feat(external_imap): 强化 OAuth 外部邮箱授权校验并完善 Outlook 文案

- OAuth 授权改为以服务商返回的真实邮箱为准，补充 ID Token 解析与邮箱一致性校验，避免默认落到本地邮箱。 - 为 Gmail 和 Microsoft 365 / Outlook OAuth 增加必要的 OIDC scope，并补充相关测试覆盖。 - Web 端新增 OAuth 授权弹窗，支持填写外部邮箱与存储模式；同步更新账号展示信息。 - 同步修正 README 与部署说明中的 Outlook 表述。
2026-06-25 21:17:04 +08:00
parent 39f5249008
commit 081cfad02d
7 changed files with 211 additions and 16 deletions
@@ -31,6 +31,7 @@ import (
 	"github.com/emersion/go-sasl"
 	smtpclient "github.com/emersion/go-smtp"
 	"golang.org/x/crypto/bcrypt"
+	"golang.org/x/oauth2"
 )

 func newTestApp(t *testing.T) *App {
@@ -503,6 +504,102 @@ func TestExternalIMAPRejectsPrivateHostsByDefault(t *testing.T) {
 	}
 }

+func TestExternalIMAPOAuthStateDoesNotDefaultToLocalMailbox(t *testing.T) {
+	dir := t.TempDir()
+	a := newTestAppWithConfig(t, Config{
+		Addr:                            ":0",
+		DBPath:                          filepath.Join(dir, "lanqin.db"),
+		DataDir:                         filepath.Join(dir, "data"),
+		CookieName:                      "lanqin_test",
+		SessionTTLHours:                 24,
+		AdminEmail:                      "admin@lanqin.local",
+		AdminPassword:                   "ChangeMe123!",
+		PublicHostname:                  "mail.example.test",
+		PublicBaseURL:                   "http://localhost:5173",
+		AllowInsecureHTTP:               true,
+		ExternalIMAPSecretKey:           "test-secret",
+		ExternalIMAPOutlookClientID:     "client-id",
+		ExternalIMAPOutlookClientSecret: "client-secret",
+	})
+	ts := httptest.NewServer(a.Router())
+	defer ts.Close()
+	admin := &testClient{t: t, server: ts}
+	if code := admin.do("POST", "/api/auth/login", map[string]string{"email": "admin@lanqin.local", "password": "ChangeMe123!"}, nil); code != http.StatusOK {
+		t.Fatalf("login code=%d", code)
+	}
+	_, mb := defaultAdminUserAndMailbox(t, a)
+
+	var start struct {
+		URL string `json:"url"`
+	}
+	if code := admin.do("POST", "/api/me/external-imap-oauth/outlook/start", map[string]any{"mailboxId": mb.ID, "storageMode": "local", "syncReadState": true, "enabled": true}, &start); code != http.StatusOK {
+		t.Fatalf("start oauth code=%d url=%q", code, start.URL)
+	}
+	stateValue := mustOAuthStateFromURL(t, start.URL)
+	state, err := a.decryptExternalIMAPOAuthState(stateValue)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if state.Email != "" {
+		t.Fatalf("oauth state defaulted to local mailbox email: %q", state.Email)
+	}
+
+	if code := admin.do("POST", "/api/me/external-imap-oauth/outlook/start", map[string]any{"mailboxId": mb.ID, "email": "User@Example.COM", "storageMode": "remote", "syncReadState": true, "enabled": true}, &start); code != http.StatusOK {
+		t.Fatalf("start oauth with email code=%d url=%q", code, start.URL)
+	}
+	stateValue = mustOAuthStateFromURL(t, start.URL)
+	state, err = a.decryptExternalIMAPOAuthState(stateValue)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if state.Email != "user@example.com" {
+		t.Fatalf("oauth state did not preserve requested external email, got %q", state.Email)
+	}
+}
+
+func TestExternalIMAPOAuthEmailFromIDToken(t *testing.T) {
+	token := (&oauth2.Token{AccessToken: "access"}).WithExtra(map[string]any{
+		"id_token": testIDToken(map[string]any{"preferred_username": "User@Example.COM"}),
+	})
+	email, err := externalIMAPOAuthEmail(externalIMAPOAuthOutlook, token)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if email != "user@example.com" {
+		t.Fatalf("unexpected outlook oauth email %q", email)
+	}
+
+	token = (&oauth2.Token{AccessToken: "access"}).WithExtra(map[string]any{
+		"id_token": testIDToken(map[string]any{"email": "Person@Gmail.COM"}),
+	})
+	email, err = externalIMAPOAuthEmail(externalIMAPOAuthGmail, token)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if email != "person@gmail.com" {
+		t.Fatalf("unexpected gmail oauth email %q", email)
+	}
+}
+
+func mustOAuthStateFromURL(t *testing.T, rawURL string) string {
+	t.Helper()
+	u, err := url.Parse(rawURL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	state := u.Query().Get("state")
+	if state == "" {
+		t.Fatalf("oauth url missing state: %s", rawURL)
+	}
+	return state
+}
+
+func testIDToken(claims map[string]any) string {
+	header, _ := json.Marshal(map[string]any{"alg": "none"})
+	payload, _ := json.Marshal(claims)
+	return base64.RawURLEncoding.EncodeToString(header) + "." + base64.RawURLEncoding.EncodeToString(payload) + "."
+}
+
 func TestExternalIMAPAccountOwnershipIsolation(t *testing.T) {
 	dir := t.TempDir()
 	a := newTestAppWithConfig(t, Config{
@@ -418,9 +418,10 @@ func (a *App) handleStartExternalIMAPOAuth(w http.ResponseWriter, r *http.Reques
 		respondError(w, http.StatusNotFound, "mailbox not found")
 		return
 	}
-	email := strings.TrimSpace(req.Email)
-	if email == "" {
-		email = mb.Address
+	email := normalizeEmail(req.Email)
+	if email != "" && !strings.Contains(email, "@") {
+		badRequest(w, errors.New("invalid oauth email"))
+		return
 	}
 	req.StorageMode = strings.ToLower(strings.TrimSpace(req.StorageMode))
 	if req.StorageMode == "" {
@@ -511,9 +512,18 @@ func (a *App) handleExternalIMAPOAuthCallback(w http.ResponseWriter, r *http.Req
 	if !token.Expiry.IsZero() {
 		expiry = token.Expiry.UTC().Format(time.RFC3339Nano)
 	}
+	authorizedEmail, err := externalIMAPOAuthEmail(provider, token)
+	if err != nil {
+		respondError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	if state.Email != "" && !strings.EqualFold(normalizeEmail(state.Email), authorizedEmail) {
+		respondError(w, http.StatusBadRequest, "oauth account email does not match requested external email")
+		return
+	}
 	id := newID("ximap")
 	_, err = a.db.ExecContext(r.Context(), `INSERT INTO external_imap_accounts(id,user_id,mailbox_id,name,host,port,tls_mode,username,password_ciphertext,auth_mode,oauth_provider,oauth_email,oauth_access_token_ciphertext,oauth_refresh_token_ciphertext,oauth_expiry,storage_mode,sync_read_state,enabled,last_status,created_at,updated_at)
-		VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`, id, state.UserID, state.MailboxID, name, profile.Host, profile.Port, externalIMAPTLS, state.Email, "", externalIMAPAuthOAuth2, provider, state.Email, accessCipher, refreshCipher, expiry, state.StorageMode, boolInt(state.SyncReadState), boolInt(state.Enabled), "idle", now, now)
+		VALUES(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`, id, state.UserID, state.MailboxID, name, profile.Host, profile.Port, externalIMAPTLS, authorizedEmail, "", externalIMAPAuthOAuth2, provider, authorizedEmail, accessCipher, refreshCipher, expiry, state.StorageMode, boolInt(state.SyncReadState), boolInt(state.Enabled), "idle", now, now)
 	if err != nil {
 		respondError(w, http.StatusInternalServerError, "failed to save oauth account")
 		return
@@ -871,7 +881,7 @@ func (a *App) externalIMAPOAuthConfig(provider string) (*oauth2.Config, external
 			ClientID:     a.cfg.ExternalIMAPGmailClientID,
 			ClientSecret: a.cfg.ExternalIMAPGmailClientSecret,
 			RedirectURL:  callback,
-			Scopes:       []string{"https://mail.google.com/"},
+			Scopes:       []string{"openid", "email", "profile", "https://mail.google.com/"},
 			Endpoint: oauth2.Endpoint{
 				AuthURL:  "https://accounts.google.com/o/oauth2/v2/auth",
 				TokenURL: "https://oauth2.googleapis.com/token",
@@ -885,7 +895,7 @@ func (a *App) externalIMAPOAuthConfig(provider string) (*oauth2.Config, external
 			ClientID:     a.cfg.ExternalIMAPOutlookClientID,
 			ClientSecret: a.cfg.ExternalIMAPOutlookClientSecret,
 			RedirectURL:  callback,
-			Scopes:       []string{"offline_access", "https://outlook.office.com/IMAP.AccessAsUser.All"},
+			Scopes:       []string{"openid", "email", "profile", "offline_access", "https://outlook.office.com/IMAP.AccessAsUser.All"},
 			Endpoint: oauth2.Endpoint{
 				AuthURL:  "https://login.microsoftonline.com/common/oauth2/v2.0/authorize",
 				TokenURL: "https://login.microsoftonline.com/common/oauth2/v2.0/token",
@@ -896,6 +906,45 @@ func (a *App) externalIMAPOAuthConfig(provider string) (*oauth2.Config, external
 	}
 }

+func externalIMAPOAuthEmail(provider string, token *oauth2.Token) (string, error) {
+	if token == nil {
+		return "", errors.New("oauth token is missing")
+	}
+	idToken, _ := token.Extra("id_token").(string)
+	claims, err := externalIMAPOIDCClaims(idToken)
+	if err != nil {
+		return "", err
+	}
+	fields := []string{"email"}
+	if provider == externalIMAPOAuthOutlook {
+		fields = []string{"email", "preferred_username", "upn"}
+	}
+	for _, field := range fields {
+		value, _ := claims[field].(string)
+		email := normalizeEmail(value)
+		if email != "" && strings.Contains(email, "@") {
+			return email, nil
+		}
+	}
+	return "", errors.New("oauth provider did not return an email address")
+}
+
+func externalIMAPOIDCClaims(idToken string) (map[string]any, error) {
+	parts := strings.Split(idToken, ".")
+	if len(parts) < 2 {
+		return nil, errors.New("oauth provider did not return an id token")
+	}
+	payload, err := base64.RawURLEncoding.DecodeString(parts[1])
+	if err != nil {
+		return nil, errors.New("invalid oauth id token")
+	}
+	var claims map[string]any
+	if err := json.Unmarshal(payload, &claims); err != nil {
+		return nil, errors.New("invalid oauth id token")
+	}
+	return claims, nil
+}
+
 func (a *App) encryptExternalIMAPOAuthState(state externalIMAPOAuthState) (string, error) {
 	raw, err := json.Marshal(state)
 	if err != nil {