AdGuardHome/internal/home/auth.go

566 lines
12 KiB
Go

package home
import (
"crypto/rand"
"crypto/sha256"
"encoding/binary"
"encoding/hex"
"encoding/json"
"fmt"
"math"
"math/big"
"net/http"
"strings"
"sync"
"time"
"github.com/AdguardTeam/golibs/log"
"go.etcd.io/bbolt"
"golang.org/x/crypto/bcrypt"
)
const (
cookieTTL = 365 * 24 // in hours
sessionCookieName = "agh_session"
)
type session struct {
userName string
expire uint32 // expiration time (in seconds)
}
func (s *session) serialize() []byte {
const (
expireLen = 4
nameLen = 2
)
data := make([]byte, expireLen+nameLen+len(s.userName))
binary.BigEndian.PutUint32(data[0:4], s.expire)
binary.BigEndian.PutUint16(data[4:6], uint16(len(s.userName)))
copy(data[6:], []byte(s.userName))
return data
}
func (s *session) deserialize(data []byte) bool {
if len(data) < 4+2 {
return false
}
s.expire = binary.BigEndian.Uint32(data[0:4])
nameLen := binary.BigEndian.Uint16(data[4:6])
data = data[6:]
if len(data) < int(nameLen) {
return false
}
s.userName = string(data)
return true
}
// Auth - global object
type Auth struct {
db *bbolt.DB
sessions map[string]*session
users []User
lock sync.Mutex
sessionTTL uint32
}
// User object
type User struct {
Name string `yaml:"name"`
PasswordHash string `yaml:"password"` // bcrypt hash
}
// InitAuth - create a global object
func InitAuth(dbFilename string, users []User, sessionTTL uint32) *Auth {
log.Info("Initializing auth module: %s", dbFilename)
a := Auth{}
a.sessionTTL = sessionTTL
a.sessions = make(map[string]*session)
var err error
a.db, err = bbolt.Open(dbFilename, 0o644, nil)
if err != nil {
log.Error("Auth: open DB: %s: %s", dbFilename, err)
if err.Error() == "invalid argument" {
log.Error("AdGuard Home cannot be initialized due to an incompatible file system.\nPlease read the explanation here: https://github.com/AdguardTeam/AdGuardHome/internal/wiki/Getting-Started#limitations")
}
return nil
}
a.loadSessions()
a.users = users
log.Info("Auth: initialized. users:%d sessions:%d", len(a.users), len(a.sessions))
return &a
}
// Close - close module
func (a *Auth) Close() {
_ = a.db.Close()
}
func bucketName() []byte {
return []byte("sessions-2")
}
// load sessions from file, remove expired sessions
func (a *Auth) loadSessions() {
tx, err := a.db.Begin(true)
if err != nil {
log.Error("Auth: bbolt.Begin: %s", err)
return
}
defer func() {
_ = tx.Rollback()
}()
bkt := tx.Bucket(bucketName())
if bkt == nil {
return
}
removed := 0
if tx.Bucket([]byte("sessions")) != nil {
_ = tx.DeleteBucket([]byte("sessions"))
removed = 1
}
now := uint32(time.Now().UTC().Unix())
forEach := func(k, v []byte) error {
s := session{}
if !s.deserialize(v) || s.expire <= now {
err = bkt.Delete(k)
if err != nil {
log.Error("Auth: bbolt.Delete: %s", err)
} else {
removed++
}
return nil
}
a.sessions[hex.EncodeToString(k)] = &s
return nil
}
_ = bkt.ForEach(forEach)
if removed != 0 {
err = tx.Commit()
if err != nil {
log.Error("bolt.Commit(): %s", err)
}
}
log.Debug("Auth: loaded %d sessions from DB (removed %d expired)", len(a.sessions), removed)
}
// store session data in file
func (a *Auth) addSession(data []byte, s *session) {
name := hex.EncodeToString(data)
a.lock.Lock()
a.sessions[name] = s
a.lock.Unlock()
if a.storeSession(data, s) {
log.Debug("Auth: created session %s: expire=%d", name, s.expire)
}
}
// store session data in file
func (a *Auth) storeSession(data []byte, s *session) bool {
tx, err := a.db.Begin(true)
if err != nil {
log.Error("Auth: bbolt.Begin: %s", err)
return false
}
defer func() {
_ = tx.Rollback()
}()
bkt, err := tx.CreateBucketIfNotExists(bucketName())
if err != nil {
log.Error("Auth: bbolt.CreateBucketIfNotExists: %s", err)
return false
}
err = bkt.Put(data, s.serialize())
if err != nil {
log.Error("Auth: bbolt.Put: %s", err)
return false
}
err = tx.Commit()
if err != nil {
log.Error("Auth: bbolt.Commit: %s", err)
return false
}
return true
}
// remove session from file
func (a *Auth) removeSession(sess []byte) {
tx, err := a.db.Begin(true)
if err != nil {
log.Error("Auth: bbolt.Begin: %s", err)
return
}
defer func() {
_ = tx.Rollback()
}()
bkt := tx.Bucket(bucketName())
if bkt == nil {
log.Error("Auth: bbolt.Bucket")
return
}
err = bkt.Delete(sess)
if err != nil {
log.Error("Auth: bbolt.Put: %s", err)
return
}
err = tx.Commit()
if err != nil {
log.Error("Auth: bbolt.Commit: %s", err)
return
}
log.Debug("Auth: removed session from DB")
}
// checkSessionResult is the result of checking a session.
type checkSessionResult int
// checkSessionResult constants.
const (
checkSessionOK checkSessionResult = 0
checkSessionNotFound checkSessionResult = -1
checkSessionExpired checkSessionResult = 1
)
// checkSession checks if the session is valid.
func (a *Auth) checkSession(sess string) (res checkSessionResult) {
now := uint32(time.Now().UTC().Unix())
update := false
a.lock.Lock()
defer a.lock.Unlock()
s, ok := a.sessions[sess]
if !ok {
return checkSessionNotFound
}
if s.expire <= now {
delete(a.sessions, sess)
key, _ := hex.DecodeString(sess)
a.removeSession(key)
return checkSessionExpired
}
newExpire := now + a.sessionTTL
if s.expire/(24*60*60) != newExpire/(24*60*60) {
// update expiration time once a day
update = true
s.expire = newExpire
}
if update {
key, _ := hex.DecodeString(sess)
if a.storeSession(key, s) {
log.Debug("Auth: updated session %s: expire=%d", sess, s.expire)
}
}
return checkSessionOK
}
// RemoveSession - remove session
func (a *Auth) RemoveSession(sess string) {
key, _ := hex.DecodeString(sess)
a.lock.Lock()
delete(a.sessions, sess)
a.lock.Unlock()
a.removeSession(key)
}
type loginJSON struct {
Name string `json:"name"`
Password string `json:"password"`
}
func getSession(u *User) ([]byte, error) {
maxSalt := big.NewInt(math.MaxUint32)
salt, err := rand.Int(rand.Reader, maxSalt)
if err != nil {
return nil, err
}
d := []byte(fmt.Sprintf("%s%s%s", salt, u.Name, u.PasswordHash))
hash := sha256.Sum256(d)
return hash[:], nil
}
func (a *Auth) httpCookie(req loginJSON) (string, error) {
u := a.UserFind(req.Name, req.Password)
if len(u.Name) == 0 {
return "", nil
}
sess, err := getSession(&u)
if err != nil {
return "", err
}
now := time.Now().UTC()
expire := now.Add(cookieTTL * time.Hour)
expstr := expire.Format(time.RFC1123)
expstr = expstr[:len(expstr)-len("UTC")] // "UTC" -> "GMT"
expstr += "GMT"
s := session{}
s.userName = u.Name
s.expire = uint32(now.Unix()) + a.sessionTTL
a.addSession(sess, &s)
return fmt.Sprintf("%s=%s; Path=/; HttpOnly; Expires=%s",
sessionCookieName, hex.EncodeToString(sess), expstr), nil
}
func handleLogin(w http.ResponseWriter, r *http.Request) {
req := loginJSON{}
err := json.NewDecoder(r.Body).Decode(&req)
if err != nil {
httpError(w, http.StatusBadRequest, "json decode: %s", err)
return
}
cookie, err := Context.auth.httpCookie(req)
if err != nil {
httpError(w, http.StatusBadRequest, "crypto rand reader: %s", err)
return
}
if len(cookie) == 0 {
log.Info("Auth: invalid user name or password: name=%q", req.Name)
time.Sleep(1 * time.Second)
http.Error(w, "invalid user name or password", http.StatusBadRequest)
return
}
w.Header().Set("Set-Cookie", cookie)
w.Header().Set("Cache-Control", "no-store, no-cache, must-revalidate, proxy-revalidate")
w.Header().Set("Pragma", "no-cache")
w.Header().Set("Expires", "0")
returnOK(w)
}
func handleLogout(w http.ResponseWriter, r *http.Request) {
cookie := r.Header.Get("Cookie")
sess := parseCookie(cookie)
Context.auth.RemoveSession(sess)
w.Header().Set("Location", "/login.html")
s := fmt.Sprintf("%s=; Path=/; HttpOnly; Expires=Thu, 01 Jan 1970 00:00:00 GMT",
sessionCookieName)
w.Header().Set("Set-Cookie", s)
w.WriteHeader(http.StatusFound)
}
// RegisterAuthHandlers - register handlers
func RegisterAuthHandlers() {
Context.mux.Handle("/control/login", postInstallHandler(ensureHandler(http.MethodPost, handleLogin)))
httpRegister(http.MethodGet, "/control/logout", handleLogout)
}
func parseCookie(cookie string) string {
pairs := strings.Split(cookie, ";")
for _, pair := range pairs {
pair = strings.TrimSpace(pair)
kv := strings.SplitN(pair, "=", 2)
if len(kv) != 2 {
continue
}
if kv[0] == sessionCookieName {
return kv[1]
}
}
return ""
}
// optionalAuthThird return true if user should authenticate first.
func optionalAuthThird(w http.ResponseWriter, r *http.Request) (authFirst bool) {
authFirst = false
// redirect to login page if not authenticated
ok := false
cookie, err := r.Cookie(sessionCookieName)
if glProcessCookie(r) {
log.Debug("Auth: authentification was handled by GL-Inet submodule")
ok = true
} else if err == nil {
r := Context.auth.checkSession(cookie.Value)
if r == checkSessionOK {
ok = true
} else if r < 0 {
log.Debug("Auth: invalid cookie value: %s", cookie)
}
} else {
// there's no Cookie, check Basic authentication
user, pass, ok2 := r.BasicAuth()
if ok2 {
u := Context.auth.UserFind(user, pass)
if len(u.Name) != 0 {
ok = true
} else {
log.Info("Auth: invalid Basic Authorization value")
}
}
}
if !ok {
if r.URL.Path == "/" || r.URL.Path == "/index.html" {
if glProcessRedirect(w, r) {
log.Debug("Auth: redirected to login page by GL-Inet submodule")
} else {
w.Header().Set("Location", "/login.html")
w.WriteHeader(http.StatusFound)
}
} else {
w.WriteHeader(http.StatusForbidden)
_, _ = w.Write([]byte("Forbidden"))
}
authFirst = true
}
return authFirst
}
func optionalAuth(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r *http.Request) {
if r.URL.Path == "/login.html" {
// redirect to dashboard if already authenticated
authRequired := Context.auth != nil && Context.auth.AuthRequired()
cookie, err := r.Cookie(sessionCookieName)
if authRequired && err == nil {
r := Context.auth.checkSession(cookie.Value)
if r == checkSessionOK {
w.Header().Set("Location", "/")
w.WriteHeader(http.StatusFound)
return
} else if r == checkSessionNotFound {
log.Debug("Auth: invalid cookie value: %s", cookie)
}
}
} else if strings.HasPrefix(r.URL.Path, "/assets/") ||
strings.HasPrefix(r.URL.Path, "/login.") {
// process as usual
// no additional auth requirements
} else if Context.auth != nil && Context.auth.AuthRequired() {
if optionalAuthThird(w, r) {
return
}
}
handler(w, r)
}
}
type authHandler struct {
handler http.Handler
}
func (a *authHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
optionalAuth(a.handler.ServeHTTP)(w, r)
}
func optionalAuthHandler(handler http.Handler) http.Handler {
return &authHandler{handler}
}
// UserAdd - add new user
func (a *Auth) UserAdd(u *User, password string) {
if len(password) == 0 {
return
}
hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
if err != nil {
log.Error("bcrypt.GenerateFromPassword: %s", err)
return
}
u.PasswordHash = string(hash)
a.lock.Lock()
a.users = append(a.users, *u)
a.lock.Unlock()
log.Debug("Auth: added user: %s", u.Name)
}
// UserFind - find a user
func (a *Auth) UserFind(login, password string) User {
a.lock.Lock()
defer a.lock.Unlock()
for _, u := range a.users {
if u.Name == login &&
bcrypt.CompareHashAndPassword([]byte(u.PasswordHash), []byte(password)) == nil {
return u
}
}
return User{}
}
// getCurrentUser returns the current user. It returns an empty User if the
// user is not found.
func (a *Auth) getCurrentUser(r *http.Request) User {
cookie, err := r.Cookie(sessionCookieName)
if err != nil {
// There's no Cookie, check Basic authentication.
user, pass, ok := r.BasicAuth()
if ok {
return Context.auth.UserFind(user, pass)
}
return User{}
}
a.lock.Lock()
defer a.lock.Unlock()
s, ok := a.sessions[cookie.Value]
if !ok {
return User{}
}
for _, u := range a.users {
if u.Name == s.userName {
return u
}
}
return User{}
}
// GetUsers - get users
func (a *Auth) GetUsers() []User {
a.lock.Lock()
users := a.users
a.lock.Unlock()
return users
}
// AuthRequired - if authentication is required
func (a *Auth) AuthRequired() bool {
if GLMode {
return true
}
a.lock.Lock()
r := (len(a.users) != 0)
a.lock.Unlock()
return r
}