feat: imgproxy

src/Feed/ImgProxy.ts

@@ -0,0 +1,39 @@
+import * as secp from "@noble/secp256k1"
+import * as base64 from "@protobufjs/base64"
+import { useSelector } from "react-redux";
+import { RootState } from "State/Store";
+
+export interface ImgProxySettings {
+    url: string,
+    key: string,
+    salt: string
+}
+
+export default function useImgProxy() {
+    const settings = useSelector((s: RootState) => s.login.preferences.imgProxyConfig);
+    const te = new TextEncoder();
+
+    function urlSafe(s: string) {
+        return s.replace(/=/g, '').replace(/\+/g, '-').replace(/\//g, '_');
+    }
+
+    async function signUrl(u: string) {
+        const result = await secp.utils.hmacSha256(
+            secp.utils.hexToBytes(settings!.key),
+            secp.utils.hexToBytes(settings!.salt),
+            te.encode(u));
+        return urlSafe(base64.encode(result, 0, result.byteLength));
+    }
+
+    return {
+        proxy: async (url: string, resize?: number) => {
+            if (!settings) return url;
+            const opt = resize ? `rs:fit:${resize}:${resize}` : "";
+            const urlBytes = te.encode(url);
+            const urlEncoded = urlSafe(base64.encode(urlBytes, 0, urlBytes.byteLength));
+            const path = `/${opt}/${urlEncoded}`;
+            const sig = await signUrl(path);
+            return `${new URL(settings.url).toString()}${sig}${path}`;
+        }
+    }
+}