| 1 | package console |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/sha256" |
| 6 | "crypto/subtle" |
| 7 | "log" |
| 8 | "net/http" |
| 9 | netmail "net/mail" |
| 10 | "net/url" |
| 11 | "strings" |
| 12 | "sync" |
| 13 | "time" |
| 14 | ) |
| 15 | |
| 16 | // nextCookie carries a safe return path across the Keymail round trip, beside |
| 17 | // the auth cookie. (An email sign-in keeps its next on the challenge row.) |
| 18 | const nextCookie = "carlos_console_next" |
| 19 | |
| 20 | // flowCookie holds this browser's sign-in flow: a random token, set whenever |
| 21 | // a sign-in form renders and kept for ConfirmationTTL from the last one. A |
| 22 | // sign-in challenge stores the flow's hash, so a code typed here is checked |
| 23 | // against this flow's newest live challenge and a second request from here |
| 24 | // replaces it. Its value never depends on how /auth/continue answered. |
| 25 | const flowCookie = "carlos_console_flow" |
| 26 | |
| 27 | // linkConfirmCookie holds the nonce the emailed link's confirm page also puts |
| 28 | // in its form (spec 5.1). A cross-site POST carries no Lax cookie, so an |
| 29 | // attacker cannot submit their own link into someone else's browser. |
| 30 | const linkConfirmCookie = "carlos_console_linkconfirm" |
| 31 | |
| 32 | // Sign-in sends run off the request (spec 4.2): at most challengeSendSlots at |
| 33 | // once, each with challengeSendTimeout to get a slot and finish. |
| 34 | const ( |
| 35 | challengeSendSlots = 4 |
| 36 | challengeSendTimeout = 20 * time.Second |
| 37 | ) |
| 38 | |
| 39 | // signinView is the approved front-page and "Check your email" copy the |
| 40 | // templates show; render fills it on every page. |
| 41 | type signinView struct { |
| 42 | EmailLabel, EmailPlaceholder, EmailButton, Small, NoMail string |
| 43 | CheckTitle, CodeLabel, CodeButton, Nothing, AgainButton string |
| 44 | LinkButton string |
| 45 | // The email step-up's code box and its link's confirm button. |
| 46 | StepUpCodeLabel, StepUpCodeButton, StepUpLinkButton string |
| 47 | } |
| 48 | |
| 49 | var approvedSigninView = signinView{ |
| 50 | EmailLabel: copyText("home.email_label"), |
| 51 | EmailPlaceholder: copyText("home.email_placeholder"), |
| 52 | EmailButton: copyText("home.email_button"), |
| 53 | Small: copyText("home.small"), |
| 54 | NoMail: copyText("home.no_mail"), |
| 55 | CheckTitle: copyText("check.title"), |
| 56 | CodeLabel: copyText("check.code_label"), |
| 57 | CodeButton: copyText("check.code_button"), |
| 58 | Nothing: copyText("check.nothing"), |
| 59 | AgainButton: copyText("check.again_button"), |
| 60 | LinkButton: copyText("link.button"), |
| 61 | StepUpCodeLabel: copyText("stepup.code_label"), |
| 62 | StepUpCodeButton: copyText("stepup.code_button"), |
| 63 | StepUpLinkButton: copyText("stepup.link_button"), |
| 64 | } |
| 65 | |
| 66 | // sameOrigin reports whether a form POST came from this console's own pages: |
| 67 | // an Origin header must name the configured origin's host; without one, |
| 68 | // Sec-Fetch-Site must be same-origin or none; a request carrying neither (an |
| 69 | // old browser, a script) passes, as every other form here does. |
| 70 | func (s *Server) sameOrigin(r *http.Request) bool { |
| 71 | if o := r.Header.Get("Origin"); o != "" { |
| 72 | got, err := url.Parse(o) |
| 73 | if err != nil || got.Host == "" { |
| 74 | return false |
| 75 | } |
| 76 | want, err := url.Parse(s.cfg.Origin) |
| 77 | return err == nil && want.Host != "" && strings.EqualFold(got.Host, want.Host) |
| 78 | } |
| 79 | switch r.Header.Get("Sec-Fetch-Site") { |
| 80 | case "", "same-origin", "none": |
| 81 | return true |
| 82 | } |
| 83 | return false |
| 84 | } |
| 85 | |
| 86 | // canonicalAddress is the one form of a typed address used everywhere after |
| 87 | // the front door (spec 11): trimmed and lower-cased, and accepted only when it |
| 88 | // is a bare address, so display-name and list forms are refused before any |
| 89 | // challenge, rate-limit key or user row exists. |
| 90 | func canonicalAddress(raw string) (string, bool) { |
| 91 | a := strings.ToLower(strings.TrimSpace(raw)) |
| 92 | if !ValidAddress(a) { |
| 93 | return "", false |
| 94 | } |
| 95 | if parsed, err := netmail.ParseAddress(a); err != nil || parsed.Address != a { |
| 96 | return "", false |
| 97 | } |
| 98 | return a, true |
| 99 | } |
| 100 | |
| 101 | // keymailAddress is discovery (spec 4.1): the configured Keymail host's own |
| 102 | // addresses, or, when mayLookup, any address Keymail's public lookup says is |
| 103 | // a mailbox. Only those public answers decide; any lookup failure means email. |
| 104 | func (s *Server) keymailAddress(ctx context.Context, addr string, mayLookup bool) bool { |
| 105 | if s.km == nil { |
| 106 | return false |
| 107 | } |
| 108 | if h := s.km.Host(); h != "" && addr[strings.LastIndex(addr, "@")+1:] == h { |
| 109 | return true |
| 110 | } |
| 111 | if !mayLookup { |
| 112 | return false |
| 113 | } |
| 114 | ok, err := s.km.HasMailbox(ctx, addr) |
| 115 | if err != nil { |
| 116 | log.Printf("console: keymail lookup for %s: %v (sending email)", addr, err) |
| 117 | return false |
| 118 | } |
| 119 | return ok |
| 120 | } |
| 121 | |
| 122 | // mailReady reports whether the console mailer can send now. No mailer is |
| 123 | // not ready. |
| 124 | func (s *Server) mailReady(ctx context.Context) bool { |
| 125 | return s.consoleMail != nil && s.consoleMail.Ready(ctx) |
| 126 | } |
| 127 | |
| 128 | // sendChallengeAsync sends a sign-in or step-up message through the console |
| 129 | // mailer on its own goroutine, so the page renders at once and send latency |
| 130 | // is no oracle. A send that cannot get one of the challengeSendSlots within |
| 131 | // its context is dropped; every failure is logged. |
| 132 | func (s *Server) sendChallengeAsync(to, subject, body string) { |
| 133 | mailer := s.consoleMail |
| 134 | go func() { |
| 135 | defer func() { |
| 136 | if s.challengeSent != nil { |
| 137 | s.challengeSent <- struct{}{} |
| 138 | } |
| 139 | }() |
| 140 | ctx, cancel := context.WithTimeout(context.Background(), challengeSendTimeout) |
| 141 | defer cancel() |
| 142 | select { |
| 143 | case s.challengeSem <- struct{}{}: |
| 144 | defer func() { <-s.challengeSem }() |
| 145 | case <-ctx.Done(): |
| 146 | log.Printf("console: sign-in email to %s dropped: no send slot free", to) |
| 147 | return |
| 148 | } |
| 149 | if mailer == nil { |
| 150 | log.Printf("console: sign-in email to %s dropped: no console mailer", to) |
| 151 | return |
| 152 | } |
| 153 | if err := mailer.Send(ctx, to, subject, body); err != nil { |
| 154 | log.Printf("console: sign-in email to %s: %v", to, err) |
| 155 | } |
| 156 | }() |
| 157 | } |
| 158 | |
| 159 | // requestFlow is this browser's sign-in flow token, or a fresh one when it |
| 160 | // sent none we could have minted. It is "" only when no randomness was to be |
| 161 | // had. |
| 162 | func (s *Server) requestFlow(r *http.Request) string { |
| 163 | if c, err := r.Cookie(flowCookie); err == nil && len(c.Value) >= 32 && len(c.Value) <= 128 { |
| 164 | return c.Value |
| 165 | } |
| 166 | t, err := randomToken() |
| 167 | if err != nil { |
| 168 | log.Printf("console: sign-in flow token: %v", err) |
| 169 | return "" |
| 170 | } |
| 171 | return t |
| 172 | } |
| 173 | |
| 174 | // setFlow (re)sets the flow cookie for another ConfirmationTTL. |
| 175 | func (s *Server) setFlow(w http.ResponseWriter, flow string) { |
| 176 | if flow != "" { |
| 177 | s.setCookie(w, flowCookie, flow, int(ConfirmationTTL.Seconds())) |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | // flowLock serialises /auth/continue's limits and challenge writes for one |
| 182 | // flow, so overlapping submissions from one browser (a double-clicked |
| 183 | // Continue) cannot both see "no challenge yet". Striped by the flow's hash: |
| 184 | // bounded memory, and two flows rarely share a stripe. |
| 185 | func (s *Server) flowLock(flow string) *sync.Mutex { |
| 186 | sum := sha256.Sum256([]byte(flow)) |
| 187 | return &s.flowLocks[sum[0]] |
| 188 | } |
| 189 | |
| 190 | // homeForm is what the front page's one form starts with. flow, when set, is |
| 191 | // the flow the caller already holds for this request. |
| 192 | type homeForm struct { |
| 193 | Prefill, Next, Banner, Error string |
| 194 | NoMail bool |
| 195 | flow string |
| 196 | } |
| 197 | |
| 198 | // renderHome renders the signed-out front page and (re)sets the browser's |
| 199 | // sign-in flow. |
| 200 | func (s *Server) renderHome(w http.ResponseWriter, r *http.Request, f homeForm) { |
| 201 | if f.flow == "" { |
| 202 | f.flow = s.requestFlow(r) |
| 203 | } |
| 204 | s.setFlow(w, f.flow) |
| 205 | s.render(w, http.StatusOK, "home", page{ |
| 206 | Title: "Sign in", Prefill: f.Prefill, Next: safeNext(f.Next), |
| 207 | Banner: f.Banner, Error: f.Error, NoMail: f.NoMail, |
| 208 | }) |
| 209 | } |
| 210 | |
| 211 | // renderCheck renders "Check your email" for addr and (re)sets the flow |
| 212 | // cookie. Every email-bound outcome of the front door renders exactly this, |
| 213 | // so the page never says whether a message was sent, throttled or refused. |
| 214 | func (s *Server) renderCheck(w http.ResponseWriter, flow, addr, next string) { |
| 215 | s.renderCheckError(w, flow, addr, next, "") |
| 216 | } |
| 217 | |
| 218 | // renderCheckError is the same page with a refusal of a typed code under the |
| 219 | // code box. Its address and next are what the request carried, never the |
| 220 | // stored challenge's, so a refused request's page and a sent one's stay the |
| 221 | // same through every later code. |
| 222 | func (s *Server) renderCheckError(w http.ResponseWriter, flow, addr, next, codeErr string) { |
| 223 | s.setFlow(w, flow) |
| 224 | sent := "" |
| 225 | if addr != "" { |
| 226 | sent = copyText("check.sent", "address", addr) |
| 227 | } |
| 228 | s.render(w, http.StatusOK, "check", page{ |
| 229 | Title: copyText("check.title"), |
| 230 | CheckSent: sent, |
| 231 | Prefill: addr, |
| 232 | Next: safeNext(next), |
| 233 | CodeError: codeErr, |
| 234 | }) |
| 235 | } |
| 236 | |
| 237 | // safeNext returns raw when it is a local path and "" otherwise: it starts |
| 238 | // with "/", not "//", has no backslash, and parses with no scheme or host. |
| 239 | // Anything else is dropped silently and the usual landing applies. |
| 240 | func safeNext(raw string) string { |
| 241 | if !strings.HasPrefix(raw, "/") || strings.HasPrefix(raw, "//") || strings.Contains(raw, `\`) { |
| 242 | return "" |
| 243 | } |
| 244 | u, err := url.Parse(raw) |
| 245 | if err != nil || u.Scheme != "" || u.Host != "" { |
| 246 | return "" |
| 247 | } |
| 248 | return raw |
| 249 | } |
| 250 | |
| 251 | // finishSignin is what signing in does once a door has proved an address, |
| 252 | // shared by the Keymail callback and the email link and code handlers: record |
| 253 | // the user, store the Keymail grant (Keymail only), open a session that |
| 254 | // remembers its method, set the cookies, then land. An email sign-in also |
| 255 | // records a step-up at the moment of use, the same proof a step-up would ask |
| 256 | // for minutes later. The current account is resolved (minted for a new user) |
| 257 | // before any redirect, so onboarding runs before next. |
| 258 | func (s *Server) finishSignin(w http.ResponseWriter, r *http.Request, addr, keymailToken, method, next string) { |
| 259 | now := time.Now() |
| 260 | created, err := s.store.EnsureUser(addr, now) |
| 261 | if err != nil { |
| 262 | s.renderMessage(w, r, http.StatusInternalServerError, "Error", "Could not record your account. Please try again.") |
| 263 | return |
| 264 | } |
| 265 | if keymailToken != "" { |
| 266 | if err := s.store.SetGrantToken(addr, keymailToken, now); err != nil { |
| 267 | s.renderMessage(w, r, http.StatusInternalServerError, "Error", "Could not store your sign-in grant. Please try again.") |
| 268 | return |
| 269 | } |
| 270 | } |
| 271 | raw, err := s.store.CreateSessionMethod(addr, keymailToken, method, now) |
| 272 | if err != nil { |
| 273 | s.renderMessage(w, r, http.StatusInternalServerError, "Error", "Could not create your session. Please try again.") |
| 274 | return |
| 275 | } |
| 276 | s.clearCookie(w, authCookie) |
| 277 | s.setCookie(w, sessionCookie, raw, int(SessionTTL.Seconds())) |
| 278 | if created { |
| 279 | s.setCookie(w, welcomeCookie, "1", 300) |
| 280 | } |
| 281 | if method == MethodEmail { |
| 282 | if err := s.store.RecordStepUp(raw, addr, now, now); err != nil { |
| 283 | // Not fatal: the session is good, and the first sensitive action |
| 284 | // will ask for a fresh proof. |
| 285 | log.Printf("console: step-up record for %s: %v", addr, err) |
| 286 | } |
| 287 | } |
| 288 | if n := safeNext(next); n != "" { |
| 289 | if _, err := s.currentAccount(r.Context(), addr); err != nil { |
| 290 | log.Printf("console: landing for %s: %v", addr, err) |
| 291 | s.renderMessage(w, r, http.StatusInternalServerError, "Error", "Could not open your account. Please try again.") |
| 292 | return |
| 293 | } |
| 294 | http.Redirect(w, r, n, http.StatusSeeOther) |
| 295 | return |
| 296 | } |
| 297 | s.redirectToCurrentAccount(w, r, addr, http.StatusSeeOther) |
| 298 | } |
| 299 | |
| 300 | // renderLinkExpired is the answer to an unknown, expired or spent link. |
| 301 | func (s *Server) renderLinkExpired(w http.ResponseWriter, r *http.Request) { |
| 302 | s.renderMessage(w, r, http.StatusGone, "Link expired", copyText("link.expired")) |
| 303 | } |
| 304 | |
| 305 | // handleEmailLinkPage is GET /auth/email/link?t= (spec 5.1). It never spends |
| 306 | // the link, so a mail scanner's fetch leaves it good: it renders a confirm |
| 307 | // page naming the address, whose form POSTs the token with a fresh nonce that |
| 308 | // is also set in linkConfirmCookie. |
| 309 | func (s *Server) handleEmailLinkPage(w http.ResponseWriter, r *http.Request) { |
| 310 | link := r.URL.Query().Get("t") |
| 311 | c, ok := s.store.PeekEmailLink(link, time.Now()) |
| 312 | if link == "" || !ok { |
| 313 | s.renderLinkExpired(w, r) |
| 314 | return |
| 315 | } |
| 316 | switch c.Purpose { |
| 317 | case ChallengeSignIn: |
| 318 | case ChallengeStepUp: |
| 319 | s.stepUpLinkPage(w, r, link, c) |
| 320 | return |
| 321 | default: |
| 322 | s.renderLinkExpired(w, r) |
| 323 | return |
| 324 | } |
| 325 | nonce, err := randomToken() |
| 326 | if err != nil { |
| 327 | s.renderMessage(w, r, http.StatusInternalServerError, "Error", "Could not start the sign-in flow. Please try again.") |
| 328 | return |
| 329 | } |
| 330 | s.setCookie(w, linkConfirmCookie, nonce, int(ConfirmationTTL.Seconds())) |
| 331 | s.render(w, http.StatusOK, "email_link", page{ |
| 332 | Title: copyText("link.title", "address", c.Address), |
| 333 | LinkToken: link, |
| 334 | LinkNonce: nonce, |
| 335 | }) |
| 336 | } |
| 337 | |
| 338 | // handleEmailLink is POST /auth/email/link (spec 5.1): it spends the link and |
| 339 | // signs this browser in, whichever browser it is. Login CSRF is refused |
| 340 | // first, before anything is spent, so a refused POST leaves the link good: the |
| 341 | // request must be same-origin and carry linkConfirmCookie equal to the form's |
| 342 | // nonce. |
| 343 | func (s *Server) handleEmailLink(w http.ResponseWriter, r *http.Request) { |
| 344 | nonce := r.PostFormValue("nonce") |
| 345 | ck, err := r.Cookie(linkConfirmCookie) |
| 346 | if !s.sameOrigin(r) || err != nil || ck.Value == "" || nonce == "" || |
| 347 | subtle.ConstantTimeCompare([]byte(ck.Value), []byte(nonce)) != 1 { |
| 348 | s.renderMessage(w, r, http.StatusForbidden, "Refused", copyText("link.wrong_site")) |
| 349 | return |
| 350 | } |
| 351 | s.clearCookie(w, linkConfirmCookie) |
| 352 | now := time.Now() |
| 353 | link := r.PostFormValue("t") |
| 354 | peek, ok := s.store.PeekEmailLink(link, now) |
| 355 | if link == "" || !ok { |
| 356 | s.renderLinkExpired(w, r) |
| 357 | return |
| 358 | } |
| 359 | switch peek.Purpose { |
| 360 | case ChallengeSignIn: |
| 361 | case ChallengeStepUp: |
| 362 | // Never a sign-in: a step-up link only confirms the session it was |
| 363 | // sent for. |
| 364 | s.stepUpLink(w, r, link, peek, now) |
| 365 | return |
| 366 | default: |
| 367 | s.renderLinkExpired(w, r) |
| 368 | return |
| 369 | } |
| 370 | // Spending it also ends the flow's other sign-in challenges. |
| 371 | c, ok := s.store.TakeEmailLink(link, now) |
| 372 | if !ok || c.Purpose != ChallengeSignIn { |
| 373 | s.renderLinkExpired(w, r) |
| 374 | return |
| 375 | } |
| 376 | s.finishSignin(w, r, c.Address, "", MethodEmail, c.Next) |
| 377 | } |
| 378 | |
| 379 | // handleEmailCode is POST /auth/email/code (spec 5.2): the typed code is |
| 380 | // checked only against the newest live sign-in challenge of this browser's |
| 381 | // flow. A challenge that was sent and one a refused request recorded unsent |
| 382 | // answer alike, so the code box says nothing about throttling. Wrong codes |
| 383 | // count against the challenge's address and the client IP across every |
| 384 | // challenge (spec 5); past either cap the code is refused unchecked and |
| 385 | // nothing is burned, so the emailed link still works. |
| 386 | func (s *Server) handleEmailCode(w http.ResponseWriter, r *http.Request) { |
| 387 | if !s.sameOrigin(r) { |
| 388 | s.renderMessage(w, r, http.StatusForbidden, "Refused", "Cross-site request blocked.") |
| 389 | return |
| 390 | } |
| 391 | now := time.Now() |
| 392 | flow := s.requestFlow(r) |
| 393 | // The page shows the address and next the form carried, never the stored |
| 394 | // challenge's: shown only, never used as a key. |
| 395 | addr, _ := canonicalAddress(r.PostFormValue("address")) |
| 396 | next := r.PostFormValue("next") |
| 397 | c, ok := s.store.LiveEmailChallenge(ChallengeSignIn, hashToken(flow), now) |
| 398 | if flow == "" || !ok { |
| 399 | s.renderCheckError(w, flow, addr, next, copyText("check.code_used_up")) |
| 400 | return |
| 401 | } |
| 402 | // The cap is keyed by the stored challenge's address, never by the form. |
| 403 | // One guess is reserved before the check, so concurrent guesses cannot all |
| 404 | // pass on the same count; only a right code takes it back. |
| 405 | ip := s.clientIP(r) |
| 406 | done, allowed := s.limits.reserveGuess(c.Address, ip) |
| 407 | if !allowed { |
| 408 | log.Printf("console: code for %s from %s refused: too many wrong codes", c.Address, ip) |
| 409 | s.renderCheckError(w, flow, addr, next, copyText("check.code_throttled")) |
| 410 | return |
| 411 | } |
| 412 | got, res := s.store.TakeEmailCode(c, strings.TrimSpace(r.PostFormValue("code")), now) |
| 413 | done(res == CodeOK) |
| 414 | switch res { |
| 415 | case CodeOK: |
| 416 | s.finishSignin(w, r, got.Address, "", MethodEmail, got.Next) |
| 417 | case CodeWrong: |
| 418 | s.renderCheckError(w, flow, addr, next, copyText("check.code_wrong")) |
| 419 | default: |
| 420 | // CodeBurned (this wrong code was the last) or CodeGone (the challenge |
| 421 | // went meanwhile, or predates a restart); both keep the reservation. |
| 422 | s.renderCheckError(w, flow, addr, next, copyText("check.code_used_up")) |
| 423 | } |
| 424 | } |
| 425 | |
| 426 | // ---- re-confirmation by email (spec 6) -------------------------------------- |
| 427 | // |
| 428 | // A session that signed in by email proves it is still there the way it |
| 429 | // signed in: an emailed link or code. The step-up gate's properties hold as |
| 430 | // for Keymail (stepup.go): the challenge is bound to the session that asked |
| 431 | // and to the held action's hash, the held action is redeemed only through |
| 432 | // takePendingActionByHash, and requireFreshAuth still runs after every |
| 433 | // membership and CSRF gate. A step-up challenge never signs anyone in. |
| 434 | |
| 435 | // emailStepUp is requireFreshAuth's answer for an email session that is not |
| 436 | // fresh: hold the action, email a link and code bound to this session and |
| 437 | // that action, and show "Confirm it's you". With no mailer ready it fails |
| 438 | // closed, holding nothing. Over the send limit, a session that already has a |
| 439 | // live step-up challenge sees that one's page again (the earlier email still |
| 440 | // works); any other fails closed. |
| 441 | func (s *Server) emailStepUp(w http.ResponseWriter, r *http.Request, addr, raw string, now time.Time) { |
| 442 | if !s.mailReady(r.Context()) { |
| 443 | log.Printf("console: step-up for %s: the console mailer is not ready", addr) |
| 444 | s.renderMessage(w, r, http.StatusServiceUnavailable, "Error", stepUpHoldFailed) |
| 445 | return |
| 446 | } |
| 447 | if !s.limits.stepUpSend(addr) { |
| 448 | if c, ok := s.liveStepUp(raw, now); ok { |
| 449 | s.renderStepUp(w, r, c.Address, "") |
| 450 | return |
| 451 | } |
| 452 | log.Printf("console: step-up email to %s over its limits; not sent", addr) |
| 453 | s.renderMessage(w, r, http.StatusServiceUnavailable, "Error", stepUpHoldFailed) |
| 454 | return |
| 455 | } |
| 456 | pending, ok := s.stashRequest(w, r, addr, raw, now) |
| 457 | if !ok { |
| 458 | return |
| 459 | } |
| 460 | // It replaces this session's earlier step-up challenge, if any. |
| 461 | link, code, err := s.store.CreateEmailChallenge(EmailChallenge{ |
| 462 | Purpose: ChallengeStepUp, |
| 463 | Address: addr, |
| 464 | SessionHash: hashToken(raw), |
| 465 | PendingHash: hashToken(pending), |
| 466 | ExpiresAt: now.Add(stepUpFlowTTL), |
| 467 | }, now) |
| 468 | if err != nil { |
| 469 | log.Printf("console: step-up challenge for %s: %v", addr, err) |
| 470 | s.renderMessage(w, r, http.StatusInternalServerError, "Error", "Could not start the confirmation. Please try again.") |
| 471 | return |
| 472 | } |
| 473 | console := s.consoleName() |
| 474 | s.sendChallengeAsync(addr, |
| 475 | copyText("email.stepup.subject", "console", console), |
| 476 | copyText("email.stepup.body", "console", console, "address", addr, |
| 477 | "link", s.cfg.Origin+"/auth/email/link?t="+link, "code", code)) |
| 478 | s.renderStepUp(w, r, addr, "") |
| 479 | } |
| 480 | |
| 481 | // stepUpFor reports whether c is a step-up challenge made for the session raw. |
| 482 | func stepUpFor(c *EmailChallenge, raw string) bool { |
| 483 | return c != nil && c.Purpose == ChallengeStepUp && c.SessionHash != "" && |
| 484 | subtle.ConstantTimeCompare([]byte(c.SessionHash), []byte(hashToken(raw))) == 1 |
| 485 | } |
| 486 | |
| 487 | // liveStepUp is the newest live step-up challenge made for the session raw. |
| 488 | func (s *Server) liveStepUp(raw string, now time.Time) (*EmailChallenge, bool) { |
| 489 | c, ok := s.store.LiveEmailChallenge(ChallengeStepUp, hashToken(raw), now) |
| 490 | if !ok || !stepUpFor(c, raw) { |
| 491 | return nil, false |
| 492 | } |
| 493 | return c, true |
| 494 | } |
| 495 | |
| 496 | // renderStepUp renders "Confirm it's you" for addr, with a refusal of a typed |
| 497 | // code under the code box when codeErr is set. |
| 498 | func (s *Server) renderStepUp(w http.ResponseWriter, r *http.Request, addr, codeErr string) { |
| 499 | p := s.basePage(r) |
| 500 | p.Title = copyText("stepup.title") |
| 501 | p.CheckSent = copyText("stepup.sent", "address", addr) |
| 502 | p.CodeError = codeErr |
| 503 | s.render(w, http.StatusOK, "stepup_email", p) |
| 504 | } |
| 505 | |
| 506 | // renderStepUpExpired answers a step-up that has expired, was used, or has no |
| 507 | // held action left to resume. |
| 508 | func (s *Server) renderStepUpExpired(w http.ResponseWriter, r *http.Request) { |
| 509 | s.renderMessage(w, r, http.StatusGone, "Confirmation expired", copyText("stepup.expired")) |
| 510 | } |
| 511 | |
| 512 | // renderStepUpWrongBrowser answers a step-up link opened anywhere but the |
| 513 | // session that asked for it. |
| 514 | func (s *Server) renderStepUpWrongBrowser(w http.ResponseWriter, r *http.Request) { |
| 515 | s.renderMessage(w, r, http.StatusForbidden, copyText("stepup.link_title"), copyText("stepup.wrong_browser")) |
| 516 | } |
| 517 | |
| 518 | // stepUpLinkPage is GET /auth/email/link for a step-up challenge. It spends |
| 519 | // nothing. Only the session the challenge was made for gets the confirm page |
| 520 | // (with its login-CSRF nonce, as for sign-in); anyone else is told to use the |
| 521 | // browser where they started. |
| 522 | func (s *Server) stepUpLinkPage(w http.ResponseWriter, r *http.Request, link string, c *EmailChallenge) { |
| 523 | _, raw, ok := s.session(r) |
| 524 | if !ok || !stepUpFor(c, raw) { |
| 525 | s.renderStepUpWrongBrowser(w, r) |
| 526 | return |
| 527 | } |
| 528 | nonce, err := randomToken() |
| 529 | if err != nil { |
| 530 | s.renderMessage(w, r, http.StatusInternalServerError, "Error", "Could not start the confirmation. Please try again.") |
| 531 | return |
| 532 | } |
| 533 | s.setCookie(w, linkConfirmCookie, nonce, int(ConfirmationTTL.Seconds())) |
| 534 | p := s.basePage(r) |
| 535 | p.Title = copyText("stepup.link_title") |
| 536 | p.LinkToken = link |
| 537 | p.LinkNonce = nonce |
| 538 | p.StepUpLink = true |
| 539 | s.render(w, http.StatusOK, "email_link", p) |
| 540 | } |
| 541 | |
| 542 | // stepUpLink is POST /auth/email/link for a step-up challenge, after the |
| 543 | // nonce and origin checks: a session other than the one the challenge was |
| 544 | // made for is refused with the link unspent; the right one spends it and |
| 545 | // finishes the step-up. |
| 546 | func (s *Server) stepUpLink(w http.ResponseWriter, r *http.Request, link string, peek *EmailChallenge, now time.Time) { |
| 547 | addr, raw, ok := s.session(r) |
| 548 | if !ok || !stepUpFor(peek, raw) { |
| 549 | s.renderStepUpWrongBrowser(w, r) |
| 550 | return |
| 551 | } |
| 552 | c, ok := s.store.TakeEmailLink(link, now) |
| 553 | if !ok { |
| 554 | s.renderStepUpExpired(w, r) |
| 555 | return |
| 556 | } |
| 557 | s.finishStepUp(w, r, addr, raw, c, now) |
| 558 | } |
| 559 | |
| 560 | // handleStepUpEmailCode is POST /auth/email/stepup/code: the typed code is |
| 561 | // checked only against the newest live step-up challenge made for this |
| 562 | // browser's session. Wrong codes count against the |
| 563 | // challenge's address and the client IP, as for sign-in codes. |
| 564 | func (s *Server) handleStepUpEmailCode(w http.ResponseWriter, r *http.Request) { |
| 565 | addr, raw, ok := s.session(r) |
| 566 | if !ok { |
| 567 | http.Redirect(w, r, "/", http.StatusFound) |
| 568 | return |
| 569 | } |
| 570 | if !s.sameOrigin(r) { |
| 571 | s.renderMessage(w, r, http.StatusForbidden, "Refused", "Cross-site request blocked.") |
| 572 | return |
| 573 | } |
| 574 | now := time.Now() |
| 575 | c, ok := s.liveStepUp(raw, now) |
| 576 | if !ok { |
| 577 | s.renderStepUpExpired(w, r) |
| 578 | return |
| 579 | } |
| 580 | ip := s.clientIP(r) |
| 581 | done, allowed := s.limits.reserveGuess(c.Address, ip) |
| 582 | if !allowed { |
| 583 | log.Printf("console: step-up code for %s from %s refused: too many wrong codes", c.Address, ip) |
| 584 | s.renderStepUp(w, r, c.Address, copyText("check.code_throttled")) |
| 585 | return |
| 586 | } |
| 587 | got, res := s.store.TakeEmailCode(c, strings.TrimSpace(r.PostFormValue("code")), now) |
| 588 | done(res == CodeOK) |
| 589 | switch res { |
| 590 | case CodeOK: |
| 591 | s.finishStepUp(w, r, addr, raw, got, now) |
| 592 | case CodeWrong: |
| 593 | s.renderStepUp(w, r, c.Address, copyText("check.code_wrong")) |
| 594 | default: |
| 595 | s.renderStepUpExpired(w, r) |
| 596 | } |
| 597 | } |
| 598 | |
| 599 | // finishStepUp is the tail both step-up doors share, the same as |
| 600 | // handleStepUpCallback's: record presence at the moment the link or code was |
| 601 | // used, redeem the held action this challenge names, and resume it through |
| 602 | // the router. A spent challenge that was not this session's, or names another |
| 603 | // address, records nothing. |
| 604 | func (s *Server) finishStepUp(w http.ResponseWriter, r *http.Request, addr, raw string, c *EmailChallenge, now time.Time) { |
| 605 | if !stepUpFor(c, raw) || c.Address != addr { |
| 606 | s.renderStepUpExpired(w, r) |
| 607 | return |
| 608 | } |
| 609 | if err := s.store.RecordStepUp(raw, addr, now, now); err != nil { |
| 610 | log.Printf("console: record step-up: %v", err) |
| 611 | s.renderMessage(w, r, http.StatusInternalServerError, "Error", "Could not record your confirmation. Please try the action again.") |
| 612 | return |
| 613 | } |
| 614 | pending, ok := s.store.takePendingActionByHash(c.PendingHash, raw, now) |
| 615 | if !ok { |
| 616 | s.renderStepUpExpired(w, r) |
| 617 | return |
| 618 | } |
| 619 | s.resume(w, r, pending) |
| 620 | } |
| 621 | |
amadan