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fix: refresh token only once for all concurrent requests 

Signed-off-by: m.nabokikh <maksim.nabokikh@flant.com>
This commit is contained in:
m.nabokikh 2022-10-02 22:40:22 +02:00
parent ffeb4d5e16
commit 4b5f1d5289
4 changed files with 357 additions and 85 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

205
server/refreshhandlers.go
View File

@ -28,6 +28,10 @@ type refreshError struct {
desc string
}
func (r *refreshError) Error() string {
return fmt.Sprintf("refresh token error: status %d, %q %s", r.code, r.msg, r.desc)
}
func newInternalServerError() *refreshError {
return &refreshError{msg: errInvalidRequest, desc: "", code: http.StatusInternalServerError}
}
@ -60,10 +64,23 @@ func (s *Server) extractRefreshTokenFromRequest(r *http.Request) (*internal.Refr
return token, nil
}
type refreshContext struct {
storageToken *storage.RefreshToken
requestToken *internal.RefreshToken
connector Connector
connectorData []byte
scopes []string
}
// getRefreshTokenFromStorage checks that refresh token is valid and exists in the storage and gets its info
func (s *Server) getRefreshTokenFromStorage(clientID string, token *internal.RefreshToken) (*storage.RefreshToken, *refreshError) {
func (s *Server) getRefreshTokenFromStorage(clientID string, token *internal.RefreshToken) (*refreshContext, *refreshError) {
refreshCtx := refreshContext{requestToken: token}
invalidErr := newBadRequestError("Refresh token is invalid or has already been claimed by another client.")
// Get RefreshToken
refresh, err := s.storage.GetRefresh(token.RefreshId)
if err != nil {
if err != storage.ErrNotFound {
@ -103,7 +120,31 @@ func (s *Server) getRefreshTokenFromStorage(clientID string, token *internal.Ref
return nil, expiredErr
}
return &refresh, nil
refreshCtx.storageToken = &refresh
// Get Connector
refreshCtx.connector, err = s.getConnector(refresh.ConnectorID)
if err != nil {
s.logger.Errorf("connector with ID %q not found: %v", refresh.ConnectorID, err)
return nil, newInternalServerError()
}
// Get Connector Data
session, err := s.storage.GetOfflineSessions(refresh.Claims.UserID, refresh.ConnectorID)
switch {
case err != nil:
if err != storage.ErrNotFound {
s.logger.Errorf("failed to get offline session: %v", err)
return nil, newInternalServerError()
}
case len(refresh.ConnectorData) > 0:
// Use the old connector data if it exists, should be deleted once used
refreshCtx.connectorData = refresh.ConnectorData
default:
refreshCtx.connectorData = session.ConnectorData
}
return &refreshCtx, nil
}
func (s *Server) getRefreshScopes(r *http.Request, refresh *storage.RefreshToken) ([]string, *refreshError) {
@ -138,59 +179,23 @@ func (s *Server) getRefreshScopes(r *http.Request, refresh *storage.RefreshToken
return requestedScopes, nil
}
func (s *Server) refreshWithConnector(ctx context.Context, token *internal.RefreshToken, refresh *storage.RefreshToken, scopes []string) (connector.Identity, *refreshError) {
var connectorData []byte
session, err := s.storage.GetOfflineSessions(refresh.Claims.UserID, refresh.ConnectorID)
switch {
case err != nil:
if err != storage.ErrNotFound {
s.logger.Errorf("failed to get offline session: %v", err)
return connector.Identity{}, newInternalServerError()
}
case len(refresh.ConnectorData) > 0:
// Use the old connector data if it exists, should be deleted once used
connectorData = refresh.ConnectorData
default:
connectorData = session.ConnectorData
}
conn, err := s.getConnector(refresh.ConnectorID)
if err != nil {
s.logger.Errorf("connector with ID %q not found: %v", refresh.ConnectorID, err)
return connector.Identity{}, newInternalServerError()
}
ident := connector.Identity{
UserID: refresh.Claims.UserID,
Username: refresh.Claims.Username,
PreferredUsername: refresh.Claims.PreferredUsername,
Email: refresh.Claims.Email,
EmailVerified: refresh.Claims.EmailVerified,
Groups: refresh.Claims.Groups,
ConnectorData: connectorData,
}
// user's token was previously updated by a connector and is allowed to reuse
// it is excessive to refresh identity in upstream
if s.refreshTokenPolicy.AllowedToReuse(refresh.LastUsed) && token.Token == refresh.ObsoleteToken {
return ident, nil
}
func (s *Server) refreshWithConnector(ctx context.Context, rCtx *refreshContext, ident connector.Identity) (connector.Identity, *refreshError) {
// Can the connector refresh the identity? If so, attempt to refresh the data
// in the connector.
//
// TODO(ericchiang): We may want a strict mode where connectors that don't implement
// this interface can't perform refreshing.
if refreshConn, ok := conn.Connector.(connector.RefreshConnector); ok {
newIdent, err := refreshConn.Refresh(ctx, parseScopes(scopes), ident)
if refreshConn, ok := rCtx.connector.Connector.(connector.RefreshConnector); ok {
s.logger.Debugf("connector data before refresh: %s", ident.ConnectorData)
newIdent, err := refreshConn.Refresh(ctx, parseScopes(rCtx.scopes), ident)
if err != nil {
s.logger.Errorf("failed to refresh identity: %v", err)
return connector.Identity{}, newInternalServerError()
return ident, newInternalServerError()
}
ident = newIdent
}
return newIdent, nil
}
return ident, nil
}
@ -200,8 +205,14 @@ func (s *Server) updateOfflineSession(refresh *storage.RefreshToken, ident conne
if old.Refresh[refresh.ClientID].ID != refresh.ID {
return old, errors.New("refresh token invalid")
}
old.Refresh[refresh.ClientID].LastUsed = lastUsed
old.ConnectorData = ident.ConnectorData
if len(ident.ConnectorData) > 0 {
old.ConnectorData = ident.ConnectorData
}
s.logger.Debugf("saved connector data: %s %s", ident.UserID, ident.ConnectorData)
return old, nil
}
@ -217,33 +228,74 @@ func (s *Server) updateOfflineSession(refresh *storage.RefreshToken, ident conne
}
// updateRefreshToken updates refresh token and offline session in the storage
func (s *Server) updateRefreshToken(token *internal.RefreshToken, refresh *storage.RefreshToken, ident connector.Identity) (*internal.RefreshToken, *refreshError) {
newToken := token
if s.refreshTokenPolicy.RotationEnabled() {
newToken = &internal.RefreshToken{
RefreshId: refresh.ID,
Token: storage.NewID(),
}
func (s *Server) updateRefreshToken(ctx context.Context, rCtx *refreshContext) (*internal.RefreshToken, connector.Identity, *refreshError) {
var rerr *refreshError
newToken := &internal.RefreshToken{
Token: rCtx.requestToken.Token,
RefreshId: rCtx.requestToken.RefreshId,
}
lastUsed := s.now()
ident := connector.Identity{
UserID: rCtx.storageToken.Claims.UserID,
Username: rCtx.storageToken.Claims.Username,
PreferredUsername: rCtx.storageToken.Claims.PreferredUsername,
Email: rCtx.storageToken.Claims.Email,
EmailVerified: rCtx.storageToken.Claims.EmailVerified,
Groups: rCtx.storageToken.Claims.Groups,
ConnectorData: rCtx.connectorData,
}
refreshTokenUpdater := func(old storage.RefreshToken) (storage.RefreshToken, error) {
if s.refreshTokenPolicy.RotationEnabled() {
if old.Token != token.Token {
if s.refreshTokenPolicy.AllowedToReuse(old.LastUsed) && old.ObsoleteToken == token.Token {
newToken.Token = old.Token
// Do not update last used time for offline session if token is allowed to be reused
lastUsed = old.LastUsed
return old, nil
}
rotationEnabled := s.refreshTokenPolicy.RotationEnabled()
reusingAllowed := s.refreshTokenPolicy.AllowedToReuse(old.LastUsed)
switch {
case !rotationEnabled && reusingAllowed:
// If rotation is disabled and the offline session was updated not so long ago - skip further actions.
return old, nil
case rotationEnabled && reusingAllowed:
if old.Token != rCtx.requestToken.Token && old.ObsoleteToken != rCtx.requestToken.Token {
return old, errors.New("refresh token claimed twice")
}
// Return previously generated token for all requests with an obsolete tokens
if old.ObsoleteToken == rCtx.requestToken.Token {
newToken.Token = old.Token
}
// Do not update last used time for offline session if token is allowed to be reused
lastUsed = old.LastUsed
ident.ConnectorData = nil
return old, nil
case rotationEnabled && !reusingAllowed:
if old.Token != rCtx.requestToken.Token {
return old, errors.New("refresh token claimed twice")
}
// Issue new refresh token
old.ObsoleteToken = old.Token
newToken.Token = storage.NewID()
}
old.Token = newToken.Token
old.LastUsed = lastUsed
// ConnectorData has been moved to OfflineSession
old.ConnectorData = []byte{}
// Call only once if there is a request which is not in the reuse interval.
// This is required to avoid multiple calls to the external IdP for concurrent requests.
// Dex will call the connector's Refresh method only once if request is not in reuse interval.
ident, rerr = s.refreshWithConnector(ctx, rCtx, ident)
if rerr != nil {
return old, rerr
}
// Update the claims of the refresh token.
//
// UserID intentionally ignored for now.
@ -252,26 +304,23 @@ func (s *Server) updateRefreshToken(token *internal.RefreshToken, refresh *stora
old.Claims.Email = ident.Email
old.Claims.EmailVerified = ident.EmailVerified
old.Claims.Groups = ident.Groups
old.LastUsed = lastUsed
// ConnectorData has been moved to OfflineSession
old.ConnectorData = []byte{}
return old, nil
}
// Update refresh token in the storage.
err := s.storage.UpdateRefreshToken(refresh.ID, refreshTokenUpdater)
err := s.storage.UpdateRefreshToken(rCtx.storageToken.ID, refreshTokenUpdater)
if err != nil {
s.logger.Errorf("failed to update refresh token: %v", err)
return nil, newInternalServerError()
return nil, ident, newInternalServerError()
}
rerr := s.updateOfflineSession(refresh, ident, lastUsed)
rerr = s.updateOfflineSession(rCtx.storageToken, ident, lastUsed)
if rerr != nil {
return nil, rerr
return nil, ident, rerr
}
return newToken, nil
return newToken, ident, nil
}
// handleRefreshToken handles a refresh token request https://tools.ietf.org/html/rfc6749#section-6
@ -283,19 +332,19 @@ func (s *Server) handleRefreshToken(w http.ResponseWriter, r *http.Request, clie
return
}
refresh, rerr := s.getRefreshTokenFromStorage(client.ID, token)
rCtx, rerr := s.getRefreshTokenFromStorage(client.ID, token)
if rerr != nil {
s.refreshTokenErrHelper(w, rerr)
return
}
scopes, rerr := s.getRefreshScopes(r, refresh)
rCtx.scopes, rerr = s.getRefreshScopes(r, rCtx.storageToken)
if rerr != nil {
s.refreshTokenErrHelper(w, rerr)
return
}
ident, rerr := s.refreshWithConnector(r.Context(), token, refresh, scopes)
newToken, ident, rerr := s.updateRefreshToken(r.Context(), rCtx)
if rerr != nil {
s.refreshTokenErrHelper(w, rerr)
return
@ -310,26 +359,20 @@ func (s *Server) handleRefreshToken(w http.ResponseWriter, r *http.Request, clie
Groups: ident.Groups,
}
accessToken, err := s.newAccessToken(client.ID, claims, scopes, refresh.Nonce, refresh.ConnectorID)
accessToken, err := s.newAccessToken(client.ID, claims, rCtx.scopes, rCtx.storageToken.Nonce, rCtx.storageToken.ConnectorID)
if err != nil {
s.logger.Errorf("failed to create new access token: %v", err)
s.refreshTokenErrHelper(w, newInternalServerError())
return
}
idToken, expiry, err := s.newIDToken(client.ID, claims, scopes, refresh.Nonce, accessToken, "", refresh.ConnectorID)
idToken, expiry, err := s.newIDToken(client.ID, claims, rCtx.scopes, rCtx.storageToken.Nonce, accessToken, "", rCtx.storageToken.ConnectorID)
if err != nil {
s.logger.Errorf("failed to create ID token: %v", err)
s.refreshTokenErrHelper(w, newInternalServerError())
return
}
newToken, rerr := s.updateRefreshToken(token, refresh, ident)
if rerr != nil {
s.refreshTokenErrHelper(w, rerr)
return
}
rawNewToken, err := internal.Marshal(newToken)
if err != nil {
s.logger.Errorf("failed to marshal refresh token: %v", err)

124
storage/kubernetes/lock.go Normal file
View File

@ -0,0 +1,124 @@
package kubernetes
import (
"fmt"
"time"
)
const (
lockAnnotation = "dexidp.com/resource-lock"
lockTimeFormat = time.RFC3339
)
var (
lockTimeout = 10 * time.Second
lockCheckPeriod = 100 * time.Millisecond
)
// refreshTokenLock is an implementation of annotation-based optimistic locking.
//
// Refresh token contains data to refresh identity in external authentication system.
// There is a requirement that refresh should be called only once because of several reasons:
// * Some of OIDC providers could use the refresh token rotation feature which requires calling refresh only once.
// * Providers can limit the rate of requests to the token endpoint, which will lead to the error
// in case of many concurrent requests.
type refreshTokenLock struct {
cli *client
waitingState bool
}
func newRefreshTokenLock(cli *client) *refreshTokenLock {
return &refreshTokenLock{cli: cli}
}
func (l *refreshTokenLock) Lock(id string) error {
for i := 0; i <= 60; i++ {
ok, err := l.setLockAnnotation(id)
if err != nil {
return err
}
if !ok {
return nil
}
time.Sleep(lockCheckPeriod)
}
return fmt.Errorf("timeout waiting for refresh token %s lock", id)
}
func (l *refreshTokenLock) Unlock(id string) {
if l.waitingState {
// Do not need to unlock for waiting goroutines, because the have not set it.
return
}
r, err := l.cli.getRefreshToken(id)
if err != nil {
l.cli.logger.Debugf("failed to get resource to release lock for refresh token %s: %v", id, err)
return
}
r.Annotations = nil
err = l.cli.put(resourceRefreshToken, r.ObjectMeta.Name, r)
if err != nil {
l.cli.logger.Debugf("failed to release lock for refresh token %s: %v", id, err)
}
}
func (l *refreshTokenLock) setLockAnnotation(id string) (bool, error) {
r, err := l.cli.getRefreshToken(id)
if err != nil {
return false, err
}
currentTime := time.Now()
lockData := map[string]string{
lockAnnotation: currentTime.Add(lockTimeout).Format(lockTimeFormat),
}
val, ok := r.Annotations[lockAnnotation]
if !ok {
if l.waitingState {
return false, nil
}
r.Annotations = lockData
err := l.cli.put(resourceRefreshToken, r.ObjectMeta.Name, r)
if err == nil {
return false, nil
}
if isKubernetesAPIConflictError(err) {
l.waitingState = true
return true, nil
}
return false, err
}
until, err := time.Parse(lockTimeFormat, val)
if err != nil {
return false, fmt.Errorf("lock annotation value is malformed: %v", err)
}
if !currentTime.After(until) {
// waiting for the lock to be released
l.waitingState = true
return true, nil
}
// Lock time is out, lets break the lock and take the advantage
r.Annotations = lockData
err = l.cli.put(resourceRefreshToken, r.ObjectMeta.Name, r)
if err == nil {
// break lock annotation
return false, nil
}
l.cli.logger.Debugf("break lock annotation error: %v", err)
if isKubernetesAPIConflictError(err) {
l.waitingState = true
// after breaking error waiting for the lock to be released
return true, nil
}
return false, err
}

9
storage/kubernetes/storage.go
View File

@ -451,11 +451,19 @@ func (cli *client) DeleteConnector(id string) error {
}
func (cli *client) UpdateRefreshToken(id string, updater func(old storage.RefreshToken) (storage.RefreshToken, error)) error {
lock := newRefreshTokenLock(cli)
if err := lock.Lock(id); err != nil {
return err
}
defer lock.Unlock(id)
return retryOnConflict(context.TODO(), func() error {
r, err := cli.getRefreshToken(id)
if err != nil {
return err
}
updated, err := updater(toStorageRefreshToken(r))
if err != nil {
return err
@ -464,6 +472,7 @@ func (cli *client) UpdateRefreshToken(id string, updater func(old storage.Refres
newToken := cli.fromStorageRefreshToken(updated)
newToken.ObjectMeta = r.ObjectMeta
return cli.put(resourceRefreshToken, r.ObjectMeta.Name, newToken)
})
}

104
storage/kubernetes/storage_test.go
View File

@ -11,6 +11,7 @@ import (
"path/filepath"
"strings"
"testing"
"time"
"github.com/sirupsen/logrus"
"github.com/stretchr/testify/require"
@ -35,19 +36,22 @@ type StorageTestSuite struct {
client *client
}
func (s *StorageTestSuite) expandDir(dir string) string {
func expandDir(dir string) (string, error) {
dir = strings.Trim(dir, `"`)
if strings.HasPrefix(dir, "~/") {
homedir, err := os.UserHomeDir()
s.Require().NoError(err)
if err != nil {
return "", err
}
dir = filepath.Join(homedir, strings.TrimPrefix(dir, "~/"))
}
return dir
return dir, nil
}
func (s *StorageTestSuite) SetupTest() {
kubeconfigPath := s.expandDir(os.Getenv(kubeconfigPathVariableName))
kubeconfigPath, err := expandDir(os.Getenv(kubeconfigPathVariableName))
s.Require().NoError(err)
config := Config{
KubeConfigFile: kubeconfigPath,
@ -292,3 +296,95 @@ func TestRetryOnConflict(t *testing.T) {
})
}
}
func TestRefreshTokenLock(t *testing.T) {
if os.Getenv(kubeconfigPathVariableName) == "" {
t.Skipf("variable %q not set, skipping kubernetes storage tests\n", kubeconfigPathVariableName)
}
kubeconfigPath, err := expandDir(os.Getenv(kubeconfigPathVariableName))
require.NoError(t, err)
config := Config{
KubeConfigFile: kubeconfigPath,
}
logger := &logrus.Logger{
Out: os.Stderr,
Formatter: &logrus.TextFormatter{DisableColors: true},
Level: logrus.DebugLevel,
}
kubeClient, err := config.open(logger, true)
require.NoError(t, err)
lockCheckPeriod = time.Nanosecond
// Creating a storage with an existing refresh token and offline session for the user.
id := storage.NewID()
r := storage.RefreshToken{
ID: id,
Token: "bar",
Nonce: "foo",
ClientID: "client_id",
ConnectorID: "client_secret",
Scopes: []string{"openid", "email", "profile"},
CreatedAt: time.Now().UTC().Round(time.Millisecond),
LastUsed: time.Now().UTC().Round(time.Millisecond),
Claims: storage.Claims{
UserID: "1",
Username: "jane",
Email: "jane.doe@example.com",
EmailVerified: true,
Groups: []string{"a", "b"},
},
ConnectorData: []byte(`{"some":"data"}`),
}
err = kubeClient.CreateRefresh(r)
require.NoError(t, err)
t.Run("Timeout lock error", func(t *testing.T) {
err = kubeClient.UpdateRefreshToken(r.ID, func(r storage.RefreshToken) (storage.RefreshToken, error) {
r.Token = "update-result-1"
err := kubeClient.UpdateRefreshToken(r.ID, func(r storage.RefreshToken) (storage.RefreshToken, error) {
r.Token = "timeout-err"
return r, nil
})
require.Equal(t, fmt.Errorf("timeout waiting for refresh token %s lock", r.ID), err)
return r, nil
})
require.NoError(t, err)
token, err := kubeClient.GetRefresh(r.ID)
require.NoError(t, err)
require.Equal(t, "update-result-1", token.Token)
})
t.Run("Break the lock", func(t *testing.T) {
var lockBroken bool
lockTimeout = -time.Hour
err = kubeClient.UpdateRefreshToken(r.ID, func(r storage.RefreshToken) (storage.RefreshToken, error) {
r.Token = "update-result-2"
if lockBroken {
return r, nil
}
err := kubeClient.UpdateRefreshToken(r.ID, func(r storage.RefreshToken) (storage.RefreshToken, error) {
r.Token = "should-break-the-lock-and-finish-updating"
return r, nil
})
require.NoError(t, err)
lockBroken = true
return r, nil
})
require.NoError(t, err)
token, err := kubeClient.GetRefresh(r.ID)
require.NoError(t, err)
// Because concurrent update breaks the lock, the final result will be the value of the first update
require.Equal(t, "update-result-2", token.Token)
})
}