2025-11-13 22:33:26 -07:00

166 lines
5.2 KiB
JavaScript

var define_IMAGES_LOCAL_PATTERNS_default = [];
var define_IMAGES_REMOTE_PATTERNS_default = [];
let NEXT_IMAGE_REGEXP;
async function fetchImage(fetcher, imageUrl, ctx) {
if (!imageUrl || imageUrl.length > 3072 || imageUrl.startsWith("//")) {
return getUrlErrorResponse();
}
if (imageUrl.startsWith("/")) {
const url2 = URL.parse(imageUrl, "http://n");
if (url2 == null) {
return getUrlErrorResponse();
}
const pathname = decodeURIComponent(url2.pathname);
NEXT_IMAGE_REGEXP ??= /\/_next\/image($|\/)/;
if (NEXT_IMAGE_REGEXP.test(pathname)) {
return getUrlErrorResponse();
}
if (define_IMAGES_LOCAL_PATTERNS_default.length > 0 && !define_IMAGES_LOCAL_PATTERNS_default.some((p) => matchLocalPattern(p, url2))) {
return getUrlErrorResponse();
}
return fetcher?.fetch(`http://assets.local${imageUrl}`);
}
let url;
try {
url = new URL(imageUrl);
} catch {
return getUrlErrorResponse();
}
if (url.protocol !== "http:" && url.protocol !== "https:") {
return getUrlErrorResponse();
}
if (!define_IMAGES_REMOTE_PATTERNS_default.some((p) => matchRemotePattern(p, url))) {
return getUrlErrorResponse();
}
const imgResponse = await fetch(imageUrl, { cf: { cacheEverything: true } });
if (!imgResponse.body) {
return imgResponse;
}
const buffer = new ArrayBuffer(32);
try {
let contentType;
const [respBody, contentBody] = imgResponse.body.tee();
const reader = contentBody.getReader({ mode: "byob" });
const { value } = await reader.read(new Uint8Array(buffer));
ctx.waitUntil(reader.cancel());
if (value) {
contentType = detectContentType(value);
}
if (!contentType) {
contentType = imgResponse.headers.get("content-type") ?? "";
}
if (!contentType.startsWith("image/") || contentType.includes(",")) {
contentType = void 0;
}
if (contentType && !(contentType === SVG && true)) {
const headers = new Headers(imgResponse.headers);
headers.set("content-type", contentType);
headers.set("content-disposition", "attachment");
headers.set("content-security-policy", "script-src 'none'; frame-src 'none'; sandbox;");
return new Response(respBody, { ...imgResponse, headers });
}
ctx.waitUntil(respBody.cancel());
return new Response('"url" parameter is valid but image type is not allowed', {
status: 400
});
} catch {
return new Response('"url" parameter is valid but upstream response is invalid', {
status: 400
});
}
}
function matchRemotePattern(pattern, url) {
if (pattern.protocol !== void 0 && pattern.protocol.replace(/:$/, "") !== url.protocol.replace(/:$/, "")) {
return false;
}
if (pattern.port !== void 0 && pattern.port !== url.port) {
return false;
}
if (pattern.hostname === void 0 || !new RegExp(pattern.hostname).test(url.hostname)) {
return false;
}
if (pattern.search !== void 0 && pattern.search !== url.search) {
return false;
}
return new RegExp(pattern.pathname).test(url.pathname);
}
function matchLocalPattern(pattern, url) {
if (pattern.search !== void 0 && pattern.search !== url.search) {
return false;
}
return new RegExp(pattern.pathname).test(url.pathname);
}
function getUrlErrorResponse() {
return new Response(`"url" parameter is not allowed`, { status: 400 });
}
const AVIF = "image/avif";
const WEBP = "image/webp";
const PNG = "image/png";
const JPEG = "image/jpeg";
const JXL = "image/jxl";
const JP2 = "image/jp2";
const HEIC = "image/heic";
const GIF = "image/gif";
const SVG = "image/svg+xml";
const ICO = "image/x-icon";
const ICNS = "image/x-icns";
const TIFF = "image/tiff";
const BMP = "image/bmp";
const PDF = "application/pdf";
function detectContentType(buffer) {
if ([255, 216, 255].every((b, i) => buffer[i] === b)) {
return JPEG;
}
if ([137, 80, 78, 71, 13, 10, 26, 10].every((b, i) => buffer[i] === b)) {
return PNG;
}
if ([71, 73, 70, 56].every((b, i) => buffer[i] === b)) {
return GIF;
}
if ([82, 73, 70, 70, 0, 0, 0, 0, 87, 69, 66, 80].every((b, i) => !b || buffer[i] === b)) {
return WEBP;
}
if ([60, 63, 120, 109, 108].every((b, i) => buffer[i] === b)) {
return SVG;
}
if ([60, 115, 118, 103].every((b, i) => buffer[i] === b)) {
return SVG;
}
if ([0, 0, 0, 0, 102, 116, 121, 112, 97, 118, 105, 102].every((b, i) => !b || buffer[i] === b)) {
return AVIF;
}
if ([0, 0, 1, 0].every((b, i) => buffer[i] === b)) {
return ICO;
}
if ([105, 99, 110, 115].every((b, i) => buffer[i] === b)) {
return ICNS;
}
if ([73, 73, 42, 0].every((b, i) => buffer[i] === b)) {
return TIFF;
}
if ([66, 77].every((b, i) => buffer[i] === b)) {
return BMP;
}
if ([255, 10].every((b, i) => buffer[i] === b)) {
return JXL;
}
if ([0, 0, 0, 12, 74, 88, 76, 32, 13, 10, 135, 10].every((b, i) => buffer[i] === b)) {
return JXL;
}
if ([0, 0, 0, 0, 102, 116, 121, 112, 104, 101, 105, 99].every((b, i) => !b || buffer[i] === b)) {
return HEIC;
}
if ([37, 80, 68, 70, 45].every((b, i) => buffer[i] === b)) {
return PDF;
}
if ([0, 0, 0, 12, 106, 80, 32, 32, 13, 10, 135, 10].every((b, i) => buffer[i] === b)) {
return JP2;
}
}
export {
detectContentType,
fetchImage,
matchLocalPattern,
matchRemotePattern
};