Add claim encoding for payment channels

packages/ripple-binary-codec/src/binary.js

@@ -1,5 +1,6 @@
 /* eslint-disable func-style */
 
+const BN = require('bn.js');
 const types = require('./types');
 const {HashPrefix} = require('./hash-prefixes');
 const {BinaryParser} = require('./serdes/binary-parser');
@@ -30,6 +31,19 @@ function signingData(tx, prefix = HashPrefix.transactionSig) {
   return serializeObject(tx, {prefix, signingFieldsOnly: true});
 }
 
+function signingClaimData(claim) {
+  const prefix = HashPrefix.paymentChannelClaim
+  const channel = types.Hash256.from(claim.channel).toBytes()
+  const amount = new types.UInt64(new BN(claim.amount)).toBytes();
+
+  const bytesList = new BytesList();
+
+  bytesList.put(prefix)
+  bytesList.put(channel)
+  bytesList.put(amount)
+  return bytesList.toBytes()
+}
+
 function multiSigningData(tx, signingAccount) {
   const prefix = HashPrefix.transactionMultiSig;
   const suffix = types.AccountID.from(signingAccount).toBytes();
@@ -47,6 +61,7 @@ module.exports = {
   parseBytes,
   multiSigningData,
   signingData,
+  signingClaimData,
   binaryToJSON,
   sha512Half,
   transactionID,

packages/ripple-binary-codec/src/hash-prefixes.js

@@ -21,7 +21,9 @@ const HashPrefix = {
   // validation for signing
   validation: bytes(0x56414C00),
   // proposal for signing
-  proposal: bytes(0x50525000)
+  proposal: bytes(0x50525000),
+  // payment channel claim
+  paymentChannelClaim: bytes(0x434C4D00)
 };
 
 module.exports = {

packages/ripple-binary-codec/src/index.js

@@ -3,6 +3,7 @@ const coreTypes = require('./coretypes');
 const {quality,
        binary: {bytesToHex,
                 signingData,
+                signingClaimData,
                 multiSigningData,
                 binaryToJSON,
                 serializeObject}} = coreTypes;
@@ -22,6 +23,11 @@ function encodeForSigning(json) {
   return bytesToHex(signingData(json));
 }
 
+function encodeForSigningClaim(json) {
+  assert(typeof json === 'object');
+  return bytesToHex(signingClaimData(json));
+}
+
 function encodeForMultisigning(json, signer) {
   assert(typeof json === 'object');
   assert.equal(json.SigningPubKey, '');
@@ -42,6 +48,7 @@ module.exports = {
   decode,
   encode,
   encodeForSigning,
+  encodeForSigningClaim,
   encodeForMultisigning,
   encodeQuality,
   decodeQuality

packages/ripple-binary-codec/test/signing-data-encoding-test.js

@@ -1,6 +1,7 @@
 const _ = require('lodash');
 const assert = require('assert-diff');
-const {encodeForSigning, encodeForMultisigning} = require('../src');
+const {encodeForSigning, encodeForSigningClaim, encodeForMultisigning} =
+  require('../src');
 
 const tx_json = {
   Account: 'r9LqNeG6qHxjeUocjvVki2XR35weJ9mZgQ',
@@ -101,4 +102,19 @@ describe('Signing data', function() {
           'C0A5ABEF242802EFED4B041E8F2D4A8CC86AE3D1'].join('')
       );
   });
+  it('can create claim blob', function() {
+    const channel =
+      '43904CBFCDCEC530B4037871F86EE90BF799DF8D2E0EA564BC8A3F332E4F5FB1'
+    const amount = '1000'
+    const json = {channel, amount}
+    const actual = encodeForSigningClaim(json)
+    assert.equal(actual, [
+      // hash prefix
+      '434C4D00',
+      // channel ID
+      '43904CBFCDCEC530B4037871F86EE90BF799DF8D2E0EA564BC8A3F332E4F5FB1',
+      // amount as a uint64
+      '00000000000003E8'
+    ].join(''))
+  })
 });