tx: wip sign/verify

lib/bcoin/script.js

@@ -70,3 +70,69 @@ script.encode = function encode(s) {
 
   return res;
 };
+
+script.subscript = function subscript(s) {
+  if (!s)
+    return [];
+
+  var lastSep = -1;
+  for (var i = 0; i < s.length; i++) {
+    if (s[i] === 'codesep')
+      lastSep = i;
+    else if (s[i] === 'checksig' ||
+             s[i] === 'checksigverify' ||
+             s[i] === 'checkmultisig' ||
+             s[i] === 'checkmultisigverify') {
+      break;
+    }
+  }
+
+  var res = [];
+  for (var i = lastSep + 1; i < s.length; i++)
+    if (s[i] !== 'codesep')
+      res.push(s[i]);
+
+  return res;
+};
+
+script.execute = function execute(s, stack, tx) {
+  for (var i = 0; i < s.length; i++) {
+    var o = s[i];
+    if (Array.isArray(o)) {
+      stack.push(o);
+    } else if (o === 'dup') {
+      if (stack.length === 0)
+        return false;
+
+      stack.push(stack[stack.length - 1]);
+    } else if (o === 'hash160') {
+      if (stack.length === 0)
+        return false;
+
+      stack.push(bcoin.utils.ripesha(stack.pop()));
+    } else if (o === 'eqverify' || o === 'eq') {
+      if (stack.length < 2)
+        return false;
+
+      var res = bcoin.utils.isEqual(stack.pop(), stack.pop());
+      stack.push([ res ? 1 : 0 ]);
+      if (!res && o === 'eqverify')
+        return false;
+    } else if (o === 'checksigverify' || o === 'checksig') {
+      if (!tx || stack.length < 2)
+        return false;
+
+      var pub = stack.pop();
+      var sig = stack.pop();
+      var res = bcoin.ecdsa.verify(tx, sig, pub);
+      stack.push([ res ? 1 : 0 ]);
+      if (!res && o ==='checksigverify')
+        return false;
+    } else {
+      // Unknown operation
+      return false;
+    }
+  }
+
+  return true;
+};

lib/bcoin/tx.js

@@ -1,3 +1,4 @@
+var assert = require('assert');
 var bn = require('bn.js');
 
 var bcoin = require('../bcoin');
@@ -53,7 +54,7 @@ TX.prototype.render = function render() {
 
 TX.prototype.input = function input(i, index) {
   if (i instanceof TX)
-    i = { tx: i, index: i };
+    i = { tx: i, index: index };
 
   var hash;
   if (i.tx)
@@ -106,10 +107,37 @@ TX.prototype.out = function out(output, value) {
 };
 
 TX.prototype.getSubscript = function getSubscript(index) {
-  var input = this.inputs[index];
-  assert(input);
+  var output = this.outputs[index];
+  assert(output);
 
-  var script = input.script;
-
-  for (var i = 0; input.script.
+  var script = output.script;
+  return bcoin.script.subscript(script);
+};
+
+TX.prototype.subscriptHash = function subscriptHash(index, s, type) {
+  var copy = this.clone();
+
+  copy.inputs.forEach(function(input, i) {
+    input.script = index === i ? s : [];
+  });
+  var verifyStr = copy.render();
+  verifyStr = verifyStr.concat(bcoin.protocol.constants.hashType[type]);
+  var hash = utils.dsha256(verifyStr);
+
+  return hash;
+};
+
+TX.prototype.validate = function validate() {
+  return this.inputs.every(function(input, i) {
+    assert(input.out.tx);
+    assert(input.out.tx.outputs.length > input.out.index);
+
+    var subscript = input.out.tx.getSubscript(input.out.index);
+    var hash = this.subscriptHash(i, subscript, 'all');
+
+    var stack = [];
+    bcoin.script.execute(input.script, stack);
+    var prev = input.out.tx.outputs[input.out.index].script;
+    return bcoin.script.execute(prev, stack, hash);
+  }, this);
 };

lib/bcoin/utils.js

@@ -272,6 +272,17 @@ function testTarget(target, hash) {
 }
 utils.testTarget = testTarget;
 
+utils.isEqual = function isEqual(a, b) {
+  if (a.length !== b.length)
+    return false;
+
+  for (var i = 0; i < a.length; i++)
+    if (a[i] !== b[i])
+      return false;
+
+  return true;
+};
+
 // TODO(indutny): use process.nextTick in node.js
 utils.nextTick = function nextTick(fn) {
   setTimeout(fn, 0);

lib/bcoin/wallet.js

@@ -56,7 +56,7 @@ Wallet.prototype.own = function own(tx) {
     return output.script.length === 5 &&
            output.script[0] === 'dup' &&
            output.script[1] === 'hash160' &&
-           utils.toHex(output.script[2]) === utils.toHex(this.getHash()) &&
+           utils.isEqual(output.script[2], this.getHash()) &&
            output.script[3] === 'eqverify' &&
            output.script[4] === 'checksig';
   }, this);
@@ -75,17 +75,15 @@ Wallet.prototype.sign = function sign(tx, type) {
 
   // Add signature script to each input
   inputs.forEach(function(input, i) {
-    var copy = tx.clone();
     var s = input.out.tx.getSubscript(input.out.index);
 
-    copy.inputs.forEach(function(input, j) {
-      input.script = i === j ? s : [];
-    });
+    var hash = tx.subscriptHash(i, s, type);
+    var signature = bcoin.ecdsa.sign(hash, this.key).toDER();
 
-    var verifyStr = copy.render();
-    verifyStr = verifyStr.concat(bcoin.protocol.constants.hashType[type]);
-    var hash = utils.dsha256(verifyStr);
-    var signature = this.key.sign(hash).toDER();
+    input.script = [
+      signature,
+      pub
+    ];
   }, this);
 
   return inputs.length;

package.json

@@ -22,8 +22,8 @@
   "homepage": "https://github.com/indutny/bcoin",
   "dependencies": {
     "async": "^0.8.0",
-    "bn.js": "^0.2.0",
-    "elliptic": "^0.7.0",
+    "bn.js": "^0.3.0",
+    "elliptic": "^0.8.0",
     "hash.js": "^0.2.0"
   },
   "devDependencies": {

test/wallet-test.js

@@ -29,9 +29,10 @@ describe('Wallet', function() {
     assert(w.own(src));
 
     var tx = bcoin.tx()
-      .input(src, 1)
+      .input(src, 0)
       .out(w.getAddress(), 5460);
 
     w.sign(tx);
+    assert(tx.validate());
   });
 });