Add ZCash support in bitcoinjs-lib

Summary:
Add ZCash support when creating transactions

Merge branch 'add-zcash-support' of github.com:BitGo/bitcoinjs-lib into add-zcash-support

Merge branch 'add-zcash-support' of github.com:BitGo/bitcoinjs-lib into add-zcash-support

Add zcash to the network file

Merge branch 'add-zcash-support' of github.com:BitGo/bitcoinjs-lib into add-zcash-support

Reviewers: tyler, taylor, arik, alex

Reviewed By: taylor, arik, alex

Subscribers: taylor

Differential Revision: https://phabricator.bitgo.com/D8644

.arcconfig

@@ -0,0 +1,3 @@
+{
+  "phabricator.uri" : "https://phabricator.bitgo.com"
+}

.arclint

@@ -0,0 +1,19 @@
+{
+  "linters": {
+    "filename": {
+      "type": "filename"
+    },
+    "generated": {
+      "type": "generated"
+    },
+    "merge-conflict": {
+      "type": "merge-conflict"
+    },
+    "nolint": {
+      "type": "nolint"
+    },
+    "spelling": {
+      "type": "spelling"
+    }
+  }
+}

.gitignore

@@ -2,3 +2,4 @@ coverage
 node_modules
 .nyc_output
 npm-debug.log
+.idea

package.json

@@ -1,6 +1,6 @@
 {
   "name": "bitgo-bitcoinjs-lib",
-  "version": "3.1.1",
+  "version": "3.2.0",
   "description": "Client-side Bitcoin JavaScript library",
   "main": "./src/index.js",
   "engines": {

src/address.js

@@ -12,10 +12,13 @@ function fromBase58Check (address) {
 
   // TODO: 4.0.0, move to "toOutputScript"
   if (payload.length < 21) throw new TypeError(address + ' is too short')
-  if (payload.length > 21) throw new TypeError(address + ' is too long')
+  if (payload.length > 22) throw new TypeError(address + ' is too long')
 
-  var version = payload.readUInt8(0)
-  var hash = payload.slice(1)
+  var multibyte = payload.length === 22
+  var offset = multibyte ? 2 : 1
+
+  var version = multibyte ? payload.readUInt16BE(0) : payload[0]
+  var hash = payload.slice(offset)
 
   return { version: version, hash: hash }
 }
@@ -32,11 +35,17 @@ function fromBech32 (address) {
 }
 
 function toBase58Check (hash, version) {
-  typeforce(types.tuple(types.Hash160bit, types.UInt8), arguments)
+  typeforce(types.tuple(types.Hash160bit, types.UInt16), arguments)
+
+  // Zcash adds an extra prefix resulting in a bigger (22 bytes) payload. We identify them Zcash by checking if the
+  // version is multibyte (2 bytes instead of 1)
+  var multibyte = version > 0xff
+  var size = multibyte ? 22 : 21
+  var offset = multibyte ? 2 : 1
 
-  var payload = Buffer.allocUnsafe(21)
-  payload.writeUInt8(version, 0)
-  hash.copy(payload, 1)
+  var payload = Buffer.allocUnsafe(size)
+  multibyte ? payload.writeUInt16BE(version, 0) : payload.writeUInt8(version, 0)
+  hash.copy(payload, offset)
 
   return bs58check.encode(payload)
 }

src/block.js

@@ -54,7 +54,7 @@ Block.fromBuffer = function (buffer) {
   }
 
   function readTransaction () {
-    var tx = Transaction.fromBuffer(buffer.slice(offset), true)
+    var tx = Transaction.fromBuffer(buffer.slice(offset), null, true)
     offset += tx.byteLength()
     return tx
   }

src/coins.js

@@ -0,0 +1,28 @@
+// Coins supported by bitgo-bitcoinjs-lib
+
+const typeforce = require('typeforce')
+
+const coins = {
+  BCH: 'bch',
+  BTC: 'btc',
+  BTG: 'btg',
+  ZEC: 'zec'
+}
+
+coins.isBitcoin = function (value) {
+  return typeforce.String(value) && value === coins.BTC
+}
+
+coins.isBitcoinCash = function (value) {
+  return typeforce.String(value) && value === coins.BCH
+}
+
+coins.isBitcoinGold = function (value) {
+  return typeforce.String(value) && value === coins.BTG
+}
+
+coins.isZcash = function (value) {
+  return typeforce.String(value) && value === coins.ZEC
+}
+
+module.exports = coins

src/ecpair.js

@@ -65,7 +65,7 @@ ECPair.fromWIF = function (string, network) {
   if (types.Array(network)) {
     network = network.filter(function (x) {
       return version === x.wif
-    }).pop()
+    }).pop()  // We should not use pop since it depends on the order of the networks for the same wif
 
     if (!network) throw new Error('Unknown network version')
 

src/index.js

@@ -16,6 +16,7 @@ module.exports = {
   TransactionBuilder: require('./transaction_builder'),
 
   address: require('./address'),
+  coins: require('./coins'),
   crypto: require('./crypto'),
   networks: require('./networks'),
   opcodes: require('bitcoin-ops'),

src/networks.js

@@ -2,6 +2,28 @@
 // Dogecoin BIP32 is a proposed standard: https://bitcointalk.org/index.php?topic=409731
 
 module.exports = {
+  zcash: {
+    messagePrefix: '\x18ZCash Signed Message:\n',
+    bech32: 'bc',
+    bip32: {
+      public: 0x0488b21e,
+      private: 0x0488ade4
+    },
+    pubKeyHash: 0x1cb8,
+    scriptHash: 0x1cbd,
+    wif: 0x80
+  },
+  zcashTest: {
+    messagePrefix: '\x18ZCash Signed Message:\n',
+    bech32: 'tb',
+    bip32: {
+      public: 0x043587cf,
+      private: 0x04358394
+    },
+    pubKeyHash: 0x1d25,
+    scriptHash: 0x1cba,
+    wif: 0xef
+  },
   bitcoingold: {
     messagePrefix: '\x18Bitcoin Gold Signed Message:\n',
     bip32: {

src/templates/nulldata.js

@@ -14,15 +14,20 @@ function check (script) {
 check.toJSON = function () { return 'null data output' }
 
 function encode (data) {
-  typeforce(types.Buffer, data)
+  // Allow arrays types since decompile returns an array too
+  typeforce(typeforce.oneOf(types.Buffer, types.Array), data)
 
-  return bscript.compile([OPS.OP_RETURN, data])
+  return bscript.compile([OPS.OP_RETURN].concat(data))
 }
 
 function decode (buffer) {
   typeforce(check, buffer)
 
-  return buffer.slice(2)
+  var chunks = bscript.decompile(buffer)
+
+  chunks.shift()
+
+  return chunks.length === 1 ? chunks[0] : chunks
 }
 
 module.exports = {