Create ImageProxy.ts

src/libs/ImageProxy.ts

@@ -0,0 +1,27 @@
+import { createHmac } from 'crypto';
+import Environment from '../providers/Environment';
+
+export default class ImagePorxy {
+    public static signImageProxyURL(url: string, modifiers: string | undefined = undefined) {
+        const urlSafeBase64 = (string: Buffer) => {
+            return Buffer.from(string).toString('base64').replace(/=/g, '').replace(/\+/g, '-').replace(/\//g, '_');
+        };
+
+        const hexDecode = (hex: string) => Buffer.from(hex, 'hex');
+
+        const sign = (salt: string, target: string, secret: string) => {
+            const hmac = createHmac('sha256', hexDecode(secret));
+            hmac.update(hexDecode(salt));
+            hmac.update(target);
+            return urlSafeBase64(hmac.digest());
+        };
+
+        let path;
+        if (modifiers) path = `/${modifiers}/plain/${url}`;
+        else path = `/plain/${url}`;
+
+        const signature = sign(Environment.get().IMGPROXY_SALT, path, Environment.get().IMGPROXY_KEY);
+        const result = `${Environment.get().IMGPROXY_HOST}${signature}${path}`;
+        return result;
+    }
+}