vue-blocklink
Version:
Vue support for the Blockchain Link browser extension
77 lines (76 loc) • 2.46 kB
JavaScript
import * as crypto from 'crypto';
import * as ethUtil from 'ethereumjs-util';
import { B } from './configured_bignumber';
const WORD_LENGTH = 32;
const WORD_CEIL = new B.BigNumber(2).pow(WORD_LENGTH * 8);
export const hexUtils = {
concat,
random,
leftPad,
rightPad,
invert,
slice,
hash,
size,
toHex,
isHex,
};
function concat(...args) {
return ethUtil.bufferToHex(Buffer.concat(args.map(h => ethUtil.toBuffer(h))));
}
function random(_size = WORD_LENGTH) {
return ethUtil.bufferToHex(crypto.randomBytes(_size));
}
function leftPad(n, _size = WORD_LENGTH) {
return ethUtil.bufferToHex(ethUtil.setLengthLeft(ethUtil.toBuffer(hexUtils.toHex(n)), _size));
}
function rightPad(n, _size = WORD_LENGTH) {
return ethUtil.bufferToHex(ethUtil.setLengthRight(ethUtil.toBuffer(hexUtils.toHex(n)), _size));
}
function invert(n, _size = WORD_LENGTH) {
const buf = ethUtil.setLengthLeft(ethUtil.toBuffer(hexUtils.toHex(n)), _size);
return ethUtil.bufferToHex(Buffer.from(buf.map(b => ~b)));
}
function slice(n, start, end) {
const hex = hexUtils.toHex(n).substr(2);
const sliceStart = start >= 0 ? start * 2 : Math.max(0, hex.length + start * 2);
let sliceEnd = hex.length;
if (end !== undefined) {
sliceEnd = end >= 0 ? end * 2 : Math.max(0, hex.length + end * 2);
}
return '0x'.concat(hex.substring(sliceStart, sliceEnd));
}
function hash(n) {
return ethUtil.bufferToHex(ethUtil.keccak256(ethUtil.toBuffer(hexUtils.toHex(n))));
}
function size(hex) {
return Math.ceil((hex.length - 2) / 2);
}
function toHex(n, _size = WORD_LENGTH) {
if (Buffer.isBuffer(n)) {
return `0x${n.toString('hex')}`;
}
if (typeof n === 'string' && /^0x[0-9a-f]+$/i.test(n)) {
return n;
}
let _n = new B.BigNumber(n);
if (_n.isNegative()) {
_n = new B.BigNumber(invert(toHex(_n.abs()), _size).substr(2), 16).plus(1).mod(WORD_CEIL);
}
return `0x${_n.toString(16)}`;
}
function isHex(s) {
return /^0x[0-9a-f]+$/i.test(s);
}
export function isHexPrefixed(str) {
if (typeof str !== 'string') {
throw new Error("[is-hex-prefixed] value must be type 'string', is currently type " + (typeof str) + ", while checking isHexPrefixed.");
}
return str.slice(0, 2) === '0x';
}
export function stripHexPrefix(str) {
if (typeof str !== 'string') {
return str;
}
return isHexPrefixed(str) ? str.slice(2) : str;
}