WIP: add support for mangling headers, so people don't have to use other plugins for that

src/background.html

@@ -4,4 +4,5 @@
 	<title>:: Imagus :: bgProcess</title>
 	<script src="./js/app_bg.js"></script>
 	<script src="./js/background.js"></script>
-</head>
+	<script src="./js/headers.js"></script>
+</head>

src/js/headers.js

@@ -0,0 +1,93 @@
+// TODO: Allow configuring, or re-use sieve
+let needsTarget = new Set(['webmshare\.com\/', 'i\\d+\.vipr\\.im\/', '\.imagetwist\.com\/']);
+let needsRemove = new Set(['sankakucomplex\\.com']);
+let needsCustom = new Map([
+    ['tiktokcdn\\.com', 'https://www\\.tiktok\\.com']
+]);
+let needsBypassCORS = new Set(['\.cdninstagram.com\/']);
+
+chrome.webRequest.onBeforeSendHeaders.addListener(function(details) {
+    let shouldRemove = false;
+    let shouldSetTarget = false;
+    let shouldSetCustom = false;
+    let newReferer = '';
+    for (let rule of needsTarget.values()) {
+        let regex = new RegExp(rule);
+        if (regex.test(details.url)) {
+            shouldSetTarget = true;
+            newReferer = details.url;
+            break;
+        }
+    }
+    if (!shouldSetTarget) {
+        for (const rule of needsRemove.values()) {
+            let regex = new RegExp(rule);
+            if (regex.test(details.url)) {
+                shouldRemove = true;
+                break;
+            }
+        }
+    }
+
+    if (!shouldRemove && !shouldSetTarget) {
+        for (const [rule, value] of needsCustom.entries()) {
+            let regex = new RegExp(rule);
+            if (regex.test(details.url)) {
+                shouldSetCustom = true;
+                custom = value;
+                break;
+            }
+        }
+    }
+
+    var headers = details.requestHeaders;
+    if (!shouldRemove && !shouldSetTarget && !shouldSetCustom) {
+        return {requestHeaders: headers};
+    }
+
+    // Strip out referer
+    var newHeaders = [];
+    for(var i = 0, l = headers.length; i < l; ++i) {
+        if (bypassCORS && headers[i].name.toLowerCase() == 'cross-origin-resource-policy') {
+            continue;
+        }
+        if (headers[i].name.toLowerCase() != 'referer') {
+            newHeaders.push(headers[i]);
+            continue;
+        }
+    }
+
+    if (!shouldRemove) {
+        newHeaders.push({
+            name: "Referer",
+            value: newReferer
+        });
+    }
+
+    details.requestHeaders = newHeaders
+    return {requestHeaders: newHeaders};
+}, { urls: [ "<all_urls>" ] }, ['requestHeaders','blocking','extraHeaders']);
+
+chrome.webRequest.onHeadersReceived.addListener(function(details) {
+    let bypassCORS = false;
+    for (let rule of needsBypassCORS.values()) {
+        let regex = new RegExp(rule);
+        if (regex.test(details.url)) {
+            bypassCORS = true;
+            break;
+        }
+    }
+    var headers = details.responseHeaders;
+    if (!bypassCORS) {
+        return {responseHeaders: headers};
+    }
+    var newHeaders = [];
+    for(var i = 0, l = headers.length; i < l; ++i) {
+        if (headers[i].name.toLowerCase() == 'cross-origin-resource-policy') {
+            continue;
+        }
+        newHeaders.push(headers[i]);
+    }
+    details.responseHeaders = newHeaders
+    return {responseHeaders: newHeaders};
+}, { urls: [ "<all_urls>" ] }, ['responseHeaders', 'blocking', 'extraHeaders']);

src/manifest.json

@@ -36,6 +36,6 @@
         "open_in_tab": true,
         "page": "options.html"
     },
-    "permissions": [ "*://*/*", "downloads", "history", "storage" ],
+    "permissions": [ "*://*/*", "downloads", "history", "storage", "webRequest", "webRequestBlocking" ],
     "version": "0.9.8.74"
 }