Beginning of malware warning

res/static/script/Toolbar.js

@@ -30,7 +30,45 @@ var Toolbar = {
 		}
 	},
 	download: function () {
-		document.getElementById("download_frame").src = "/api/file/" + Viewer.currentFile + "?download";
+		var triggerDL = function(){
+			document.getElementById("download_frame").src = "/api/file/" + Viewer.currentFile + "?download";
+		}
+
+		if (captchaKey === "a"){
+			// If the server doesn't support captcha there's no use in checking
+			// availability
+			triggerDL();
+			return;
+		}
+
+		$.getJSON(
+			apiEndpoint + "/file/" + Viewer.currentFile + "/availability"
+		).done(function(data){
+			if(data.success === true){
+				// Downloading is allowed, start the download
+				triggerDL();
+			}
+		}).fail(function(data){
+			console.log(data);
+			if(data.responseJSON.success === false) {
+				var popupDiv = document.getElementById("captcha_popup");
+
+				if(data.responseJSON.value === "file_rate_limited_captcha_required") {
+					popupDiv.innerHTML = '<div class="highlight_light border_top border_bottom">Rate limiting enabled!</div>'+
+						data.responseJSON.message;
+				}else if(data.responseJSON.value === "virus_detected_captcha_required"){
+					popupDiv.innerHTML = '<div class="highlight_light border_top border_bottom">Malware warning!</div>'+
+						data.responseJSON.message+
+						"<hr/>Malware type: " + data.responseJSON.extra;
+				}
+
+				popupDiv.style.opacity = "1";
+				popupDiv.style.visibility = "visible";
+			}else{
+				// No JSON, try download anyway
+				triggerDL();
+			}
+		});
 	},
 	downloadList: function(){
 		if(!Viewer.isList){

res/static/style/viewer.css

@@ -208,6 +208,24 @@ body{
 	box-shadow: var(--shadow_color) 0px 0px 50px;
 	z-index: 100;
 }
+.captcha_popup{
+	position: fixed;
+	visibility: hidden;
+	opacity: 0;
+	transition: visibility 1s, opacity 1s, left 1s;
+	background-color: var(--background_color);
+	height: auto;
+	width: 500px;
+	max-width: 100%;
+	top: 50px;
+	left: 50%;
+	margin-left: -200px;
+	padding: 0 10px;
+	box-sizing: border-box;
+	text-align: left;
+	box-shadow: var(--shadow_color) 0px 0px 50px;
+	z-index: 100;
+}
 
 table {width: auto !important;}
 table > tbody > tr {border: none !important;}