bitmessage-js/lib/wif.js

46 lines
1.3 KiB
JavaScript

/**
* Implements WIF encoding/decoding.
* @see {@link https://en.bitcoin.it/wiki/Wallet_import_format}
* @module bitmessage/wif
*/
"use strict";
var bufferEqual = require("buffer-equal");
var bs58 = require("bs58");
var assert = require("./_util").assert;
var bmcrypto = require("./crypto");
// Compute the WIF checksum for the given data.
function getwifchecksum(data) {
return bmcrypto.sha256(bmcrypto.sha256(data)).slice(0, 4);
}
/**
* Decode WIF-encoded private key (corresponded to a uncompressed public
* key).
* @param {string} wif - Encoded key
* @return {Buffer} Private key.
*/
exports.decode = function(wif) {
var bytes = bs58.decode(wif);
assert(bytes[0] === 0x80, "Bad WIF");
var data = Buffer.from(bytes.slice(0, -4));
var checksum = Buffer.from(bytes.slice(-4));
assert(bufferEqual(checksum, getwifchecksum(data)), "Bad checkum");
return data.slice(1);
};
/**
* Convert private key to a WIF (corresponded to a uncompressed public
* key).
* @param {Buffer} privateKey - A private key to encode
* @return {string} WIF-encoded private key.
*/
exports.encode = function(privateKey) {
var data = Buffer.concat([Buffer.from([0x80]), privateKey]);
var checksum = getwifchecksum(data);
var bytes = Buffer.concat([data, checksum]);
return bs58.encode(bytes);
};