auth

Paddy 2015-04-11 Parent:026adb0c7fc4 Child:cf6c1f05eb21

157:202e991accc2 Go to Latest

auth/session.go

Wire up the postgres database for authd. Have authd use the AUTH_PG_DB environment variable to detect support for the postgres *Stores, and if postgres is supported, use it. If postgres isn't supported, fall back on the in-memory store. Also create-if-not-exists the test scopes, instead of panicking when the scope already exists.

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paddy@70 1 package auth
paddy@70 2
paddy@70 3 import (
paddy@132 4 "crypto/rand"
paddy@98 5 "crypto/sha256"
paddy@132 6 "encoding/base64"
paddy@98 7 "encoding/hex"
paddy@119 8 "encoding/json"
paddy@70 9 "errors"
paddy@98 10 "log"
paddy@98 11 "net/http"
paddy@89 12 "sort"
paddy@135 13 "strings"
paddy@70 14 "time"
paddy@70 15
paddy@107 16 "code.secondbit.org/pass.hg"
paddy@107 17 "code.secondbit.org/uuid.hg"
paddy@98 18 "github.com/gorilla/mux"
paddy@98 19 )
paddy@98 20
paddy@98 21 const (
paddy@132 22 authCookieName = "auth"
paddy@98 23 loginTemplateName = "login"
paddy@70 24 )
paddy@70 25
paddy@119 26 func init() {
paddy@119 27 RegisterGrantType("password", GrantType{
paddy@119 28 Validate: credentialsValidate,
paddy@119 29 Invalidate: nil,
paddy@119 30 IssuesRefresh: true,
paddy@119 31 ReturnToken: RenderJSONToken,
paddy@124 32 AuditString: credentialsAuditString,
paddy@119 33 })
paddy@119 34 }
paddy@119 35
paddy@70 36 var (
paddy@70 37 // ErrNoSessionStore is returned when a Context tries to act on a sessionStore without setting on first.
paddy@70 38 ErrNoSessionStore = errors.New("no sessionStore was specified for the Context")
paddy@70 39 // ErrSessionNotFound is returned when a Session is requested but not found in the sessionStore.
paddy@70 40 ErrSessionNotFound = errors.New("session not found in sessionStore")
paddy@70 41 // ErrInvalidSession is returned when a Session is specified but is not valid.
paddy@70 42 ErrInvalidSession = errors.New("session is not valid")
paddy@77 43 // ErrSessionAlreadyExists is returned when a sessionStore tries to store a Session with an ID that already exists in the sessionStore.
paddy@77 44 ErrSessionAlreadyExists = errors.New("session already exists")
paddy@132 45 // ErrCSRFAttempt is returned when a CSRF attempt is detected.
paddy@132 46 ErrCSRFAttempt = errors.New("CSRF attempt")
paddy@98 47
paddy@98 48 passphraseSchemes = map[int]passphraseScheme{
paddy@98 49 1: {
paddy@98 50 check: pbkdf2sha256check,
paddy@98 51 create: pbkdf2sha256create,
paddy@98 52 calculateIterations: pbkdf2sha256calc,
paddy@98 53 },
paddy@98 54 }
paddy@70 55 )
paddy@70 56
paddy@98 57 type passphraseScheme struct {
paddy@98 58 check func(profile Profile, passphrase string) (bool, error)
paddy@103 59 create func(passphrase string, iterations int) (result, salt string, err error)
paddy@98 60 calculateIterations func() (int, error)
paddy@98 61 }
paddy@98 62
paddy@70 63 // Session represents a user's authenticated session, associating it with a profile
paddy@70 64 // and some audit data.
paddy@70 65 type Session struct {
paddy@70 66 ID string
paddy@70 67 IP string
paddy@70 68 UserAgent string
paddy@70 69 ProfileID uuid.ID
paddy@98 70 Login string
paddy@70 71 Created time.Time
paddy@132 72 Expires time.Time
paddy@70 73 Active bool
paddy@132 74 CSRFToken string
paddy@70 75 }
paddy@70 76
paddy@89 77 type sortedSessions []Session
paddy@89 78
paddy@89 79 func (s sortedSessions) Len() int {
paddy@89 80 return len(s)
paddy@89 81 }
paddy@89 82
paddy@89 83 func (s sortedSessions) Less(i, j int) bool {
paddy@89 84 return s[i].Created.After(s[j].Created)
paddy@89 85 }
paddy@89 86
paddy@89 87 func (s sortedSessions) Swap(i, j int) {
paddy@89 88 s[i], s[j] = s[j], s[i]
paddy@89 89 }
paddy@89 90
paddy@70 91 type sessionStore interface {
paddy@70 92 createSession(session Session) error
paddy@70 93 getSession(id string) (Session, error)
paddy@70 94 removeSession(id string) error
paddy@70 95 listSessions(profile uuid.ID, before time.Time, num int64) ([]Session, error)
paddy@70 96 }
paddy@77 97
paddy@77 98 func (m *memstore) createSession(session Session) error {
paddy@77 99 m.sessionLock.Lock()
paddy@77 100 defer m.sessionLock.Unlock()
paddy@77 101 if _, ok := m.sessions[session.ID]; ok {
paddy@77 102 return ErrSessionAlreadyExists
paddy@77 103 }
paddy@77 104 m.sessions[session.ID] = session
paddy@77 105 return nil
paddy@77 106 }
paddy@77 107
paddy@77 108 func (m *memstore) getSession(id string) (Session, error) {
paddy@77 109 m.sessionLock.RLock()
paddy@77 110 defer m.sessionLock.RUnlock()
paddy@77 111 if _, ok := m.sessions[id]; !ok {
paddy@77 112 return Session{}, ErrSessionNotFound
paddy@77 113 }
paddy@77 114 return m.sessions[id], nil
paddy@77 115 }
paddy@77 116
paddy@77 117 func (m *memstore) removeSession(id string) error {
paddy@77 118 m.sessionLock.Lock()
paddy@77 119 defer m.sessionLock.Unlock()
paddy@77 120 if _, ok := m.sessions[id]; !ok {
paddy@77 121 return ErrSessionNotFound
paddy@77 122 }
paddy@77 123 delete(m.sessions, id)
paddy@77 124 return nil
paddy@77 125 }
paddy@77 126
paddy@77 127 func (m *memstore) listSessions(profile uuid.ID, before time.Time, num int64) ([]Session, error) {
paddy@77 128 m.sessionLock.RLock()
paddy@77 129 defer m.sessionLock.RUnlock()
paddy@77 130 res := []Session{}
paddy@77 131 for _, session := range m.sessions {
paddy@77 132 if int64(len(res)) >= num {
paddy@77 133 break
paddy@77 134 }
paddy@77 135 if profile != nil && !profile.Equal(session.ProfileID) {
paddy@77 136 continue
paddy@77 137 }
paddy@77 138 if !before.IsZero() && session.Created.After(before) {
paddy@77 139 continue
paddy@77 140 }
paddy@77 141 res = append(res, session)
paddy@77 142 }
paddy@89 143 sorted := sortedSessions(res)
paddy@89 144 sort.Sort(sorted)
paddy@89 145 res = []Session(sorted)
paddy@77 146 return res, nil
paddy@77 147 }
paddy@98 148
paddy@98 149 // RegisterSessionHandlers adds handlers to the passed router to handle the session endpoints, like login and logout.
paddy@98 150 func RegisterSessionHandlers(r *mux.Router, context Context) {
paddy@98 151 r.Handle("/login", wrap(context, CreateSessionHandler))
paddy@128 152 // BUG(paddy): We need to implement a handler for listing sessions active on a profile.
paddy@128 153 // BUG(paddy): We need to implement a handler for terminating sessions.
paddy@98 154 }
paddy@98 155
paddy@132 156 func checkCSRF(r *http.Request, s Session) error {
paddy@132 157 if r.PostFormValue("csrftoken") != s.CSRFToken {
paddy@132 158 return ErrCSRFAttempt
paddy@132 159 }
paddy@132 160 return nil
paddy@132 161 }
paddy@132 162
paddy@98 163 func checkCookie(r *http.Request, context Context) (Session, error) {
paddy@98 164 cookie, err := r.Cookie(authCookieName)
paddy@98 165 if err == http.ErrNoCookie {
paddy@98 166 return Session{}, ErrNoSession
paddy@98 167 } else if err != nil {
paddy@98 168 log.Println(err)
paddy@98 169 return Session{}, err
paddy@98 170 }
paddy@98 171 sess, err := context.GetSession(cookie.Value)
paddy@98 172 if err == ErrSessionNotFound {
paddy@98 173 return Session{}, ErrInvalidSession
paddy@98 174 } else if err != nil {
paddy@98 175 return Session{}, err
paddy@98 176 }
paddy@98 177 if !sess.Active {
paddy@98 178 return Session{}, ErrInvalidSession
paddy@98 179 }
paddy@132 180 if time.Now().After(sess.Expires) {
paddy@132 181 return Session{}, ErrInvalidSession
paddy@132 182 }
paddy@98 183 return sess, nil
paddy@98 184 }
paddy@98 185
paddy@98 186 func buildLoginRedirect(r *http.Request, context Context) string {
paddy@98 187 if context.loginURI == nil {
paddy@98 188 return ""
paddy@98 189 }
paddy@98 190 uri := *context.loginURI
paddy@98 191 q := uri.Query()
paddy@98 192 q.Set("from", r.URL.String())
paddy@98 193 uri.RawQuery = q.Encode()
paddy@98 194 return uri.String()
paddy@98 195 }
paddy@98 196
paddy@98 197 func pbkdf2sha256check(profile Profile, passphrase string) (bool, error) {
paddy@98 198 realPass, err := hex.DecodeString(profile.Passphrase)
paddy@98 199 if err != nil {
paddy@98 200 return false, err
paddy@98 201 }
paddy@103 202 realSalt, err := hex.DecodeString(profile.Salt)
paddy@103 203 if err != nil {
paddy@103 204 return false, err
paddy@103 205 }
paddy@103 206 candidate := pass.Check(sha256.New, profile.Iterations, []byte(passphrase), []byte(realSalt))
paddy@98 207 if !pass.Compare(candidate, realPass) {
paddy@98 208 return false, ErrIncorrectAuth
paddy@98 209 }
paddy@98 210 return true, nil
paddy@98 211 }
paddy@98 212
paddy@103 213 func pbkdf2sha256create(passphrase string, iters int) (result, salt string, err error) {
paddy@103 214 passBytes, saltBytes, err := pass.Create(sha256.New, iters, []byte(passphrase))
paddy@103 215 if err != nil {
paddy@103 216 return "", "", err
paddy@103 217 }
paddy@103 218 result = hex.EncodeToString(passBytes)
paddy@103 219 salt = hex.EncodeToString(saltBytes)
paddy@103 220 return result, salt, err
paddy@98 221 }
paddy@98 222
paddy@98 223 func pbkdf2sha256calc() (int, error) {
paddy@98 224 return pass.CalculateIterations(sha256.New)
paddy@98 225 }
paddy@98 226
paddy@139 227 func isAuthError(err error) bool {
paddy@139 228 return err == ErrIncorrectAuth || err == ErrProfileCompromised || err == ErrProfileLocked || err == ErrInvalidPassphraseScheme
paddy@139 229 }
paddy@139 230
paddy@98 231 func authenticate(user, passphrase string, context Context) (Profile, error) {
paddy@98 232 profile, err := context.GetProfileByLogin(user)
paddy@98 233 if err != nil {
paddy@98 234 if err == ErrProfileNotFound || err == ErrLoginNotFound {
paddy@98 235 return Profile{}, ErrIncorrectAuth
paddy@98 236 }
paddy@98 237 return Profile{}, err
paddy@98 238 }
paddy@98 239 if profile.Compromised {
paddy@98 240 return Profile{}, ErrProfileCompromised
paddy@98 241 }
paddy@98 242 if !profile.LockedUntil.IsZero() && profile.LockedUntil.After(time.Now()) {
paddy@98 243 return profile, ErrProfileLocked
paddy@98 244 }
paddy@98 245 scheme, ok := passphraseSchemes[profile.PassphraseScheme]
paddy@98 246 if !ok {
paddy@98 247 return Profile{}, ErrInvalidPassphraseScheme
paddy@98 248 }
paddy@98 249 result, err := scheme.check(profile, passphrase)
paddy@98 250 if !result {
paddy@98 251 return Profile{}, err
paddy@98 252 }
paddy@98 253 return profile, nil
paddy@98 254 }
paddy@98 255
paddy@98 256 // CreateSessionHandler allows the user to log into their account and create their session.
paddy@98 257 func CreateSessionHandler(w http.ResponseWriter, r *http.Request, context Context) {
paddy@98 258 errors := []error{}
paddy@98 259 if r.Method == "POST" {
paddy@98 260 profile, err := authenticate(r.PostFormValue("login"), r.PostFormValue("passphrase"), context)
paddy@98 261 if err == nil {
paddy@98 262 ip := r.Header.Get("X-Forwarded-For")
paddy@98 263 if ip == "" {
paddy@98 264 ip = r.RemoteAddr
paddy@98 265 }
paddy@132 266 sessionID := make([]byte, 32)
paddy@132 267 csrfToken := make([]byte, 32)
paddy@132 268 _, err = rand.Read(sessionID)
paddy@132 269 if err != nil {
paddy@132 270 log.Println("Error reading CSPRNG for session ID:", err)
paddy@132 271 w.WriteHeader(http.StatusInternalServerError)
paddy@132 272 w.Write([]byte("Internal error"))
paddy@132 273 return
paddy@132 274 }
paddy@132 275 _, err = rand.Read(csrfToken)
paddy@132 276 if err != nil {
paddy@132 277 log.Println("Error reading CSPRNG for CSRF token:", err)
paddy@132 278 w.WriteHeader(http.StatusInternalServerError)
paddy@132 279 w.Write([]byte("internal error"))
paddy@132 280 return
paddy@132 281 }
paddy@98 282 session := Session{
paddy@132 283 ID: base64.StdEncoding.EncodeToString(sessionID),
paddy@98 284 IP: ip,
paddy@98 285 UserAgent: r.UserAgent(),
paddy@98 286 ProfileID: profile.ID,
paddy@98 287 Login: r.PostFormValue("login"),
paddy@98 288 Created: time.Now(),
paddy@132 289 Expires: time.Now().Add(time.Hour),
paddy@98 290 Active: true,
paddy@132 291 CSRFToken: base64.StdEncoding.EncodeToString(csrfToken),
paddy@98 292 }
paddy@98 293 err = context.CreateSession(session)
paddy@98 294 if err != nil {
paddy@98 295 w.WriteHeader(http.StatusInternalServerError)
paddy@98 296 w.Write([]byte(err.Error()))
paddy@98 297 return
paddy@98 298 }
paddy@132 299 // BUG(paddy): We really need to do a security audit on our cookies.
paddy@98 300 cookie := http.Cookie{
paddy@98 301 Name: authCookieName,
paddy@98 302 Value: session.ID,
paddy@132 303 Expires: session.Expires,
paddy@98 304 HttpOnly: true,
paddy@132 305 Secure: context.config.secureCookie,
paddy@98 306 }
paddy@98 307 http.SetCookie(w, &cookie)
paddy@98 308 redirectTo := r.URL.Query().Get("from")
paddy@98 309 if redirectTo == "" {
paddy@98 310 redirectTo = "/"
paddy@98 311 }
paddy@98 312 http.Redirect(w, r, redirectTo, http.StatusFound)
paddy@98 313 return
paddy@139 314 } else if !isAuthError(err) {
paddy@98 315 w.WriteHeader(http.StatusInternalServerError)
paddy@98 316 w.Write([]byte(err.Error()))
paddy@98 317 return
paddy@98 318 } else {
paddy@98 319 errors = append(errors, err)
paddy@98 320 }
paddy@98 321 }
paddy@98 322 context.Render(w, loginTemplateName, map[string]interface{}{
paddy@98 323 "errors": errors,
paddy@98 324 })
paddy@98 325 }
paddy@119 326
paddy@135 327 func credentialsValidate(w http.ResponseWriter, r *http.Request, context Context) (scopes []string, profileID uuid.ID, valid bool) {
paddy@119 328 enc := json.NewEncoder(w)
paddy@119 329 username := r.PostFormValue("username")
paddy@119 330 password := r.PostFormValue("password")
paddy@135 331 scopes = strings.Split(r.PostFormValue("scope"), " ")
paddy@119 332 profile, err := authenticate(username, password, context)
paddy@119 333 if err != nil {
paddy@139 334 if isAuthError(err) {
paddy@119 335 w.WriteHeader(http.StatusBadRequest)
paddy@119 336 renderJSONError(enc, "invalid_grant")
paddy@119 337 return
paddy@119 338 }
paddy@119 339 w.WriteHeader(http.StatusInternalServerError)
paddy@119 340 w.Write([]byte(err.Error()))
paddy@119 341 return
paddy@119 342 }
paddy@119 343 profileID = profile.ID
paddy@119 344 valid = true
paddy@119 345 return
paddy@119 346 }
paddy@124 347
paddy@124 348 func credentialsAuditString(r *http.Request) string {
paddy@124 349 return "credentials"
paddy@124 350 }