Add an easier way to log in

2 files changed, 65 insertions, 0 deletions

diff --git a/roseh.moe.go b/roseh.moe.go
index 53deb02..e8f2d41 100644
--- a/roseh.moe.go
+++ b/roseh.moe.go
@@ -829,6 +829,63 @@ func logout(w http.ResponseWriter, r *http.Request) {
 }
 
 var (
+	//go:embed templates/otp.html.template
+	otpString   string
+	otpTemplate = template.Must(outlinedTemplate(otpString))
+
+	otpMu      sync.Mutex
+	currentOTP string
+)
+
+type otpTemplateArgs struct {
+	URL string
+	QR  string
+}
+
+func otp(w http.ResponseWriter, r *http.Request) {
+	buf := make([]byte, 20)
+	rand.Read(buf)
+	newOTP := new(strings.Builder)
+	for i := range 10 {
+		if i > 0 {
+			newOTP.WriteString("-")
+		}
+		newOTP.WriteString(wordlist.Words[binary.NativeEndian.Uint16(buf[2*i:])&0x1fff])
+	}
+	otpMu.Lock()
+	currentOTP = newOTP.String()
+	otpMu.Unlock()
+	downloadURL := selfURL.String() + "/otp/" + newOTP.String()
+	if err := otpTemplate.Execute(w, otpTemplateArgs{
+		URL: downloadURL,
+		QR:  "/qr.png?" + url.Values{"t": []string{downloadURL}, "s": []string{base64.RawURLEncoding.EncodeToString(mac([]byte(downloadURL), "qr"))}}.Encode(),
+	}); err != nil {
+		log.Printf("Warning: otp: %s", err)
+	}
+}
+
+func otpCode(w http.ResponseWriter, r *http.Request) {
+	code := r.PathValue("code")
+	if code == "" {
+		notFound(w, r)
+		return
+	}
+	matched := false
+	otpMu.Lock()
+	if code == currentOTP {
+		currentOTP = ""
+		matched = true
+	}
+	otpMu.Unlock()
+	if !matched {
+		notFound(w, r)
+		return
+	}
+	attachCookie(w)
+	io.WriteString(w, "logged in\n")
+}
+
+var (
 	//go:embed templates/note.html.template
 	notepadString   string
 	notepadTemplate = template.Must(outlinedTemplate(notepadString))
@@ -1140,6 +1197,8 @@ func main() {
 	mux.HandleFunc("GET /wormhole/{hole}", wormholeDownload)
 	mux.HandleFunc("GET /login", serveLogin)
 	mux.HandleFunc("POST /login", login)
+	mux.Handle("GET /otp", &authHandler{h: http.HandlerFunc(otp)})
+	mux.HandleFunc("GET /otp/{code}", otpCode)
 	mux.Handle("GET /logout", &authHandler{h: http.HandlerFunc(logout), noRedirect: true})
 	mux.Handle("GET /notepad", &authHandler{h: http.HandlerFunc(notepad)})
 	mux.Handle("POST /notepad", &authHandler{h: http.HandlerFunc(autosave), noRedirect: true})
diff --git a/templates/otp.html.template b/templates/otp.html.template
new file mode 100644
index 0000000..3b765f7
--- /dev/null
+++ b/templates/otp.html.template
@@ -0,0 +1,6 @@
+<title>OTP</title>
+
+<div style="display:flex;flex-direction:column;align-items:center;font-size:50px">
+	<p><a href="{{.URL}}">{{.URL}}</a></p>
+	<img src="{{.QR}}" alt="QR code for {{.URL}}" width="500px">
+</div>