From 5227d33d1d389e078601587386f4243f5a917fea Mon Sep 17 00:00:00 2001
From: Maran <maran.hidskes@gmail.com>
Date: Thu, 14 Aug 2014 19:04:52 +0200
Subject: [PATCH] Implement check for OP_RETURN

---
 examples/Opreturn.js | 20 ++++++++++++++++++++
 lib/Script.js        | 13 ++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)
 create mode 100644 examples/Opreturn.js

diff --git a/examples/Opreturn.js b/examples/Opreturn.js
new file mode 100644
index 0000000..66ce779
--- /dev/null
+++ b/examples/Opreturn.js
@@ -0,0 +1,20 @@
+'use strict';
+
+var run = function() {
+  // Replace '../bitcore' with 'bitcore' if you use this code elsewhere.
+  var bitcore = require('../bitcore');
+  var Address = bitcore.Address;
+  var coinUtil = bitcore.util;
+  var Script = bitcore.Script;
+  var network = bitcore.networks.testnet;
+
+  var script = 'OP_RETURN 58434c524e4748530000000000000000000000010000000005f5e100';
+  var s = Script.fromHumanReadable(script);
+  var result = (s.classify() == Script.TX_RETURN)
+  console.log("Is op_return:", result); 
+};
+
+module.exports.run = run;
+if (require.main === module) {
+  run();
+}
diff --git a/lib/Script.js b/lib/Script.js
index ea2217f..86e9a02 100644
--- a/lib/Script.js
+++ b/lib/Script.js
@@ -11,13 +11,15 @@ var TX_PUBKEY = 1;
 var TX_PUBKEYHASH = 2;
 var TX_MULTISIG = 3;
 var TX_SCRIPTHASH = 4;
+var TX_RETURN = 5;
 
 var TX_TYPES = [
   'unknown',
   'pubkey',
   'pubkeyhash',
   'multisig',
-  'scripthash'
+  'scripthash',
+  'return'
 ];
 
 function Script(buffer) {
@@ -35,6 +37,7 @@ Script.TX_PUBKEY = TX_PUBKEY;
 Script.TX_PUBKEYHASH = TX_PUBKEYHASH;
 Script.TX_MULTISIG = TX_MULTISIG;
 Script.TX_SCRIPTHASH = TX_SCRIPTHASH;
+Script.TX_RETURN = TX_RETURN;
 
 Script.prototype.parse = function() {
   this.chunks = [];
@@ -90,6 +93,12 @@ Script.prototype.isPubkey = function() {
     this.chunks[1] == Opcode.map.OP_CHECKSIG);
 };
 
+Script.prototype.isReturn = function() {
+  return (this.chunks.length == 2 &&
+    Buffer.isBuffer(this.chunks[1]) &&
+    this.chunks[0] == Opcode.map.OP_RETURN);
+};
+
 Script.prototype.isPubkeyHash = function() {
   return (this.chunks.length == 5 &&
     this.chunks[0] == Opcode.map.OP_DUP &&
@@ -282,6 +291,8 @@ Script.prototype.classify = function() {
     return TX_MULTISIG;
   if (this.isPubkey())
     return TX_PUBKEY;
+  if (this.isReturn())
+    return TX_RETURN;
   return TX_UNKNOWN;
 };