Files
carvalho-finances/apps/api/internal/middleware/auth.go
T
Mlcavalho1andClaude Sonnet 4.6 2cf6d94a03 fix: auth stateless com HMAC — sessões sobrevivem restarts do container
Tokens assinados com APP_PASSWORD via HMAC-SHA256 eliminam o in-memory
sessions map. Também corrige env vars (_USERNAME→APP_USERNAME).

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>
2026-05-27 15:48:01 -03:00

120 lines
3.0 KiB
Go

package middleware
import (
"crypto/hmac"
"crypto/rand"
"crypto/sha256"
"encoding/hex"
"encoding/json"
"fmt"
"net/http"
"os"
"strconv"
"strings"
"time"
)
const cookieName = "cf_session"
const sessionDuration = 30 * 24 * time.Hour
func secret() []byte {
// Use APP_PASSWORD as signing secret so tokens survive container restarts.
return []byte(os.Getenv("APP_PASSWORD"))
}
func signToken(expiry int64) string {
nonce := make([]byte, 8)
rand.Read(nonce)
payload := fmt.Sprintf("%s.%d", hex.EncodeToString(nonce), expiry)
mac := hmac.New(sha256.New, secret())
mac.Write([]byte(payload))
sig := hex.EncodeToString(mac.Sum(nil))
return payload + "." + sig
}
func validToken(token string) bool {
parts := strings.SplitN(token, ".", 3)
if len(parts) != 3 {
return false
}
payload := parts[0] + "." + parts[1]
expiry, err := strconv.ParseInt(parts[1], 10, 64)
if err != nil || time.Now().Unix() > expiry {
return false
}
mac := hmac.New(sha256.New, secret())
mac.Write([]byte(payload))
expected := hex.EncodeToString(mac.Sum(nil))
return hmac.Equal([]byte(parts[2]), []byte(expected))
}
func jsonErr(w http.ResponseWriter, status int, msg string) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(status)
json.NewEncoder(w).Encode(map[string]string{"error": msg})
}
func RequireAuth(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
cookie, err := r.Cookie(cookieName)
if err != nil || !validToken(cookie.Value) {
jsonErr(w, http.StatusUnauthorized, "unauthorized")
return
}
next.ServeHTTP(w, r)
})
}
func LoginHandler(w http.ResponseWriter, r *http.Request) {
var body struct {
Username string `json:"username"`
Password string `json:"password"`
}
if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
jsonErr(w, http.StatusBadRequest, "corpo inválido")
return
}
wantUser := os.Getenv("APP_USERNAME")
wantPass := os.Getenv("APP_PASSWORD")
if wantUser == "" || body.Username != wantUser || body.Password != wantPass {
jsonErr(w, http.StatusUnauthorized, "credenciais inválidas")
return
}
expiry := time.Now().Add(sessionDuration).Unix()
token := signToken(expiry)
http.SetCookie(w, &http.Cookie{
Name: cookieName,
Value: token,
Path: "/",
HttpOnly: true,
Secure: true,
SameSite: http.SameSiteStrictMode,
MaxAge: int(sessionDuration.Seconds()),
})
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
json.NewEncoder(w).Encode(map[string]string{"ok": "true"})
}
func LogoutHandler(w http.ResponseWriter, r *http.Request) {
http.SetCookie(w, &http.Cookie{
Name: cookieName,
Value: "",
Path: "/",
MaxAge: -1,
})
w.WriteHeader(http.StatusNoContent)
}
func MeHandler(w http.ResponseWriter, r *http.Request) {
cookie, err := r.Cookie(cookieName)
if err != nil || !validToken(cookie.Value) {
jsonErr(w, http.StatusUnauthorized, "unauthorized")
return
}
w.WriteHeader(http.StatusNoContent)
}