From 3df71d4177e14004a0ca83081ed3c76082d16528 Mon Sep 17 00:00:00 2001
From: Daniel Mai <daniel@dgraph.io>
Date: Tue, 22 Jan 2019 09:44:56 -0800
Subject: [PATCH] Make reCAPTCHA configuration optional.

---
 main.go              | 59 +++++++++++++++++++++++++-------------------
 static/client.js     |  4 ++-
 templates/index.tmpl |  4 +++
 3 files changed, 41 insertions(+), 26 deletions(-)

diff --git a/main.go b/main.go
index cbcc058..8949959 100644
--- a/main.go
+++ b/main.go
@@ -48,14 +48,18 @@ var c Specification
 // Specification is the config struct
 type Specification struct {
 	Port           string `envconfig:"PORT" required:"true"`
-	CaptchaSitekey string `required:"true"`
-	CaptchaSecret  string `required:"true"`
+	CaptchaSitekey string `required:"false"`
+	CaptchaSecret  string `required:"false"`
 	SlackToken     string `required:"true"`
 	CocUrl         string `required:"false" default:"http://coc.golangbridge.org/"`
 	EnforceHTTPS   bool
 	Debug          bool // toggles nlopes/slack client's debug flag
 }
 
+func recaptchaEnabled() bool {
+	return len(c.CaptchaSitekey) > 0 && len(c.CaptchaSecret) > 0
+}
+
 func init() {
 	var showUsage = flag.Bool("h", false, "Show usage")
 	flag.Parse()
@@ -81,14 +85,17 @@ func init() {
 	m.Set("missing_last_name", &missingLastName)
 	m.Set("missing_email", &missingEmail)
 	m.Set("missing_coc", &missingCoC)
-	m.Set("failed_captcha", &failedCaptcha)
-	m.Set("invalid_captcha", &invalidCaptcha)
-	m.Set("successful_captcha", &successfulCaptcha)
 	m.Set("successful_invites", &successfulInvites)
 	m.Set("active_user_count", &activeUserCount)
 	m.Set("user_count", &userCount)
 
-	captcha = recaptcha.New(c.CaptchaSecret)
+	if recaptchaEnabled() {
+		m.Set("failed_captcha", &failedCaptcha)
+		m.Set("invalid_captcha", &invalidCaptcha)
+		m.Set("successful_captcha", &successfulCaptcha)
+		captcha = recaptcha.New(c.CaptchaSecret)
+	}
+
 	api = slack.New(c.SlackToken)
 
 	if c.Debug {
@@ -200,27 +207,29 @@ func handleInvite(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
 		return
 	}
-	captchaResponse := r.FormValue("g-recaptcha-response")
-	remoteIP, _, err := net.SplitHostPort(r.RemoteAddr)
-	if err != nil {
-		failedCaptcha.Add(1)
-		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
-		return
-	}
+	if recaptchaEnabled() {
+		captchaResponse := r.FormValue("g-recaptcha-response")
+		remoteIP, _, err := net.SplitHostPort(r.RemoteAddr)
+		if err != nil {
+			failedCaptcha.Add(1)
+			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+			return
+		}
 
-	valid, err := captcha.Verify(captchaResponse, remoteIP)
-	if err != nil {
-		failedCaptcha.Add(1)
-		http.Error(w, "Error validating recaptcha.. Did you click it?", http.StatusPreconditionFailed)
-		return
-	}
-	if !valid {
-		invalidCaptcha.Add(1)
-		http.Error(w, "Invalid recaptcha", http.StatusInternalServerError)
-		return
+		valid, err := captcha.Verify(captchaResponse, remoteIP)
+		if err != nil {
+			failedCaptcha.Add(1)
+			http.Error(w, "Error validating recaptcha.. Did you click it?", http.StatusPreconditionFailed)
+			return
+		}
+		if !valid {
+			invalidCaptcha.Add(1)
+			http.Error(w, "Invalid recaptcha", http.StatusInternalServerError)
+			return
 
+		}
+		successfulCaptcha.Add(1)
 	}
-	successfulCaptcha.Add(1)
 	fname := r.FormValue("fname")
 	lname := r.FormValue("lname")
 	email := r.FormValue("email")
@@ -245,7 +254,7 @@ func handleInvite(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "You need to accept the code of conduct", http.StatusPreconditionFailed)
 		return
 	}
-	err = api.InviteToTeam(ourTeam.Domain(), fname, lname, email)
+	err := api.InviteToTeam(ourTeam.Domain(), fname, lname, email)
 	if err != nil {
 		log.Println("InviteToTeam error:", err)
 		inviteErrors.Add(1)
diff --git a/static/client.js b/static/client.js
index 37aad4d..b93ed81 100644
--- a/static/client.js
+++ b/static/client.js
@@ -14,12 +14,14 @@ var button = body.querySelector('button');
 button.className = '';
 
 // capture submit
+recaptcha_elem = document.getElementById("g-recaptcha-response");
+recaptcha_res = recaptcha_elem === null ? null : recaptcha_elem.value;
 body.addEventListener('submit', function(ev){
   ev.preventDefault();
   button.disabled = true;
   button.className = '';
   button.innerHTML = 'Please Wait';
-  invite(coc && coc.checked ? 1 : 0, email.value, first_name.value, last_name.value, document.getElementById("g-recaptcha-response").value, function(err){
+  invite(coc && coc.checked ? 1 : 0, email.value, first_name.value, last_name.value, recaptcha_res, function(err){
     if (err) {
       button.removeAttribute('disabled');
       button.className = 'error';
diff --git a/templates/index.tmpl b/templates/index.tmpl
index a624da6..e2fccbd 100644
--- a/templates/index.tmpl
+++ b/templates/index.tmpl
@@ -3,7 +3,9 @@
     <title>Join {{.Team.Name}} on Slack!</title>
     <meta name="viewport" content="width=device-width,initial-scale=1.0,minimum-scale=1.0,user-scalable=no">
     <link rel="shortcut icon" href="https://slack.global.ssl.fastly.net/272a/img/icons/favicon-32.png">
+    {{ if .SiteKey }}
     <script src="https://www.google.com/recaptcha/api.js"></script>
+    {{ end }}
 </head>
 <body>
     <div class="splash">
@@ -24,7 +26,9 @@
                 <label><input name="coc" type="checkbox" value="1">I agree to
                 the <a href="{{.CocUrl}}">Code of Conduct</a>.</label>
             </div><br>
+            {{ if .SiteKey }}
             <div class="g-recaptcha" data-sitekey="{{.SiteKey}}"></div>
+            {{ end }}
             <button class="loading">Get my Invite</button>
         </form>
         <p class="signin">or <a href="https://{{.Team.Domain}}.slack.com" target=