Haketilo

/**

 * This file is part of Haketilo.

 *

 * Function: Miscellaneous operations refactored to a separate file.

 *

 * Copyright (C) 2021 Wojtek Kosior

 * Copyright (C) 2021 jahoti

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * As additional permission under GNU GPL version 3 section 7, you

 * may distribute forms of that code without the copy of the GNU

 * GPL normally required by section 4, provided you include this

 * license notice and, in case of non-source distribution, a URL

 * through which recipients can access the Corresponding Source.

 * If you modify file(s) with this exception, you may extend this

 * exception to your version of the file(s), but you are not

 * obligated to do so. If you do not wish to do so, delete this

 * exception statement from your version.

 *

 * As a special exception to the GPL, any HTML file which merely

 * makes function calls to this code, and for that purpose

 * includes it by reference shall be deemed a separate work for

 * copyright law purposes. If you modify this code, you may extend

 * this exception to your version of the code, but you are not

 * obligated to do so. If you do not wish to do so, delete this

 * exception statement from your version.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 *

 * I, Wojtek Kosior, thereby promise not to sue for violation of this file's

 * license. Although I request that you do not make use of this code in a

 * proprietary program, I am not going to enforce this in court.

 */

/*

 * uint8_to_hex is a separate function used in cryptographic functions and when

 * dealing with binary data.

 */

const uint8_to_hex =

      array => [...array].map(b => ("0" + b.toString(16)).slice(-2)).join("");

#EXPORT uint8_to_hex

/*

 * Asynchronously compute hex string representation of a sha256 digest of a

 * UTF-8 string.

 */

async function sha256_async(string) {

    const input_ab = new TextEncoder("utf-8").encode(string);

    const digest_ab = await crypto.subtle.digest("SHA-256", input_ab);

    return uint8_to_hex(new Uint8Array(digest_ab));

}

#EXPORT sha256_async

/*

 * Generate a unique value that can be computed synchronously and is impossible

 * to guess for a malicious website.

 */

function gen_nonce(length=16) {

    const random_data = new Uint8Array(length);

    crypto.getRandomValues(random_data);

    return uint8_to_hex(random_data);

}

#EXPORT gen_nonce

/* Check if some HTTP header might define CSP rules. */

const csp_header_regex =

      /^\s*(content-security-policy|x-webkit-csp|x-content-security-policy)\s*$/i;

#EXPORT csp_header_regex

/*

 * Check if url corresponds to a browser's special page (or a directory index in

 * case of `file://' protocol).

 */

#IF MOZILLA

const priv_reg = /^moz-extension:\/\/|^about:|^view-source:|^file:\/\/[^?#]*\/([?#]|$)/;

#ELIF CHROMIUM

const priv_reg = /^chrome(-extension)?:\/\/|^about:|^view-source:|^file:\/\/[^?#]*\/([?#]|$)/;

#ENDIF

#EXPORT  url => priv_reg.test(url)  AS is_privileged_url

/* Make it possible to serialize en Error object. */

function error_data_jsonifiable(error) {

    const jsonifiable = {};

    for (const property of ["name", "message", "fileName", "lineNumber"])

	jsonifiable[property] = error[property];

    return jsonifiable;

}

#EXPORT error_data_jsonifiable