Files
snort/packages/app/src/Hooks/useImgProxy.ts

43 lines
1.3 KiB
TypeScript

import * as utils from "@noble/curves/abstract/utils";
import { base64 } from "@scure/base";
import { hmacSha256, unwrap } from "@/SnortUtils";
import useLogin from "@/Hooks/useLogin";
export interface ImgProxySettings {
url: string;
key: string;
salt: string;
}
export default function useImgProxy() {
const settings = useLogin(s => s.appData.item.preferences.imgProxyConfig);
return {
proxy: (url: string, resize?: number) => proxyImg(url, settings, resize),
};
}
export function proxyImg(url: string, settings?: ImgProxySettings, resize?: number) {
const te = new TextEncoder();
function urlSafe(s: string) {
return s.replace(/=/g, "").replace(/\+/g, "-").replace(/\//g, "_");
}
function signUrl(u: string) {
const result = hmacSha256(
utils.hexToBytes(unwrap(settings).key),
utils.hexToBytes(unwrap(settings).salt),
te.encode(u),
);
return urlSafe(base64.encode(result));
}
if (!settings) return url;
if (url.startsWith("data:") || url.startsWith("blob:") || url.length == 0) return url;
const opt = resize ? `rs:fit:${resize}:${resize}/dpr:${window.devicePixelRatio}` : "";
const urlBytes = te.encode(url);
const urlEncoded = urlSafe(base64.encode(urlBytes));
const path = `/${opt}/${urlEncoded}`;
const sig = signUrl(path);
return `${new URL(settings.url).toString()}${sig}${path}`;
}