bcryptCost)
default:
return nil, fmt.Errorf("unexpected database type")
}

MODIFY
userapi/storage/accounts/storage_wasm.go
userapi/storage/accounts/storage_wasm.go
@@ -25,10 +25,11 @@ import (
func NewDatabase(
dbProperties *config.DatabaseOptions,
serverName gomatrixserverlib.ServerName,
+ bcryptCost int,
) (Database, error) {
switch {
case dbProperties.ConnectionString.IsSQLite():
- return sqlite3.NewDatabase(dbProperties, serverName)
+ return sqlite3.NewDatabase(dbProperties, serverName, bcryptCost)
case dbProperties.ConnectionString.IsPostgres():
return nil, fmt.Errorf("can't use Postgres implementation")
default:

MODIFY
userapi/userapi.go
userapi/userapi.go
@@ -37,7 +37,6 @@ func AddInternalRoutes(router *mux.Router, intAPI api.UserInternalAPI) {
func NewInternalAPI(
accountDB accounts.Database, cfg *config.UserAPI, appServices []config.ApplicationService, keyAPI keyapi.KeyInternalAPI,
) api.UserInternalAPI {
-
deviceDB, err := devices.NewDatabase(&cfg.DeviceDatabase, cfg.Matrix.ServerName)
if err != nil {
logrus.WithError(err).Panicf("failed to connect to device db")

MODIFY
userapi/userapi_test.go
userapi/userapi_test.go
@@ -16,6 +16,7 @@ import (
"github.com/matrix-org/dendrite/userapi/inthttp"
"github.com/matrix-org/dendrite/userapi/storage/accounts"
"github.com/matrix-org/gomatrixserverlib"
+ "golang.org/x/crypto/bcrypt"
)
const (
@@ -25,7 +26,7 @@ const (
func MustMakeInternalAPI(t *testing.T) (api.UserInternalAPI, accounts.Database) {
accountDB, err := accounts.NewDatabase(&config.DatabaseOptions{
ConnectionString: "file::memory:",
- }, serverName)
+ }, serverName, bcrypt.MinCost)
if err != nil {
t.Fatalf("failed to create account DB: %s", err)
}

Make bcrypt cost configurable (#1793)