hd: refactor hardening handling.

lib/hd/common.js

@@ -6,6 +6,7 @@
 
 'use strict';
 
+const assert = require('assert');
 const LRU = require('../utils/lru');
 const common = exports;
 
@@ -17,14 +18,6 @@ const common = exports;
 
 common.HARDENED = 0x80000000;
 
-/**
- * Max index (u32max + 1).
- * @const {Number}
- * @default
- */
-
-common.MAX_INDEX = 0x100000000;
-
 /**
  * Min entropy bits.
  * @const {Number}
@@ -52,13 +45,13 @@ common.cache = new LRU(500);
  * Parse a derivation path and return an array of indexes.
  * @see https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki
  * @param {String} path
- * @param {Number?} max - Max index.
+ * @param {Boolean} hard
  * @returns {Number[]}
  */
 
-common.parsePath = function parsePath(path, max) {
+common.parsePath = function parsePath(path, hard) {
-  if (max == null)
+  assert(typeof path === 'string');
-    max = common.MAX_INDEX;
+  assert(typeof hard === 'boolean');
 
   const parts = path.split('/');
   const root = parts.shift();
@@ -72,23 +65,28 @@ common.parsePath = function parsePath(path, max) {
 
   const result = [];
 
-  for (let index of parts) {
+  for (let part of parts) {
-    const hardened = index[index.length - 1] === '\'';
+    const hardened = part[part.length - 1] === '\'';
 
     if (hardened)
-      index = index.slice(0, -1);
+      part = part.slice(0, -1);
 
-    if (!/^\d+$/.test(index))
+    if (!/^\d+$/.test(part))
       throw new Error('Non-number path index.');
 
-    index = parseInt(index, 10);
+    let index = parseInt(part, 10);
 
-    if (hardened)
+    if ((index >>> 0) !== index)
-      index += common.HARDENED;
-
-    if (!(index >= 0 && index < max))
       throw new Error('Index out of range.');
 
+    if (hardened) {
+      index |= common.HARDENED;
+      index >>>= 0;
+    }
+
+    if (!hard && (index & common.HARDENED))
+      throw new Error('Cannot derive hardened.');
+
     result.push(index);
   }
 
@@ -116,10 +114,11 @@ common.isMaster = function isMaster(key) {
 
 common.isBIP44 = function isBIP44(key, account) {
   if (account != null) {
-    if (key.childIndex !== common.HARDENED + account)
+    const index = (common.HARDENED | account) >>> 0;
+    if (key.childIndex !== index)
       return false;
   }
-  return key.depth === 3 && key.childIndex >= common.HARDENED;
+  return key.depth === 3 && (key.childIndex & common.HARDENED) !== 0;
 };
 
 /**
@@ -129,5 +128,5 @@ common.isBIP44 = function isBIP44(key, account) {
  */
 
 common.isBIP45 = function isBIP45(key) {
-  return key.depth === 1 && key.childIndex === common.HARDENED + 45;
+  return key.depth === 1 && (key.childIndex & ~common.HARDENED) === 45;
 };

lib/hd/private.js

@@ -183,13 +183,12 @@ HDPrivateKey.prototype.destroy = function destroy(pub) {
  */
 
 HDPrivateKey.prototype.derive = function derive(index, hardened) {
-  assert(typeof index === 'number');
+  assert(util.isU32(index));
 
-  if (hardened && index < common.HARDENED)
+  if (hardened) {
-    index += common.HARDENED;
+    index |= common.HARDENED;
-
+    index >>>= 0;
-  if (index < 0 || index >= common.MAX_INDEX)
+  }
-    throw new Error('Index out of range.');
 
   if (this.depth >= 0xff)
     throw new Error('Depth too high.');
@@ -202,7 +201,7 @@ HDPrivateKey.prototype.derive = function derive(index, hardened) {
 
   const bw = new StaticWriter(37);
 
-  if (index >= common.HARDENED) {
+  if (index & common.HARDENED) {
     bw.writeU8(0);
     bw.writeBytes(this.privateKey);
     bw.writeU32BE(index);
@@ -360,16 +359,12 @@ HDPrivateKey.isRaw = function isRaw(data, network) {
 /**
  * Test whether a string is a valid path.
  * @param {String} path
- * @param {Boolean?} hardened
  * @returns {Boolean}
  */
 
 HDPrivateKey.isValidPath = function isValidPath(path) {
-  if (typeof path !== 'string')
-    return false;
-
   try {
-    common.parsePath(path, common.MAX_INDEX);
+    common.parsePath(path, true);
     return true;
   } catch (e) {
     return false;
@@ -384,7 +379,8 @@ HDPrivateKey.isValidPath = function isValidPath(path) {
  */
 
 HDPrivateKey.prototype.derivePath = function derivePath(path) {
-  const indexes = common.parsePath(path, common.MAX_INDEX);
+  const indexes = common.parsePath(path, true);
+
   let key = this;
 
   for (const index of indexes)

lib/hd/public.js

@@ -151,14 +151,11 @@ HDPublicKey.prototype.destroy = function destroy() {
  */
 
 HDPublicKey.prototype.derive = function derive(index, hardened) {
-  assert(typeof index === 'number');
+  assert(util.isU32(index));
 
-  if (index >= common.HARDENED || hardened)
+  if ((index & common.HARDENED) || hardened)
     throw new Error('Cannot derive hardened.');
 
-  if (index < 0)
-    throw new Error('Index out of range.');
-
   if (this.depth >= 0xff)
     throw new Error('Depth too high.');
 
@@ -280,11 +277,8 @@ HDPublicKey.prototype.isBIP45 = function isBIP45() {
  */
 
 HDPublicKey.isValidPath = function isValidPath(path) {
-  if (typeof path !== 'string')
-    return false;
-
   try {
-    common.parsePath(path, common.HARDENED);
+    common.parsePath(path, false);
     return true;
   } catch (e) {
     return false;
@@ -300,7 +294,8 @@ HDPublicKey.isValidPath = function isValidPath(path) {
  */
 
 HDPublicKey.prototype.derivePath = function derivePath(path) {
-  const indexes = common.parsePath(path, common.HARDENED);
+  const indexes = common.parsePath(path, false);
+
   let key = this;
 
   for (const index of indexes)

lib/node/config.js

@@ -767,21 +767,21 @@ Config.prototype.parseConfig = function parseConfig(text) {
 
     if (colon !== -1 && (colon < equal || equal === -1)) {
       if (seen && !colons)
-        throw new Error(`Expected \`=\` on line ${num}: "${line}".`);
+        throw new Error(`Expected '=' on line ${num}: "${line}".`);
 
       index = colon;
       seen = true;
       colons = true;
     } else if (equal !== -1) {
       if (seen && colons)
-        throw new Error(`Expected \`:\` on line ${num}: "${line}".`);
+        throw new Error(`Expected ':' on line ${num}: "${line}".`);
 
       index = equal;
       seen = true;
       colons = false;
     } else {
       const symbol = colons ? ':' : '=';
-      throw new Error(`Expected \`${symbol}\` on line ${num}: "${line}".`);
+      throw new Error(`Expected '${symbol}' on line ${num}: "${line}".`);
     }
 
     let key = line.substring(0, index).trim();