Some small simplifications

4 files changed, 144 insertions, 106 deletions

diff --git a/roseh.moe.go b/roseh.moe.go
index bd07aed..3b9a54d 100644
--- a/roseh.moe.go
+++ b/roseh.moe.go
@@ -26,7 +26,6 @@ import (
 	"context"
 	"crypto"
 	"crypto/ecdsa"
-	"crypto/ed25519"
 	"crypto/hkdf"
 	"crypto/hmac"
 	"crypto/rand"
@@ -123,10 +122,6 @@ func sigVerifier(keyBytes []byte) (func(msg, sig []byte) bool, error) {
 			hash := sha256.Sum256(msg)
 			return rsa.VerifyPKCS1v15(key, crypto.SHA256, hash[:], sig) == nil
 		}, nil
-	case ed25519.PublicKey:
-		return func(msg, sig []byte) bool {
-			return ed25519.Verify(key, msg, sig)
-		}, nil
 	default:
 		return nil, fmt.Errorf("unsupported key type")
 	}
@@ -228,7 +223,12 @@ func loadConfig() (*serviceConfiguration, error) {
 			return nil, fmt.Errorf("%s: duplicate name %q", *configFile, passkey.ID)
 		}
 		names[passkey.ID] = true
-		keyBytes, err := base64.RawURLEncoding.DecodeString(passkey.Key)
+		keyBytes, err := base64.RawURLEncoding.DecodeString(strings.Map(func(r rune) rune {
+			if unicode.IsSpace(r) {
+				return -1
+			}
+			return r
+		}, passkey.Key))
 		if err != nil {
 			return nil, fmt.Errorf("%s: invalid key for passkey %q: %s", *configFile, passkey.ID, err)
 		}
@@ -842,10 +842,27 @@ func cookieAuth(r *http.Request) bool {
 	return true
 }
 
+func verifyRedirect(redirect string) bool {
+	u, err := url.Parse(redirect)
+	if err != nil {
+		return false
+	}
+	switch u.Host {
+	case
+		"cinema." + selfURL.Host,
+		"downloads." + selfURL.Host,
+		selfURL.Host:
+
+		return true
+	}
+	return false
+}
+
+const challengeExpiry = 10 * time.Minute
+
 var (
-	challengeMu    sync.Mutex
-	challenge      []byte
-	challengePosed time.Time
+	challengeMu sync.Mutex
+	challenges  = make(map[string]time.Time)
 )
 
 var (
@@ -860,8 +877,8 @@ type loginTemplateArgs struct {
 
 func serveLogin(w http.ResponseWriter, r *http.Request) {
 	if cookieAuth(r) {
-		redirect, ok := verifyHMAC(r.FormValue("redirect"), "redirect")
-		if !ok {
+		redirect := r.FormValue("redirect")
+		if !verifyRedirect(redirect) {
 			redirect = "/"
 		}
 		http.Redirect(w, r, redirect, http.StatusSeeOther)
@@ -869,9 +886,14 @@ func serveLogin(w http.ResponseWriter, r *http.Request) {
 	}
 	buf := make([]byte, 32)
 	rand.Read(buf)
+	now := time.Now()
 	challengeMu.Lock()
-	challenge = buf
-	challengePosed = time.Now()
+	if len(challenges) >= 100 {
+		challengeMu.Unlock()
+		http.Error(w, "Too many active requests", http.StatusTooManyRequests)
+		return
+	}
+	challenges[string(buf)] = now
 	challengeMu.Unlock()
 	if err := loginTemplate.Execute(w, loginTemplateArgs{
 		Challenge: base64.StdEncoding.EncodeToString(buf),
@@ -881,19 +903,6 @@ func serveLogin(w http.ResponseWriter, r *http.Request) {
 }
 
 func login(w http.ResponseWriter, r *http.Request) {
-	challengeMu.Lock()
-	myChallenge := challenge
-	challenge = nil
-	posed := challengePosed
-	challengeMu.Unlock()
-	if len(myChallenge) == 0 {
-		http.Error(w, "Request already consumed", http.StatusConflict)
-		return
-	}
-	if time.Since(posed) > 10*time.Minute {
-		http.Error(w, "Challenge is too old. Please try again", http.StatusConflict)
-		return
-	}
 	user, err := base64.StdEncoding.DecodeString(r.FormValue("user"))
 	if err != nil {
 		http.Error(w, "Bad user", http.StatusBadRequest)
@@ -909,27 +918,6 @@ func login(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "Bad client data: invalid base64", http.StatusBadRequest)
 		return
 	}
-	var cd struct {
-		Type        string `json:"type"`
-		Challenge   string `json:"challenge"`
-		Origin      string `json:"origin"`
-		CrossOrigin bool   `json:"crossOrigin"`
-	}
-	if err := json.Unmarshal(clientData, &cd); err != nil {
-		http.Error(w, "Bad client data: invalid JSON", http.StatusBadRequest)
-		return
-	}
-	challengeBase64 := base64.RawURLEncoding.EncodeToString(myChallenge)
-	if cd.Type != "webauthn.get" || cd.Challenge != challengeBase64 || cd.Origin != selfURL.String() || cd.CrossOrigin {
-		http.Error(w, "Bad client data", http.StatusBadRequest)
-		return
-	}
-	expectedRPHash := sha256.Sum256([]byte(selfURL.Hostname()))
-	const flagUserPresence, flagUserVerification = 0x01, 0x04
-	if len(authData) < 37 || !bytes.Equal(authData[:32], expectedRPHash[:]) || authData[32]&(flagUserPresence|flagUserVerification) != (flagUserPresence|flagUserVerification) {
-		http.Error(w, "Bad authenticator data", http.StatusBadRequest)
-		return
-	}
 	sig, err := base64.StdEncoding.DecodeString(r.FormValue("sig"))
 	if err != nil {
 		http.Error(w, "Bad sig", http.StatusBadRequest)
@@ -951,12 +939,49 @@ func login(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "Challenge failed", http.StatusBadRequest)
 		return
 	}
+	var cd struct {
+		Type        string `json:"type"`
+		Challenge   string `json:"challenge"`
+		Origin      string `json:"origin"`
+		CrossOrigin bool   `json:"crossOrigin"`
+	}
+	if err := json.Unmarshal(clientData, &cd); err != nil {
+		http.Error(w, "Bad client data: invalid JSON", http.StatusBadRequest)
+		return
+	}
+	challenge, err := base64.RawURLEncoding.DecodeString(cd.Challenge)
+	if err != nil {
+		http.Error(w, "Bad client data: bad challenge", http.StatusBadRequest)
+		return
+	}
+	challengeMu.Lock()
+	initiated, ok := challenges[string(challenge)]
+	delete(challenges, string(challenge))
+	challengeMu.Unlock()
+	if !ok {
+		http.Error(w, "Request already consumed", http.StatusConflict)
+		return
+	}
+	if time.Since(initiated) > challengeExpiry {
+		http.Error(w, "Challenge is too old. Please try again", http.StatusConflict)
+		return
+	}
+	if cd.Type != "webauthn.get" || cd.Origin != selfURL.String() || cd.CrossOrigin {
+		http.Error(w, "Bad client data", http.StatusBadRequest)
+		return
+	}
+	expectedRPHash := sha256.Sum256([]byte(selfURL.Hostname()))
+	const flagUserPresence, flagUserVerification = 0x01, 0x04
+	if len(authData) < 37 || !bytes.Equal(authData[:32], expectedRPHash[:]) || authData[32]&(flagUserPresence|flagUserVerification) != (flagUserPresence|flagUserVerification) {
+		http.Error(w, "Bad authenticator data", http.StatusBadRequest)
+		return
+	}
 	attachCookie(w, &authToken{
 		expiry: time.Now().Add(30 * 24 * time.Hour),
 		userID: user,
 	})
-	redirect, ok := verifyHMAC(r.FormValue("redirect"), "redirect")
-	if !ok {
+	redirect := r.FormValue("redirect")
+	if !verifyRedirect(redirect) {
 		redirect = "/"
 	}
 	http.Redirect(w, r, redirect, http.StatusSeeOther)
@@ -985,6 +1010,19 @@ func serveRegister(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func wrap(s string) string {
+	out := new(strings.Builder)
+	for s != "" {
+		if out.Len() > 0 {
+			out.WriteString("\n\t              ")
+		}
+		n := min(50, len(s))
+		out.WriteString(s[:n])
+		s = s[n:]
+	}
+	return out.String()
+}
+
 var (
 	//go:embed templates/register/register-success.html.template
 	registerSuccessTemplateString string
@@ -1014,7 +1052,7 @@ func register(w http.ResponseWriter, r *http.Request) {
 	}
 	if err := registerSuccessTemplate.Execute(w, registerSuccessTemplateArgs{
 		ID:  r.FormValue("name"),
-		Key: base64.RawURLEncoding.EncodeToString(slices.Concat(userID, key)),
+		Key: wrap(base64.RawURLEncoding.EncodeToString(slices.Concat(userID, key))),
 	}); err != nil {
 		log.Printf("Warning: register: %s", err)
 	}
@@ -1344,21 +1382,9 @@ func (h *authHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			http.Error(w, "not logged in", http.StatusUnauthorized)
 		} else {
 			u := *r.URL
-			switch r.Host {
-			case
-				"cinema." + selfURL.Host,
-				"downloads." + selfURL.Host:
-
-				u.Host = r.Host
-			default:
-				u.Host = selfURL.Host
-			}
-			u.Scheme = "http"
-			if *https != "" {
-				u.Scheme = "https"
-			}
-			redirect := signMsg(u.String(), "redirect")
-			http.Redirect(w, r, "//"+selfURL.Host+"/login?redirect="+url.QueryEscape(redirect), http.StatusSeeOther)
+			u.Host = r.Host
+			u.Scheme = selfURL.Scheme
+			http.Redirect(w, r, "//"+selfURL.Host+"/login?redirect="+url.QueryEscape(u.String()), http.StatusSeeOther)
 		}
 		return
 	}
@@ -1414,7 +1440,7 @@ func (h *hstsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 }
 
 func (h *removeAuthCookieHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	/*var cookies []*http.Cookie
+	var cookies []*http.Cookie
 	for _, c := range r.Cookies() {
 		if c.Name != authCookieName {
 			cookies = append(cookies, c)
@@ -1423,7 +1449,7 @@ func (h *removeAuthCookieHandler) ServeHTTP(w http.ResponseWriter, r *http.Reque
 	r.Header.Del("Cookie")
 	for _, c := range cookies {
 		r.AddCookie(c)
-	}*/
+	}
 	h.h.ServeHTTP(w, r)
 }
 
@@ -1446,6 +1472,19 @@ func main() {
 		}
 	}()
 
+	go func() {
+		for now := range time.NewTicker(time.Hour).C {
+			log.Printf("Cleaning expired challenges")
+			challengeMu.Lock()
+			for challenge, initiated := range challenges {
+				if now.Sub(initiated) > challengeExpiry {
+					delete(challenges, challenge)
+				}
+			}
+			challengeMu.Unlock()
+		}
+	}()
+
 	mux := http.NewServeMux()
 	indexTemplate, err := outlinedTemplate(indexString)
 	if err != nil {
diff --git a/templates/login.html.template b/templates/login.html.template
index ae0874a..2a498a5 100644
--- a/templates/login.html.template
+++ b/templates/login.html.template
@@ -27,19 +27,19 @@
 </form>
 
 <script>
-async function main() {
-	const publicKeyCredential = await navigator.credentials.get({publicKey: {
-		challenge: Uint8Array.fromBase64("{{.Challenge}}").buffer,
-	}});
-	const rsp = publicKeyCredential.response;
-	document.getElementById("user").value = new Uint8Array(rsp.userHandle).toBase64();
-	document.getElementById("auth-data").value = new Uint8Array(rsp.authenticatorData).toBase64();
-	document.getElementById("client-data").value = new Uint8Array(rsp.clientDataJSON).toBase64();
-	document.getElementById("sig").value = new Uint8Array(rsp.signature).toBase64();
-	document.getElementById("form").submit();
-}
+	async function main() {
+		const publicKeyCredential = await navigator.credentials.get({publicKey: {
+			challenge: Uint8Array.fromBase64("{{.Challenge}}").buffer,
+		}});
+		const rsp = publicKeyCredential.response;
+		document.getElementById("user").value = new Uint8Array(rsp.userHandle).toBase64();
+		document.getElementById("auth-data").value = new Uint8Array(rsp.authenticatorData).toBase64();
+		document.getElementById("client-data").value = new Uint8Array(rsp.clientDataJSON).toBase64();
+		document.getElementById("sig").value = new Uint8Array(rsp.signature).toBase64();
+		document.getElementById("form").submit();
+	}
 
-main();
+	main();
 </script>
 
 This page requires JavaScript™ to be enabled
diff --git a/templates/register/register-success.html.template b/templates/register/register-success.html.template
index 847f97a..d9c64e1 100644
--- a/templates/register/register-success.html.template
+++ b/templates/register/register-success.html.template
@@ -24,5 +24,5 @@
 	<p>A device key has been generated, but it must be authorized on
 	the server:</p>
 	<pre>	&lt;Passkey ID="{{.ID | xmlEscape}}"
-	         Key="{{.Key | xmlEscape}}"/&gt;</pre>
+	         Key="{{.Key}}"/&gt;</pre>
 </section>
diff --git a/templates/register/register.html.template b/templates/register/register.html.template
index 833a1a7..d97b585 100644
--- a/templates/register/register.html.template
+++ b/templates/register/register.html.template
@@ -37,30 +37,29 @@
 </section>
 
 <script>
-async function generateKey() {
-	const name = document.getElementById("name").value;
-	const publicKeyCredential = await navigator.credentials.create({publicKey: {
-		authenticatorSelection: {
-			residentKey: "required",
-			userVerification: "required",
-		},
-		challenge: Uint8Array.fromBase64("{{.Challenge}}").buffer,
-		pubKeyCredParams: [
-			{alg: -9,   type: "public-key"},
-			{alg: -257, type: "public-key"},
-			{alg: -7,   type: "public-key"},
-			{alg: -8,   type: "public-key"},
-		],
-		rp: {
-			name: "roseh.moe",
-		},
-		user: {
-			displayName: name,
-			id: Uint8Array.fromBase64(document.getElementById("id").value).buffer,
-			name: name,
-		},
-	}});
-	document.getElementById("key").value = new Uint8Array(publicKeyCredential.response.getPublicKey()).toBase64();
-	document.getElementById("form").submit();
-}
+	async function generateKey() {
+		const name = document.getElementById("name").value;
+		const publicKeyCredential = await navigator.credentials.create({publicKey: {
+			authenticatorSelection: {
+				residentKey: "required",
+				userVerification: "required",
+			},
+			challenge: Uint8Array.fromBase64("{{.Challenge}}").buffer,
+			pubKeyCredParams: [
+				{alg: -9,   type: "public-key"},
+				{alg: -257, type: "public-key"},
+				{alg: -7,   type: "public-key"},
+			],
+			rp: {
+				name: "roseh.moe",
+			},
+			user: {
+				displayName: name,
+				id: Uint8Array.fromBase64(document.getElementById("id").value).buffer,
+				name: name,
+			},
+		}});
+		document.getElementById("key").value = new Uint8Array(publicKeyCredential.response.getPublicKey()).toBase64();
+		document.getElementById("form").submit();
+	}
 </script>