AdGuardHome/internal/home/auth.go

697 lines
16 KiB
Go

package home
import (
"crypto/rand"
"encoding/binary"
"encoding/hex"
"encoding/json"
"fmt"
"net"
"net/http"
"strconv"
"strings"
"sync"
"time"
"github.com/AdguardTeam/AdGuardHome/internal/aghhttp"
"github.com/AdguardTeam/golibs/log"
"github.com/AdguardTeam/golibs/netutil"
"github.com/AdguardTeam/golibs/timeutil"
"go.etcd.io/bbolt"
"golang.org/x/crypto/bcrypt"
)
// cookieTTL is the time-to-live of the session cookie.
const cookieTTL = 365 * timeutil.Day
// sessionCookieName is the name of the session cookie.
const sessionCookieName = "agh_session"
// sessionTokenSize is the length of session token in bytes.
const sessionTokenSize = 16
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
blocker *authRateLimiter
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, blocker *authRateLimiter) *Auth {
log.Info("Initializing auth module: %s", dbFilename)
a := &Auth{
sessionTTL: sessionTTL,
blocker: blocker,
sessions: make(map[string]*session),
users: users,
}
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/wiki/Getting-Started#limitations")
}
return nil
}
a.loadSessions()
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"`
}
// newSessionToken returns cryptographically secure randomly generated slice of
// bytes of sessionTokenSize length.
//
// TODO(e.burkov): Think about using byte array instead of byte slice.
func newSessionToken() (data []byte, err error) {
randData := make([]byte, sessionTokenSize)
_, err = rand.Read(randData)
if err != nil {
return nil, err
}
return randData, nil
}
// cookieTimeFormat is the format to be used in (time.Time).Format for cookie's
// expiry field.
const cookieTimeFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
// cookieExpiryFormat returns the formatted exp to be used in cookie string.
// It's quite simple for now, but probably will be expanded in the future.
func cookieExpiryFormat(exp time.Time) (formatted string) {
return exp.Format(cookieTimeFormat)
}
func (a *Auth) httpCookie(req loginJSON, addr string) (cookie string, err error) {
blocker := a.blocker
u := a.UserFind(req.Name, req.Password)
if len(u.Name) == 0 {
if blocker != nil {
blocker.inc(addr)
}
return "", err
}
if blocker != nil {
blocker.remove(addr)
}
var sess []byte
sess, err = newSessionToken()
if err != nil {
return "", err
}
now := time.Now().UTC()
a.addSession(sess, &session{
userName: u.Name,
expire: uint32(now.Unix()) + a.sessionTTL,
})
return fmt.Sprintf(
"%s=%s; Path=/; HttpOnly; Expires=%s",
sessionCookieName, hex.EncodeToString(sess),
cookieExpiryFormat(now.Add(cookieTTL)),
), nil
}
// realIP extracts the real IP address of the client from an HTTP request using
// the known HTTP headers.
//
// TODO(a.garipov): Currently, this is basically a copy of a similar function in
// module dnsproxy. This should really become a part of module golibs and be
// replaced both here and there. Or be replaced in both places by
// a well-maintained third-party module.
//
// TODO(a.garipov): Support header Forwarded from RFC 7329.
func realIP(r *http.Request) (ip net.IP, err error) {
proxyHeaders := []string{
"CF-Connecting-IP",
"True-Client-IP",
"X-Real-IP",
}
for _, h := range proxyHeaders {
v := r.Header.Get(h)
ip = net.ParseIP(v)
if ip != nil {
return ip, nil
}
}
// If none of the above yielded any results, get the leftmost IP address
// from the X-Forwarded-For header.
s := r.Header.Get("X-Forwarded-For")
ipStrs := strings.SplitN(s, ", ", 2)
ip = net.ParseIP(ipStrs[0])
if ip != nil {
return ip, nil
}
// When everything else fails, just return the remote address as understood
// by the stdlib.
ipStr, err := netutil.SplitHost(r.RemoteAddr)
if err != nil {
return nil, fmt.Errorf("getting ip from client addr: %w", err)
}
return net.ParseIP(ipStr), nil
}
func handleLogin(w http.ResponseWriter, r *http.Request) {
req := loginJSON{}
err := json.NewDecoder(r.Body).Decode(&req)
if err != nil {
aghhttp.Error(r, w, http.StatusBadRequest, "json decode: %s", err)
return
}
var remoteAddr string
// realIP cannot be used here without taking TrustedProxies into account due
// to security issues.
//
// See https://github.com/AdguardTeam/AdGuardHome/issues/2799.
//
// TODO(e.burkov): Use realIP when the issue will be fixed.
if remoteAddr, err = netutil.SplitHost(r.RemoteAddr); err != nil {
aghhttp.Error(r, w, http.StatusBadRequest, "auth: getting remote address: %s", err)
return
}
if blocker := Context.auth.blocker; blocker != nil {
if left := blocker.check(remoteAddr); left > 0 {
w.Header().Set("Retry-After", strconv.Itoa(int(left.Seconds())))
aghhttp.Error(r, w, http.StatusTooManyRequests, "auth: blocked for %s", left)
return
}
}
var cookie string
cookie, err = Context.auth.httpCookie(req, remoteAddr)
if err != nil {
aghhttp.Error(r, w, http.StatusBadRequest, "crypto rand reader: %s", err)
return
}
// Use realIP here, since this IP address is only used for logging.
ip, err := realIP(r)
if err != nil {
log.Error("auth: getting real ip from request: %s", err)
} else if ip == nil {
// Technically shouldn't happen.
log.Error("auth: unknown ip")
}
if len(cookie) == 0 {
log.Info("auth: failed to login user %q from ip %v", req.Name, ip)
time.Sleep(1 * time.Second)
http.Error(w, "invalid username or password", http.StatusBadRequest)
return
}
log.Info("auth: user %q successfully logged in from ip %v", req.Name, ip)
h := w.Header()
h.Set("Set-Cookie", cookie)
h.Set("Cache-Control", "no-store, no-cache, must-revalidate, proxy-revalidate")
h.Set("Pragma", "no-cache")
h.Set("Expires", "0")
aghhttp.OK(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: authentication 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
}