Agent-System-Backend/internal/server/accounts.go

package server

// 账号与会话 API（阶段 2：管理员发放制，2026-09-30 用户裁定）：
// 无自助注册；登录（用户名+密码）建立服务端会话（HttpOnly cookie）；
// 初始/重置密码后首登强制改密；管理员建号与重置密码。

import (
	"crypto/rand"
	"encoding/hex"
	"encoding/json"
	"errors"
	"net/http"
	"strings"
	"sync"
	"time"

	"agent-system-backend/internal/store"
)

var errBadPassword = errors.New("password must be 8-256 characters")

func decodeJSON(r *http.Request, v any) error {
	return json.NewDecoder(r.Body).Decode(v)
}

// 登录失败退避（进程内；管理员发放制下用户量小，进程内即可，实例重启清零）。
var loginGuard = struct {
	sync.Mutex
	fails map[string][]time.Time
}{fails: map[string][]time.Time{}}

const (
	loginMaxFails   = 5
	loginLockWindow = 30 * time.Second
)

func loginLocked(owner string) bool {
	loginGuard.Lock()
	defer loginGuard.Unlock()
	cut := time.Now().Add(-loginLockWindow)
	kept := loginGuard.fails[owner][:0]
	for _, t := range loginGuard.fails[owner] {
		if t.After(cut) {
			kept = append(kept, t)
		}
	}
	loginGuard.fails[owner] = kept
	return len(kept) >= loginMaxFails
}

func loginFail(owner string) {
	loginGuard.Lock()
	defer loginGuard.Unlock()
	loginGuard.fails[owner] = append(loginGuard.fails[owner], time.Now())
}

func loginClear(owner string) {
	loginGuard.Lock()
	defer loginGuard.Unlock()
	delete(loginGuard.fails, owner)
}

func setSessionCookie(w http.ResponseWriter, token string, maxAge int) {
	http.SetCookie(w, &http.Cookie{
		Name: SessionCookie, Value: token, Path: "/", HttpOnly: true,
		SameSite: http.SameSiteLaxMode, MaxAge: maxAge,
	})
}

func authStateJSON(st store.UserAuthState) map[string]any {
	return map[string]any{
		"owner": st.Owner, "name": st.Name, "isAdmin": st.IsAdmin,
		"mustChangePassword": st.MustChangePassword, "auth": true,
	}
}

// login：用户名+密码 → 会话。失败统一 401（不区分账号是否存在）；
// 连续失败触发进程内退避（429）。
func (s *Server) login(w http.ResponseWriter, r *http.Request) {
	if s.Auth == nil || !s.Auth.Enabled {
		http.Error(w, "auth disabled (embedded single-tenant mode)", http.StatusPreconditionFailed)
		return
	}
	var req struct {
		Owner    string `json:"owner"`
		Password string `json:"password"`
	}
	if err := decodeJSON(r, &req); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	owner := strings.TrimSpace(req.Owner)
	if owner == "" || len(req.Password) > 256 {
		http.Error(w, "owner and password required", http.StatusBadRequest)
		return
	}
	if loginLocked(owner) {
		http.Error(w, "too many failed attempts; retry later", http.StatusTooManyRequests)
		return
	}
	st, ok := s.st.VerifyLogin(owner, req.Password)
	if !ok {
		loginFail(owner)
		http.Error(w, "invalid owner or password", http.StatusUnauthorized)
		return
	}
	loginClear(owner)
	token, err := s.st.CreateSession(owner)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	setSessionCookie(w, token, 7*24*3600)
	writeJSON(w, http.StatusOK, authStateJSON(st))
}

// logout：注销当前会话。
func (s *Server) logout(w http.ResponseWriter, r *http.Request) {
	if tok := sessionToken(r); tok != "" {
		s.st.DeleteSession(tok)
	}
	setSessionCookie(w, "", -1)
	writeJSON(w, http.StatusOK, map[string]any{"ok": true})
}

// changePassword：会话登录者改密。校验当前密码 → 新哈希落库 → 清 must_change →
// 吊销其余会话（保留当前）。重置后的首登改密走同一路径。
func (s *Server) changePassword(w http.ResponseWriter, r *http.Request) {
	tok := sessionToken(r)
	if tok == "" {
		http.Error(w, "session login required (API keys do not own passwords)", http.StatusUnauthorized)
		return
	}
	owner, ok := s.st.SessionOwner(tok)
	if !ok {
		http.Error(w, "session expired", http.StatusUnauthorized)
		return
	}
	var req struct {
		Current string `json:"current"`
		Next    string `json:"next"`
	}
	if err := decodeJSON(r, &req); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	if _, ok := s.st.VerifyLogin(owner, req.Current); !ok {
		http.Error(w, "current password incorrect", http.StatusUnauthorized)
		return
	}
	if err := validPassword(req.Next); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	hash, err := store.HashPassword(req.Next)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if err := s.st.SetUserPassword(owner, hash); err != nil {
		writeStoreErr(w, err)
		return
	}
	// SetUserPassword 置了 must_change=1（重置语义）；本人主动改密后即清除。
	if err := s.st.ClearMustChangePassword(owner); err != nil {
		writeStoreErr(w, err)
		return
	}
	s.st.DeleteUserSessions(owner, tok)
	st, _ := s.st.GetUserAuthState(owner)
	writeJSON(w, http.StatusOK, authStateJSON(st))
}

func validPassword(pw string) error {
	if len(pw) < 8 {
		return errBadPassword
	}
	if len(pw) > 256 {
		return errBadPassword
	}
	return nil
}

// ---- 管理员：用户发放与重置（requireAdmin）----

func (s *Server) requireAdmin(w http.ResponseWriter, r *http.Request) (string, bool) {
	owner := s.owner(r)
	st, err := s.st.GetUserAuthState(owner)
	if err != nil || !st.IsAdmin {
		http.Error(w, "admin required", http.StatusForbidden)
		return "", false
	}
	return owner, true
}

func (s *Server) listAdminUsers(w http.ResponseWriter, r *http.Request) {
	if _, ok := s.requireAdmin(w, r); !ok {
		return
	}
	users, err := s.st.ListUsersAdmin()
	writeJSONOr(w, users, err)
}

func (s *Server) createAdminUser(w http.ResponseWriter, r *http.Request) {
	if _, ok := s.requireAdmin(w, r); !ok {
		return
	}
	var req struct {
		Owner    string `json:"owner"`
		Name     string `json:"name"`
		Password string `json:"password"`
		IsAdmin  bool   `json:"isAdmin"`
	}
	if err := decodeJSON(r, &req); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	req.Owner = strings.TrimSpace(req.Owner)
	if req.Owner == "" || strings.ContainsAny(req.Owner, " \t/") {
		http.Error(w, "owner required (no spaces or slashes)", http.StatusBadRequest)
		return
	}
	if err := validPassword(req.Password); err != nil {
		http.Error(w, "initial password must be 8+ characters", http.StatusBadRequest)
		return
	}
	hash, err := store.HashPassword(req.Password)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if err := s.st.CreateAccount(req.Owner, strings.TrimSpace(req.Name), hash, req.IsAdmin); err != nil {
		writeStoreErr(w, err)
		return
	}
	st, _ := s.st.GetUserAuthState(req.Owner)
	writeJSON(w, http.StatusOK, map[string]any{
		"owner": st.Owner, "name": st.Name, "isAdmin": st.IsAdmin,
		"mustChangePassword": st.MustChangePassword,
	})
}

// resetAdminUserPassword：管理员重置密码 → must_change=1，吊销该用户全部会话。
func (s *Server) resetAdminUserPassword(w http.ResponseWriter, r *http.Request) {
	if _, ok := s.requireAdmin(w, r); !ok {
		return
	}
	owner := r.PathValue("owner")
	var req struct {
		Password string `json:"password"`
	}
	if err := decodeJSON(r, &req); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	if err := validPassword(req.Password); err != nil {
		http.Error(w, "new password must be 8+ characters", http.StatusBadRequest)
		return
	}
	hash, err := store.HashPassword(req.Password)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if err := s.st.SetUserPassword(owner, hash); err != nil {
		writeStoreErr(w, err)
		return
	}
	s.st.DeleteUserSessions(owner, "")
	st, _ := s.st.GetUserAuthState(owner)
	writeJSON(w, http.StatusOK, map[string]any{
		"owner": st.Owner, "mustChangePassword": st.MustChangePassword,
	})
}

// RandomPassword 生成随机初始密码（管理员/CLI 未显式给定密码时）。
func RandomPassword() string {
	raw := make([]byte, 9)
	rand.Read(raw)
	return hex.EncodeToString(raw)
}