ethers.js/src.ts/utils/address.ts
2018-06-22 20:30:50 -04:00

136 lines
4.5 KiB
TypeScript

'use strict';
// We use this for base 36 maths
import BN from 'bn.js';
import { BigNumber } from './bignumber';
import { arrayify, Arrayish, stripZeros, hexlify } from './bytes';
import { keccak256 } from './keccak256';
import { encode } from './rlp';
import errors = require('./errors');
function getChecksumAddress(address: string): string {
if (typeof(address) !== 'string' || !address.match(/^0x[0-9A-Fa-f]{40}$/)) {
errors.throwError('invalid address', errors.INVALID_ARGUMENT, { arg: 'address', value: address });
}
address = address.toLowerCase();
let chars = address.substring(2).split('');
let hashed = new Uint8Array(40);
for (let i = 0; i < 40; i++) {
hashed[i] = chars[i].charCodeAt(0);
}
hashed = arrayify(keccak256(hashed));
for (var i = 0; i < 40; i += 2) {
if ((hashed[i >> 1] >> 4) >= 8) {
chars[i] = chars[i].toUpperCase();
}
if ((hashed[i >> 1] & 0x0f) >= 8) {
chars[i + 1] = chars[i + 1].toUpperCase();
}
}
return '0x' + chars.join('');
}
// Shims for environments that are missing some required constants and functions
var MAX_SAFE_INTEGER: number = 0x1fffffffffffff;
function log10(x: number): number {
if (Math.log10) { return Math.log10(x); }
return Math.log(x) / Math.LN10;
}
// See: https://en.wikipedia.org/wiki/International_Bank_Account_Number
// Create lookup table
var ibanLookup: { [character: string]: string } = {};
for (var i = 0; i < 10; i++) { ibanLookup[String(i)] = String(i); }
for (var i = 0; i < 26; i++) { ibanLookup[String.fromCharCode(65 + i)] = String(10 + i); }
// How many decimal digits can we process? (for 64-bit float, this is 15)
var safeDigits = Math.floor(log10(MAX_SAFE_INTEGER));
function ibanChecksum(address: string): string {
address = address.toUpperCase();
address = address.substring(4) + address.substring(0, 2) + '00';
var expanded = '';
address.split('').forEach(function(c) {
expanded += ibanLookup[c];
});
// Javascript can handle integers safely up to 15 (decimal) digits
while (expanded.length >= safeDigits){
var block = expanded.substring(0, safeDigits);
expanded = parseInt(block, 10) % 97 + expanded.substring(block.length);
}
var checksum = String(98 - (parseInt(expanded, 10) % 97));
while (checksum.length < 2) { checksum = '0' + checksum; }
return checksum;
};
export function getAddress(address: string): string {
var result = null;
if (typeof(address) !== 'string') {
errors.throwError('invalid address', errors.INVALID_ARGUMENT, { arg: 'address', value: address });
}
if (address.match(/^(0x)?[0-9a-fA-F]{40}$/)) {
// Missing the 0x prefix
if (address.substring(0, 2) !== '0x') { address = '0x' + address; }
result = getChecksumAddress(address);
// It is a checksummed address with a bad checksum
if (address.match(/([A-F].*[a-f])|([a-f].*[A-F])/) && result !== address) {
errors.throwError('bad address checksum', errors.INVALID_ARGUMENT, { arg: 'address', value: address });
}
// Maybe ICAP? (we only support direct mode)
} else if (address.match(/^XE[0-9]{2}[0-9A-Za-z]{30,31}$/)) {
// It is an ICAP address with a bad checksum
if (address.substring(2, 4) !== ibanChecksum(address)) {
errors.throwError('bad icap checksum', errors.INVALID_ARGUMENT, { arg: 'address', value: address });
}
result = (new BN.BN(address.substring(4), 36)).toString(16);
while (result.length < 40) { result = '0' + result; }
result = getChecksumAddress('0x' + result);
} else {
errors.throwError('invalid address', errors.INVALID_ARGUMENT, { arg: 'address', value: address });
}
return result;
}
export function getIcapAddress(address: string): string {
var base36 = (new BN.BN(getAddress(address).substring(2), 16)).toString(36).toUpperCase();
while (base36.length < 30) { base36 = '0' + base36; }
return 'XE' + ibanChecksum('XE00' + base36) + base36;
}
// http://ethereum.stackexchange.com/questions/760/how-is-the-address-of-an-ethereum-contract-computed
export function getContractAddress(transaction: { from: string, nonce: Arrayish | BigNumber | number }) {
if (!transaction.from) { throw new Error('missing from address'); }
var nonce = transaction.nonce;
return getAddress('0x' + keccak256(encode([
getAddress(transaction.from),
stripZeros(hexlify(nonce))
])).substring(26));
}