forgejo/services/auth/sspi_windows.go
Lunny Xiao 900e158064
refactor auth interface to return error when verify failure (#22119) (#22259)
backport #22119

This PR changed the Auth interface signature from `Verify(http
*http.Request, w http.ResponseWriter, store DataStore, sess
SessionStore) *user_model.User`
to 
`Verify(http *http.Request, w http.ResponseWriter, store DataStore, sess
SessionStore) (*user_model.User, error)`.

There is a new return argument `error` which means the verification
condition matched but verify process failed, we should stop the auth
process.

Before this PR, when return a `nil` user, we don't know the reason why
it returned `nil`. If the match condition is not satisfied or it
verified failure? For these two different results, we should have
different handler. If the match condition is not satisfied, we should
try next auth method and if there is no more auth method, it's an
anonymous user. If the condition matched but verify failed, the auth
process should be stop and return immediately.

This will fix #20563

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: Jason Song <i@wolfogre.com>
2022-12-29 13:50:09 +08:00

244 lines
7.3 KiB
Go

// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package auth
import (
"context"
"errors"
"net/http"
"strings"
"code.gitea.io/gitea/models/auth"
"code.gitea.io/gitea/models/avatars"
user_model "code.gitea.io/gitea/models/user"
"code.gitea.io/gitea/modules/base"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/templates"
"code.gitea.io/gitea/modules/util"
"code.gitea.io/gitea/modules/web/middleware"
"code.gitea.io/gitea/services/auth/source/sspi"
"code.gitea.io/gitea/services/mailer"
gouuid "github.com/google/uuid"
"github.com/quasoft/websspi"
"github.com/unrolled/render"
)
const (
tplSignIn base.TplName = "user/auth/signin"
)
var (
// sspiAuth is a global instance of the websspi authentication package,
// which is used to avoid acquiring the server credential handle on
// every request
sspiAuth *websspi.Authenticator
// Ensure the struct implements the interface.
_ Method = &SSPI{}
_ Named = &SSPI{}
_ Initializable = &SSPI{}
_ Freeable = &SSPI{}
)
// SSPI implements the SingleSignOn interface and authenticates requests
// via the built-in SSPI module in Windows for SPNEGO authentication.
// On successful authentication returns a valid user object.
// Returns nil if authentication fails.
type SSPI struct {
rnd *render.Render
}
// Init creates a new global websspi.Authenticator object
func (s *SSPI) Init(ctx context.Context) error {
config := websspi.NewConfig()
var err error
sspiAuth, err = websspi.New(config)
if err != nil {
return err
}
_, s.rnd = templates.HTMLRenderer(ctx)
return nil
}
// Name represents the name of auth method
func (s *SSPI) Name() string {
return "sspi"
}
// Free releases resources used by the global websspi.Authenticator object
func (s *SSPI) Free() error {
return sspiAuth.Free()
}
// Verify uses SSPI (Windows implementation of SPNEGO) to authenticate the request.
// If authentication is successful, returns the corresponding user object.
// If negotiation should continue or authentication fails, immediately returns a 401 HTTP
// response code, as required by the SPNEGO protocol.
func (s *SSPI) Verify(req *http.Request, w http.ResponseWriter, store DataStore, sess SessionStore) (*user_model.User, error) {
if !s.shouldAuthenticate(req) {
return nil, nil
}
cfg, err := s.getConfig()
if err != nil {
log.Error("could not get SSPI config: %v", err)
return nil, err
}
log.Trace("SSPI Authorization: Attempting to authenticate")
userInfo, outToken, err := sspiAuth.Authenticate(req, w)
if err != nil {
log.Warn("Authentication failed with error: %v\n", err)
sspiAuth.AppendAuthenticateHeader(w, outToken)
// Include the user login page in the 401 response to allow the user
// to login with another authentication method if SSPI authentication
// fails
store.GetData()["Flash"] = map[string]string{
"ErrorMsg": err.Error(),
}
store.GetData()["EnableOpenIDSignIn"] = setting.Service.EnableOpenIDSignIn
store.GetData()["EnableSSPI"] = true
err := s.rnd.HTML(w, http.StatusUnauthorized, string(tplSignIn), templates.BaseVars().Merge(store.GetData()))
if err != nil {
log.Error("%v", err)
}
return nil, err
}
if outToken != "" {
sspiAuth.AppendAuthenticateHeader(w, outToken)
}
username := sanitizeUsername(userInfo.Username, cfg)
if len(username) == 0 {
return nil, nil
}
log.Info("Authenticated as %s\n", username)
user, err := user_model.GetUserByName(req.Context(), username)
if err != nil {
if !user_model.IsErrUserNotExist(err) {
log.Error("GetUserByName: %v", err)
return nil, err
}
if !cfg.AutoCreateUsers {
log.Error("User '%s' not found", username)
return nil, nil
}
user, err = s.newUser(username, cfg)
if err != nil {
log.Error("CreateUser: %v", err)
return nil, err
}
}
// Make sure requests to API paths and PWA resources do not create a new session
if !middleware.IsAPIPath(req) && !isAttachmentDownload(req) {
handleSignIn(w, req, sess, user)
}
log.Trace("SSPI Authorization: Logged in user %-v", user)
return user, nil
}
// getConfig retrieves the SSPI configuration from login sources
func (s *SSPI) getConfig() (*sspi.Source, error) {
sources, err := auth.ActiveSources(auth.SSPI)
if err != nil {
return nil, err
}
if len(sources) == 0 {
return nil, errors.New("no active login sources of type SSPI found")
}
if len(sources) > 1 {
return nil, errors.New("more than one active login source of type SSPI found")
}
return sources[0].Cfg.(*sspi.Source), nil
}
func (s *SSPI) shouldAuthenticate(req *http.Request) (shouldAuth bool) {
shouldAuth = false
path := strings.TrimSuffix(req.URL.Path, "/")
if path == "/user/login" {
if req.FormValue("user_name") != "" && req.FormValue("password") != "" {
shouldAuth = false
} else if req.FormValue("auth_with_sspi") == "1" {
shouldAuth = true
}
} else if middleware.IsAPIPath(req) || isAttachmentDownload(req) {
shouldAuth = true
}
return shouldAuth
}
// newUser creates a new user object for the purpose of automatic registration
// and populates its name and email with the information present in request headers.
func (s *SSPI) newUser(username string, cfg *sspi.Source) (*user_model.User, error) {
email := gouuid.New().String() + "@localhost.localdomain"
user := &user_model.User{
Name: username,
Email: email,
Passwd: gouuid.New().String(),
Language: cfg.DefaultLanguage,
UseCustomAvatar: true,
Avatar: avatars.DefaultAvatarLink(),
}
emailNotificationPreference := user_model.EmailNotificationsDisabled
overwriteDefault := &user_model.CreateUserOverwriteOptions{
IsActive: util.OptionalBoolOf(cfg.AutoActivateUsers),
KeepEmailPrivate: util.OptionalBoolTrue,
EmailNotificationsPreference: &emailNotificationPreference,
}
if err := user_model.CreateUser(user, overwriteDefault); err != nil {
return nil, err
}
mailer.SendRegisterNotifyMail(user)
return user, nil
}
// stripDomainNames removes NETBIOS domain name and separator from down-level logon names
// (eg. "DOMAIN\user" becomes "user"), and removes the UPN suffix (domain name) and separator
// from UPNs (eg. "user@domain.local" becomes "user")
func stripDomainNames(username string) string {
if strings.Contains(username, "\\") {
parts := strings.SplitN(username, "\\", 2)
if len(parts) > 1 {
username = parts[1]
}
} else if strings.Contains(username, "@") {
parts := strings.Split(username, "@")
if len(parts) > 1 {
username = parts[0]
}
}
return username
}
func replaceSeparators(username string, cfg *sspi.Source) string {
newSep := cfg.SeparatorReplacement
username = strings.ReplaceAll(username, "\\", newSep)
username = strings.ReplaceAll(username, "/", newSep)
username = strings.ReplaceAll(username, "@", newSep)
return username
}
func sanitizeUsername(username string, cfg *sspi.Source) string {
if len(username) == 0 {
return ""
}
if cfg.StripDomainNames {
username = stripDomainNames(username)
}
// Replace separators even if we have already stripped the domain name part,
// as the username can contain several separators: eg. "MICROSOFT\useremail@live.com"
username = replaceSeparators(username, cfg)
return username
}