| 1 | package docs |
| 2 | |
| 3 | // Returning to the page you came from after signing in (spec §9.4), and |
| 4 | // the two sign-in behaviours that go with it: an already-signed-in |
| 5 | // GET /signin goes straight back, and signing out lands on a page that |
| 6 | // says so. |
| 7 | // |
| 8 | // With Home configured, the return path already rode the Home hand-off |
| 9 | // (home_routes.go's signin remembers it in __Host-oficina-docs-home- |
| 10 | // return). What did not honour it was the local email link: rastrillo's |
| 11 | // auth.Verify always lands on its fixed SignedInPath, so the value cannot |
| 12 | // ride the emailed link and lives in that same sealed, 600-second cookie |
| 13 | // instead, read at /auth/local/complete. |
| 14 | // |
| 15 | // Standalone Docs (no Home) had nothing: rastrillo's RequireSession drops |
| 16 | // the path (its refuseSession redirects to a bare /signin) and its |
| 17 | // SignedInPath was "/". It now gets the same cookie, sealed under a key |
| 18 | // derived from the instance key, the same /auth/local/complete landing, |
| 19 | // and a guard that puts return_to on the sign-in redirect. (Spec §9.4 |
| 20 | // left standalone as "a small return cookie of its own, or lands on /"; |
| 21 | // this is the first, so the Playwright deep-link gate can run against a |
| 22 | // local dev server.) |
| 23 | // |
| 24 | // auth_navigation.go's "never comes from return_to" governs the Keymail |
| 25 | // authorize URL, which must be exactly https://…/oauth/authorize. The |
| 26 | // path here is a separate value, validated by handoff.SafePath (a |
| 27 | // same-origin path: no scheme, no host, no //, no control characters), |
| 28 | // so it can never become an off-site destination. |
| 29 | |
| 30 | import ( |
| 31 | "crypto/sha256" |
| 32 | "net/http" |
| 33 | "net/url" |
| 34 | "strings" |
| 35 | "time" |
| 36 | |
| 37 | "amadan.net/oficina/home/handoff" |
| 38 | "amadan.net/oficina/home/handoff/seal" |
| 39 | rauth "amadan.net/rastrillo/rastrillo/auth" |
| 40 | ) |
| 41 | |
| 42 | // standaloneReturn builds the standalone instance's return memory: the |
| 43 | // same sealed cookie localLinkNavigation keeps for Home instances, keyed |
| 44 | // from the instance key rather than Home's DEK (standalone has none). |
| 45 | func standaloneReturn(instanceKey, origin string) (*localLinkNavigation, error) { |
| 46 | key := sha256.Sum256([]byte("oficina/docs standalone return v1\x00" + instanceKey)) |
| 47 | sealer, err := seal.New(key[:], "oficina/docs") |
| 48 | if err != nil { |
| 49 | return nil, err |
| 50 | } |
| 51 | u, err := url.Parse(origin) |
| 52 | if err != nil { |
| 53 | return nil, err |
| 54 | } |
| 55 | return &localLinkNavigation{sealer: sealer, origin: origin, host: u.Host, now: time.Now}, nil |
| 56 | } |
| 57 | |
| 58 | // requestedReturn is the return_to a sign-in GET carries, when it is |
| 59 | // exactly one same-origin path. |
| 60 | func requestedReturn(r *http.Request) (string, bool) { |
| 61 | q, err := url.ParseQuery(r.URL.RawQuery) |
| 62 | if err != nil { |
| 63 | return "", false |
| 64 | } |
| 65 | values, ok := q["return_to"] |
| 66 | if !ok || len(values) != 1 || !handoff.SafePath(values[0]) { |
| 67 | return "", false |
| 68 | } |
| 69 | return values[0], true |
| 70 | } |
| 71 | |
| 72 | // signinOutcome reports whether GET /signin is showing an outcome of the |
| 73 | // email flow (?sent, ?err, ?force) rather than starting one. |
| 74 | func signinOutcome(r *http.Request) bool { |
| 75 | q := r.URL.Query() |
| 76 | return q.Has("sent") || q.Has("err") || q.Has("force") |
| 77 | } |
| 78 | |
| 79 | // alreadySignedIn sends a signed-in GET /signin back where it came |
| 80 | // from, with no form (spec §9.2: 303 to return_to or /). |
| 81 | func alreadySignedIn(w http.ResponseWriter, r *http.Request) { |
| 82 | target := "/" |
| 83 | if path, ok := requestedReturn(r); ok { |
| 84 | target = path |
| 85 | } |
| 86 | w.Header().Set("Cache-Control", "no-store") |
| 87 | http.Redirect(w, r, target, http.StatusSeeOther) |
| 88 | } |
| 89 | |
| 90 | // admitted reports whether the signed-in routes would let this request's |
| 91 | // session in right now, by running the same guard chain (h.requireCurrent: |
| 92 | // session, identity, admission) around a probe. A session is not enough: |
| 93 | // a guest whose last share was revoked still holds a valid one, admission |
| 94 | // sends GET / to /signin, and skipping the form for them sent /signin |
| 95 | // straight back to / — forever (review finding, Astra, #65). |
| 96 | func (h *handlers) admitted(r *http.Request) bool { |
| 97 | if h.requireCurrent == nil { |
| 98 | return false |
| 99 | } |
| 100 | probe := r.Clone(r.Context()) |
| 101 | probe.Method = http.MethodGet |
| 102 | probe.URL = &url.URL{Path: "/"} |
| 103 | probe.RequestURI = "/" |
| 104 | reached := false |
| 105 | h.requireCurrent(http.HandlerFunc(func(http.ResponseWriter, *http.Request) { reached = true })). |
| 106 | ServeHTTP(&signinResponse{header: make(http.Header)}, probe) |
| 107 | return reached |
| 108 | } |
| 109 | |
| 110 | // standaloneSignin is GET /signin without Home: already signed in (and |
| 111 | // admitted) goes back; a return_to is remembered for the landing; then |
| 112 | // the form. |
| 113 | func (h *handlers) standaloneSignin(n *localLinkNavigation) http.HandlerFunc { |
| 114 | return func(w http.ResponseWriter, r *http.Request) { |
| 115 | if !signinOutcome(r) && h.admitted(r) { |
| 116 | alreadySignedIn(w, r) |
| 117 | return |
| 118 | } |
| 119 | // Starting a sign-in remembers where to come back to, and a plain |
| 120 | // /signin remembers the list: a page remembered by an earlier, |
| 121 | // abandoned attempt must not win over the one being made now. The |
| 122 | // email flow's own outcomes (?sent, ?err) leave it alone. Home's |
| 123 | // /signin does the same (home_routes.go). |
| 124 | if !signinOutcome(r) { |
| 125 | path, ok := requestedReturn(r) |
| 126 | if !ok { |
| 127 | path = "/" |
| 128 | } |
| 129 | n.rememberReturn(w, path) |
| 130 | } |
| 131 | h.signin(w, r) |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | // completeStandalone is the standalone SignedInPath: land on the |
| 136 | // remembered page, once, or on the list. |
| 137 | func (n *localLinkNavigation) completeStandalone(w http.ResponseWriter, r *http.Request) { |
| 138 | if !n.guard(w, r, localLinkCompletePath) { |
| 139 | return |
| 140 | } |
| 141 | target := n.returnPath(r) |
| 142 | localNavigationCookie(w, homeReturnCookie, "", -1) |
| 143 | http.Redirect(w, r, target, http.StatusSeeOther) |
| 144 | } |
| 145 | |
| 146 | // requireSessionReturning is rastrillo's RequireSession, except that a |
| 147 | // signed-out page request is sent to /signin with return_to, as |
| 148 | // rastrillo's own sessions.Require already does and auth.RequireSession |
| 149 | // (its refuseSession) does not. Anything else is exactly what it was. |
| 150 | func requireSessionReturning(a *rauth.Auth) func(http.Handler) http.Handler { |
| 151 | return func(next http.Handler) http.Handler { |
| 152 | guarded := a.RequireSession(next) |
| 153 | return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 154 | if r.Method == http.MethodGet || r.Method == http.MethodHead { |
| 155 | if _, ok := a.SessionFrom(r); !ok { |
| 156 | http.Redirect(w, r, "/signin?return_to="+url.QueryEscape(r.URL.RequestURI()), http.StatusSeeOther) |
| 157 | return |
| 158 | } |
| 159 | } |
| 160 | guarded.ServeHTTP(w, r) |
| 161 | }) |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | // signoutToSignedOut is rastrillo's Signout, landing on /signed-out ("You’re |
| 166 | // signed out") rather than straight back on the sign-in form, which read |
| 167 | // as though nothing had happened. |
| 168 | func signoutToSignedOut(signout http.HandlerFunc) http.HandlerFunc { |
| 169 | return func(w http.ResponseWriter, r *http.Request) { |
| 170 | result := &signinResponse{header: make(http.Header)} |
| 171 | signout(result, r) |
| 172 | if result.status == http.StatusSeeOther && strings.HasPrefix(result.header.Get("Location"), "/signin") { |
| 173 | result.header.Set("Location", "/signed-out") |
| 174 | } |
| 175 | for name, values := range result.header { |
| 176 | for _, value := range values { |
| 177 | w.Header().Add(name, value) |
| 178 | } |
| 179 | } |
| 180 | if result.status == 0 { |
| 181 | result.status = http.StatusOK |
| 182 | } |
| 183 | w.WriteHeader(result.status) |
| 184 | _, _ = w.Write(result.body.Bytes()) |
| 185 | } |
| 186 | } |
| 187 | |
amadan