Implement HTML-based downloading

src/download.js

@@ -1,27 +1,39 @@
+import { getHashString } from "./utils";
+
 export async function downloadDispatcher(request, env, ctx) {
     const url = new URL(request.url);
     const uri = url.pathname;
 
     const bucket = env.EXP_DATA;
+    const signatureBase = env.SIGNATURE_BASE;
     const adminSecret = env.ADMIN_SECRET;
 
-    if (request.headers.get('x-access-token') !== adminSecret)
-        return new Response(null, { status: 401, statusText: 'Unauthorized' });
-    try {
     const key = uri.slice(10); // '/download/'.length
+    const signature = url.searchParams.get('signature');
+    const timestamp = url.searchParams.get('timestamp');
+    
+    if (!signature && request.headers.get('x-access-token') !== adminSecret)
+        return new Response(null, { status: 403, statusText: 'Forbidden' });
+    else {
+        const hash = await getHashString(`${key}${timestamp}${signatureBase}`, 'SHA-1');
+        if (signature !== hash)
+            return new Response(null, { status: 403, statusText: 'Forbidden' });
+    }
+
+    try {
         const object = await bucket.get(key);
         if (object === null)
             return new Response(null, { status: 404, statusText: 'Not Found' });
 
         const { body, etag, httpMetadata, customMetadata } = object;
         return new Response(body, { headers: {
-            etag: etag,
+            etag,
             'content-type': httpMetadata.contentType,
             'content-length': body.length,
             'x-metadata': JSON.stringify(customMetadata),
         }});
 
-    } catch (e) { return new Response(null, { status: 400 }); }
+    } catch (e) { return new Response(null, { status: 500 }); }
 }
 
 export default downloadDispatcher;

src/list.js

@@ -1,17 +1,29 @@
+import { getHashString, adaptiveFilesize } from "./utils";
+
 export async function listDispatcher(request, env, ctx) {
+    const url = new URL(request.url);
+    const headers = request.headers;
+    
     const bucket = env.EXP_DATA;
+    const signatureBase = env.SIGNATURE_BASE;
     const adminSecret = env.ADMIN_SECRET;
     const badRequest = new Response(null, { status: 400 });
     
-    if (request.headers.get('x-access-token') !== adminSecret)
+    const token = url.searchParams.get('accessToken') || headers.get('x-access-token');
+    if (token !== adminSecret)
         return new Response(null, { status: 401, statusText: 'Unauthorized' });
+    
+    const resType = url.searchParams.get('resType') || headers.get('x-res-type') || 'html';
+    if (!['json', 'html'].includes(resType))
+        return badRequest;
+
     try {
-        const type = request.headers.get('x-list-type') || 'prefix';
-        let pattern = request.headers.get('x-pattern') || '';
+        const type = url.searchParams.get('type') || headers.get('x-type') || 'prefix';
+        let pattern = url.searchParams.get('pattern') || headers.get('x-pattern') || '';
         
         let objects = [];
         let truncated = true;
-        let cursor = "";
+        let cursor;
         switch (type) {
             case 'prefix':
                 while (truncated) {
@@ -37,12 +49,47 @@ export async function listDispatcher(request, env, ctx) {
                 return badRequest;
         }
 
-        const res = JSON.stringify(objects, ['key', 'etag', 'size', 'uploaded']);
-        return new Response(res, { status: 200 });
-    } catch (e) {
-        console.error(e);
-        return badRequest;
+        const timestamp = Date.now();
+        const baseUrl = `${url.protocol}//${url.hostname}:${url.port}`;
+        const res = await Promise.all(objects.map(async object => {
+            const { key, etag, size, uploaded } = object;
+            const hash = await getHashString(`${key}${timestamp}${signatureBase}`, 'SHA-1');
+            return { key, etag, size, uploaded,
+                     presignedUrl: `${baseUrl}/download/${key}?signature=${hash}&timestamp=${timestamp}` };
+        }));
+        console.log(objects[0]);
+        if (resType === 'json')
+            return new Response(JSON.stringify(res), { status: 200 });
+        else if (resType === 'html') {
+            // Generate a table of links with URLs, sizes, and upload dates
+            const body = res.map(obj => `
+                <tr>
+                    <td><a href="${obj.presignedUrl}">${obj.key}</a></td>
+                    <td>${adaptiveFilesize(obj.size)}</td>
+                    <td>${obj.uploaded.toISOString()}</td>
+                </tr>
+            `).join('');
+            return new Response(`
+                <html>
+                    <head>
+                        <title>Object List</title>
+                        <meta charset="utf-8">
+                    </head>
+                    <body>
+                        <table>
+                            <tr>
+                                <th>Key</th>
+                                <th>Size</th>
+                                <th>Uploaded</th>
+                            </tr>
+                            ${body}
+                        </table>
+                    </body>
+                </html>
+            `, { status: 200, headers: { 'content-type': 'text/html' } });
         }
+
+    } catch (e) { console.log(e); return badRequest; }
 }
 
 export default listDispatcher;

src/utils.js

@@ -5,3 +5,9 @@ export async function getHashString(string, method = 'SHA-256') {
 	const hashArray = Array.from(new Uint8Array(hash));
 	return hashArray.map(b => b.toString(16).padStart(2, '0')).join('');
 }
+
+export function adaptiveFilesize(bytes, digits = 2) {
+	if (bytes < 1024) return `${bytes} B`;
+	else if (bytes < 1048576) return `${(bytes / 1024).toFixed(digits)} KB`;
+	else return `${(bytes / 1048576).toFixed(digits)} MB`;
+}