bitcoinjs-lib/src/bip32.js
2014-01-10 16:09:59 +07:00

133 lines
4.3 KiB
JavaScript

var util = require('./util'),
conv = require('./convert'),
ECKey = require('./eckey').ECKey,
ECPubKey = require('./eckey').ECPubKey,
base58 = require('./base58'),
Crypto = require('./crypto-js/crypto');
var BIP32key = function(opts) {
if (!opts) opts = {}
if (typeof opts == 'string') {
try {
opts = BIP32key.deserialize(opts);
}
catch(e) {
opts = BIP32key.fromMasterKey(opts);
}
}
this.vbytes = opts.vbytes;
this.depth = opts.depth;
this.fingerprint = opts.fingerprint;
this.i = opts.i;
this.chaincode = opts.chaincode;
this.key = opts.key;
this.type = conv.bytesToString(this.vbytes) == PRIVDERIV ? 'priv' : 'pub'
return this;
}
var PRIVDERIV = BIP32key.PRIVDERIV = '\x04\x88\xAD\xE4'
var PUBDERIV = BIP32key.PUBDERIV = '\x04\x88\xB2\x1E'
BIP32key.deserialize = function(str) {
var bytes = base58.decode(str)
var front = bytes.slice(0,bytes.length-4),
back = bytes.slice(bytes.length-4);
var checksum = Crypto.SHA256(Crypto.SHA256(front,{asBytes: true}), {asBytes: true})
.slice(0,4);
if ('' + checksum != '' + back) {
throw new Error('Checksum failed');
}
var type = conv.bytesToString(bytes.slice(0,4)) == PRIVDERIV ? 'priv' : 'pub';
return new BIP32key({
type: type,
vbytes: bytes.slice(0,4),
depth: bytes[4],
fingerprint: bytes.slice(5,9),
i: util.bytesToNum(bytes.slice(9,13).reverse()),
chaincode: bytes.slice(13,45),
key: type == 'priv' ? new ECKey(bytes.slice(46,78).concat([1]),true)
: new ECPubKey(bytes.slice(45,78),true)
})
}
BIP32key.prototype.serialize = function() {
var bytes = this.vbytes.concat(
[this.depth],
this.fingerprint,
util.numToBytes(this.i,4).reverse(),
this.chaincode,
this.type == 'priv' ? [0].concat(this.key.export('bytes').slice(0,32))
: this.key.export('bytes'))
var checksum = Crypto.SHA256(Crypto.SHA256(bytes,{asBytes: true}), {asBytes: true})
.slice(0,4)
return base58.encode(bytes.concat(checksum))
}
BIP32key.prototype.ckd = function(i) {
var priv, pub, newkey, fingerprint, blob, I;
if (this.type == 'priv') {
priv = this.key.export('bytes')
pub = this.key.getPub().export('bytes')
}
else pub = this.key.export('bytes')
if (i >= 2147483648) {
if (!priv) throw new Error("Can't do private derivation on public key!")
blob = [0].concat(priv.slice(0,32),util.numToBytes(i,4).reverse())
}
else blob = pub.concat(util.numToBytes(i,4).reverse())
I = Crypto.HMAC(Crypto.SHA512,blob,this.chaincode,{ asBytes: true })
if (this.type == 'priv') {
newkey = this.key.add(ECKey(I.slice(0,32).concat([1])))
fingerprint = util.sha256ripe160(this.key.getPub().export('bytes')).slice(0,4)
}
else {
newkey = this.key.add(ECKey(I.slice(0,32).concat([1])).getPub());
fingerprint = util.sha256ripe160(this.key.export('bytes')).slice(0,4)
}
return new BIP32key({
vbytes: this.vbytes,
type: this.type,
depth: this.depth + 1,
fingerprint: fingerprint,
i: i,
chaincode: I.slice(32),
key: newkey
})
}
BIP32key.prototype.clone = function() {
return new BIP32key(this);
}
BIP32key.prototype.privtopub = BIP32key.prototype.getPub = function() {
if (this.type == 'pub') return this.clone()
return new BIP32key({
vbytes: conv.stringToBytes(PUBDERIV),
type: 'pub',
depth: this.depth,
fingerprint: this.fingerprint,
i: this.i,
chaincode: this.chaincode,
key: this.key.getPub()
})
}
BIP32key.fromMasterKey = function(seed) {
var I = Bitcoin.Crypto.HMAC(Bitcoin.Crypto.SHA512,seed, 'Bitcoin seed' , { asBytes: true })
return new BIP32key({
vbytes: conv.stringToBytes(PRIVDERIV),
type: 'priv',
depth: 0,
fingerprint: [0,0,0,0],
i: 0,
chaincode: I.slice(32),
key: new ECKey(I.slice(0,32).concat([1]),true)
})
}
BIP32key.prototype.getKey = function() { return this.key }
module.exports = BIP32key;