import { mnemonicToSeed, validateMnemonic } from 'bip39'; import { createDecipheriv, createHash } from 'crypto'; import { privateToAddress } from 'ethereumjs-util'; import HDkey from 'hdkey'; import { stripHexPrefixAndLower } from 'libs/values'; // adapted from https://github.com/kvhnuke/etherwallet/blob/de536ffebb4f2d1af892a32697e89d1a0d906b01/app/scripts/myetherwallet.js#L230 export function decryptPrivKey(encprivkey: string, password: string): Buffer { const cipher = encprivkey.slice(0, 128); const decryptedCipher = decodeCryptojsSalt(cipher); const evp = evp_kdf(new Buffer(password), decryptedCipher.salt, { keysize: 32, ivsize: 16 }); const decipher = createDecipheriv('aes-256-cbc', evp.key, evp.iv); const privKey = decipherBuffer(decipher, new Buffer(decryptedCipher.ciphertext)); return new Buffer(privKey.toString(), 'hex'); } // adapted from https://github.com/kvhnuke/etherwallet/blob/de536ffebb4f2d1af892a32697e89d1a0d906b01/app/scripts/myetherwallet.js#L284 export function decodeCryptojsSalt(input: string): any { const ciphertext = new Buffer(input, 'base64'); if (ciphertext.slice(0, 8).toString() === 'Salted__') { return { salt: ciphertext.slice(8, 16), ciphertext: ciphertext.slice(16) }; } else { return { ciphertext }; } } // adapted from https://github.com/kvhnuke/etherwallet/blob/de536ffebb4f2d1af892a32697e89d1a0d906b01/app/scripts/myetherwallet.js#L297 export function evp_kdf(data: Buffer, salt: Buffer, opts: any) { // A single EVP iteration, returns `D_i`, where block equlas to `D_(i-1)` function iter(block: Buffer) { let hash = createHash(opts.digest || 'md5'); hash.update(block); hash.update(data); hash.update(salt); block = hash.digest(); for (let e = 1; e < (opts.count || 1); e++) { hash = createHash(opts.digest || 'md5'); hash.update(block); block = hash.digest(); } return block; } const keysize = opts.keysize || 16; const ivsize = opts.ivsize || 16; const ret: any[] = []; let i = 0; while (Buffer.concat(ret).length < keysize + ivsize) { ret[i] = iter(i === 0 ? new Buffer(0) : ret[i - 1]); i++; } const tmp = Buffer.concat(ret); return { key: tmp.slice(0, keysize), iv: tmp.slice(keysize, keysize + ivsize) }; } export function decipherBuffer(decipher: any, data: Buffer): Buffer { return Buffer.concat([decipher.update(data), decipher.final()]); } export function decryptMnemonicToPrivKey( phrase: string, pass: string, path: string, address: string ): Buffer { phrase = phrase.trim(); address = stripHexPrefixAndLower(address); if (!validateMnemonic(phrase)) { throw new Error('Invalid mnemonic'); } const seed = mnemonicToSeed(phrase, pass); const derived = HDkey.fromMasterSeed(seed).derive(path); const dPrivKey = derived.privateKey; const dAddress = privateToAddress(dPrivKey).toString('hex'); if (dAddress !== address) { throw new Error(`Derived ${dAddress}, expected ${address}`); } return dPrivKey; }