| 1 | package idear |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "log/slog" |
| 7 | "net/http" |
| 8 | "strconv" |
| 9 | "strings" |
| 10 | |
| 11 | "github.com/carlosframework/rastrillo/flash" |
| 12 | ) |
| 13 | |
| 14 | // The copy every refusal renders. Fixed strings, never the error's own |
| 15 | // text: a store error can carry a subject, an address or a driver |
| 16 | // message, and a page that echoed it would publish them to whoever |
| 17 | // provoked it. The log line gets the detail; the page gets the class. |
| 18 | const ( |
| 19 | invalidCopy = "That request was not valid." |
| 20 | forbiddenCopy = "You may not do that." |
| 21 | lastOwnerCopy = "The owner cannot be removed. Transfer ownership first." |
| 22 | noInvitationCopy = "That invitation is no longer available." |
| 23 | failedCopy = "Something went wrong. Please try again." |
| 24 | signInFirstCopy = "Sign in first, then open this invitation link again." |
| 25 | rateLimitedCopy = "Too many requests. Please wait a moment and try again." |
| 26 | ) |
| 27 | |
| 28 | // The notices a successful mutation flashes. They are one-shot display |
| 29 | // state (rastrillo/flash), read back by Members on the redirect that |
| 30 | // follows. |
| 31 | const ( |
| 32 | invitedNotice = "Invitation created." |
| 33 | deliveredNotice = "Invitation sent." |
| 34 | undeliveredNotice = "The invitation was created but could not be sent. Revoke it and try again." |
| 35 | revokedNotice = "Invitation revoked." |
| 36 | roleNotice = "Role updated." |
| 37 | removedNotice = "Member removed." |
| 38 | restoredNotice = "Member restored." |
| 39 | transferNotice = "Ownership transferred." |
| 40 | joinedNotice = "Welcome — your membership is set up." |
| 41 | alreadyNotice = "You are already a member here." |
| 42 | ) |
| 43 | |
| 44 | // flashError is the flash Kind that lands in MembersPage.Error rather |
| 45 | // than MembersPage.Notice. Anything else is a notice. |
| 46 | const flashError = "error" |
| 47 | |
| 48 | // MembersPage is what RenderMembers receives. |
| 49 | // |
| 50 | // Grantable is the roles the VIEWER may hand out, and a role selector |
| 51 | // must be built from it rather than from the three constants. An Admin |
| 52 | // may grant only Member — checkInviteRole refuses a grant that is not |
| 53 | // STRICTLY BELOW the actor's own rank — so a form that offered Admin |
| 54 | // to an Admin would 403 on every submit, and one that offered Owner |
| 55 | // would 403 for everybody including the Owner. It is computed by |
| 56 | // Grantable, which asks the same predicate the store enforces, so the |
| 57 | // selector cannot drift from the rule. |
| 58 | type MembersPage struct { |
| 59 | Viewer *Member |
| 60 | Members []Member |
| 61 | Invitations []Invitation |
| 62 | Grantable []Role |
| 63 | Error string |
| 64 | Notice string |
| 65 | } |
| 66 | |
| 67 | // InvitationPage is what RenderInvitation receives, on the public |
| 68 | // invitation routes. |
| 69 | // |
| 70 | // THERE IS NO ADDRESS FIELD, and that is the design rather than an |
| 71 | // omission. GET /invitations/{token} is an unauthenticated lookup of a |
| 72 | // secret: it names the instance and the role so the holder knows what |
| 73 | // they are accepting, and it must not echo the invited address, which |
| 74 | // would turn a leaked or guessed link into a disclosure. A renderer |
| 75 | // cannot print what it is never handed. |
| 76 | // |
| 77 | // SignedIn says the viewer has a session; Reconcile says they have one |
| 78 | // AND no member row — the orphan POST is for. A template shows the |
| 79 | // "accept" button to a Reconcile viewer, and a "sign up with this |
| 80 | // link" form to everybody else. |
| 81 | type InvitationPage struct { |
| 82 | Role Role |
| 83 | Site string |
| 84 | Token string |
| 85 | Error string |
| 86 | SignedIn bool |
| 87 | Reconcile bool |
| 88 | } |
| 89 | |
| 90 | // HandlerConfig wires the flows to the app's own shell. Roster and |
| 91 | // both renderers are required; everything else has a serviceable |
| 92 | // default. |
| 93 | // |
| 94 | // There is deliberately NO NotFound here, though the design sketch |
| 95 | // shows one: the 404 renderer lives on idear.Config, because Require |
| 96 | // is a method on the Roster and answers non-members long before a |
| 97 | // handler runs. Two hooks would mean two 404 pages, and a 404 that |
| 98 | // varies with which layer refused is the membership oracle the whole |
| 99 | // design is arranged to avoid. Set Config.NotFound to the same |
| 100 | // renderer the app gives chi's own NotFound and every refusal in idear |
| 101 | // renders through it. |
| 102 | type HandlerConfig struct { |
| 103 | Roster *Roster |
| 104 | RenderMembers func(w http.ResponseWriter, r *http.Request, d MembersPage) |
| 105 | RenderInvitation func(w http.ResponseWriter, r *http.Request, d InvitationPage) |
| 106 | |
| 107 | // Site names this instance on the invitation page — "Acme's |
| 108 | // board". |
| 109 | // |
| 110 | // SET IT IN PRODUCTION. The default is the request's Host, and |
| 111 | // Host is a CLIENT-SUPPLIED HEADER: on the public, unauthenticated |
| 112 | // invitation page, an attacker who mails somebody a link and can |
| 113 | // steer the Host (a permissive reverse proxy, a wildcard vhost, |
| 114 | // a raw request) has the page render text of their choosing as |
| 115 | // the instance's name — "Acme Security, verify your password at |
| 116 | // ...". idear escapes nothing on the app's behalf either; the |
| 117 | // renderer owns that. The default is honest about where the |
| 118 | // request landed, which is useful in development and is not a |
| 119 | // name you should show a stranger. |
| 120 | Site string |
| 121 | |
| 122 | // MembersPath is where a successful mutation redirects. Default |
| 123 | // "/members". An app that mounts the members page elsewhere must |
| 124 | // say so here, or every 303 lands on a 404. |
| 125 | MembersPath string |
| 126 | |
| 127 | // InvitationPath is the prefix a redeemable link is built from: |
| 128 | // InvitationPath + token. Default "/invitations/". |
| 129 | InvitationPath string |
| 130 | |
| 131 | // Deliver mails the invitation link. It is given the request (for |
| 132 | // an origin, a locale, a logger), the invitation and the link. |
| 133 | // |
| 134 | // When it is nil idear puts the LINK ITSELF in the flash notice, |
| 135 | // so a bare mount is usable: the token is shown exactly once, to |
| 136 | // the admin who minted it, and can then be pasted into whatever |
| 137 | // channel the team uses. |
| 138 | // |
| 139 | // That fallback puts a live credential in a cookie, and |
| 140 | // rastrillo/flash sets HttpOnly, SameSite=Lax and MaxAge=60 but |
| 141 | // NOT Secure — so on a plain-http origin the token crosses the |
| 142 | // wire in clear text, and it is written by a package idear does |
| 143 | // not own, so idear cannot add the flag. An app that can send |
| 144 | // mail should set this and keep the token out of the browser |
| 145 | // entirely; NewHandlers logs a warning when it is nil. |
| 146 | Deliver func(r *http.Request, inv *Invitation, link string) error |
| 147 | |
| 148 | // RateLimit bounds the two public routes. See RateLimit — the |
| 149 | // zero value is the documented default, and there is no way to |
| 150 | // turn the limiter off. |
| 151 | RateLimit RateLimit |
| 152 | |
| 153 | // ClientKey is the rate-limit key for a request. Default: the IP |
| 154 | // half of RemoteAddr. Behind a reverse proxy, set this to read |
| 155 | // the app's own TRUSTED forwarding header — see clientIP for why |
| 156 | // idear will not guess at one. |
| 157 | ClientKey func(r *http.Request) string |
| 158 | } |
| 159 | |
| 160 | // Handlers is idear's HTTP surface: the members page, the six |
| 161 | // management mutations, and the two public invitation routes. Build |
| 162 | // one at boot and mount Routes. |
| 163 | type Handlers struct { |
| 164 | cfg HandlerConfig |
| 165 | limit *limiter |
| 166 | } |
| 167 | |
| 168 | // NewHandlers validates cfg and returns the handlers. It errors unless |
| 169 | // the Roster and BOTH renderers are set, following jobs.NewHandlers: |
| 170 | // a nil renderer is a nil call in a request, and a boot error is a |
| 171 | // better place to learn about it than a production panic. |
| 172 | func NewHandlers(cfg HandlerConfig) (*Handlers, error) { |
| 173 | if cfg.Roster == nil { |
| 174 | return nil, errors.New("idear: HandlerConfig.Roster is required") |
| 175 | } |
| 176 | if cfg.RenderMembers == nil { |
| 177 | return nil, errors.New("idear: HandlerConfig.RenderMembers is required") |
| 178 | } |
| 179 | if cfg.RenderInvitation == nil { |
| 180 | return nil, errors.New("idear: HandlerConfig.RenderInvitation is required") |
| 181 | } |
| 182 | if cfg.MembersPath == "" { |
| 183 | cfg.MembersPath = "/members" |
| 184 | } |
| 185 | if cfg.InvitationPath == "" { |
| 186 | cfg.InvitationPath = "/invitations/" |
| 187 | } |
| 188 | if cfg.ClientKey == nil { |
| 189 | cfg.ClientKey = clientIP |
| 190 | } |
| 191 | if cfg.Deliver == nil { |
| 192 | // Once, at boot, rather than on every invitation: the |
| 193 | // fallback is usable and it is not what a deployed app should |
| 194 | // be doing. See HandlerConfig.Deliver. |
| 195 | cfg.Roster.cfg.Logger.Warn("idear: no HandlerConfig.Deliver, so invitation LINKS will be flashed to the inviting admin's browser in a cookie that rastrillo/flash does not mark Secure; set Deliver to mail them instead") |
| 196 | } |
| 197 | return &Handlers{cfg: cfg, limit: newLimiter(cfg.RateLimit)}, nil |
| 198 | } |
| 199 | |
| 200 | // Route is one mounted handler: the method and pattern idear suggests, |
| 201 | // the handler ALREADY WRAPPED in the middleware it requires, and the |
| 202 | // rank that wrapping enforces. |
| 203 | // |
| 204 | // The handler is pre-guarded on purpose. Require and RequireRole have |
| 205 | // a stacking order that is wrong in two different ways when it is got |
| 206 | // wrong (RequireRole mounted bare 403s a stranger, which tells them |
| 207 | // the route exists; Require mounted outside the app's session guard |
| 208 | // 404s everyone including the Owner), so Routes hands out the correct |
| 209 | // composition rather than a bare handler and a comment. What an app |
| 210 | // still owns is the paths and the session guard these are mounted |
| 211 | // inside. |
| 212 | // |
| 213 | // Min is the rank floor the handler enforces, and Public says the |
| 214 | // route is unauthenticated. They are not decoration: they let a |
| 215 | // caller — an app's route audit, or idear's own authorization suite — |
| 216 | // DERIVE what each route should refuse instead of restating a list |
| 217 | // that can drift from the one being mounted. |
| 218 | type Route struct { |
| 219 | Method string |
| 220 | Pattern string |
| 221 | Handler http.Handler |
| 222 | Min Role |
| 223 | Public bool |
| 224 | } |
| 225 | |
| 226 | // Routes is the whole HTTP surface, in the order the design lists it. |
| 227 | // |
| 228 | // The patterns are defaults; paths belong to the app. An app that |
| 229 | // mounts them elsewhere must set MembersPath and InvitationPath to |
| 230 | // match, since those are what the redirects and the invitation links |
| 231 | // are built from. |
| 232 | func (h *Handlers) Routes() []Route { |
| 233 | rs := h.cfg.Roster |
| 234 | guard := func(min Role, fn http.HandlerFunc) http.Handler { |
| 235 | return rs.Require(rs.RequireRole(min)(fn)) |
| 236 | } |
| 237 | return []Route{ |
| 238 | {http.MethodGet, "/members", guard(RoleMember, h.Members), RoleMember, false}, |
| 239 | {http.MethodPost, "/members/invitations", guard(RoleAdmin, h.Invite), RoleAdmin, false}, |
| 240 | {http.MethodPost, "/members/invitations/{id}/revoke", guard(RoleAdmin, h.Revoke), RoleAdmin, false}, |
| 241 | {http.MethodPost, "/members/{id}/role", guard(RoleAdmin, h.SetRole), RoleAdmin, false}, |
| 242 | {http.MethodPost, "/members/{id}/remove", guard(RoleAdmin, h.Remove), RoleAdmin, false}, |
| 243 | {http.MethodPost, "/members/{id}/restore", guard(RoleAdmin, h.Restore), RoleAdmin, false}, |
| 244 | {http.MethodPost, "/members/transfer", guard(RoleOwner, h.Transfer), RoleOwner, false}, |
| 245 | {http.MethodGet, "/invitations/{token}", http.HandlerFunc(h.Invitation), "", true}, |
| 246 | {http.MethodPost, "/invitations/{token}", http.HandlerFunc(h.Accept), "", true}, |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | // Grantable is the roles actor may hand out, highest first — what a |
| 251 | // role selector must be built from. |
| 252 | // |
| 253 | // It is derived from the store's OWN predicates and never from a |
| 254 | // second copy of the rule: mayManage is the authority floor Invite and |
| 255 | // SetRole check first (active, and at least Admin), and |
| 256 | // checkInviteRole is the rank rule they check next, both inside their |
| 257 | // transactions. So the form and the store cannot disagree, and a |
| 258 | // deactivated actor — whose row outlives their privileges, because |
| 259 | // removal is never a delete — is offered nothing at all. RoleOwner is |
| 260 | // never in it for anybody: ownership moves only by Transfer. |
| 261 | func Grantable(actor *Member) []Role { |
| 262 | if actor == nil || mayManage(actor) != nil { |
| 263 | return nil |
| 264 | } |
| 265 | var out []Role |
| 266 | for _, role := range []Role{RoleOwner, RoleAdmin, RoleMember} { |
| 267 | if checkInviteRole(actor, role) == nil { |
| 268 | out = append(out, role) |
| 269 | } |
| 270 | } |
| 271 | return out |
| 272 | } |
| 273 | |
| 274 | // Members is GET /members: the roster, the pending invitations, and |
| 275 | // whatever the last mutation flashed. |
| 276 | func (h *Handlers) Members(w http.ResponseWriter, r *http.Request) { |
| 277 | viewer, ok := h.viewer(w, r) |
| 278 | if !ok { |
| 279 | return |
| 280 | } |
| 281 | d := h.membersPage(r.Context(), viewer) |
| 282 | if f, ok := flash.Take(w, r); ok { |
| 283 | if f.Kind == flashError { |
| 284 | d.Error = f.Message |
| 285 | } else { |
| 286 | d.Notice = f.Message |
| 287 | } |
| 288 | } |
| 289 | h.cfg.RenderMembers(w, r, d) |
| 290 | } |
| 291 | |
| 292 | // Invite is POST /members/invitations. |
| 293 | // |
| 294 | // The role IS read from the form here, and that is safe for exactly |
| 295 | // one reason: checkInviteRole refuses RoleOwner outright, for every |
| 296 | // actor including the Owner, and refuses anything not strictly below |
| 297 | // the actor's own rank. A posted role can therefore only ever be worth |
| 298 | // LESS than the poster already holds. Every other field is read by |
| 299 | // name too — there is no struct binding anywhere in this file, so a |
| 300 | // field nobody named cannot arrive. |
| 301 | func (h *Handlers) Invite(w http.ResponseWriter, r *http.Request) { |
| 302 | viewer, ok := h.viewer(w, r) |
| 303 | if !ok { |
| 304 | return |
| 305 | } |
| 306 | role, valid := ParseRole(field(r, "role")) |
| 307 | if !valid { |
| 308 | h.refuse(w, r, viewer, ErrInvalidRole) |
| 309 | return |
| 310 | } |
| 311 | inv, token, err := h.cfg.Roster.Invite(r.Context(), viewer, field(r, "email"), role) |
| 312 | if err != nil { |
| 313 | h.refuse(w, r, viewer, err) |
| 314 | return |
| 315 | } |
| 316 | |
| 317 | link := h.cfg.InvitationPath + token |
| 318 | if h.cfg.Deliver == nil { |
| 319 | // No delivery hook: the link is the notice. See |
| 320 | // HandlerConfig.Deliver. |
| 321 | h.done(w, r, invitedNotice+" "+link) |
| 322 | return |
| 323 | } |
| 324 | if err := h.cfg.Deliver(r, inv, link); err != nil { |
| 325 | h.log().Error("idear: an invitation was created but could not be delivered", |
| 326 | "invitation_id", inv.ID, "err", err) |
| 327 | h.flash(w, r, flashError, undeliveredNotice) |
| 328 | return |
| 329 | } |
| 330 | h.done(w, r, deliveredNotice) |
| 331 | } |
| 332 | |
| 333 | // Revoke is POST /members/invitations/{id}/revoke. The id comes from |
| 334 | // the URL, never from the body. |
| 335 | func (h *Handlers) Revoke(w http.ResponseWriter, r *http.Request) { |
| 336 | viewer, ok := h.viewer(w, r) |
| 337 | if !ok { |
| 338 | return |
| 339 | } |
| 340 | id, err := pathID(r) |
| 341 | if err != nil { |
| 342 | h.refuse(w, r, viewer, err) |
| 343 | return |
| 344 | } |
| 345 | if err := h.cfg.Roster.Revoke(r.Context(), viewer, id); err != nil { |
| 346 | h.refuse(w, r, viewer, err) |
| 347 | return |
| 348 | } |
| 349 | h.done(w, r, revokedNotice) |
| 350 | } |
| 351 | |
| 352 | // SetRole is POST /members/{id}/role — the target from the URL, the |
| 353 | // new role from the form. See Invite for why a posted role is safe |
| 354 | // here and cannot reach Owner. |
| 355 | func (h *Handlers) SetRole(w http.ResponseWriter, r *http.Request) { |
| 356 | viewer, target, ok := h.target(w, r) |
| 357 | if !ok { |
| 358 | return |
| 359 | } |
| 360 | role, valid := ParseRole(field(r, "role")) |
| 361 | if !valid { |
| 362 | h.refuse(w, r, viewer, ErrInvalidRole) |
| 363 | return |
| 364 | } |
| 365 | if err := h.cfg.Roster.SetRole(r.Context(), viewer, target, role); err != nil { |
| 366 | h.refuse(w, r, viewer, err) |
| 367 | return |
| 368 | } |
| 369 | h.done(w, r, roleNotice) |
| 370 | } |
| 371 | |
| 372 | // Remove is POST /members/{id}/remove: deactivation, never a delete. |
| 373 | func (h *Handlers) Remove(w http.ResponseWriter, r *http.Request) { |
| 374 | viewer, target, ok := h.target(w, r) |
| 375 | if !ok { |
| 376 | return |
| 377 | } |
| 378 | if err := h.cfg.Roster.Deactivate(r.Context(), viewer, target); err != nil { |
| 379 | h.refuse(w, r, viewer, err) |
| 380 | return |
| 381 | } |
| 382 | h.done(w, r, removedNotice) |
| 383 | } |
| 384 | |
| 385 | // Restore is POST /members/{id}/restore: readmission at the role the |
| 386 | // row still carries. It is the only way back in for someone who was |
| 387 | // removed — see Roster.Reactivate. |
| 388 | func (h *Handlers) Restore(w http.ResponseWriter, r *http.Request) { |
| 389 | viewer, target, ok := h.target(w, r) |
| 390 | if !ok { |
| 391 | return |
| 392 | } |
| 393 | if err := h.cfg.Roster.Reactivate(r.Context(), viewer, target); err != nil { |
| 394 | h.refuse(w, r, viewer, err) |
| 395 | return |
| 396 | } |
| 397 | h.done(w, r, restoredNotice) |
| 398 | } |
| 399 | |
| 400 | // Transfer is POST /members/transfer, the one mutation whose target id |
| 401 | // comes from the FORM and not the URL: the path has no id in it, |
| 402 | // because the actor is always the current Owner and the route is not |
| 403 | // addressed by them. |
| 404 | // |
| 405 | // No role is read here at all. Transfer is the only path to RoleOwner, |
| 406 | // and it decides both roles itself. |
| 407 | func (h *Handlers) Transfer(w http.ResponseWriter, r *http.Request) { |
| 408 | viewer, ok := h.viewer(w, r) |
| 409 | if !ok { |
| 410 | return |
| 411 | } |
| 412 | id, err := parseID(field(r, "member")) |
| 413 | if err != nil { |
| 414 | h.refuse(w, r, viewer, err) |
| 415 | return |
| 416 | } |
| 417 | target, err := h.cfg.Roster.ByID(r.Context(), id) |
| 418 | if err != nil { |
| 419 | h.refuse(w, r, viewer, err) |
| 420 | return |
| 421 | } |
| 422 | if err := h.cfg.Roster.Transfer(r.Context(), viewer, target); err != nil { |
| 423 | h.refuse(w, r, viewer, err) |
| 424 | return |
| 425 | } |
| 426 | h.done(w, r, transferNotice) |
| 427 | } |
| 428 | |
| 429 | // Invitation is GET /invitations/{token}: PUBLIC, unauthenticated, and |
| 430 | // a lookup of a secret. |
| 431 | // |
| 432 | // It renders the ROLE and the INSTANCE, and never the invited address: |
| 433 | // InvitationPage has no field for one. Every unusable token — no such |
| 434 | // token, spent, revoked, expired — renders the SAME copy at the same |
| 435 | // status, because ErrNoInvitation is deliberately one error and not |
| 436 | // four, and a page that told them apart would answer questions the |
| 437 | // holder is not entitled to ask. |
| 438 | // |
| 439 | // It is rate-limited. See RateLimit. |
| 440 | func (h *Handlers) Invitation(w http.ResponseWriter, r *http.Request) { |
| 441 | if !h.allow(w, r) { |
| 442 | return |
| 443 | } |
| 444 | token := r.PathValue("token") |
| 445 | signedIn, reconcile := h.standing(r) |
| 446 | |
| 447 | inv, err := h.cfg.Roster.pendingInvitation(r.Context(), token) |
| 448 | if err != nil { |
| 449 | h.deadInvitation(w, r, err, signedIn) |
| 450 | return |
| 451 | } |
| 452 | h.cfg.RenderInvitation(w, r, InvitationPage{ |
| 453 | Role: inv.Role, |
| 454 | Site: h.site(r), |
| 455 | Token: token, |
| 456 | SignedIn: signedIn, |
| 457 | Reconcile: reconcile, |
| 458 | }) |
| 459 | } |
| 460 | |
| 461 | // Accept is POST /invitations/{token}: the RECONCILIATION route, and |
| 462 | // the only path by which a member row is created from an already-live |
| 463 | // session. |
| 464 | // |
| 465 | // It exists because admission cannot be one transaction. Roster. |
| 466 | // Admitting calls the app's opaque Create and then writes the member; |
| 467 | // a failure between them leaves a user row with no membership, and a |
| 468 | // retry does NOT heal it — the retry's Create fails on the now |
| 469 | // duplicate email and password.Signup renders that as 422 without ever |
| 470 | // reaching the member write. The orphan can sign IN and 404s on every |
| 471 | // guarded route forever. Two concurrent first signups reach the same |
| 472 | // place with no failure at all: one wins the Claim and the |
| 473 | // ErrOwnerExists loser is an orphan. |
| 474 | // |
| 475 | // What it does, in order, for a viewer who is SIGNED IN: |
| 476 | // |
| 477 | // 1. already a member: nothing to reconcile — a notice and a |
| 478 | // redirect, and the token is NOT spent. |
| 479 | // 2. a DEACTIVATED member: refused. Readmission is Restore, by an |
| 480 | // admin; an invitation must not be a way for a removed person to |
| 481 | // let themselves back in. |
| 482 | // 3. the roster has ZERO ROWS: Claim, exactly as admission would |
| 483 | // have. An unclaimed instance's first account is its Owner, and |
| 484 | // the only way to be signed in against an empty roster is to be |
| 485 | // the orphan whose Claim did not commit. |
| 486 | // 4. otherwise: the token must be REDEEMABLE BY THIS VIEWER — |
| 487 | // issued to their address, wherever idear can learn it (keymail's |
| 488 | // Subject is the address; under password, Config.EmailForSubject |
| 489 | // resolves one) — and then Accept it, through the CAS in the |
| 490 | // store, so a Revoke racing this never admits. Under password |
| 491 | // with no resolver there is no address to match and the token |
| 492 | // alone decides; that gap is Config.EmailForSubject's whole |
| 493 | // subject matter. |
| 494 | // |
| 495 | // The member row is written by the STORE, from the live session |
| 496 | // Subject, and never assembled here: Subject is canonicalised on every |
| 497 | // write (normalizeSubject), and under keymail the raw subject is the |
| 498 | // address as the visitor typed it. A Member literal built in this |
| 499 | // handler would reintroduce exactly the bug that canonicalisation |
| 500 | // exists to close. |
| 501 | // |
| 502 | // It needs a VALID TOKEN. A claim-race loser holds none, so they are |
| 503 | // healed only after somebody invites them — at which point they redeem |
| 504 | // here rather than through sign-up, which would fail on the duplicate |
| 505 | // email. That is the design spec's corrected wording and it is the |
| 506 | // reason this route is not a general "make me a member" button. |
| 507 | // |
| 508 | // It is rate-limited. See RateLimit. |
| 509 | func (h *Handlers) Accept(w http.ResponseWriter, r *http.Request) { |
| 510 | if !h.allow(w, r) { |
| 511 | return |
| 512 | } |
| 513 | token := r.PathValue("token") |
| 514 | rs := h.cfg.Roster |
| 515 | ctx := r.Context() |
| 516 | |
| 517 | subject, ok := rs.cfg.Subject(r) |
| 518 | subject = strings.TrimSpace(subject) |
| 519 | if !ok || subject == "" { |
| 520 | // Not signed in. Reconciliation writes a member for the |
| 521 | // session in hand; there is no session in hand. The page says |
| 522 | // so rather than pretending the token is bad — and it says it |
| 523 | // at 403, because this is a refusal and a 200 would let a |
| 524 | // caller read "sign in first" as "accepted". The token is not |
| 525 | // touched, so the invitee can redeem it once they have a |
| 526 | // session. |
| 527 | w.WriteHeader(http.StatusForbidden) |
| 528 | h.cfg.RenderInvitation(w, r, InvitationPage{ |
| 529 | Site: h.site(r), |
| 530 | Token: token, |
| 531 | Error: signInFirstCopy, |
| 532 | }) |
| 533 | return |
| 534 | } |
| 535 | |
| 536 | // 1 and 2: an existing row, active or not. |
| 537 | switch m, err := rs.BySubject(ctx, subject); { |
| 538 | case err == nil && m.Active(): |
| 539 | h.done(w, r, alreadyNotice) |
| 540 | return |
| 541 | case err == nil: |
| 542 | h.log().Info("idear: a deactivated member tried to redeem an invitation; readmission is Restore", |
| 543 | "subject", subject, "member_id", m.ID) |
| 544 | h.deadInvitation(w, r, ErrNoInvitation, true) |
| 545 | return |
| 546 | case errors.Is(err, ErrNotFound): |
| 547 | // The orphan. Carry on. |
| 548 | default: |
| 549 | h.log().Error("idear: reconciliation could not resolve the viewer", "subject", subject, "err", err) |
| 550 | h.failInvitation(w, r, token) |
| 551 | return |
| 552 | } |
| 553 | |
| 554 | // 3: the unclaimed instance. |
| 555 | empty, err := rs.IsEmpty(ctx) |
| 556 | if err != nil { |
| 557 | h.log().Error("idear: reconciliation could not count the roster", "subject", subject, "err", err) |
| 558 | h.failInvitation(w, r, token) |
| 559 | return |
| 560 | } |
| 561 | if empty { |
| 562 | switch _, err := rs.Claim(ctx, subject, addressOf(subject), ""); { |
| 563 | case err == nil: |
| 564 | h.log().Info("idear: reconciliation claimed the instance for a signed-in orphan", "subject", subject) |
| 565 | h.done(w, r, joinedNotice) |
| 566 | return |
| 567 | case errors.Is(err, ErrOwnerExists): |
| 568 | // Somebody claimed it between the count and here. They |
| 569 | // may still hold an invitation of their own; fall through. |
| 570 | default: |
| 571 | h.log().Error("idear: reconciliation could not claim the instance", "subject", subject, "err", err) |
| 572 | h.failInvitation(w, r, token) |
| 573 | return |
| 574 | } |
| 575 | } |
| 576 | |
| 577 | // 4: the token — plus the email match, WHEREVER IDEAR CAN MAKE |
| 578 | // ONE. |
| 579 | // |
| 580 | // It can when the session Subject IS an address, which is what |
| 581 | // keymail mints; and it can under password when the app supplied |
| 582 | // Config.EmailForSubject to resolve its own user id. Either way |
| 583 | // the rule is the one admission applies: possession of the token |
| 584 | // AND an email match. |
| 585 | // |
| 586 | // With NEITHER — the password path, no resolver — the token alone |
| 587 | // is the credential here, and that is not parity with admission, |
| 588 | // which always has a submitted address to match against. A |
| 589 | // signed-in orphan can then spend any live token they get hold |
| 590 | // of, at whatever role it carries. Config.EmailForSubject states |
| 591 | // that asymmetry in full; it is written down rather than papered |
| 592 | // over, and setting the hook closes it. |
| 593 | addr, known, err := rs.addressFor(ctx, subject) |
| 594 | if err != nil { |
| 595 | h.log().Error("idear: reconciliation could not resolve the viewer's address; refusing", |
| 596 | "subject", subject, "err", err) |
| 597 | h.failInvitation(w, r, token) |
| 598 | return |
| 599 | } |
| 600 | if known { |
| 601 | inv, err := rs.pendingInvitation(ctx, token) |
| 602 | switch { |
| 603 | case err != nil: |
| 604 | // An unusable token, or a lookup that failed: one answer |
| 605 | // for all of them, as everywhere else on this route. |
| 606 | h.deadInvitation(w, r, ErrNoInvitation, true) |
| 607 | return |
| 608 | case addr == "": |
| 609 | // The resolver ran and placed this subject nowhere. Fail |
| 610 | // closed: a viewer idear cannot identify must not redeem |
| 611 | // an invitation issued to one it can. |
| 612 | h.log().Warn("idear: reconciliation could not place the viewer's subject in the app's own records; refusing", |
| 613 | "subject", subject) |
| 614 | h.deadInvitation(w, r, ErrNoInvitation, true) |
| 615 | return |
| 616 | case normalizeEmail(inv.Email) != addr: |
| 617 | h.log().Warn("idear: reconciliation presented an invitation issued to another address", |
| 618 | "subject", subject) |
| 619 | h.deadInvitation(w, r, ErrNoInvitation, true) |
| 620 | return |
| 621 | } |
| 622 | } |
| 623 | |
| 624 | m, err := rs.Accept(ctx, token, subject, "") |
| 625 | if err != nil { |
| 626 | if !errors.Is(err, ErrNoInvitation) { |
| 627 | h.log().Error("idear: reconciliation could not redeem an invitation", "subject", subject, "err", err) |
| 628 | h.failInvitation(w, r, token) |
| 629 | return |
| 630 | } |
| 631 | h.deadInvitation(w, r, err, true) |
| 632 | return |
| 633 | } |
| 634 | h.log().Info("idear: reconciliation healed an orphan", "subject", subject, "member_id", m.ID, "role", string(m.Role)) |
| 635 | h.done(w, r, joinedNotice) |
| 636 | } |
| 637 | |
| 638 | // viewer is the guarded handlers' first line: the member Require |
| 639 | // resolved. |
| 640 | // |
| 641 | // A nil viewer here is a MOUNT BUG — the handler ran outside Require — |
| 642 | // and it is answered with the app's 404 and a loud log line rather |
| 643 | // than a panic or, worse, a nil actor handed to the store. Every store |
| 644 | // mutation refuses a nil actor, so this is defence in depth; what it |
| 645 | // buys is a log line that names the cause. |
| 646 | func (h *Handlers) viewer(w http.ResponseWriter, r *http.Request) (*Member, bool) { |
| 647 | m := From(r) |
| 648 | if m == nil { |
| 649 | h.log().Error("idear: a handler ran with no viewer; it must be mounted INSIDE Roster.Require", |
| 650 | "path", r.URL.Path) |
| 651 | h.cfg.Roster.cfg.NotFound(w, r) |
| 652 | return nil, false |
| 653 | } |
| 654 | return m, true |
| 655 | } |
| 656 | |
| 657 | // target resolves the viewer and the {id} in the path to a member row. |
| 658 | // A miss renders the app's own 404 — the same page a non-member gets, |
| 659 | // through the same hook. |
| 660 | func (h *Handlers) target(w http.ResponseWriter, r *http.Request) (*Member, *Member, bool) { |
| 661 | viewer, ok := h.viewer(w, r) |
| 662 | if !ok { |
| 663 | return nil, nil, false |
| 664 | } |
| 665 | id, err := pathID(r) |
| 666 | if err != nil { |
| 667 | h.refuse(w, r, viewer, err) |
| 668 | return nil, nil, false |
| 669 | } |
| 670 | target, err := h.cfg.Roster.ByID(r.Context(), id) |
| 671 | if err != nil { |
| 672 | h.refuse(w, r, viewer, err) |
| 673 | return nil, nil, false |
| 674 | } |
| 675 | return viewer, target, true |
| 676 | } |
| 677 | |
| 678 | // done is the success path: flash a notice, then 303 back to the |
| 679 | // members page so a refresh cannot repost the mutation. |
| 680 | func (h *Handlers) done(w http.ResponseWriter, r *http.Request, notice string) { |
| 681 | h.flash(w, r, "notice", notice) |
| 682 | } |
| 683 | |
| 684 | func (h *Handlers) flash(w http.ResponseWriter, r *http.Request, kind, msg string) { |
| 685 | flash.Set(w, kind, msg) |
| 686 | http.Redirect(w, r, h.cfg.MembersPath, http.StatusSeeOther) |
| 687 | } |
| 688 | |
| 689 | // refuse renders a store refusal at the status its CLASS earns. |
| 690 | // |
| 691 | // The classes are the whole point of errors.go: ErrInvalid is 400, |
| 692 | // ErrForbidden is 403 — and ErrLastOwner unwraps to ErrForbidden, so |
| 693 | // this package's most security-relevant refusal renders 403 and not |
| 694 | // 500 — ErrNotFound is the app's own 404 page, and anything left is a |
| 695 | // 500 with no detail on it. Matching the CLASS with errors.Is rather |
| 696 | // than the sentinel is what keeps a new sentinel from silently |
| 697 | // becoming a server error. |
| 698 | func (h *Handlers) refuse(w http.ResponseWriter, r *http.Request, viewer *Member, err error) { |
| 699 | switch { |
| 700 | case errors.Is(err, ErrNotFound): |
| 701 | // A member id that resolves to nothing is answered exactly as |
| 702 | // a non-member is: same hook, same bytes. |
| 703 | h.cfg.Roster.cfg.NotFound(w, r) |
| 704 | case errors.Is(err, ErrNoInvitation): |
| 705 | h.page(w, r, viewer, http.StatusNotFound, noInvitationCopy) |
| 706 | case errors.Is(err, ErrLastOwner): |
| 707 | // Checked before the ErrForbidden arm it unwraps to, because |
| 708 | // the reason is true for every actor at every rank and the |
| 709 | // generic copy would imply somebody senior could do it. |
| 710 | h.page(w, r, viewer, http.StatusForbidden, lastOwnerCopy) |
| 711 | case errors.Is(err, ErrInvalid): |
| 712 | h.page(w, r, viewer, http.StatusBadRequest, invalidCopy) |
| 713 | case errors.Is(err, ErrForbidden): |
| 714 | h.page(w, r, viewer, http.StatusForbidden, forbiddenCopy) |
| 715 | default: |
| 716 | h.log().Error("idear: a members mutation failed", "path", r.URL.Path, "err", err) |
| 717 | h.page(w, r, viewer, http.StatusInternalServerError, failedCopy) |
| 718 | } |
| 719 | } |
| 720 | |
| 721 | // page renders the members page carrying an error, at status. |
| 722 | // |
| 723 | // The status is written BEFORE the renderer runs, so an app's renderer |
| 724 | // must not write its own — the first WriteHeader wins and a second one |
| 725 | // is a logged no-op. That is the cost of keeping Status off MembersPage; |
| 726 | // what it buys is that a renderer cannot accidentally answer 200 to a |
| 727 | // refusal. |
| 728 | func (h *Handlers) page(w http.ResponseWriter, r *http.Request, viewer *Member, status int, msg string) { |
| 729 | d := h.membersPage(r.Context(), viewer) |
| 730 | d.Error = msg |
| 731 | w.WriteHeader(status) |
| 732 | h.cfg.RenderMembers(w, r, d) |
| 733 | } |
| 734 | |
| 735 | // membersPage gathers what the members page shows. A listing failure |
| 736 | // is logged and rendered as an EMPTY list rather than as a 500: this |
| 737 | // is also the failure path's own renderer, and a refusal that turned |
| 738 | // into a server error because the list behind it could not be read |
| 739 | // would report the wrong problem. |
| 740 | func (h *Handlers) membersPage(ctx context.Context, viewer *Member) MembersPage { |
| 741 | d := MembersPage{Viewer: viewer, Grantable: Grantable(viewer)} |
| 742 | members, err := h.cfg.Roster.Members(ctx) |
| 743 | if err != nil { |
| 744 | h.log().Error("idear: listing the roster failed", "err", err) |
| 745 | } |
| 746 | d.Members = members |
| 747 | invitations, err := h.cfg.Roster.PendingInvitations(ctx) |
| 748 | if err != nil { |
| 749 | h.log().Error("idear: listing pending invitations failed", "err", err) |
| 750 | } |
| 751 | d.Invitations = invitations |
| 752 | return d |
| 753 | } |
| 754 | |
| 755 | // deadInvitation renders the one answer every unusable invitation |
| 756 | // gets. A storage failure is NOT routed here — it renders failedCopy |
| 757 | // instead, because telling someone their live invitation is dead |
| 758 | // because the database hiccuped sends them to an admin for a new one |
| 759 | // that will fail the same way. |
| 760 | func (h *Handlers) deadInvitation(w http.ResponseWriter, r *http.Request, err error, signedIn bool) { |
| 761 | if !errors.Is(err, ErrNoInvitation) { |
| 762 | h.log().Error("idear: looking up an invitation failed", "err", err) |
| 763 | w.WriteHeader(http.StatusInternalServerError) |
| 764 | h.cfg.RenderInvitation(w, r, InvitationPage{Site: h.site(r), Error: failedCopy, SignedIn: signedIn}) |
| 765 | return |
| 766 | } |
| 767 | w.WriteHeader(http.StatusNotFound) |
| 768 | h.cfg.RenderInvitation(w, r, InvitationPage{Site: h.site(r), Error: noInvitationCopy, SignedIn: signedIn}) |
| 769 | } |
| 770 | |
| 771 | // failInvitation is the invitation routes' 500: a storage failure, with |
| 772 | // nothing about it on the page. |
| 773 | func (h *Handlers) failInvitation(w http.ResponseWriter, r *http.Request, token string) { |
| 774 | w.WriteHeader(http.StatusInternalServerError) |
| 775 | h.cfg.RenderInvitation(w, r, InvitationPage{ |
| 776 | Site: h.site(r), |
| 777 | Token: token, |
| 778 | Error: failedCopy, |
| 779 | SignedIn: true, |
| 780 | }) |
| 781 | } |
| 782 | |
| 783 | // standing answers the two questions the invitation page asks about |
| 784 | // the viewer: are they signed in, and are they the orphan this route |
| 785 | // is for. A deactivated member is NOT a reconcile candidate — they |
| 786 | // have a row, and Accept refuses them. |
| 787 | func (h *Handlers) standing(r *http.Request) (signedIn, reconcile bool) { |
| 788 | rs := h.cfg.Roster |
| 789 | subject, ok := rs.cfg.Subject(r) |
| 790 | if !ok || strings.TrimSpace(subject) == "" { |
| 791 | return false, false |
| 792 | } |
| 793 | switch _, err := rs.BySubject(r.Context(), subject); { |
| 794 | case err == nil: |
| 795 | return true, false |
| 796 | case errors.Is(err, ErrNotFound): |
| 797 | return true, true |
| 798 | default: |
| 799 | h.log().Error("idear: resolving the invitation viewer failed", "err", err) |
| 800 | return true, false |
| 801 | } |
| 802 | } |
| 803 | |
| 804 | // allow spends one rate-limit token, answering 429 itself when there |
| 805 | // is none. Plain text: this is the response an abusive client gets, |
| 806 | // and rendering the app's own page for it would put a template render |
| 807 | // on the cheapest path an attacker has. |
| 808 | func (h *Handlers) allow(w http.ResponseWriter, r *http.Request) bool { |
| 809 | if h.limit.allow(h.cfg.ClientKey(r)) { |
| 810 | return true |
| 811 | } |
| 812 | h.log().Warn("idear: rate-limited a public invitation request", "path", r.URL.Path) |
| 813 | w.Header().Set("Retry-After", strconv.Itoa(int(h.limit.every.Seconds()))) |
| 814 | http.Error(w, rateLimitedCopy, http.StatusTooManyRequests) |
| 815 | return false |
| 816 | } |
| 817 | |
| 818 | // site names the instance on the invitation page. With no configured |
| 819 | // Site this is the request's Host — a client-supplied header. See |
| 820 | // HandlerConfig.Site. |
| 821 | func (h *Handlers) site(r *http.Request) string { |
| 822 | if h.cfg.Site != "" { |
| 823 | return h.cfg.Site |
| 824 | } |
| 825 | return r.Host |
| 826 | } |
| 827 | |
| 828 | // log is the Roster's logger. The handlers deliberately share it |
| 829 | // rather than taking one of their own: the distinctions idear refuses |
| 830 | // to render — which member was refused, whether a 404 was a stranger |
| 831 | // or a deactivated member — are only ever visible in the log, and they |
| 832 | // must all land in the same place. |
| 833 | func (h *Handlers) log() *slog.Logger { return h.cfg.Roster.cfg.Logger } |
| 834 | |
| 835 | // field reads ONE named field from the POSTED BODY. |
| 836 | // |
| 837 | // By name, one at a time, never by binding a struct: a struct binding |
| 838 | // accepts every field the struct has, and the fields idear's structs |
| 839 | // have include Role and DeactivatedAt. It reads PostForm and not Form |
| 840 | // as well, so a value in the QUERY STRING cannot stand in for a body |
| 841 | // field — otherwise a link could carry ?role=owner into a POST whose |
| 842 | // body never mentioned one. |
| 843 | func field(r *http.Request, name string) string { |
| 844 | if r.PostForm == nil { |
| 845 | // An unparseable body leaves an empty form behind, which every |
| 846 | // caller here treats as a missing field: 400, not a default. |
| 847 | // |
| 848 | // MULTIPART IS PARSED EXPLICITLY. ParseForm does not populate |
| 849 | // PostForm for multipart/form-data — it parses only the query |
| 850 | // — so an app whose members form carries a file input would |
| 851 | // otherwise 400 on every submit with nothing to explain it. |
| 852 | // The failure direction was right and the diagnosis was |
| 853 | // impossible. |
| 854 | // |
| 855 | // The memory bound is small because nothing here reads a file: |
| 856 | // these are three short text fields. Anything larger spills to |
| 857 | // a temp file, which is why this runs only on the |
| 858 | // admin-guarded mutations — the public routes read no fields |
| 859 | // at all. |
| 860 | if strings.HasPrefix(r.Header.Get("Content-Type"), "multipart/form-data") { |
| 861 | _ = r.ParseMultipartForm(multipartMemory) |
| 862 | // Values are already copied into PostForm; nothing below |
| 863 | // reads a file, so the temp files this may have spilled |
| 864 | // need not outlive the request. |
| 865 | if r.MultipartForm != nil { |
| 866 | r.MultipartForm.RemoveAll() |
| 867 | } |
| 868 | } else { |
| 869 | _ = r.ParseForm() |
| 870 | } |
| 871 | } |
| 872 | return r.PostForm.Get(name) |
| 873 | } |
| 874 | |
| 875 | // multipartMemory bounds what a multipart mutation may hold in memory. |
| 876 | // idear reads only short text fields; the limit exists so a body that |
| 877 | // is not that costs nothing. |
| 878 | const multipartMemory = 1 << 20 |
| 879 | |
| 880 | // pathID is the {id} wildcard, as an int64. Ids come from the URL on |
| 881 | // every route that has one. |
| 882 | func pathID(r *http.Request) (int64, error) { |
| 883 | return parseID(r.PathValue("id")) |
| 884 | } |
| 885 | |
| 886 | func parseID(s string) (int64, error) { |
| 887 | id, err := strconv.ParseInt(strings.TrimSpace(s), 10, 64) |
| 888 | if err != nil || id <= 0 { |
| 889 | return 0, ErrInvalidID |
| 890 | } |
| 891 | return id, nil |
| 892 | } |
| 893 | |
| 894 | // addressOf returns subject when it is an ADDRESS — which is what |
| 895 | // keymail mints as the session Subject — and "" when it is anything |
| 896 | // else, such as password's decimal user id. It is the one place idear |
| 897 | // decides whether it knows the viewer's address from the session |
| 898 | // alone. |
| 899 | func addressOf(subject string) string { |
| 900 | if strings.Contains(subject, "@") { |
| 901 | return subject |
| 902 | } |
| 903 | return "" |
| 904 | } |
| 905 | |
| 906 | // addressFor answers what address a session Subject belongs to, and — |
| 907 | // the part that matters — whether idear CAN know at all. |
| 908 | // |
| 909 | // known false is the honest "no idea": a subject that is not an |
| 910 | // address, on an app that supplied no Config.EmailForSubject. The |
| 911 | // caller must not read that as "no match"; it is the absence of a |
| 912 | // question, and reconciliation's behaviour in that case is the |
| 913 | // documented permissive path. |
| 914 | // |
| 915 | // known true with an empty address is a different answer: the app's |
| 916 | // own resolver ran and placed the subject nowhere. That is a refusal, |
| 917 | // not an unknown. |
| 918 | // |
| 919 | // The address is normalised on the way out so callers compare like |
| 920 | // with like, and so an app may return whatever spelling its user table |
| 921 | // happens to hold. |
| 922 | func (rs *Roster) addressFor(ctx context.Context, subject string) (string, bool, error) { |
| 923 | if addr := addressOf(subject); addr != "" { |
| 924 | return normalizeEmail(addr), true, nil |
| 925 | } |
| 926 | if rs.cfg.EmailForSubject == nil { |
| 927 | return "", false, nil |
| 928 | } |
| 929 | addr, err := rs.cfg.EmailForSubject(ctx, subject) |
| 930 | if err != nil { |
| 931 | return "", true, err |
| 932 | } |
| 933 | return normalizeEmail(addr), true, nil |
| 934 | } |
| 935 | |
amadan