cmd/faucet: protocol relative websockets, noauth mode

cmd/faucet/faucet.go

@@ -83,7 +83,8 @@ var (
 	captchaToken  = flag.String("captcha.token", "", "Recaptcha site key to authenticate client side")
 	captchaSecret = flag.String("captcha.secret", "", "Recaptcha secret key to authenticate server side")
 
-	logFlag = flag.Int("loglevel", 3, "Log level to use for Ethereum and the faucet")
+	noauthFlag = flag.Bool("noauth", false, "Enables funding requests without authentication")
+	logFlag    = flag.Int("loglevel", 3, "Log level to use for Ethereum and the faucet")
 )
 
 var (
@@ -132,6 +133,7 @@ func main() {
 		"Amounts":   amounts,
 		"Periods":   periods,
 		"Recaptcha": *captchaToken,
+		"NoAuth":    *noauthFlag,
 	})
 	if err != nil {
 		log.Crit("Failed to render the faucet template", "err", err)
@@ -374,7 +376,7 @@ func (f *faucet) apiHandler(conn *websocket.Conn) {
 		if err = websocket.JSON.Receive(conn, &msg); err != nil {
 			return
 		}
-		if !strings.HasPrefix(msg.URL, "https://gist.github.com/") && !strings.HasPrefix(msg.URL, "https://twitter.com/") &&
+		if !*noauthFlag && !strings.HasPrefix(msg.URL, "https://gist.github.com/") && !strings.HasPrefix(msg.URL, "https://twitter.com/") &&
 			!strings.HasPrefix(msg.URL, "https://plus.google.com/") && !strings.HasPrefix(msg.URL, "https://www.facebook.com/") {
 			if err = sendError(conn, errors.New("URL doesn't link to supported services")); err != nil {
 				log.Warn("Failed to send URL error to client", "err", err)
@@ -442,6 +444,8 @@ func (f *faucet) apiHandler(conn *websocket.Conn) {
 			username, avatar, address, err = authGooglePlus(msg.URL)
 		case strings.HasPrefix(msg.URL, "https://www.facebook.com/"):
 			username, avatar, address, err = authFacebook(msg.URL)
+		case *noauthFlag:
+			username, avatar, address, err = authNoAuth(msg.URL)
 		default:
 			err = errors.New("Something funky happened, please open an issue at https://github.com/ethereum/go-ethereum/issues")
 		}
@@ -776,3 +780,14 @@ func authFacebook(url string) (string, string, common.Address, error) {
 	}
 	return username + "@facebook", avatar, address, nil
 }
+
+// authNoAuth tries to interpret a faucet request as a plain Ethereum address,
+// without actually performing any remote authentication. This mode is prone to
+// Byzantine attack, so only ever use for truly private networks.
+func authNoAuth(url string) (string, string, common.Address, error) {
+	address := common.HexToAddress(regexp.MustCompile("0x[0-9a-fA-F]{40}").FindString(url))
+	if address == (common.Address{}) {
+		return "", "", common.Address{}, errors.New("No Ethereum address found to fund")
+	}
+	return address.Hex() + "@noauth", "", address, nil
+}

cmd/faucet/faucet.html

@@ -93,6 +93,11 @@
 
 							<dt style="width: auto; margin-left: 40px;"><i class="fa fa-facebook" aria-hidden="true" style="font-size: 36px;"></i></dt>
 							<dd style="margin-left: 88px; margin-bottom: 10px;"></i> To request funds via Facebook, publish a new <strong>public</strong> post with your Ethereum address embedded into the content (surrounding text doesn't matter).<br/>Copy-paste the <a href="https://www.facebook.com/help/community/question/?id=282662498552845" target="_about:blank">posts URL</a> into the above input box and fire away!</dd>
+
+							{{if .NoAuth}}
+								<dt class="text-danger" style="width: auto; margin-left: 40px;"><i class="fa fa-unlock-alt" aria-hidden="true" style="font-size: 36px;"></i></dt>
+								<dd class="text-danger" style="margin-left: 88px; margin-bottom: 10px;"></i> To request funds <strong>without authentication</strong>, simply copy-paste your Ethereum address into the above input box (surrounding text doesn't matter) and fire away.<br/>This mode is susceptible to Byzantine attacks. Only use for debugging or private networks!</dd>
+							{{end}}
 						</dl>
 						<p>You can track the current pending requests below the input field to see how much you have to wait until your turn comes.</p>
 						{{if .Recaptcha}}<em>The faucet is running invisible reCaptcha protection against bots.</em>{{end}}
@@ -126,12 +131,7 @@
 			};
 			// Define a method to reconnect upon server loss
 			var reconnect = function() {
-				if (attempt % 2 == 0) {
-					server = new WebSocket("wss://" + location.host + "/api");
-				} else {
-					server = new WebSocket("ws://" + location.host + "/api");
-				}
-				attempt++;
+				server = new WebSocket(((window.location.protocol === "https:") ? "wss://" : "ws://") + window.location.host + "/api");
 
 				server.onmessage = function(event) {
 					var msg = JSON.parse(event.data);