From bd3fd3e218de33fdaa4469fd37d243799a18d03d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Oliveira?= <josepfo.w@gmail.com>
Date: Tue, 3 Aug 2021 18:58:19 +0100
Subject: [PATCH] feat: lamassu eth recovery script

---
 bin/lamassu-eth-recovery.js | 54 +++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 bin/lamassu-eth-recovery.js

diff --git a/bin/lamassu-eth-recovery.js b/bin/lamassu-eth-recovery.js
new file mode 100644
index 00000000..4431db2a
--- /dev/null
+++ b/bin/lamassu-eth-recovery.js
@@ -0,0 +1,54 @@
+const hdkey = require('ethereumjs-wallet/hdkey')
+const hkdf = require('futoin-hkdf')
+const db = require('../lib/db')
+const mnemonicHelpers = require('../lib/mnemonic-helpers')
+
+const pify = require('pify')
+const fs = pify(require('fs'))
+
+const options = require('../lib/options')
+
+const paymentPrefixPath = "m/44'/60'/0'/0'"
+const defaultPrefixPath = "m/44'/60'/1'/0'"
+
+const address = process.argv[2]
+
+function run (address) {
+  Promise.all([fetchMnemonic(), searchForHdIndex(address)])
+    .then(([mnemonic, hdIndex]) => {
+      if (!mnemonic || !hdIndex) {
+        console.log(`Error while retrieving private key!`)
+        return
+      }
+      console.log(`Private key: `, paymentHdNode(mnemonic).deriveChild(hdIndex).getWallet().getPrivateKeyString())
+    })
+}
+
+function searchForHdIndex (address) {
+  const sql = `SELECT hd_index FROM cash_out_txs WHERE to_address = $1`
+  return db.oneOrNone(sql, [address])
+}
+
+function fetchMnemonic () {
+  return fs.readFile(options.mnemonicPath, 'utf8')
+    .then(mnemonic => computeSeed(mnemonic))
+}
+
+function computeSeed (seed) {
+  const masterSeed = mnemonicHelpers.toEntropyBuffer(seed)
+  return hkdf(masterSeed, 32, { salt: 'lamassu-server-salt', info: 'wallet-seed' })
+}
+
+function paymentHdNode (masterSeed) {
+  if (!masterSeed) throw new Error('No master seed!')
+  const key = hdkey.fromMasterSeed(masterSeed)
+  return key.derivePath(paymentPrefixPath)
+}
+
+function defaultHdNode (masterSeed) {
+  if (!masterSeed) throw new Error('No master seed!')
+  const key = hdkey.fromMasterSeed(masterSeed)
+  return key.derivePath(defaultPrefixPath)
+}
+
+run(address)