ECPair/script_signature: switch to 64-byte RS buffers only

src/ecpair.js

@@ -115,7 +115,8 @@ ECPair.prototype.getPublicKeyBuffer = function () {
 ECPair.prototype.sign = function (hash) {
   if (!this.d) throw new Error('Missing private key')
 
-  return ecdsa.sign(hash, this.d)
+  let signature = ecdsa.sign(hash, this.d)
+  return Buffer.concat([signature.r.toBuffer(32), signature.s.toBuffer(32)], 64)
 }
 
 ECPair.prototype.toWIF = function () {
@@ -125,6 +126,11 @@ ECPair.prototype.toWIF = function () {
 }
 
 ECPair.prototype.verify = function (hash, signature) {
+  signature = {
+    r: BigInteger.fromBuffer(signature.slice(0, 32)),
+    s: BigInteger.fromBuffer(signature.slice(32, 64))
+  }
+
   return ecdsa.verify(hash, signature, this.Q)
 }
 

src/script_signature.js

@@ -1,50 +1,56 @@
-var bip66 = require('bip66')
-var BigInteger = require('bigi')
-var Buffer = require('safe-buffer').Buffer
-var typeforce = require('typeforce')
-var types = require('./types')
+let bip66 = require('bip66')
+let Buffer = require('safe-buffer').Buffer
+let typeforce = require('typeforce')
+let types = require('./types')
+
+let ZERO = Buffer.alloc(1, 0)
+function toDER (x) {
+  let i = 0
+  while (x[i] === 0) ++i
+  if (i === x.length) return ZERO
+  x = x.slice(i)
+  if (x[0] & 0x80) return Buffer.concat([ZERO, x], 1 + x.length)
+  return x
+}
+
+function fromDER (x) {
+  if (x[0] === 0x00) x = x.slice(1)
+  let buffer = Buffer.alloc(32, 0)
+  let bstart = Math.max(0, 32 - x.length)
+  x.copy(buffer, bstart)
+  return buffer
+}
 
 // BIP62: 1 byte hashType flag (only 0x01, 0x02, 0x03, 0x81, 0x82 and 0x83 are allowed)
 function decode (buffer) {
-  var hashType = buffer.readUInt8(buffer.length - 1)
-  var hashTypeMod = hashType & ~0x80
+  let hashType = buffer.readUInt8(buffer.length - 1)
+  let hashTypeMod = hashType & ~0x80
   if (hashTypeMod <= 0 || hashTypeMod >= 4) throw new Error('Invalid hashType ' + hashType)
 
-  var decode = bip66.decode(buffer.slice(0, -1))
+  let decode = bip66.decode(buffer.slice(0, -1))
+  let r = fromDER(decode.r)
+  let s = fromDER(decode.s)
 
   return {
-    signature: {
-      r: BigInteger.fromDERInteger(decode.r),
-      s: BigInteger.fromDERInteger(decode.s)
-    },
+    signature: Buffer.concat([r, s], 64),
     hashType: hashType
   }
 }
 
-function toRSBuffer (signature, buffer, offset) {
-  buffer = buffer || Buffer.alloc(64)
-  signature.r.toBuffer(32).copy(buffer, offset)
-  signature.s.toBuffer(32).copy(buffer, offset + 32)
-  return buffer
-}
-
-function fromRSBuffer (buffer) {
-  typeforce(types.BufferN(64), buffer)
-
-  var r = BigInteger.fromBuffer(buffer.slice(0, 32))
-  var s = BigInteger.fromBuffer(buffer.slice(32, 64))
-  return { r: r, s: s }
-}
-
 function encode (signature, hashType) {
-  var hashTypeMod = hashType & ~0x80
+  typeforce({
+    signature: types.BufferN(64),
+    hashType: types.UInt8
+  }, { signature, hashType })
+
+  let hashTypeMod = hashType & ~0x80
   if (hashTypeMod <= 0 || hashTypeMod >= 4) throw new Error('Invalid hashType ' + hashType)
 
-  var hashTypeBuffer = Buffer.allocUnsafe(1)
+  let hashTypeBuffer = Buffer.allocUnsafe(1)
   hashTypeBuffer.writeUInt8(hashType, 0)
 
-  var r = Buffer.from(signature.r.toDERInteger())
-  var s = Buffer.from(signature.s.toDERInteger())
+  let r = toDER(signature.slice(0, 32))
+  let s = toDER(signature.slice(32, 64))
 
   return Buffer.concat([
     bip66.encode(r, s),
@@ -53,8 +59,6 @@ function encode (signature, hashType) {
 }
 
 module.exports = {
-  fromRSBuffer: fromRSBuffer,
-  toRSBuffer: toRSBuffer,
   decode: decode,
   encode: encode
 }

src/transaction_builder.js

@@ -715,9 +715,7 @@ TransactionBuilder.prototype.sign = function (vin, keyPair, redeemScript, hashTy
       input.prevOutType === scriptTypes.P2WSH
     )) throw new Error('BIP143 rejects uncompressed public keys in P2WPKH or P2WSH')
 
-    var signature = keyPair.sign(signatureHash)
-    if (Buffer.isBuffer(signature)) signature = bscript.signature.fromRSBuffer(signature)
-
+    let signature = keyPair.sign(signatureHash)
     input.signatures[i] = bscript.signature.encode(signature, hashType)
     return true
   })

test/ecpair.js

@@ -230,6 +230,7 @@ describe('ECPair', function () {
         this.mock(ecdsa, 'sign', function (h, d) {
           assert.strictEqual(h, hash)
           assert.strictEqual(d, keyPair.d)
+          return { r: BigInteger.ONE, s: BigInteger.ONE }
         }, 1)
 
         keyPair.sign(hash)
@@ -254,7 +255,11 @@ describe('ECPair', function () {
       it('wraps ecdsa.verify', hoodwink(function () {
         this.mock(ecdsa, 'verify', function (h, s, q) {
           assert.strictEqual(h, hash)
-          assert.strictEqual(s, signature)
+//            assert.strictEqual(s, signature)
+          assert.deepEqual(s, {
+            r: BigInteger.fromBuffer(signature.slice(0, 32)),
+            s: BigInteger.fromBuffer(signature.slice(32, 64))
+          })
           assert.strictEqual(q, keyPair.Q)
         }, 1)
 

test/fixtures/signature.json

@@ -4,56 +4,56 @@
       "hashType": 1,
       "hex": "3044022033a69cd2065432a30f3d1ce4eb0d59b8ab58c74f27c41a7fdb5696ad4e6108c902206f807982866f785d3f6418d24163ddae117b7db4d5fdf0071de069fa5434226201",
       "raw": {
-        "r": "23362334225185207751494092901091441011938859014081160902781146257181456271561",
-        "s": "50433721247292933944369538617440297985091596895097604618403996029256432099938"
+        "r": "33a69cd2065432a30f3d1ce4eb0d59b8ab58c74f27c41a7fdb5696ad4e6108c9",
+        "s": "6f807982866f785d3f6418d24163ddae117b7db4d5fdf0071de069fa54342262"
       }
     },
     {
       "hashType": 2,
       "hex": "3044022054c4a33c6423d689378f160a7ff8b61330444abb58fb470f96ea16d99d4a2fed022007082304410efa6b2943111b6a4e0aaa7b7db55a07e9861d1fb3cb1f421044a502",
       "raw": {
-        "r": "38341707918488238920692284707283974715538935465589664377561695343399725051885",
-        "s": "3180566392414476763164587487324397066658063772201694230600609996154610926757"
+        "r": "54c4a33c6423d689378f160a7ff8b61330444abb58fb470f96ea16d99d4a2fed",
+        "s": "07082304410efa6b2943111b6a4e0aaa7b7db55a07e9861d1fb3cb1f421044a5"
       }
     },
     {
       "hashType": 3,
       "hex": "3045022100ff466a9f1b7b273e2f4c3ffe032eb2e814121ed18ef84665d0f515360dab3dd002206fc95f5132e5ecfdc8e5e6e616cc77151455d46ed48f5589b7db7771a332b28303",
       "raw": {
-        "r": "115464191557905790016094131873849783294273568009648050793030031933291767741904",
-        "s": "50562520307781850052192542766631199590053690478900449960232079510155113443971"
+        "r": "ff466a9f1b7b273e2f4c3ffe032eb2e814121ed18ef84665d0f515360dab3dd0",
+        "s": "6fc95f5132e5ecfdc8e5e6e616cc77151455d46ed48f5589b7db7771a332b283"
       }
     },
     {
       "hashType": 129,
       "hex": "3045022100c0dafec8251f1d5010289d210232220b03202cba34ec11fec58b3e93a85b91d3022075afdc06b7d6322a590955bf264e7aaa155847f614d80078a90292fe205064d381",
       "raw": {
-        "r": "87230998027579607140680851455601772643840468630989315269459846730712163783123",
-        "s": "53231320085894623106179381504478252331065330583563809963303318469380290929875"
+        "r": "c0dafec8251f1d5010289d210232220b03202cba34ec11fec58b3e93a85b91d3",
+        "s": "75afdc06b7d6322a590955bf264e7aaa155847f614d80078a90292fe205064d3"
       }
     },
     {
       "hashType": 130,
       "hex": "304402207186363571d65e084e7f02b0b77c3ec44fb1b257dee26274c38c928986fea45d02200de0b38e06807e46bda1f1e293f4f6323e854c86d58abdd00c46c16441085df682",
       "raw": {
-        "r": "51348483531757779992459563033975330355971795607481991320287437101831125115997",
-        "s": "6277080015686056199074771961940657638578000617958603212944619747099038735862"
+        "r": "7186363571d65e084e7f02b0b77c3ec44fb1b257dee26274c38c928986fea45d",
+        "s": "0de0b38e06807e46bda1f1e293f4f6323e854c86d58abdd00c46c16441085df6"
       }
     },
     {
       "hashType": 131,
       "hex": "3045022100fbfe5076a15860ba8ed00e75e9bd22e05d230f02a936b653eb55b61c99dda48702200e68880ebb0050fe4312b1b1eb0899e1b82da89baa5b895f612619edf34cbd3783",
       "raw": {
-        "r": "113979859486826658566290715281614250298918272782414232881639314569529560769671",
-        "s": "6517071009538626957379450615706485096874328019806177698938278220732027419959"
+        "r": "fbfe5076a15860ba8ed00e75e9bd22e05d230f02a936b653eb55b61c99dda487",
+        "s": "0e68880ebb0050fe4312b1b1eb0899e1b82da89baa5b895f612619edf34cbd37"
       }
     },
     {
       "hashType": 129,
       "hex": "3045022100cde1302d83f8dd835d89aef803c74a119f561fbaef3eb9129e45f30de86abbf9022006ce643f5049ee1f27890467b77a6a8e11ec4661cc38cd8badf90115fbd03cef81",
       "raw": {
-        "r": "93122007060065279508564838030979550535085999589142852106617159184757394422777",
-        "s": "3078539468410661027472930027406594684630312677495124015420811882501887769839"
+        "r": "cde1302d83f8dd835d89aef803c74a119f561fbaef3eb9129e45f30de86abbf9",
+        "s": "06ce643f5049ee1f27890467b77a6a8e11ec4661cc38cd8badf90115fbd03cef"
       }
     }
   ],
@@ -123,8 +123,8 @@
       "hashType": 7,
       "hex": "3044022033a69cd2065432a30f3d1ce4eb0d59b8ab58c74f27c41a7fdb5696ad4e6108c902206f807982866f785d3f6418d24163ddae117b7db4d5fdf0071de069fa5434226207",
       "raw": {
-        "r": "23362334225185207751494092901091441011938859014081160902781146257181456271561",
-        "s": "50433721247292933944369538617440297985091596895097604618403996029256432099938"
+        "r": "33a69cd2065432a30f3d1ce4eb0d59b8ab58c74f27c41a7fdb5696ad4e6108c9",
+        "s": "6f807982866f785d3f6418d24163ddae117b7db4d5fdf0071de069fa54342262"
       }
     },
     {
@@ -132,8 +132,8 @@
       "hashType": 140,
       "hex": "3044022033a69cd2065432a30f3d1ce4eb0d59b8ab58c74f27c41a7fdb5696ad4e6108c902206f807982866f785d3f6418d24163ddae117b7db4d5fdf0071de069fa543422628c",
       "raw": {
-        "r": "23362334225185207751494092901091441011938859014081160902781146257181456271561",
-        "s": "50433721247292933944369538617440297985091596895097604618403996029256432099938"
+        "r": "33a69cd2065432a30f3d1ce4eb0d59b8ab58c74f27c41a7fdb5696ad4e6108c9",
+        "s": "6f807982866f785d3f6418d24163ddae117b7db4d5fdf0071de069fa54342262"
       }
     }
   ]

test/integration/crypto.js

@@ -43,12 +43,14 @@ describe('bitcoinjs-lib (crypto)', function () {
         var inputB = tx.ins[j]
 
         // enforce matching r values
-        assert.strictEqual(inputA.signature.r.toString(), inputB.signature.r.toString())
-        var r = inputA.signature.r
-        var rInv = r.modInverse(n)
+        let r = inputA.signature.slice(0, 32)
+        let rB = inputB.signature.slice(0, 32)
+        assert.strictEqual(r.toString('hex'), rB.toString('hex'))
 
-        var s1 = inputA.signature.s
-        var s2 = inputB.signature.s
+        var rInv = bigi.fromBuffer(r).modInverse(n)
+
+        var s1 = bigi.fromBuffer(inputA.signature.slice(32, 64))
+        var s2 = bigi.fromBuffer(inputB.signature.slice(32, 64))
         var z1 = inputA.z
         var z2 = inputB.z
 

test/script_signature.js

@@ -2,22 +2,21 @@
 
 var assert = require('assert')
 var bscriptSig = require('../src/script').signature
-var BigInteger = require('bigi')
 var Buffer = require('safe-buffer').Buffer
 var fixtures = require('./fixtures/signature.json')
 
 describe('Script Signatures', function () {
   function fromRaw (signature) {
-    return {
-      r: new BigInteger(signature.r),
-      s: new BigInteger(signature.s)
-    }
+    return Buffer.concat([
+      Buffer.from(signature.r, 'hex'),
+      Buffer.from(signature.s, 'hex')
+    ], 64)
   }
 
   function toRaw (signature) {
     return {
-      r: signature.r.toString(),
-      s: signature.s.toString()
+      r: signature.slice(0, 32).toString('hex'),
+      s: signature.slice(32, 64).toString('hex')
     }
   }