expose signature internal functions

"sign" and "genk" ... and add some signature tests

lib/browser/Key.js

@@ -117,27 +117,6 @@ Key.prototype.regenerateSync = function() {
 Key.prototype.signSync = function(hash) {
   var ec = elliptic.curves.secp256k1;
 
-  var genk = function() {
-    //TODO: account for when >= n
-    return new bignum(SecureRandom.getRandomBuffer(8));
-  };
-
-  var sign = function(hash, priv) {
-    var d = priv;
-    var n = Point.getN();
-    var e = new bignum(hash);
-
-    do {
-      var k = genk();
-      var G = Point.getG();
-      var Q = Point.multiply(G, k);
-      var r = Q.x.mod(n);
-      var s = k.invm(n).mul(e.add(d.mul(r))).mod(n);
-    } while (r.cmp(new bignum(0)) <= 0 || s.cmp(new bignum(0)) <= 0);
-
-    return {r: r, s: s};
-  };
-
   if (!this.private) {
     throw new Error('Key does not have a private key set');
   }
@@ -146,7 +125,7 @@ Key.prototype.signSync = function(hash) {
     throw new Error('Arg should be a 32 bytes hash buffer');
   }
   var privnum = new bignum(this.private);
-  var sigrs = sign(hash, privnum);
+  var sigrs = Key.sign(hash, privnum);
   var der = Key.rs2DER(sigrs.r, sigrs.s);
 
   return der;

lib/common/Key.js

@@ -80,4 +80,25 @@ Key.rs2DER = function(r, s) {
   return der;
 };
 
+Key.sign = function(hash, priv, k) {
+  var d = priv;
+  var n = Point.getN();
+  var e = new bignum(hash);
+
+  do {
+    var k = k || Key.genk();
+    var G = Point.getG();
+    var Q = Point.multiply(G, k);
+    var r = Q.x.mod(n);
+    var s = k.invm(n).mul(e.add(d.mul(r))).mod(n);
+  } while (r.cmp(new bignum(0)) <= 0 || s.cmp(new bignum(0)) <= 0);
+
+  return {r: r, s: s};
+};
+
+Key.genk = function() {
+  //TODO: account for when >= n
+  return new bignum(SecureRandom.getRandomBuffer(8));
+};
+
 module.exports = Key;

test/test.Key.js

@@ -148,6 +148,38 @@ describe('Key (ECKey)', function() {
       parsed.sbuf.toString('hex').should.equal('0993a6ec81755b9111762fc2cf8e3ede73047515622792110867d12654275e72');
       parsed.s.toString().should.equal('4331694221846364448463828256391194279133231453999942381442030409253074198130');
     });
+
+    it('should parse this 69 byte signature', function() {
+      var sighex = '3043021f59e4705959cc78acbfcf8bd0114e9cc1b389a4287fb33152b73a38c319b50302202f7428a27284c757e409bf41506183e9e49dfb54d5063796dfa0d403a4deccfa';
+      var sig = new Buffer(sighex, 'hex');
+      var parsed = Key.parseDERsig(sig);
+      parsed.header.should.equal(0x30)
+      parsed.length.should.equal(67)
+      parsed.rlength.should.equal(31);
+      parsed.rneg.should.equal(false);
+      parsed.rbuf.toString('hex').should.equal('59e4705959cc78acbfcf8bd0114e9cc1b389a4287fb33152b73a38c319b503');
+      parsed.r.toString().should.equal('158826015856106182499128681792325160381907915189052224498209222621383996675');
+      parsed.slength.should.equal(32);
+      parsed.sneg.should.equal(false);
+      parsed.sbuf.toString('hex').should.equal('2f7428a27284c757e409bf41506183e9e49dfb54d5063796dfa0d403a4deccfa');
+      parsed.s.toString().should.equal('21463938592353267769710297084836796652964571266930856168996063301532842380538');
+    });
+
+    it('should parse this 68 byte signature', function() {
+      var sighex = '3042021e17cfe77536c3fb0526bd1a72d7a8e0973f463add210be14063c8a9c37632022061bfa677f825ded82ba0863fb0c46ca1388dd3e647f6a93c038168b59d131a51';
+      var sig = new Buffer(sighex, 'hex');
+      var parsed = Key.parseDERsig(sig);
+      parsed.header.should.equal(0x30)
+      parsed.length.should.equal(66)
+      parsed.rlength.should.equal(30);
+      parsed.rneg.should.equal(false);
+      parsed.rbuf.toString('hex').should.equal('17cfe77536c3fb0526bd1a72d7a8e0973f463add210be14063c8a9c37632');
+      parsed.r.toString().should.equal('164345250294671732127776123343329699648286106708464198588053542748255794');
+      parsed.slength.should.equal(32);
+      parsed.sneg.should.equal(false);
+      parsed.sbuf.toString('hex').should.equal('61bfa677f825ded82ba0863fb0c46ca1388dd3e647f6a93c038168b59d131a51');
+      parsed.s.toString().should.equal('44212963026209759051804639008236126356702363229859210154760104982946304432721');
+    });
   });
 
   describe('#rs2DER', function() {