@qingfu/zgapdfsigner/lib/zganode.js

A javascript tool to sign a pdf or set protection to a pdf in web browser, Google Apps Script and nodejs.

function isolateZga() {
	const m_urlparser = require("url");
	const m_h = {
		"http:": require('follow-redirects').http,
		"https:": require('follow-redirects').https,
	};
	const z = require("./zgaindex.js")();
	z.forge = require("node-forge");
	z.PDFLib = require("./pdf-lib")();
	const {Queue} = require('async-await-queue');
	z.zgaQueue = new Queue(1, 0);
	/**
	 * @param {string} url
	 * @param {UrlFetchParams} params
	 * @return {Promise<Uint8Array>}
	 */
	z.urlFetch = function (url, params) {
		return new Promise(function (resolve, reject) {
			/** @type {URL} */
			var opts = m_urlparser.parse(url);
			var http = m_h[opts.protocol];
			/** @type {string|Buffer} */
			var dat = null;
			var encoding = undefined;
			opts.method = "GET";
			if (params) {
				if (params.payload instanceof Buffer) {
					dat = params.payload;
				} else if (params.payload instanceof Uint8Array) {
					dat = Buffer.from(params.payload.buffer);
				} else if (params.payload instanceof ArrayBuffer) {
					dat = Buffer.from(params.payload);
				} else {
					dat = params.payload;
					encoding = "binary";
				}
				if (params.headers) {
					opts.headers = params.headers;
				}
				if (params.method) {
					opts.method = params.method;
				}
				if (params.validateHttpsCertificates === false) {
					opts.rejectUnauthorized = false;
				}
			}

			/** @type {http.ClientRequest} */
			var hreq = http.request(opts, function (/** @type {http.IncomingMessage} */a_res) {
				if (a_res.statusCode !== 200) {
					var a_err = new Error("Failed to request url. " + url + "\n Status Code: " + a_res.statusCode);
					a_res.resume();
					throw a_err;
				}
				/** @type {Array<Buffer>} */
				var a_bufs = [];
				var a_bufs_len = 0;
				a_res.on("data", function (/** @type {Buffer} */b_chunk) {
					a_bufs.push(b_chunk);
					a_bufs_len += b_chunk.length;
				});
				a_res.on("end", function () {
					/** @type {Buffer} */
					var b_bdat = Buffer.concat(a_bufs, a_bufs_len);
					resolve(b_bdat);
				});
			});
			hreq.on("error", function (a_err) {
				throw a_err;
			});
			hreq.end(dat, encoding);
		});
	};

	require("./zgacertsutil.js")(z);
	require("./zgapdfcryptor.js")(z);
	require("./zgapdfsigner.js")(z);
	return z
}
module.exports = isolateZga;