enigma-bbs/core/uuid_util.js

/* jslint node: true */
'use strict';

const createHash	= require('crypto').createHash;

exports.createNamedUUID	= createNamedUUID;

function createNamedUUID(namespaceUuid, key) {
	//
	//	v5 UUID generation code based on the work here:
	//	https://github.com/download13/uuidv5/blob/master/uuid.js
	//
	if(!Buffer.isBuffer(namespaceUuid)) {
		namespaceUuid = Buffer.from(namespaceUuid);
	}

	if(!Buffer.isBuffer(key)) {
		key = Buffer.from(key);
	}

	let digest = createHash('sha1').update(
		Buffer.concat( [ namespaceUuid, key ] )).digest();

	let u = Buffer.alloc(16);

	// bbbb - bb - bb - bb - bbbbbb
	digest.copy(u, 0, 0, 4);			// time_low
	digest.copy(u, 4, 4, 6);			// time_mid
	digest.copy(u, 6, 6, 8);			// time_hi_and_version

	u[6] = (u[6] & 0x0f) | 0x50;		// version, 4 most significant bits are set to version 5 (0101)
	u[8] = (digest[8] & 0x3f) | 0x80;	// clock_seq_hi_and_reserved, 2msb are set to 10
	u[9] = digest[9];

	digest.copy(u, 10, 10, 16);

	return u;
}