Fix checksum comparison error. Closes #402

lib/Base58.js

@@ -95,7 +95,7 @@ var base58Check = {
     var hash = doubleSHA256(data);
     var hash4 = hash.slice(0, 4);
 
-    if (csum.toString() != hash4.toString()) {
+    if (csum.toString('hex') !== hash4.toString('hex')) {
       throw new Error("checksum mismatch");
     }
 

test/test.Address.js

@@ -22,6 +22,8 @@ describe('Address', function() {
     ['11111111111111111111111111122222234', false], // totally invalid
     ['32QBdjycLwbDTuGafUwaU5p5GxzSLPYoF6', true],
     ['1Q1pE5vPGEEMqRcVRMbtBK842Y6Pzo6nK9', true],
+    ['1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa', true],
+    ['1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNb', false], //bad checksum ... thanks @wtogami
     ['1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW62i', true],
     ['1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW600', false],  // bad checksum
     ['1AGNa15ZQXAZUgFiqJ2i7Z2DPU2J6hW620', false],  // bad checksum

test/test.Base58.js

@@ -1,4 +1,5 @@
 var chai = chai || require('chai');
+var should = chai.should();
 var assert = chai.assert;
 var bitcore = bitcore || require('../bitcore');
 var base58 = bitcore.Base58.base58;
@@ -50,4 +51,13 @@ describe('Base58', function() {
       base58Check.decodeTest(raw, b58Check);
     });
   });
+
+  describe('base58Check', function() {
+    it('should throw a checksum error on this invalid string', function() {
+      var str1 = "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa";
+      var str2 = "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNb"; //note last character
+      base58Check.decode(str1).length.should.be.greaterThan(0);
+      (function(){base58Check.decode(str2)}).should.throw('checksum mismatch');
+    });
+  });
 });