Merge pull request #112 from matiu/feature/sign-verify-browser

Feature/sign verify browser

Key.js

@@ -1,6 +1,5 @@
 
 
-
 if (process.versions) {
   // c++ native version
   module.exports = require('bindings')('KeyModule');
@@ -8,29 +7,95 @@ if (process.versions) {
   // pure js version
   var ECKey = require('./browser/bitcoinjs-lib.js').ECKey;
   var buffertools = require('buffertools');
-  var kSpec = function(compressed, public, private) {
-    this.compressed = compressed;
-    this.public = public;
-    this.private = private;
+
+  var bufferToArray = function(buffer) {
+    var ret = [];
+
+    var l = buffer.length;
+    for(var i =0; i<l; i++) {
+      ret.push(buffer.readUInt8(i));
+    }
+
+    return ret;
+  }
+
+  var kSpec = function() {
+    this._pub = null;
   };
 
+
+  Object.defineProperty(kSpec.prototype, 'public', {
+    set: function(p){
+      if (!Buffer.isBuffer(p) ) {
+        throw new Error('Arg should be a buffer');
+      }
+      var type = p[0];
+      this.compressed = type!==4;
+      this._pub = p;
+    },
+    get: function(){
+      return this._pub;
+    }
+  });
+
   kSpec.generateSync = function() {
     var eck = new ECKey();
     eck.setCompressed(true);
     var pub = eck.getPub();
-    
-    var ret = new this(true, new Buffer(pub), new Buffer(eck.priv.toByteArrayUnsigned()));
-    ret.eck = eck;
+
+    var ret = new kSpec();
+    ret.private = new Buffer(eck.priv.toByteArrayUnsigned());
+    ret.public  = new Buffer(pub);
     return ret;
   };
 
   kSpec.prototype.regenerateSync = function() {
-    this.eck = new ECKey(buffertools.toHex(this.private));
-    this.eck.setCompressed(true);
-    this.public = new Buffer(this.eck.getPub());
+    if (!this.private) {
+      throw new Error('Key does not have a private key set');
+    }
+
+    var eck = new ECKey(buffertools.toHex(this.private));
+    eck.setCompressed(this.compressed);
+    this.public = new Buffer(eck.getPub());
     return this;
   };
 
+  kSpec.prototype.signSync = function(hash) {
+    if (!this.private) {
+      throw new Error('Key does not have a private key set');
+    }
+
+    if (!Buffer.isBuffer(hash) || hash.length !== 32) {
+      throw new Error('Arg should be a 32 bytes hash buffer');
+    }
+    var eck = new ECKey(buffertools.toHex(this.private));
+    eck.setCompressed(this.compressed);
+    var signature = eck.sign(hash);
+    // return it as a buffer to keep c++ compatibility
+    return new Buffer(signature);
+  };
+
+  kSpec.prototype.verifySignatureSync = function(hash, sig) {
+    var self = this;
+
+    if (!Buffer.isBuffer(hash) || hash.length !== 32) {
+      throw new Error('Arg 1 should be a 32 bytes hash buffer');
+    }
+    if (!Buffer.isBuffer(sig)) {
+      throw new Error('Arg 2 should be a buffer');
+    }
+    if (!self.public) {
+      throw new Error('Key does not have a public key set');
+    }
+
+    var eck = new ECKey();
+    eck.setPub( bufferToArray(self.public));
+    eck.setCompressed(self.compressed);
+    var sigA = bufferToArray(sig);
+    return eck.verify(hash,sigA);
+  };
+
+
   module.exports = {
     Key: kSpec
   };

browser/bitcoinjs-lib.js

@@ -2286,26 +2286,37 @@ ECPointFp.prototype.getEncoded = function (compressed) {
   return enc;
 };
 
-ECPointFp.decodeFrom = function (curve, enc) {
+ECPointFp.decodeFrom = function (ecparams, enc) {
   var type = enc[0];
   var dataLen = enc.length-1;
 
   // Extract x and y as byte arrays
-  var xBa = enc.slice(1, 1 + dataLen/2);
-  var yBa = enc.slice(1 + dataLen/2, 1 + dataLen);
-
-  // Prepend zero byte to prevent interpretation as negative integer
-  xBa.unshift(0);
-  yBa.unshift(0);
-
-  // Convert to BigIntegers
-  var x = new BigInteger(xBa);
-  var y = new BigInteger(yBa);
+  if (type == 4) {
+    var xBa = enc.slice(1, 1 + dataLen/2),
+        yBa = enc.slice(1 + dataLen/2, 1 + dataLen),
+        x = BigInteger.fromByteArrayUnsigned(xBa),
+        y = BigInteger.fromByteArrayUnsigned(yBa);
+  }
+  else {
+    var xBa = enc.slice(1),
+        x = BigInteger.fromByteArrayUnsigned(xBa),
+        p = ecparams.getQ(),
+        xCubedPlus7 = x.multiply(x).multiply(x).add(new BigInteger('7')).mod(p),
+        pPlus1Over4 = p.add(new BigInteger('1'))
+                       .divide(new BigInteger('4')),
+        y = xCubedPlus7.modPow(pPlus1Over4,p);
+    if (y.mod(new BigInteger('2')).toString() != ''+(type % 2)) {
+        y = p.subtract(y)
+    }
+  }
 
   // Return point
-  return new ECPointFp(curve, curve.fromBigInteger(x), curve.fromBigInteger(y));
+  return new ECPointFp(ecparams,
+                       ecparams.fromBigInteger(x),
+                       ecparams.fromBigInteger(y));
 };
 
+
 ECPointFp.prototype.add2D = function (b) {
   if(this.isInfinity()) return b;
   if(b.isInfinity()) return this;

examples/example.html

@@ -11,7 +11,7 @@
 
     <script type="text/javascript">
 
-      console.log = function(s){
+      print = function(s){
         var div = document.getElementById('content');
         div.innerHTML += s + '<br />';
       };
@@ -31,13 +31,22 @@
 
         try {
           addr.validate();
-          console.log(addr.data + ": is a valid address");
+          print(addr.data + ": is a valid address");
         } catch(e) {
-          console.log(addr.data + ": is not a valid address.");
+          print(addr.data + ": is not a valid address.");
         }
     
       });
 
+
+      var Key = bitcore.KeyModule.Key;
+      var k = Key.generateSync();
+
+      print ('Generated Key Pair:');
+      print ('Private:' + bitcore.buffertools.toHex(k.private));
+      print ('Public:'  + bitcore.buffertools.toHex(k.public));
+      
+
     </script>
   </body>
 </html>

test/test.Key.js

@@ -17,6 +17,7 @@ describe('Key', function() {
     Key = KeyModule.Key;
     should.exist(Key);
   });
+  Key = KeyModule.Key;
   it('should be able to create instance', function() {
     var k = new Key();
     should.exist(k);
@@ -55,7 +56,40 @@ describe('Key', function() {
     buffertools.toHex(k.private).should.equal(pkshex);
     buffertools.toHex(k.public).should.equal(pubhex);
   });
+  it('should not fail checking good signSync status', function() {
+    var k = Key.generateSync();
+    var b = new Buffer(32);
+    k.signSync.bind(k,b).should.not.Throw(Error);
+  });
+  it('should fail checking bad signSync params', function() {
+    var k = Key.generateSync();
+    k.signSync.bind(k,'1').should.Throw(Error);
+    k.signSync.bind(k,new Buffer(10)).should.Throw(Error);
+    k.signSync.bind(k,new Buffer(32)).should.not.Throw(Error);
+  });
 
+  var a_hash = buffertools.fromHex(new Buffer('1122334455667788990011223344556677889900112233445566778899001122'));
 
+  it('should create a signature without failling', function() {
+    var k = Key.generateSync();
+    var pkshex = 'b7dafe35d7d1aab78b53982c8ba554584518f86d50af565c98e053613c8f15e0';
+    k.private = buffertools.fromHex(new Buffer(pkshex));
+    k.regenerateSync();
+    k.compressed.should.be.ok;
+    buffertools.toHex(k.private).should.equal(pkshex);
+    k.signSync.bind(k,a_hash).should.not.Throw(Error);
+  });
+  it('roundtrip for signature/verify', function() {
+    var k = Key.generateSync();
+    var pub = k.public;
 
+    // sign 
+    var sig = k.signSync(a_hash);
+
+    // checks sig. priv unknown.
+    var k2 = new Key();
+    k2.public = pub;
+    var ret= k2.verifySignatureSync(a_hash, sig);
+    ret.should.equal(true);
+  });
 });