auth

Paddy 2015-01-18 Parent:c03b5eb3179e Child:3ec7134fa211

117:da77e083cf02 Go to Latest

auth/session.go

Change TODO to BUG. This is a refactor, not code to be added. It should show up in the gofmt bugs list.

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paddy@70 1 package auth
paddy@70 2
paddy@70 3 import (
paddy@98 4 "crypto/sha256"
paddy@98 5 "encoding/hex"
paddy@70 6 "errors"
paddy@98 7 "log"
paddy@98 8 "net/http"
paddy@89 9 "sort"
paddy@70 10 "time"
paddy@70 11
paddy@107 12 "code.secondbit.org/pass.hg"
paddy@107 13 "code.secondbit.org/uuid.hg"
paddy@98 14 "github.com/gorilla/mux"
paddy@98 15 )
paddy@98 16
paddy@98 17 const (
paddy@98 18 loginTemplateName = "login"
paddy@70 19 )
paddy@70 20
paddy@70 21 var (
paddy@70 22 // ErrNoSessionStore is returned when a Context tries to act on a sessionStore without setting on first.
paddy@70 23 ErrNoSessionStore = errors.New("no sessionStore was specified for the Context")
paddy@70 24 // ErrSessionNotFound is returned when a Session is requested but not found in the sessionStore.
paddy@70 25 ErrSessionNotFound = errors.New("session not found in sessionStore")
paddy@70 26 // ErrInvalidSession is returned when a Session is specified but is not valid.
paddy@70 27 ErrInvalidSession = errors.New("session is not valid")
paddy@77 28 // ErrSessionAlreadyExists is returned when a sessionStore tries to store a Session with an ID that already exists in the sessionStore.
paddy@77 29 ErrSessionAlreadyExists = errors.New("session already exists")
paddy@98 30
paddy@98 31 passphraseSchemes = map[int]passphraseScheme{
paddy@98 32 1: {
paddy@98 33 check: pbkdf2sha256check,
paddy@98 34 create: pbkdf2sha256create,
paddy@98 35 calculateIterations: pbkdf2sha256calc,
paddy@98 36 },
paddy@98 37 }
paddy@70 38 )
paddy@70 39
paddy@98 40 type passphraseScheme struct {
paddy@98 41 check func(profile Profile, passphrase string) (bool, error)
paddy@103 42 create func(passphrase string, iterations int) (result, salt string, err error)
paddy@98 43 calculateIterations func() (int, error)
paddy@98 44 }
paddy@98 45
paddy@70 46 // Session represents a user's authenticated session, associating it with a profile
paddy@70 47 // and some audit data.
paddy@70 48 type Session struct {
paddy@70 49 ID string
paddy@70 50 IP string
paddy@70 51 UserAgent string
paddy@70 52 ProfileID uuid.ID
paddy@98 53 Login string
paddy@70 54 Created time.Time
paddy@70 55 Active bool
paddy@70 56 }
paddy@70 57
paddy@89 58 type sortedSessions []Session
paddy@89 59
paddy@89 60 func (s sortedSessions) Len() int {
paddy@89 61 return len(s)
paddy@89 62 }
paddy@89 63
paddy@89 64 func (s sortedSessions) Less(i, j int) bool {
paddy@89 65 return s[i].Created.After(s[j].Created)
paddy@89 66 }
paddy@89 67
paddy@89 68 func (s sortedSessions) Swap(i, j int) {
paddy@89 69 s[i], s[j] = s[j], s[i]
paddy@89 70 }
paddy@89 71
paddy@70 72 type sessionStore interface {
paddy@70 73 createSession(session Session) error
paddy@70 74 getSession(id string) (Session, error)
paddy@70 75 removeSession(id string) error
paddy@70 76 listSessions(profile uuid.ID, before time.Time, num int64) ([]Session, error)
paddy@70 77 }
paddy@77 78
paddy@77 79 func (m *memstore) createSession(session Session) error {
paddy@77 80 m.sessionLock.Lock()
paddy@77 81 defer m.sessionLock.Unlock()
paddy@77 82 if _, ok := m.sessions[session.ID]; ok {
paddy@77 83 return ErrSessionAlreadyExists
paddy@77 84 }
paddy@77 85 m.sessions[session.ID] = session
paddy@77 86 return nil
paddy@77 87 }
paddy@77 88
paddy@77 89 func (m *memstore) getSession(id string) (Session, error) {
paddy@77 90 m.sessionLock.RLock()
paddy@77 91 defer m.sessionLock.RUnlock()
paddy@77 92 if _, ok := m.sessions[id]; !ok {
paddy@77 93 return Session{}, ErrSessionNotFound
paddy@77 94 }
paddy@77 95 return m.sessions[id], nil
paddy@77 96 }
paddy@77 97
paddy@77 98 func (m *memstore) removeSession(id string) error {
paddy@77 99 m.sessionLock.Lock()
paddy@77 100 defer m.sessionLock.Unlock()
paddy@77 101 if _, ok := m.sessions[id]; !ok {
paddy@77 102 return ErrSessionNotFound
paddy@77 103 }
paddy@77 104 delete(m.sessions, id)
paddy@77 105 return nil
paddy@77 106 }
paddy@77 107
paddy@77 108 func (m *memstore) listSessions(profile uuid.ID, before time.Time, num int64) ([]Session, error) {
paddy@77 109 m.sessionLock.RLock()
paddy@77 110 defer m.sessionLock.RUnlock()
paddy@77 111 res := []Session{}
paddy@77 112 for _, session := range m.sessions {
paddy@77 113 if int64(len(res)) >= num {
paddy@77 114 break
paddy@77 115 }
paddy@77 116 if profile != nil && !profile.Equal(session.ProfileID) {
paddy@77 117 continue
paddy@77 118 }
paddy@77 119 if !before.IsZero() && session.Created.After(before) {
paddy@77 120 continue
paddy@77 121 }
paddy@77 122 res = append(res, session)
paddy@77 123 }
paddy@89 124 sorted := sortedSessions(res)
paddy@89 125 sort.Sort(sorted)
paddy@89 126 res = []Session(sorted)
paddy@77 127 return res, nil
paddy@77 128 }
paddy@98 129
paddy@98 130 // RegisterSessionHandlers adds handlers to the passed router to handle the session endpoints, like login and logout.
paddy@98 131 func RegisterSessionHandlers(r *mux.Router, context Context) {
paddy@98 132 r.Handle("/login", wrap(context, CreateSessionHandler))
paddy@98 133 }
paddy@98 134
paddy@98 135 func checkCookie(r *http.Request, context Context) (Session, error) {
paddy@98 136 cookie, err := r.Cookie(authCookieName)
paddy@98 137 if err == http.ErrNoCookie {
paddy@98 138 return Session{}, ErrNoSession
paddy@98 139 } else if err != nil {
paddy@98 140 log.Println(err)
paddy@98 141 return Session{}, err
paddy@98 142 }
paddy@98 143 sess, err := context.GetSession(cookie.Value)
paddy@98 144 if err == ErrSessionNotFound {
paddy@98 145 return Session{}, ErrInvalidSession
paddy@98 146 } else if err != nil {
paddy@98 147 return Session{}, err
paddy@98 148 }
paddy@98 149 if !sess.Active {
paddy@98 150 return Session{}, ErrInvalidSession
paddy@98 151 }
paddy@98 152 return sess, nil
paddy@98 153 }
paddy@98 154
paddy@98 155 func buildLoginRedirect(r *http.Request, context Context) string {
paddy@98 156 if context.loginURI == nil {
paddy@98 157 return ""
paddy@98 158 }
paddy@98 159 uri := *context.loginURI
paddy@98 160 q := uri.Query()
paddy@98 161 q.Set("from", r.URL.String())
paddy@98 162 uri.RawQuery = q.Encode()
paddy@98 163 return uri.String()
paddy@98 164 }
paddy@98 165
paddy@98 166 func pbkdf2sha256check(profile Profile, passphrase string) (bool, error) {
paddy@98 167 realPass, err := hex.DecodeString(profile.Passphrase)
paddy@98 168 if err != nil {
paddy@98 169 return false, err
paddy@98 170 }
paddy@103 171 realSalt, err := hex.DecodeString(profile.Salt)
paddy@103 172 if err != nil {
paddy@103 173 return false, err
paddy@103 174 }
paddy@103 175 candidate := pass.Check(sha256.New, profile.Iterations, []byte(passphrase), []byte(realSalt))
paddy@98 176 if !pass.Compare(candidate, realPass) {
paddy@98 177 return false, ErrIncorrectAuth
paddy@98 178 }
paddy@98 179 return true, nil
paddy@98 180 }
paddy@98 181
paddy@103 182 func pbkdf2sha256create(passphrase string, iters int) (result, salt string, err error) {
paddy@103 183 passBytes, saltBytes, err := pass.Create(sha256.New, iters, []byte(passphrase))
paddy@103 184 if err != nil {
paddy@103 185 return "", "", err
paddy@103 186 }
paddy@103 187 result = hex.EncodeToString(passBytes)
paddy@103 188 salt = hex.EncodeToString(saltBytes)
paddy@103 189 return result, salt, err
paddy@98 190 }
paddy@98 191
paddy@98 192 func pbkdf2sha256calc() (int, error) {
paddy@98 193 return pass.CalculateIterations(sha256.New)
paddy@98 194 }
paddy@98 195
paddy@98 196 func authenticate(user, passphrase string, context Context) (Profile, error) {
paddy@98 197 profile, err := context.GetProfileByLogin(user)
paddy@98 198 if err != nil {
paddy@98 199 if err == ErrProfileNotFound || err == ErrLoginNotFound {
paddy@98 200 return Profile{}, ErrIncorrectAuth
paddy@98 201 }
paddy@98 202 return Profile{}, err
paddy@98 203 }
paddy@98 204 if profile.Compromised {
paddy@98 205 return Profile{}, ErrProfileCompromised
paddy@98 206 }
paddy@98 207 if !profile.LockedUntil.IsZero() && profile.LockedUntil.After(time.Now()) {
paddy@98 208 return profile, ErrProfileLocked
paddy@98 209 }
paddy@98 210 scheme, ok := passphraseSchemes[profile.PassphraseScheme]
paddy@98 211 if !ok {
paddy@98 212 return Profile{}, ErrInvalidPassphraseScheme
paddy@98 213 }
paddy@98 214 result, err := scheme.check(profile, passphrase)
paddy@98 215 if !result {
paddy@98 216 return Profile{}, err
paddy@98 217 }
paddy@98 218 return profile, nil
paddy@98 219 }
paddy@98 220
paddy@98 221 // CreateSessionHandler allows the user to log into their account and create their session.
paddy@98 222 func CreateSessionHandler(w http.ResponseWriter, r *http.Request, context Context) {
paddy@98 223 // BUG(paddy): Creating a session needs CSRF protection, right? This whole thing should get a security audit
paddy@98 224 errors := []error{}
paddy@98 225 if r.Method == "POST" {
paddy@98 226 profile, err := authenticate(r.PostFormValue("login"), r.PostFormValue("passphrase"), context)
paddy@98 227 if err == nil {
paddy@98 228 ip := r.Header.Get("X-Forwarded-For")
paddy@98 229 if ip == "" {
paddy@98 230 ip = r.RemoteAddr
paddy@98 231 }
paddy@98 232 session := Session{
paddy@98 233 ID: uuid.NewID().String(),
paddy@98 234 IP: ip,
paddy@98 235 UserAgent: r.UserAgent(),
paddy@98 236 ProfileID: profile.ID,
paddy@98 237 Login: r.PostFormValue("login"),
paddy@98 238 Created: time.Now(),
paddy@98 239 Active: true,
paddy@98 240 }
paddy@98 241 err = context.CreateSession(session)
paddy@98 242 if err != nil {
paddy@98 243 w.WriteHeader(http.StatusInternalServerError)
paddy@98 244 w.Write([]byte(err.Error()))
paddy@98 245 return
paddy@98 246 }
paddy@98 247 // BUG(paddy): really need to do a security audit on our cookie
paddy@98 248 cookie := http.Cookie{
paddy@98 249 Name: authCookieName,
paddy@98 250 Value: session.ID,
paddy@98 251 Expires: time.Now().Add(24 * 7 * time.Hour),
paddy@98 252 HttpOnly: true,
paddy@98 253 }
paddy@98 254 http.SetCookie(w, &cookie)
paddy@98 255 redirectTo := r.URL.Query().Get("from")
paddy@98 256 if redirectTo == "" {
paddy@98 257 redirectTo = "/"
paddy@98 258 }
paddy@98 259 http.Redirect(w, r, redirectTo, http.StatusFound)
paddy@98 260 return
paddy@98 261 } else if err != ErrIncorrectAuth && err != ErrProfileCompromised && err != ErrProfileLocked {
paddy@98 262 w.WriteHeader(http.StatusInternalServerError)
paddy@98 263 w.Write([]byte(err.Error()))
paddy@98 264 return
paddy@98 265 } else {
paddy@98 266 errors = append(errors, err)
paddy@98 267 }
paddy@98 268 }
paddy@98 269 context.Render(w, loginTemplateName, map[string]interface{}{
paddy@98 270 "errors": errors,
paddy@98 271 })
paddy@98 272 }