crypt.md

Crypt

Copyright 2017 Moddable Tech, Inc.

Revised: November 7, 2017

Warning: These notes are preliminary. Omissions and errors are likely. If you encounter problems, please ask for assistance.

class Digest (Crypt)

The Digest class creates cryptographic hashes using a variety of algorithms.

import {Digest} from "crypt";

MD5 Hash

let digest = new Digest("MD5");
digest.write("hello, world);
trace(`MD5 Hash: ${digest.close()}\n`);

SHA1 Hash

let digest = new Digest("SHA1");
digest.write("hello,");
digest.write(" world");
trace(`SHA1 Hash: ${digest.close()}\n`);

new Digest(type)

The Digest constructor takes the type of the hash to calculate as its sole argument.

let digest = new Digest("SHA1");

The following hash functions are supported:

• MD5
• SHA1
• SHA224
• SHA256
• SHA384
• SHA512

write(message)

The write function adds a message to the hash being calculated. There is no restriction on the length of the message. The message argument to write may be a String or ArrayBuffer. The write function may be called more than once for a given digest calculation.

digest.write("123");
digest.write("456");

close()

The close function returns the the calculated hash. The hash is returned as an ArrayBuffer. The close function may only be called once, as it frees all resources associated with the digest calculation.