From 468ebddc1e49881ed3a352fecb450f64feae1d45 Mon Sep 17 00:00:00 2001
From: olalonde <olalonde@gmail.com>
Date: Mon, 5 May 2014 17:15:39 +0800
Subject: [PATCH] Implemented Armory initializing from seed

---
 examples/Armory.js | 12 ++++++++++
 lib/Armory.js      | 58 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+)

diff --git a/examples/Armory.js b/examples/Armory.js
index beee650..f02553e 100644
--- a/examples/Armory.js
+++ b/examples/Armory.js
@@ -17,6 +17,8 @@ var chaincode = '84ac14bc4b388b33da099a0b4ee3b507284d99e1476639e36e5ca5e6af86481
 //var PublicX = '9df5 23e7 18b9 1f59 a790 2d46 999f 9357 ccf8 7208 24d4 3076 4516 b809 f7ab ce4e'
 //var PublicY = '66ba 5d21 4682 0dae 401d 9506 8437 2516 79f9 0c56 4186 cc50 07df c6d0 6989 1ff4';
 //var pubkey = '04' + PublicX.split(' ').join('') + PublicY.split(' ').join('');
+//console.log(pubkey);
+
 
 // mmm... can't figure out how to arrive at same pubkey as brainwallet
 var pubkey = '045a09a3286873a72f164476bde9d1d8e5c2bc044e35aa47eb6e798e325a86417f7c35b61d9905053533e0b4f2a26eca0330aadf21c638969e45aaace50e4c0c87';
@@ -28,3 +30,13 @@ for (var i = 0; i < 5; i++) {
   armory = armory.next();
   console.log(Address.fromPubKey(armory.pubkey).as('base58'));
 }
+
+// Derive stuff from root cod
+var seed = [
+  'aagh hjfj sihk ietj giik wwai awtd uodh hnji',
+  'soss uaku egod utai itos fijj ihgi jhau jtoo'
+].join('\n');
+
+console.log(seed);
+
+console.log(Armory.fromSeed(seed));
diff --git a/lib/Armory.js b/lib/Armory.js
index 03a7b10..6cc0d85 100644
--- a/lib/Armory.js
+++ b/lib/Armory.js
@@ -1,4 +1,6 @@
 var Point = require('./browser/Point'),
+  buffertools = require('buffertools'),
+  sha256 = require('../util').sha256,
   twoSha256 = require('../util').twoSha256,
   BigInteger = require('../browser/vendor-bundle.js').BigInteger;
 
@@ -38,4 +40,60 @@ Armory.prototype.next = function () {
   return new Armory(this.chaincode, next_pubkey);
 };
 
+function decode (str) {
+  var from = '0123456789abcdef';
+  var to = 'asdfghjkwertuion';
+  var res = '';
+  for (var i = 0; i < str.length; i++)
+    res += from.charAt(to.indexOf(str.charAt(i)));
+  return res;
+}
+
+Armory.decodeSeed = function (seed) {
+  var keys = seed.split('\n');
+  var lines = [];
+
+  for (var i = 0; i < keys.length; i++) {
+    var k = keys[i].replace(' ','');
+    var raw = new Buffer(decode(k), 'hex');
+    var data = raw.slice(0, 16);
+    lines.push(data);
+  }
+
+  var privKey = Buffer.concat([ lines[0], lines[1] ]);
+  var chainCode = (lines.length==4) ?
+    Buffer.concat([ lines[2], lines[3] ]) : Armory.deriveChaincode(privKey);
+
+  return {
+    privKey: privKey,
+    chainCode: chainCode
+  };
+};
+
+// Derive chain code from root key
+Armory.fromSeed = function (seed) {
+  var res = Armory.decodeSeed(seed);
+  return res;
+};
+
+Armory.deriveChaincode = function (root) {
+  var msg = 'Derive Chaincode from Root Key';
+  var hash = twoSha256(root);
+
+  var okey = [];
+  var ikey = [];
+  for (var i = 0; i < hash.length; i++) {
+    okey.push(0x5c ^ hash[i]);
+    ikey.push(0x36 ^ hash[i]);
+  }
+
+  okey = new Buffer(okey);
+  ikey = new Buffer(ikey);
+
+  var m = new Buffer(msg, 'utf8');
+  var a = sha256(Buffer.concat([ ikey, m ]));
+  var b = sha256(Buffer.concat([ okey, a ]));
+  return b;
+};
+
 module.exports = Armory;