Merge pull request #6413 from BitGo/BTC-2251.adding-prefix

refactor(utxo-core): Pay Go Functions prefix

Author: christopher-fong

modules/utxo-core/src/paygo/parsePayGoAttestation.ts

@@ -3,7 +3,8 @@ import assert from 'assert';
 import { bufferutils } from '@bitgo/utxo-lib';
 
 // The signed address will always have the following structure:
-// <varint_length><ENTROPY><ADDRESS><UUID>
+// 0x18Bitcoin Signed Message:\n<varint_length><ENTROPY><ADDRESS><UUID>
+export const Prefix = Buffer.from('\u0018Bitcoin Signed Message:\n', 'utf-8');
 
 // UUID has the structure 00000000-0000-0000-0000-000000000000, and after
 // we Buffer.from and get it's length its 36.
@@ -32,6 +33,9 @@ export function parsePayGoAttestation(message: Buffer): {
   // This generates the first part before the varint length so that we can
   // determine how many bytes this is and iterate through the Buffer.
   let offset = 0;
+  if (message.toString('hex').startsWith(Prefix.toString('hex'))) {
+    offset = Prefix.length;
+  }
 
   // we decode the varint of the message which is uint32
   // https://en.bitcoin.it/wiki/Protocol_documentation

modules/utxo-core/src/testutil/generatePayGoAttestationProof.utils.ts

@@ -1,6 +1,9 @@
 import crypto from 'crypto';
 
 import { bufferutils } from '@bitgo/utxo-lib';
+
+import { Prefix } from '../paygo';
+
 /** We have a mirrored function similar to our hsm that generates our Bitcoin signed
  * message so that we can use for testing. This creates a random entropy as well using
  * the nilUUID structure to construct our uuid buffer and given our address we can
@@ -11,7 +14,7 @@ import { bufferutils } from '@bitgo/utxo-lib';
  * @param address
  * @returns
  */
-export function generatePayGoAttestationProof(uuid: string, address: Buffer): Buffer {
+export function generatePayGoAttestationProof(uuid: string, address: Buffer, hasPrefix = true): Buffer {
   // <ENTROPY>
   const entropyLength = 64;
   const entropy = crypto.randomBytes(entropyLength);
@@ -27,8 +30,10 @@ export function generatePayGoAttestationProof(uuid: string, address: Buffer): Bu
   const msgLength = entropyLength + addressBufferLength + uuidBufferLength;
   const msgLengthBuffer = bufferutils.varuint.encode(msgLength);
 
-  // <0x18Bitcoin Signed Message:\n<LENGTH><ENTROPY><ADDRESS><UUID>
+  // <LENGTH><ENTROPY><ADDRESS><UUID>
   const proofMessage = Buffer.concat([msgLengthBuffer, entropy, address, uuidBuffer]);
 
-  return proofMessage;
+  // If hasPrefix, we return 0x18Bitcoin Signed Message:\n<proof> otherwise its just <proof>
+  // where <proof> = <VARINT_LEN><ENTROPY><ADDRESS><UUID>
+  return hasPrefix ? Buffer.concat([Prefix, proofMessage]) : proofMessage;
 }

modules/utxo-core/test/paygo/parsePayGoAttestation.ts

@@ -2,46 +2,54 @@ import * as assert from 'assert';
 
 import { parsePayGoAttestation } from '../../src/paygo';
 import { generatePayGoAttestationProof } from '../../src/testutil';
+import { NIL_UUID } from '../../src/paygo/attestation';
 
 const addressFromPubKeyBase58 = 'bitgoAddressToExtract';
 const bufferAddressPubKeyB58 = Buffer.from(addressFromPubKeyBase58);
 
-describe('extractAddressBufferFromPayGoAttestationProof', () => {
-  it('should extractAddressBufferFromPayGoAttestationProof properly', () => {
-    const paygoAttestationProof = generatePayGoAttestationProof(
-      '00000000-0000-0000-0000-000000000000',
-      bufferAddressPubKeyB58
-    );
+describe('parsePayGoAttestationProof with prefix', () => {
+  it('should extractAddressBufferFromPayGoAttestationProof properly', function () {
+    const paygoAttestationProof = generatePayGoAttestationProof(NIL_UUID, bufferAddressPubKeyB58);
     const { entropy, address, uuid } = parsePayGoAttestation(paygoAttestationProof);
-    assert.deepStrictEqual(Buffer.compare(address, bufferAddressPubKeyB58), 0);
-    assert.deepStrictEqual(uuid.toString(), '00000000-0000-0000-0000-000000000000');
+    assert.ok(address.equals(bufferAddressPubKeyB58));
+    assert.deepStrictEqual(uuid.toString(), NIL_UUID);
     assert.deepStrictEqual(entropy.length, 64);
   });
 
-  it('should extract the paygo address paygo attestation proof given a non nilUUID', () => {
+  it('should extract the paygo address paygo attestation proof given a non nilUUID', function () {
     const paygoAttestationProof = generatePayGoAttestationProof(
       '12345678-1234-4567-6890-231928472123',
       bufferAddressPubKeyB58
     );
     const { entropy, address, uuid } = parsePayGoAttestation(paygoAttestationProof);
-    assert.deepStrictEqual(Buffer.compare(address, bufferAddressPubKeyB58), 0);
-    assert.deepStrictEqual(uuid.toString(), '12345678-1234-4567-6890-231928472123');
+    assert.ok(address.equals(bufferAddressPubKeyB58));
+    assert.deepStrictEqual(uuid.toString('utf-8'), '12345678-1234-4567-6890-231928472123');
     assert.deepStrictEqual(entropy.length, 64);
   });
 
-  it('should not extract the correct address given a uuid of wrong format', () => {
+  it('should not extract the correct address given a uuid of wrong format', function () {
     const paygoAttestationProof = generatePayGoAttestationProof(
       '000000000000000-000000-0000000-000000-0000000000000000',
       bufferAddressPubKeyB58
     );
     const { address } = parsePayGoAttestation(paygoAttestationProof);
-    assert.notDeepStrictEqual(Buffer.compare(address, bufferAddressPubKeyB58), 0);
+    assert.ok(!address.equals(bufferAddressPubKeyB58));
   });
 
-  it('should throw an error if the paygo attestation proof is too short', () => {
+  it('should throw an error if the paygo attestation proof is too short', function () {
     assert.throws(
-      () => parsePayGoAttestation(Buffer.from('shortproof-shrug')),
+      () => parsePayGoAttestation(Buffer.from('shortproof-shrug', 'utf-8')),
       'PayGo attestation proof is too short to contain a valid address.'
     );
   });
 });
+
+describe('parsePayGoAttestation without prefix', function () {
+  it('should extract the parts of the proof without the prefix automatically', function () {
+    const payGoAttestationProof = generatePayGoAttestationProof(NIL_UUID, bufferAddressPubKeyB58, false);
+    const { entropy, address, uuid } = parsePayGoAttestation(payGoAttestationProof);
+    assert.ok(address.equals(bufferAddressPubKeyB58));
+    assert.deepStrictEqual(uuid.toString(), NIL_UUID);
+    assert.deepStrictEqual(entropy.length, 64);
+  });
+});