Adds BI.toPaddedBuffer and toBuffer

Author: dcousens

src/base58.js

@@ -55,12 +55,11 @@ function decode(string) {
     i++
   }
 
-  // FIXME: If BigInteger supported buffers, this could be a copy
-  var buffer = new Buffer(num.toByteArrayUnsigned())
-  var padding = new Buffer(i)
-  padding.fill(0)
+  var buffer = num.toBuffer()
+  var leadz = new Buffer(i)
+  leadz.fill(0)
 
-  return Buffer.concat([padding, buffer])
+  return Buffer.concat([leadz, buffer])
 }
 
 module.exports = {

src/bigi.js

@@ -1,7 +1,17 @@
 var assert = require('assert')
 var BigInteger = require('bigi')
 
+// Import operations
+BigInteger.fromHex = function(hex) {
+  var buffer = new Buffer(hex, 'hex')
+  assert.equal(buffer.length, Buffer.byteLength(hex) / 2)
+
+  return BigInteger.fromBuffer(buffer)
+}
+
 BigInteger.fromBuffer = function(buffer) {
+  assert(Array.isArray(buffer) || Buffer.isBuffer(buffer)) // FIXME: Transitionary
+
   // FIXME: Transitionary
   if (Buffer.isBuffer(buffer)) {
     buffer = Array.prototype.slice.call(buffer)
@@ -10,4 +20,21 @@ BigInteger.fromBuffer = function(buffer) {
   return BigInteger.fromByteArrayUnsigned(buffer)
 }
 
+// Export operations
+BigInteger.prototype.toBuffer = function() {
+  return new Buffer(this.toByteArrayUnsigned())
+}
+
+BigInteger.prototype.toHex = function() {
+  return this.toBuffer().toString('hex')
+}
+
+BigInteger.prototype.toPaddedBuffer = function(s) {
+    var buffer = this.toBuffer()
+    var padded = new Buffer(s - buffer.length)
+    padded.fill(0)
+
+    return Buffer.concat([padded, buffer], s)
+}
+
 module.exports = BigInteger

src/eckey.js

@@ -65,13 +65,7 @@ ECKey.prototype.sign = function(hash) {
 
 // Export functions
 ECKey.prototype.toBuffer = function() {
-  var buffer = new Buffer(this.D.toByteArrayUnsigned())
-
-  // pad out to atleast 32 bytes
-  var padded = new Buffer(32 - buffer.length)
-  padded.fill(0)
-
-  return Buffer.concat([padded, buffer])
+  return this.D.toPaddedBuffer(32)
 }
 ECKey.prototype.toHex = function() {
   return this.toBuffer().toString('hex')

src/message.js

@@ -25,25 +25,18 @@ function magicHash(message) {
 // TODO: parameterize compression instead of using ECKey.compressed
 function sign(key, message) {
   var hash = magicHash(message)
-  var sig = key.sign(hash)
-  var obj = ecdsa.parseSig(sig)
-  var i = ecdsa.calcPubKeyRecoveryParam(key.pub.Q, obj.r, obj.s, hash)
+  var sig = ecdsa.parseSig(key.sign(hash))
+  var i = ecdsa.calcPubKeyRecoveryParam(key.pub.Q, sig.r, sig.s, hash)
 
   i += 27
   if (key.pub.compressed) {
     i += 4
   }
 
-  var rBa = obj.r.toByteArrayUnsigned()
-  var sBa = obj.s.toByteArrayUnsigned()
+  var rB = sig.r.toPaddedBuffer(32)
+  var sB = sig.s.toPaddedBuffer(32)
 
-  // Pad to 32 bytes per value
-  while (rBa.length < 32) rBa.unshift(0);
-  while (sBa.length < 32) sBa.unshift(0);
-
-  sig = [i].concat(rBa, sBa)
-
-  return sig
+  return Buffer.concat([new Buffer([i]), rB, sB], 65)
 }
 
 // FIXME: stricter API?

test/bigi.js

@@ -0,0 +1,46 @@
+var assert = require('assert')
+var BigInteger = require('../').BigInteger
+
+var fixtures = require('./fixtures/bigi')
+
+describe('BigInteger', function() {
+  describe('fromBuffer/fromHex', function() {
+    it('should match the test vectors', function() {
+      fixtures.valid.forEach(function(f) {
+        assert.deepEqual(BigInteger.fromHex(f.hex).toString(), f.dec)
+        assert.deepEqual(BigInteger.fromHex(f.hexPadded).toString(), f.dec)
+      })
+    })
+
+    fixtures.invalid.forEach(function(f) {
+      it('throws on ' + f.description, function() {
+        assert.throws(function() {
+          BigInteger.fromHex(f.string)
+        })
+      })
+    })
+  })
+
+  describe('toBuffer/toHex', function() {
+    it('should match the test vectors', function() {
+      fixtures.valid.forEach(function(f) {
+        var actualHex = new BigInteger(f.dec).toHex()
+
+        assert.equal(actualHex, f.hex)
+      })
+    })
+  })
+
+  describe('toPaddedBuffer', function() {
+    it('should match the test vectors', function() {
+      fixtures.valid.forEach(function(f) {
+        var actualBuf = new BigInteger(f.dec).toPaddedBuffer(32)
+
+        assert.equal(actualBuf.length, 32)
+        assert.equal(actualBuf.toString('hex'), f.hexPadded)
+      })
+    })
+  })
+})
+
+module.exports = BigInteger

test/ecdsa.js

@@ -39,7 +39,7 @@ describe('ecdsa', function() {
       var sig_a = s1.sign([0])
 
       assert.ok(sig_a, 'Sign null')
-      assert.ok(s1.pub.verify(BigInteger.ZERO, sig_a))
+      assert.ok(s1.pub.verify([0], sig_a))
 
       var message = new Buffer(1024) // More or less random :P
       var hash = crypto.sha256(message)

test/fixtures/base58.js

@@ -71,4 +71,4 @@ module.exports = {
       "string": " \t\n\u000b\f\r skip \r\f\u000b\n\t a"
     }
   ]
-}
+}

test/fixtures/bigi.js

@@ -0,0 +1,46 @@
+module.exports = {
+  "valid": [
+    {
+      "dec": "1",
+      "hex": "01",
+      "hexPadded": "0000000000000000000000000000000000000000000000000000000000000001"
+    },
+    {
+      "dec": "158798437896437949616241483468158498679",
+      "hex": "77777777777777777777777777777777",
+      "hexPadded": "0000000000000000000000000000000077777777777777777777777777777777"
+    },
+    {
+      "dec": "115792089237316195423570985008687907852837564279074904382605163141518161494336",
+      "hex": "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140",
+      "hexPadded": "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140"
+    },
+    {
+      "dec": "48968302285117906840285529799176770990048954789747953886390402978935544927851",
+      "hex": "6c4313b03f2e7324d75e642f0ab81b734b724e13fec930f309e222470236d66b",
+      "hexPadded": "6c4313b03f2e7324d75e642f0ab81b734b724e13fec930f309e222470236d66b"
+    }
+  ],
+  "invalid": [
+    {
+      "description": "non-hex string",
+      "string": "invalid"
+    },
+    {
+      "description": "non-hex alphabet",
+      "string": "c2F0b3NoaQo="
+    },
+    {
+      "description": "internal whitespace",
+      "string": "11111 11111"
+    },
+    {
+      "description": "leading whitespace",
+      "string": " 1111111111"
+    },
+    {
+      "description": "trailing whitespace",
+      "string": "1111111111 "
+    }
+  ]
+}