From efacd387beedf1e415f51b7319435466bf4304c7 Mon Sep 17 00:00:00 2001
From: Daniel Cousens <github@dcousens.com>
Date: Thu, 20 Aug 2015 20:16:57 +1000
Subject: [PATCH] ECPair: extract WIF to 3rd party module

---
 package.json              |  3 +-
 src/ecpair.js             | 64 +++++++++++----------------------------
 test/bitcoin.core.js      |  2 +-
 test/ecpair.js            |  4 +--
 test/fixtures/ecpair.json | 14 ++++++---
 5 files changed, 31 insertions(+), 56 deletions(-)

diff --git a/package.json b/package.json
index d74bd03..e863c89 100644
--- a/package.json
+++ b/package.json
@@ -51,7 +51,8 @@
     "create-hmac": "^1.1.3",
     "ecurve": "^1.0.0",
     "randombytes": "^2.0.1",
-    "typeforce": "^1.3.0"
+    "typeforce": "^1.3.0",
+    "wif": "^1.1.0"
   },
   "devDependencies": {
     "async": "^0.9.0",
diff --git a/src/ecpair.js b/src/ecpair.js
index 4599039..13f2b05 100644
--- a/src/ecpair.js
+++ b/src/ecpair.js
@@ -5,6 +5,7 @@ var ecurve = require('ecurve')
 var randomBytes = require('randombytes')
 var typeforce = require('typeforce')
 var types = require('./types')
+var wif = require('wif')
 
 var NETWORKS = require('./networks')
 var BigInteger = require('bigi')
@@ -57,46 +58,25 @@ ECPair.fromPublicKeyBuffer = function (buffer, network) {
   })
 }
 
-ECPair.fromWIF = function (string, networks) {
-  var payload = bs58check.decode(string)
-  var version = payload.readUInt8(0)
-  var compressed
+ECPair.fromWIF = function (string, network) {
+  network = network || NETWORKS.bitcoin
+  var buffer = bs58check.decode(string)
 
-  if (payload.length === 34) {
-    if (payload[33] !== 0x01) throw new Error('Invalid compression flag')
+  if (types.Array(network)) {
+    var version = buffer[0]
 
-    // truncate the version/compression bytes
-    payload = payload.slice(1, -1)
-    compressed = true
-
-  // no compression flag
-  } else {
-    if (payload.length !== 33) throw new Error('Invalid WIF payload length')
-
-    // Truncate the version byte
-    payload = payload.slice(1)
-    compressed = false
-  }
-
-  var network
-
-  // list of networks?
-  if (Array.isArray(networks)) {
-    network = networks.filter(function (network) {
+    network = network.filter(function (network) {
       return version === network.wif
     }).pop() || {}
 
-  // otherwise, assume a network object (or default to bitcoin)
-  } else {
-    network = networks || NETWORKS.bitcoin
+    if (version !== network.wif) throw new Error('Invalid network version')
   }
 
-  if (version !== network.wif) throw new Error('Invalid network')
-
-  var d = BigInteger.fromBuffer(payload)
+  var decoded = wif.decodeRaw(network.wif, buffer)
+  var d = BigInteger.fromBuffer(decoded.d)
 
   return new ECPair(d, null, {
-    compressed: compressed,
+    compressed: decoded.compressed,
     network: network
   })
 }
@@ -114,22 +94,6 @@ ECPair.makeRandom = function (options) {
   return new ECPair(d, null, options)
 }
 
-ECPair.prototype.toWIF = function () {
-  if (!this.d) throw new Error('Missing private key')
-
-  var bufferLen = this.compressed ? 34 : 33
-  var buffer = new Buffer(bufferLen)
-
-  buffer.writeUInt8(this.network.wif, 0)
-  this.d.toBuffer(32).copy(buffer, 1)
-
-  if (this.compressed) {
-    buffer.writeUInt8(0x01, 33)
-  }
-
-  return bs58check.encode(buffer)
-}
-
 ECPair.prototype.getAddress = function () {
   var pubKey = this.getPublicKeyBuffer()
   var pubKeyHash = bcrypto.hash160(pubKey)
@@ -151,6 +115,12 @@ ECPair.prototype.sign = function (hash) {
   return ecdsa.sign(secp256k1, hash, this.d)
 }
 
+ECPair.prototype.toWIF = function () {
+  if (!this.d) throw new Error('Missing private key')
+
+  return wif.encode(this.network.wif, this.d.toBuffer(32), this.compressed)
+}
+
 ECPair.prototype.verify = function (hash, signature) {
   return ecdsa.verify(secp256k1, hash, signature, this.Q)
 }
diff --git a/test/bitcoin.core.js b/test/bitcoin.core.js
index cdc3b8e..e30d366 100644
--- a/test/bitcoin.core.js
+++ b/test/bitcoin.core.js
@@ -117,7 +117,7 @@ describe('Bitcoin-core', function () {
       it('throws on ' + string, function () {
         assert.throws(function () {
           bitcoin.ECPair.fromWIF(string, allowedNetworks)
-        }, /(Invalid|Unknown) (checksum|compression flag|network|WIF payload)/)
+        }, /(Invalid|Unknown) (checksum|compression flag|network version|WIF length)/)
       })
     })
   })
diff --git a/test/ecpair.js b/test/ecpair.js
index b64f1d2..db378a9 100644
--- a/test/ecpair.js
+++ b/test/ecpair.js
@@ -129,9 +129,9 @@ describe('ECPair', function () {
     })
 
     fixtures.invalid.fromWIF.forEach(function (f) {
-      it('throws on ' + f.string, function () {
+      it('throws on ' + f.WIF, function () {
         assert.throws(function () {
-          ECPair.fromWIF(f.string)
+          ECPair.fromWIF(f.WIF)
         }, new RegExp(f.exception))
       })
     })
diff --git a/test/fixtures/ecpair.json b/test/fixtures/ecpair.json
index bc117e6..662f354 100644
--- a/test/fixtures/ecpair.json
+++ b/test/fixtures/ecpair.json
@@ -85,17 +85,21 @@
       }
     ],
     "fromWIF": [
+      {
+        "exception": "Invalid network version",
+        "WIF": "92Qba5hnyWSn5Ffcka56yMQauaWY6ZLd91Vzxbi4a9CCetaHtYj"
+      },
       {
         "exception": "Invalid compression flag",
-        "string": "ju9rooVsmagsb4qmNyTysUSFB1GB6MdpD7eoGjUTPmZRAApJxRz"
+        "WIF": "KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU73sfZr2ym"
       },
       {
-        "exception": "Invalid WIF payload length",
-        "string": "7ZEtRQLhCsDQrd6ZKfmcESdXgas8ggZPN24ByEi5ey6VJW"
+        "exception": "Invalid WIF length",
+        "WIF": "3tq8Vmhh9SN5XhjTGSWgx8iKk59XbKG6UH4oqpejRuJhfYD"
       },
       {
-        "exception": "Invalid WIF payload length",
-        "string": "5qibUKwsnMo1qDiNp3prGaQkD2JfVJa8F8Na87H2CkMHvuVg6uKhw67Rh"
+        "exception": "Invalid WIF length",
+        "WIF": "38uMpGARR2BJy5p4dNFKYg9UsWNoBtkpbdrXDjmfvz8krCtw3T1W92ZDSR"
       }
     ]
   }