Merge pull request #2 from matiu/feat/sigutils

add signutils

lib/signutils.js

@@ -0,0 +1,45 @@
+
+var _ = require('lodash');
+var Bitcore = require('bitcore');
+var PrivateKey = Bitcore.PrivateKey;
+var PublicKey = Bitcore.PublicKey;
+var Signature = Bitcore.crypto.Signature;
+var ECDSA = Bitcore.crypto.ECDSA;
+var Hash = Bitcore.crypto.Hash;
+var BufferReader = Bitcore.encoding.BufferReader;
+
+  
+
+var SignUtils = function () {
+};
+
+/* TODO: It would be nice to be compatible with bitcoind signmessage. How
+ * the hash is calculated there? */
+SignUtils.hash = function (text) {
+  var buf = new Buffer(text);
+  var ret = Hash.sha256sha256(buf);
+  ret = new BufferReader(ret).readReverse();
+  return ret;
+};
+
+
+SignUtils.sign = function (text, privKey) {
+  var priv = new PrivateKey(privKey);
+  var hash = SignUtils.hash(text);
+  return ECDSA.sign(hash, priv, 'little').toString();
+};
+
+
+SignUtils.verify = function (text, signature, pubKey) {
+  var pub = new PublicKey(pubKey);
+  var hash = SignUtils.hash(text);
+
+  try {
+    var sig = new Signature.fromString(signature);
+    return ECDSA.verify(hash, sig, pub, 'little');
+  } catch (e) {
+    return false;
+  }
+};
+
+module.exports = SignUtils;

test/signutils.js

@@ -0,0 +1,69 @@
+'use strict';
+
+var _ = require('lodash');
+var chai = require('chai');
+var sinon = require('sinon');
+var should = chai.should();
+var SignUtils = require('../lib/signutils');
+
+
+var aText = 'hola';
+var aPubKey = '03bec86ad4a8a91fe7c11ec06af27246ec55094db3d86098b7d8b2f12afe47627f';
+var aPrivKey = '09458c090a69a38368975fb68115df2f4b0ab7d1bc463fc60c67aa1730641d6c';
+var aSignature = '3045022100d6186930e4cd9984e3168e15535e2297988555838ad10126d6c20d4ac0e74eb502201095a6319ea0a0de1f1e5fb50f7bf10b8069de10e0083e23dbbf8de9b8e02785';
+
+var otherPubKey = '02555a2d45e309c00cc8c5090b6ec533c6880ab2d3bc970b3943def989b3373f16';
+
+describe('SignUtils', function() {
+
+  describe('#hash', function() {
+    it('Should create a hash', function() {
+      var res = SignUtils.hash(aText);
+      res.toString('hex').should.equal('4102b8a140ec642feaa1c645345f714bc7132d4fd2f7f6202db8db305a96172f');
+    });
+  });
+
+  describe('#sign', function() {
+    it('Should sign', function() {
+      var sig = SignUtils.sign(aText, aPrivKey);
+      should.exist(sig);
+      sig.should.equal(aSignature);
+    });
+    it('Should fail to sign with wrong args', function() {
+      (function() {
+        SignUtils.sign(aText, aPubKey);
+      }).should.throw('Number');
+    });
+  });
+
+  describe('#verify', function() {
+    it('Should fail to verify a malformed signature', function() {
+      var res = SignUtils.verify(aText, 'badsignature', otherPubKey);
+      should.exist(res);
+      res.should.equal(false);
+    });
+    it('Should fail to verify a null signature', function() {
+      var res = SignUtils.verify(aText, null, otherPubKey);
+      should.exist(res);
+      res.should.equal(false);
+    });
+    it('Should fail to verify with wrong pubkey', function() {
+      var res = SignUtils.verify(aText, aSignature, otherPubKey);
+      should.exist(res);
+      res.should.equal(false);
+    });
+    it('Should verify', function() {
+      var res = SignUtils.verify(aText, aSignature, aPubKey);
+      should.exist(res);
+      res.should.equal(true);
+    });
+  });
+  describe('#sign #verify round trip', function() {
+    it('Should sign and verify', function() {
+      var aLongerText = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.";
+      var sig = SignUtils.sign(aLongerText, aPrivKey);
+      SignUtils.verify(aLongerText, sig, aPubKey).should.equal(true);
+    });
+  });
+
+});