feat: Add imgproxy signer service

- imgproxy-signer.mjs: 图片代理签名服务
2026-06-27 08:25:27 +08:00
parent 3bb5d21425
commit da239bdf09
1 changed files with 53 additions and 0 deletions
@@ -0,0 +1,53 @@
+import crypto from 'node:crypto';
+
+export function createImgproxySigner(key, salt) {
+  const keyBuf = Buffer.from(key, 'hex');
+  const saltBuf = Buffer.from(salt, 'hex');
+
+  function signPath(path) {
+    const signaturePayload = Buffer.concat([saltBuf, Buffer.from(path)]);
+    const signature = crypto.createHmac('sha256', keyBuf).update(signaturePayload).digest();
+    const signatureB64 = signature.toString('base64url');
+    return `/${signatureB64}${path}`;
+  }
+
+  function buildUrl(baseUrl, storagePath, preset = 'display') {
+    if (!baseUrl || !storagePath) {
+      throw new Error('baseUrl and storagePath are required');
+    }
+
+    let width, height, quality, format;
+    switch (preset) {
+      case 'vision':
+        width = 768;
+        height = 768;
+        quality = 60;
+        format = 'jpg';
+        break;
+      case 'thumb':
+        width = 256;
+        height = 256;
+        quality = 70;
+        format = 'jpg';
+        break;
+      case 'display':
+      default:
+        width = 1280;
+        height = 1280;
+        quality = 85;
+        format = 'jpg';
+        break;
+    }
+
+    const encodedPath = encodeURIComponent(`local://${storagePath}`);
+    const unsignedPath = `/unsafe/${width}x${height}/${quality}/${format}/${encodedPath}`;
+    const signedPath = signPath(unsignedPath);
+
+    const baseUrlNormalized = String(baseUrl).replace(/\/$/, '');
+    return `${baseUrlNormalized}${signedPath}`;
+  }
+
+  return { buildUrl, signPath };
+}
+
+export default createImgproxySigner;