package main
import (
"crypto/hmac"
"crypto/rand"
"crypto/sha256"
"crypto/subtle"
"encoding/base64"
"encoding/hex"
"encoding/json"
"fmt"
"html/template"
"net/http"
"net/url"
"os"
"path/filepath"
"strings"
"sync"
"time"
)
const portalCookieName = "portal_session"
var (
portalUsername = envOr("PORTAL_USERNAME", "admin")
portalPassword = envOr("PORTAL_PASSWORD", "changeme")
portalCookieDomain = envOr("PORTAL_COOKIE_DOMAIN", ".example.com")
portalHomeURL = envOr("PORTAL_HOME_URL", "https://dashy.example.com")
portalSessionTTL = 24 * time.Hour
portalSecretOnce sync.Once
portalSecret []byte
)
type portalClaims struct {
User string `json:"u"`
Expiry int64 `json:"e"`
}
func sessionSecret() []byte {
portalSecretOnce.Do(func() {
if raw := strings.TrimSpace(os.Getenv("PORTAL_SESSION_SECRET")); raw != "" {
sum := sha256.Sum256([]byte(raw))
portalSecret = sum[:]
return
}
path := filepath.Join(filepath.Dir(confFile), "portal-session.key")
if b, err := os.ReadFile(path); err == nil {
if decoded, err := hex.DecodeString(strings.TrimSpace(string(b))); err == nil && len(decoded) >= 32 {
portalSecret = decoded
return
}
}
portalSecret = make([]byte, 32)
if _, err := rand.Read(portalSecret); err != nil {
sum := sha256.Sum256([]byte(fmt.Sprintf("%d-%d", time.Now().UnixNano(), os.Getpid())))
portalSecret = sum[:]
}
_ = os.MkdirAll(filepath.Dir(path), 0o755)
_ = os.WriteFile(path, []byte(hex.EncodeToString(portalSecret)), 0o600)
})
return portalSecret
}
func signClaims(c portalClaims) (string, error) {
payload, err := json.Marshal(c)
if err != nil {
return "", err
}
body := base64.RawURLEncoding.EncodeToString(payload)
mac := hmac.New(sha256.New, sessionSecret())
_, _ = mac.Write([]byte(body))
sig := base64.RawURLEncoding.EncodeToString(mac.Sum(nil))
return body + "." + sig, nil
}
func verifyClaims(token string) bool {
parts := strings.Split(token, ".")
if len(parts) != 2 {
return false
}
mac := hmac.New(sha256.New, sessionSecret())
_, _ = mac.Write([]byte(parts[0]))
got, err := base64.RawURLEncoding.DecodeString(parts[1])
if err != nil || !hmac.Equal(got, mac.Sum(nil)) {
return false
}
payload, err := base64.RawURLEncoding.DecodeString(parts[0])
if err != nil {
return false
}
var c portalClaims
if json.Unmarshal(payload, &c) != nil {
return false
}
// 用户名可能已被后台改过，按当前配置比较，避免改完账号旧会话仍有效
user, _ := portalAuthConfigured()
return c.User == user && c.Expiry >= time.Now().Unix()
}
func portalAuthenticated(r *http.Request) bool {
c, err := r.Cookie(portalCookieName)
return err == nil && verifyClaims(c.Value)
}
func setPortalCookie(w http.ResponseWriter, token string, maxAge int) {
http.SetCookie(w, &http.Cookie{
Name: portalCookieName, Value: token, Path: "/", Domain: portalCookieDomain,
MaxAge: maxAge, Expires: time.Now().Add(time.Duration(maxAge) * time.Second),
HttpOnly: true, Secure: true, SameSite: http.SameSiteLaxMode,
})
}
func secureEqual(a, b string) bool {
if len(a) != len(b) {
return false
}
return subtle.ConstantTimeCompare([]byte(a), []byte(b)) == 1
}
func safePortalRedirect(raw string) string {
if strings.TrimSpace(raw) == "" {
return portalHomeURL
}
u, err := url.Parse(raw)
if err != nil || u.Scheme != "https" || u.Hostname() == "" {
return portalHomeURL
}
cfg, err := loadGateway()
if err != nil {
return portalHomeURL
}
for _, r := range cfg.Routes {
if strings.EqualFold(strings.TrimSpace(r.Host), u.Hostname()) {
return u.String()
}
}
return portalHomeURL
}
var portalLoginTemplate = template.Must(template.New("login").Parse(`
{{.Title}} - 登录
{{.Logo}}
{{.Title}}
{{.Subtitle}}
{{if .Error}}{{.Error}}
{{end}}
`))
func renderPortalLogin(w http.ResponseWriter, redirect, errText string) {
w.Header().Set("Content-Type", "text/html; charset=utf-8")
w.Header().Set("Cache-Control", "no-store")
title, subtitle, logo, icp, gongan := authPageInfo()
_ = portalLoginTemplate.Execute(w, map[string]string{
"Redirect": url.QueryEscape(redirect), "Error": errText,
"Title": title, "Subtitle": subtitle, "Logo": logo,
"Footer": beianFooter(icp, gongan),
})
}
func handlePortalLogin(w http.ResponseWriter, r *http.Request) {
redirect := safePortalRedirect(r.URL.Query().Get("redirect"))
if r.Method == http.MethodGet {
if portalAuthenticated(r) {
http.Redirect(w, r, redirect, http.StatusFound)
return
}
renderPortalLogin(w, redirect, "")
return
}
if r.Method != http.MethodPost {
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
return
}
if err := r.ParseForm(); err != nil {
renderPortalLogin(w, redirect, "请求解析失败")
return
}
if !checkPortalCredentials(r.FormValue("username"), r.FormValue("password")) {
w.WriteHeader(http.StatusUnauthorized)
renderPortalLogin(w, redirect, "用户名或密码错误")
return
}
user, _ := portalAuthConfigured()
token, err := signClaims(portalClaims{User: user, Expiry: time.Now().Add(portalSessionTTL).Unix()})
if err != nil {
http.Error(w, "session error", http.StatusInternalServerError)
return
}
setPortalCookie(w, token, int(portalSessionTTL/time.Second))
http.Redirect(w, r, redirect, http.StatusFound)
}
func handlePortalVerify(w http.ResponseWriter, r *http.Request) {
if !portalAuthenticated(r) {
w.WriteHeader(http.StatusUnauthorized)
return
}
w.Header().Set("Content-Length", "0")
w.WriteHeader(http.StatusOK)
}
func handlePortalLogout(w http.ResponseWriter, r *http.Request) {
setPortalCookie(w, "", -1)
http.Redirect(w, r, "/login", http.StatusFound)
}
func handlePortalRoot(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
}
if portalAuthenticated(r) {
http.Redirect(w, r, portalHomeURL, http.StatusFound)
return
}
http.Redirect(w, r, "/login", http.StatusFound)
}
func registerPortalAuth() {
http.HandleFunc("/login", handlePortalLogin)
http.HandleFunc("/verify", handlePortalVerify)
http.HandleFunc("/_auth", handlePortalVerify)
http.HandleFunc("/logout", handlePortalLogout)
http.HandleFunc("/auth/verify", handlePortalVerify)
}