From a2041d5790a2f9157fc6d439ef386f61c703c51c Mon Sep 17 00:00:00 2001
From: Matias Alejo Garcia <ematiu@gmail.com>
Date: Sat, 15 Mar 2014 21:12:23 -0300
Subject: [PATCH] add TX signing. Support to p2pubkeyhash

---
 Transaction.js             | 117 +++++++++++++++++++++++++++++++++++--
 test/data/unspentSign.json |   6 +-
 test/test.Transaction.js   |  35 ++++++++++-
 3 files changed, 146 insertions(+), 12 deletions(-)

diff --git a/Transaction.js b/Transaction.js
index 4fcccb1..3b58233 100644
--- a/Transaction.js
+++ b/Transaction.js
@@ -12,6 +12,8 @@ var Step               = imports.Step || require('step');
 var buffertools        = imports.buffertools || require('buffertools');
 var error              = imports.error || require('./util/error');
 var networks           = imports.networks || require('./networks');
+var WalletKey          = imports.WalletKey || require('./WalletKey');
+var PrivateKey         = imports.PrivateKey || require('./PrivateKey');
 
 var COINBASE_OP = Buffer.concat([util.NULL_HASH, new Buffer('FFFFFFFF', 'hex')]);
 var DEFAULT_FEE = 0.0001;
@@ -780,12 +782,12 @@ Transaction._scriptForAddress = function (addressString) {
  *
  *  (TODO: should we use uBTC already?)
  *
- *  If not remainderAddress is given, and there is a remainderAddress
- *  first in address will be used. (TODO: is this is reasoable?)
+ *  If no remainderAddress is given, and there is a remainderAddress
+ *  first in address will be used. (TODO: is this is reasonable?)
+ *
+ *  The address from the inputs will be added to the Transaction object 
+ *  for latter signing
  *
- *  TODO add exceptions for validations:
- *  out address - ins amount > out amount - fees < maxFees
- *  + more?
  */
 
 Transaction.create = function (ins, outs, opts) {
@@ -798,6 +800,8 @@ Transaction.create = function (ins, outs, opts) {
   txobj.ins     = [];
   txobj.outs    = [];
 
+  var inputMap = [];
+
   var l = ins.length;
   var valueInSat = bignum(0);
   for(var i=0; i<l; i++) {
@@ -816,6 +820,10 @@ Transaction.create = function (ins, outs, opts) {
 
     txin.o = Buffer.concat([hashReversed, voutBuf]);
     txobj.ins.push(txin); 
+    inputMap[i]= {
+      address: ins[i].address, 
+      scriptPubKey: ins[i].scriptPubKey
+    };
   }
 
 
@@ -860,9 +868,106 @@ Transaction.create = function (ins, outs, opts) {
   }
 
 
-  return new Transaction(txobj);
+  var tx =  new Transaction(txobj);
+  tx.inputMap = inputMap;
+  return tx;
 };
 
+/*
+ * sign
+ *
+ *  signs the transaction
+ *
+ *  @keypairs
+ *    an array of strings representing private keys to sign the 
+ *    transaction in WIF private key format OR WalletKey objects
+ *
+ *  @opts
+ *    signhash: Transaction.SIGHASH_ALL
+ *
+ *  Return the 'completeness' status of the tx (i.e, if all inputs are signed).
+ *
+ *  To sign a TX, the TX must contain .inputMap to match private keys 
+ *  with inputs and scriptPubKey
+ */
+
+Transaction.prototype.sign = function (keys, opts) {
+  var self = this;
+  var complete = false;
+  var m = keys.length;
+  opts = opts || {};
+  var signhash = opts.signhash || SIGHASH_ALL;
+
+  if (!self.inputMap) {
+    throw new Error('this TX does not have information about input address, cannot be signed');
+  }
+
+  //prepare keys
+  var walletKeyMap = {};
+  var l = keys.length;
+  var wk;
+  for(var i=0; i<l; i++) {
+    var k = keys[i];
+
+    if (typeof k === 'string') {
+      var pk = new PrivateKey(k);
+      wk = new WalletKey({network: pk.network()});
+      wk.fromObj({priv:k});
+    }
+    else if (k instanceof WalletKey) {
+      wk = k;
+    }
+    else {
+      throw new Error('argument must be an array of strings (WIF format) or WalletKey objects');
+    }
+    walletKeyMap[wk.storeObj().addr] = wk;
+  }
+
+  var inputSigned = 0;
+  l = self.ins.length;
+  for(var i=0;i<l;i++) {
+    var aIn = self.ins[i];
+    var wk = walletKeyMap[self.inputMap[i].address];
+
+    if (typeof wk === 'undefined') {
+      if ( buffertools.compare(aIn.s,util.EMPTY_BUFFER)!==0 ) 
+        inputSigned++;
+      continue;
+    }
+    var scriptBuf = new Buffer(self.inputMap[i].scriptPubKey, 'hex');
+    var s = new Script(scriptBuf);
+    if (s.classify() !==  Script.TX_PUBKEYHASH) {
+      throw new Error('input:'+i+' script type:'+ s.getRawOutType() +' not supported yet');
+    }
+
+    var txSigHash = self.hashForSignature(s, i, signhash);
+
+    var sigRaw;
+    do {
+      sigRaw = wk.privKey.signSync(txSigHash);
+    } while ( wk.privKey.verifySignatureSync(txSigHash, sigRaw) === false );
+
+
+    var sigType = new Buffer(1);
+    sigType[0] = signhash;
+    var sig = Buffer.concat([sigRaw, sigType]);
+
+    var scriptSig = new Script();
+    scriptSig.chunks.push(sig);
+    scriptSig.chunks.push(wk.privKey.public);
+    scriptSig.updateBuffer();
+    self.ins[i].s = scriptSig.getBuffer();
+    inputSigned++;
+  }
+
+  var complete = inputSigned === l;
+
+  return complete;
+};
+
+
+
+
 var TransactionInputsCache = exports.TransactionInputsCache =
 function TransactionInputsCache(tx)
 {
diff --git a/test/data/unspentSign.json b/test/data/unspentSign.json
index ce2fa69..f03e40e 100644
--- a/test/data/unspentSign.json
+++ b/test/data/unspentSign.json
@@ -3,7 +3,7 @@
     {
       "address": "n4g2TFaQo8UgedwpkYdcQFF6xE2Ei9Czvy",
       "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc1",
-      "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ac",
+      "scriptPubKey": "76a914fe021bac469a5c49915b2a8ffa7390a9ce5580f988ac",
       "vout": 1,
       "amount": 1.01,
       "confirmations":7
@@ -11,7 +11,7 @@
     {
       "address": "mhNCT9TwZAGF1tLPpZdqfkTmtBkY282YDW",
       "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc2",
-      "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ad",
+      "scriptPubKey": "76a9141448534cb1a1ec44665b0eb2326e570814afe3f188ac",
       "vout": 0,
       "confirmations": 1,
       "amount": 10
@@ -19,7 +19,7 @@
     {
       "address": "n44hn28zAooZpn8mpWKzATbabqaHDK9oNJ",
       "txid": "2ac165fa7a3a2b535d106a0041c7568d03b531e58aeccdd3199d7289ab12cfc3",
-      "scriptPubKey": "76a9146ce4e1163eb18939b1440c42844d5f0261c0338288ae",
+      "scriptPubKey": "76a914f753f58b1fb1daaa5534b10af85ca9210f3445d288ac",
       "vout": 3,
       "confirmations": 0,
       "amount": 5
diff --git a/test/test.Transaction.js b/test/test.Transaction.js
index 926bf1a..8755592 100644
--- a/test/test.Transaction.js
+++ b/test/test.Transaction.js
@@ -116,13 +116,42 @@ describe('Transaction', function() {
     tx.serialize().toString('hex').should.equal('0100000002c1cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0100000000ffffffffc2cf12ab89729d19d3cdec8ae531b5038d56c741006a105d532b3a7afa65c12a0000000000ffffffff0100127a00000000001976a914774e603bafb717bd3f070e68bbcccfd907c77d1388ac00000000');
   });
  
-  it.skip('#sign should sign a tx', function() {
-    var utxos = Transaction.selectUnspent(testdata.dataUnspentign.unspent,0.1);
+  it('#sign should sign a tx', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,0.1);
     var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
     var tx = Transaction.create(utxos, outs, opts); 
-  });
+    tx.sign(testdata.dataUnspentSign.keyStrings).should.equal(true);
 
+    var utxos2 = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,16, true);
+    var outs2 = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var tx2 = Transaction.create(utxos2, outs2, opts); 
+    tx2.sign(testdata.dataUnspentSign.keyStrings).should.equal(true);
+  });
+  it('#sign should fail to sign a tx', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,0.1);
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
+    var tx = Transaction.create(utxos, outs, opts); 
+    tx.sign(['cNpW8B7XPAzCdRR9RBWxZeveSNy3meXgHD8GuhcqUyDuy8ptCDzJ']).should.equal(false);
+  });
+  it('#sign should sign a tx in multiple steps', function() {
+    var utxos = Transaction.selectUnspent(testdata.dataUnspentSign.unspent,13, true);
+    var outs = [{address:'mrPnbY1yKDBsdgbHbS7kJ8GVm8F66hWHLE', amount:0.08}];
 
+    var tx = Transaction.create(utxos, outs, opts); 
+    var k1 = testdata.dataUnspentSign.keyStrings.slice(0,1);
+    var k23 = testdata.dataUnspentSign.keyStrings.slice(1,3);
+    tx.sign(k1).should.equal(false);
+    tx.sign(k23).should.equal(true);
+
+    var tx2 = Transaction.create(utxos, outs, opts); 
+    var k1 = testdata.dataUnspentSign.keyStrings.slice(0,1);
+    var k2 = testdata.dataUnspentSign.keyStrings.slice(1,2);
+    var k3 = testdata.dataUnspentSign.keyStrings.slice(2,3);
+    tx2.sign(k1).should.equal(false);
+    tx2.sign(k2).should.equal(false);
+    tx2.sign(k3).should.equal(true);
+ 
+  });
 
   // Read tests from test/data/tx_valid.json
   // Format is an array of arrays