| 1 | package home |
| 2 | |
| 3 | import ( |
| 4 | "encoding/base64" |
| 5 | "net/http" |
| 6 | "net/url" |
| 7 | "time" |
| 8 | |
| 9 | "amadan.net/oficina/home/handoff" |
| 10 | "amadan.net/rastrillo/rastrillo/assertion" |
| 11 | "amadan.net/rastrillo/rastrillo/sessions" |
| 12 | json "github.com/go-json-experiment/json" |
| 13 | ) |
| 14 | |
| 15 | const assertionIntentCookie = "__Host-oficina-assertion-intent" |
| 16 | |
| 17 | type assertionIntent struct { |
| 18 | Consumer string `json:"consumer"` |
| 19 | Nonce string `json:"nonce"` |
| 20 | Expires int64 `json:"expires"` |
| 21 | MaxAge int `json:"max_age,omitzero"` |
| 22 | Subject string `json:"subject,omitzero"` |
| 23 | } |
| 24 | |
| 25 | func (a *App) handleAuthorize(w http.ResponseWriter, r *http.Request) { |
| 26 | w.Header().Set("Cache-Control", "no-store") |
| 27 | q, err := url.ParseQuery(r.URL.RawQuery) |
| 28 | maxAge := 0 |
| 29 | if values, present := q["max_age"]; present { |
| 30 | if len(values) != 1 || values[0] != "300" { |
| 31 | a.failAssertion(w, r, authorizeAge) |
| 32 | return |
| 33 | } |
| 34 | maxAge = 300 |
| 35 | } |
| 36 | wantFields := 2 |
| 37 | if maxAge != 0 { |
| 38 | wantFields++ |
| 39 | } |
| 40 | if err != nil || len(q) != wantFields || len(q["consumer"]) != 1 || len(q["nonce"]) != 1 || !handoff.ValidNonce(q.Get("nonce")) || a.runtime.consumers[q.Get("consumer")] == "" { |
| 41 | a.failAssertion(w, r, authorizeRequest) |
| 42 | return |
| 43 | } |
| 44 | intent := assertionIntent{Consumer: q.Get("consumer"), Nonce: q.Get("nonce"), Expires: time.Now().Unix() + 600, MaxAge: maxAge} |
| 45 | if maxAge != 0 { |
| 46 | if session, ok := a.sessions.From(r); ok { |
| 47 | intent.Subject = session.Subject |
| 48 | } |
| 49 | } |
| 50 | b, err := json.Marshal(intent) |
| 51 | if err != nil { |
| 52 | a.failAssertion(w, r, authorizeEncode) |
| 53 | return |
| 54 | } |
| 55 | sealed, err := a.secrets.Sealer.Seal("assertion.intent", b) |
| 56 | if err != nil { |
| 57 | a.failAssertion(w, r, authorizeSeal) |
| 58 | return |
| 59 | } |
| 60 | http.SetCookie(w, &http.Cookie{Name: assertionIntentCookie, Value: base64.RawURLEncoding.EncodeToString(sealed), Path: "/", MaxAge: 600, Secure: true, HttpOnly: true, SameSite: http.SameSiteLaxMode}) |
| 61 | http.Redirect(w, r, "/authorize/resume", http.StatusSeeOther) |
| 62 | } |
| 63 | func (a *App) handleAssertion(w http.ResponseWriter, r *http.Request) { |
| 64 | w.Header().Set("Cache-Control", "no-store") |
| 65 | // no-referrer would turn the cross-origin form POST's Origin into null. |
| 66 | w.Header().Set("Referrer-Policy", "strict-origin-when-cross-origin") |
| 67 | if r.URL.RawQuery != "" { |
| 68 | a.failAssertion(w, r, assertionQuery) |
| 69 | return |
| 70 | } |
| 71 | now := time.Now() |
| 72 | intent, ok := a.readAssertionIntent(r, now) |
| 73 | if !ok { |
| 74 | a.failAssertion(w, r, assertionIntentInvalid) |
| 75 | return |
| 76 | } |
| 77 | target, ok := a.runtime.consumers[intent.Consumer] |
| 78 | if !ok { |
| 79 | a.failAssertion(w, r, assertionConsumer) |
| 80 | return |
| 81 | } |
| 82 | session, ok := sessions.Current(r) |
| 83 | if !ok { |
| 84 | a.failAssertion(w, r, assertionSession) |
| 85 | return |
| 86 | } |
| 87 | authTime := session.AuthTime |
| 88 | if authTime.IsZero() { |
| 89 | authTime = session.At |
| 90 | } |
| 91 | if intent.Subject != "" && intent.Subject != session.Subject { |
| 92 | a.failAssertion(w, r, assertionSubject) |
| 93 | return |
| 94 | } |
| 95 | if intent.MaxAge != 0 && (!sessions.Fresh(session, time.Duration(intent.MaxAge)*time.Second, now) || authTime.After(now)) { |
| 96 | http.Redirect(w, r, "/signin?return_to=%2Fauthorize%2Fresume", http.StatusSeeOther) |
| 97 | return |
| 98 | } |
| 99 | id, err := assertion.RandomID() |
| 100 | if err != nil { |
| 101 | a.failAssertion(w, r, assertionRandom) |
| 102 | return |
| 103 | } |
| 104 | token, err := assertion.Sign(a.runtime.signer, assertion.Claims{Version: 1, Issuer: a.origins.Credential, Audience: target, Subject: session.Subject, KeyID: a.runtime.keyID, ID: id, Nonce: intent.Nonce, IssuedAt: now.Unix(), ExpiresAt: now.Unix() + 120, AuthTime: authTime.Unix()}) |
| 105 | if err != nil { |
| 106 | a.failAssertion(w, r, assertionSign) |
| 107 | return |
| 108 | } |
| 109 | http.SetCookie(w, &http.Cookie{Name: assertionIntentCookie, Value: "", Path: "/", MaxAge: -1, Secure: true, HttpOnly: true, SameSite: http.SameSiteLaxMode}) |
| 110 | a.render(w, r, http.StatusOK, "assertion.html", map[string]any{"Action": target + handoff.CallbackPath, "Token": token}) |
| 111 | } |
| 112 | |
amadan