torrent download: add referer (#416)

Author: bogenpirat

src/util/cors-tricks.ts

@@ -5,10 +5,10 @@ export function registerCorsCircumventionForWebUis(allWebUis: TorrentWebUI[]): P
         const oldRuleIds = (await chrome.declarativeNetRequest.getSessionRules())
             .map(rule => rule.id);
         const newRules: chrome.declarativeNetRequest.Rule[] = [];
-        
+
         allWebUis.forEach((webUi, index) => {
             const webUiBaseUrl = webUi.createBaseUrl();
-            if(webUiBaseUrl) {
+            if (webUiBaseUrl) {
                 const rule: chrome.declarativeNetRequest.Rule = {
                     id: index + 1,
                     priority: 100,
@@ -35,4 +35,45 @@ export function registerCorsCircumventionForWebUis(allWebUis: TorrentWebUI[]): P
             addRules: newRules
         });
     });
-}
+}
+
+export function executeMethodWrappedWithReferer<T>(method: () => Promise<T>, url: string, referer: string): Promise<T> {
+    return new Promise(async (resolve, reject) => {
+        const refererSetterRuleId = (await chrome.declarativeNetRequest.getDynamicRules()).length + 1;
+        chrome.declarativeNetRequest.updateDynamicRules({
+            addRules: [
+                {
+                    id: refererSetterRuleId,
+                    priority: 100,
+                    action: {
+                        type: "modifyHeaders",
+                        requestHeaders: [
+                            {
+                                header: "Referer",
+                                operation: "set",
+                                value: referer
+                            }
+                        ]
+                    },
+                    condition: {
+                        urlFilter: `|${url}*`,
+                        resourceTypes: ["xmlhttprequest"]
+                    }
+                }
+            ]
+        }).then(async () => {
+            try {
+                resolve(await method());
+            } catch (error) {
+                reject(error);
+            } finally {
+                chrome.declarativeNetRequest.updateSessionRules({
+                    removeRuleIds: [refererSetterRuleId],
+                });
+            }
+        }, (error) => {
+            console.error("Failed to add referer rule", error);
+            reject(error);
+        });
+    });
+}

src/util/download.ts

@@ -3,6 +3,8 @@ import { getTorrentNameFromMagnetLink, getTorrentNameFromLink, parseFilesFromDec
 import { convertBlobToString } from "./converter";
 import bencode from "bencode";
 import { Buffer } from "buffer";
+import { executeMethodWrappedWithReferer } from "./cors-tricks";
+import { getBaseUrl } from "./utils";
 
 export async function downloadTorrent(url: string): Promise<Torrent> {
     return new Promise<Torrent>(async (resolve, reject) => {
@@ -11,7 +13,7 @@ export async function downloadTorrent(url: string): Promise<Torrent> {
         } else {
             let response: Response;
             try {
-                response = await fetch(url);
+                response = await executeMethodWrappedWithReferer(() => fetch(url), url, getBaseUrl(url));
                 if (!response.ok) {
                     reject(new Error(`Status not OK: ${response.status} ${response.statusText}`));
                 }

src/util/utils.ts

@@ -15,6 +15,15 @@ export function isMatchedByRegexes(url: string, regexes: RegExp[]): boolean {
     return regexes.some(regex => regex.test(url));
 }
 
+export function getBaseUrl(url: string): string {
+    try {
+        const u = new URL(url);
+        return u.origin;
+    } catch (e) {
+        return '';
+    }
+}
+
 export function addTrailingSlash(url: string): string {
     if (!url.endsWith("/")) {
         return url + "/";