From 48f8edbe804cd9ff9d5dffb129fc65bf438062de Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Mon, 16 May 2016 12:36:52 -0700
Subject: [PATCH] hd testing methods.

---
 lib/bcoin/hd.js | 124 +++++++++++++++++++++++++++---------------------
 1 file changed, 71 insertions(+), 53 deletions(-)

diff --git a/lib/bcoin/hd.js b/lib/bcoin/hd.js
index a7817636..ce0f85b0 100644
--- a/lib/bcoin/hd.js
+++ b/lib/bcoin/hd.js
@@ -139,7 +139,8 @@ Mnemonic.prototype.toSeed = function toSeed() {
   this.seed = utils.pbkdf2(
     nfkd(this.phrase),
     nfkd('mnemonic' + this.passphrase),
-    2048, 64);
+    2048,
+    64);
 
   return this.seed;
 };
@@ -560,34 +561,24 @@ HDPrivateKey.prototype.derive = function derive(index, hardened) {
  * @throws Error if key is not a master key.
  */
 
-HDPrivateKey.prototype.deriveAccount44 = function deriveAccount44(options) {
-  var coinType, accountIndex, child;
+HDPrivateKey.prototype.deriveAccount44 = function deriveAccount44(accountIndex) {
+  var coinType;
 
-  if (typeof options === 'number')
-    options = { accountIndex: options };
-
-  coinType = options.coinType;
-  accountIndex = options.accountIndex;
+  assert(utils.isNumber(accountIndex), 'accountIndex must be a number.');
 
   if (this instanceof HDPublicKey) {
-    assert(this.isAccount44());
+    assert(this.isAccount44(accountIndex), 'Cannot derive account index.');
     return this;
   }
 
-  if (coinType == null)
-    coinType = this.network === 'main' ? 0 : 1;
+  assert(this.isMaster(), 'Cannot derive account index.');
 
-  assert(utils.isNumber(coinType));
-  assert(utils.isNumber(accountIndex));
+  coinType = this.network === 'main' ? 0 : 1;
 
-  child = this
+  return this
     .derive(44, true)
     .derive(coinType, true)
     .derive(accountIndex, true);
-
-  assert(child.isAccount44());
-
-  return child;
 };
 
 /**
@@ -599,15 +590,38 @@ HDPrivateKey.prototype.derivePurpose45 = function derivePurpose45() {
   var child;
 
   if (this instanceof HDPublicKey) {
-    assert(this.isPurpose45());
+    assert(this.isPurpose45(), 'Cannot derive purpose 45.');
     return this;
   }
 
-  child = this.derive(45, true);
+  assert(this.isMaster(), 'Cannot derive purpose 45.');
 
-  assert(child.isPurpose45());
+  return this.derive(45, true);
+};
 
-  return child;
+/**
+ * Test whether the key is a master key.
+ * @returns {Boolean}
+ */
+
+HDPrivateKey.prototype.isMaster = function isMaster() {
+  return this.depth === 0
+    && this.childIndex === 0
+    && utils.readU32(this.parentFingerPrint, 0) === 0;
+};
+
+/**
+ * Test whether the key is (most likely) a BIP44 account key.
+ * @param {Number?} accountIndex
+ * @returns {Boolean}
+ */
+
+HDPrivateKey.prototype.isAccount44 = function isAccount44(accountIndex) {
+  if (accountIndex != null) {
+    if (this.childIndex !== constants.hd.HARDENED + accountIndex)
+      return false;
+  }
+  return this.depth === 3 && this.childIndex >= constants.hd.HARDENED;
 };
 
 /**
@@ -616,20 +630,7 @@ HDPrivateKey.prototype.derivePurpose45 = function derivePurpose45() {
  */
 
 HDPrivateKey.prototype.isPurpose45 = function isPurpose45() {
-  if (this.depth !== 1)
-    return false;
-  return this.childIndex === constants.hd.HARDENED + 45;
-};
-
-/**
- * Test whether the key is (most likely) a BIP44 account key.
- * @returns {Boolean}
- */
-
-HDPrivateKey.prototype.isAccount44 = function isAccount44() {
-  if (this.childIndex < constants.hd.HARDENED)
-    return false;
-  return this.depth === 3;
+  return this.depth === 1 && this.childIndex === constants.hd.HARDENED + 45;
 };
 
 /**
@@ -662,6 +663,9 @@ HDPrivateKey.isExtended = function isExtended(data) {
  */
 
 HDPrivateKey.isValidPath = function isValidPath(path) {
+  if (typeof path !== 'string')
+    return false;
+
   try {
     HD.parsePath(path, constants.hd.MAX_INDEX);
     return true;
@@ -722,8 +726,7 @@ HDPrivateKey.parseSeed = function parseSeed(seed, network) {
     parentFingerPrint: new Buffer([0, 0, 0, 0]),
     childIndex: 0,
     chainCode: chainCode,
-    privateKey: privateKey,
-    mnemonic: seed
+    privateKey: privateKey
   };
 };
 
@@ -752,14 +755,19 @@ HDPrivateKey.fromMnemonic = function fromMnemonic(mnemonic, network) {
   if (!(mnemonic instanceof Mnemonic))
     mnemonic = new Mnemonic(mnemonic);
 
-  if (mnemonic.seed || mnemonic.phrase || mnemonic.entropy)
-    return HDPrivateKey.fromSeed(mnemonic.toSeed(), network);
+  if (mnemonic.seed || mnemonic.phrase || mnemonic.entropy) {
+    key = HDPrivateKey.parseSeed(mnemonic.toSeed(), network);
+    key.mnemonic = mnemonic;
+    return new HDPrivateKey(key);
+  }
 
   // Very unlikely, but not impossible
   // to get an invalid private key.
   for (;;) {
     try {
-      key = HDPrivateKey.fromSeed(mnemonic.toSeed(), network);
+      key = HDPrivateKey.parseSeed(mnemonic.toSeed(), network);
+      key.mnemonic = mnemonic;
+      key = new HDPrivateKey(key);
     } catch (e) {
       if (e.message === 'Master private key is invalid.') {
         mnemonic.seed = null;
@@ -896,8 +904,7 @@ HDPrivateKey.prototype.toBase58 = function toBase58(network) {
  */
 
 HDPrivateKey.fromBase58 = function fromBase58(xkey) {
-  var data = HDPrivateKey.parseBase58(xkey);
-  return new HDPrivateKey(data);
+  return new HDPrivateKey(HDPrivateKey.parseBase58(xkey));
 };
 
 /**
@@ -1149,6 +1156,23 @@ HDPublicKey.prototype.deriveAccount44 = HDPrivateKey.prototype.deriveAccount44;
 
 HDPublicKey.prototype.derivePurpose45 = HDPrivateKey.prototype.derivePurpose45;
 
+/**
+ * Test whether the key is a master key.
+ * @method
+ * @returns {Boolean}
+ */
+
+HDPublicKey.prototype.isMaster = HDPrivateKey.prototype.isMaster;
+
+/**
+ * Test whether the key is (most likely) a BIP44 account key.
+ * @method
+ * @param {Number?} accountIndex
+ * @returns {Boolean}
+ */
+
+HDPublicKey.prototype.isAccount44 = HDPrivateKey.prototype.isAccount44;
+
 /**
  * Test whether the key is a BIP45 purpose key.
  * @method
@@ -1157,14 +1181,6 @@ HDPublicKey.prototype.derivePurpose45 = HDPrivateKey.prototype.derivePurpose45;
 
 HDPublicKey.prototype.isPurpose45 = HDPrivateKey.prototype.isPurpose45;
 
-/**
- * Test whether the key is (most likely) a BIP44 account key.
- * @method
- * @returns {Boolean}
- */
-
-HDPublicKey.prototype.isAccount44 = HDPrivateKey.prototype.isAccount44;
-
 /**
  * Test whether a string is a valid path.
  * @param {String} path
@@ -1173,6 +1189,9 @@ HDPublicKey.prototype.isAccount44 = HDPrivateKey.prototype.isAccount44;
  */
 
 HDPublicKey.isValidPath = function isValidPath(path) {
+  if (typeof path !== 'string')
+    return false;
+
   try {
     HD.parsePath(path, constants.hd.HARDENED);
     return true;
@@ -1314,8 +1333,7 @@ HDPublicKey.prototype.toBase58 = function toBase58(network) {
  */
 
 HDPublicKey.fromBase58 = function fromBase58(xkey) {
-  var data = HDPublicKey.parseBase58(xkey);
-  return new HDPublicKey(data);
+  return new HDPublicKey(HDPublicKey.parseBase58(xkey));
 };
 
 /**