1 var scrypt = require('scrypt-js');
2 var cryp = require('crypto-browserify');
3 var sha3_256 = require('js-sha3').sha3_256;
4 var _ = require('lodash')
5 var ED25519 =require('./ed25519');
6 var Curve25519 = new ED25519.Curve;
8 function decrypt(v3Keystore, password) {
9 /* jshint maxcomplexity: 10 */
11 if (!_.isString(password)) {
12 throw new Error('No password given.');
15 var json = (_.isObject(v3Keystore)) ? v3Keystore : JSON.parse(v3Keystore);
18 if (json.crypto.kdf === 'scrypt') {
19 kdfparams = json.crypto.kdfparams;
21 // FIXME: support progress reporting callback
22 derivedKey = scrypt.syncScrypt(Buffer.from(password), Buffer.from(kdfparams.salt, 'hex'), kdfparams.n, kdfparams.r, kdfparams.p, kdfparams.dklen);
23 } else if (json.crypto.kdf === 'pbkdf2') {
24 kdfparams = json.crypto.kdfparams;
26 if (kdfparams.prf !== 'hmac-sha256') {
27 throw new Error('Unsupported parameters to PBKDF2');
30 derivedKey = cryp.pbkdf2Sync(Buffer.from(password), Buffer.from(kdfparams.salt, 'hex'), kdfparams.c, kdfparams.dklen, 'sha3256');
32 throw new Error('Unsupported key derivation scheme');
35 var ciphertext = Buffer.from(json.crypto.ciphertext, 'hex');
37 var mac = sha3_256(Buffer.concat([Buffer(derivedKey.slice(16, 32)), ciphertext]));
38 if (mac !== json.crypto.mac) {
39 throw new Error('Key derivation failed - possibly wrong password');
42 var decipher = cryp.createDecipheriv(json.crypto.cipher, derivedKey.slice(0, 16), Buffer.from(json.crypto.cipherparams.iv, 'hex'));
43 var privateKey = Buffer.concat([decipher.update(ciphertext), decipher.final()]);
48 function scalarmult_base (q){
49 var base = Curve25519.point().base();
50 var scalar = Curve25519.scalar().setBytes(new Uint8Array(q));
51 var target = Curve25519.point().mul(scalar, base);
53 return target.toString();
56 export function restoreFromKeyStore(v3Keystore, password){
57 const privatekey = decrypt(v3Keystore, password);
58 const publickey = scalarmult_base(privatekey.slice(0, privatekey.length/2)) + privatekey.slice(privatekey.length/2, privatekey.length).toString('hex')