[ripple-binary-codec] fix ISO when parsing currency code (#1921)

packages/ripple-binary-codec/HISTORY.md

@@ -2,10 +2,13 @@
 
 ## Unreleased
 ### Added
-- Exported `TRANSACTION_TYPES` value 
+- Exported `TRANSACTION_TYPES` value
 ### Fixed
 - Adds missing fields from XLS-20 NFT implementation
 
+## 1.2.3 (2022-2-2)
+- Fix issue where ISO is invalid when parsing currency code
+
 ## 1.2.2 (2021-12-2)
 - Fix issue where unsupported currency codes weren't being correctly processed
 - Added a workaround for rippled UNLModify encoding bug (#1830)

packages/ripple-binary-codec/src/types/currency.ts

@@ -1,8 +1,11 @@
 import { Hash160 } from './hash-160'
 import { Buffer } from 'buffer/'
 
+const XRP_HEX_REGEX = /^0{40}$/
 const ISO_REGEX = /^[A-Z0-9]{3}$/
 const HEX_REGEX = /^[A-F0-9]{40}$/
+// eslint-disable-next-line no-control-regex
+const STANDARD_FORMAT_HEX_REGEX = /^0{24}[\x00-\x7F]{6}0{10}$/
 
 /**
  * Convert an ISO code to a currency bytes representation
@@ -85,14 +88,14 @@ class Currency extends Hash160 {
 
   constructor(byteBuf: Buffer) {
     super(byteBuf ?? Currency.XRP.bytes)
-    const code = this.bytes.slice(12, 15)
+    const hex = this.bytes.toString('hex')
 
-    if (this.bytes[0] !== 0) {
-      this._iso = null
-    } else if (/^0*$/.test(this.bytes.toString('hex'))) {
+    if (XRP_HEX_REGEX.test(hex)) {
       this._iso = 'XRP'
+    } else if (STANDARD_FORMAT_HEX_REGEX.test(hex)) {
+      this._iso = isoCodeFromHex(this.bytes.slice(12, 15))
     } else {
-      this._iso = isoCodeFromHex(code)
+      this._iso = null
     }
   }
 

packages/ripple-binary-codec/test/hash.test.js

@@ -50,7 +50,7 @@ describe('Hash256', function () {
 })
 
 describe('Currency', function () {
-  test('Will throw an error for dodgy XRP ', function () {
+  test('Will throw an error for dodgy XRP', function () {
     expect(() =>
       Currency.from('0000000000000000000000005852500000000000'),
     ).toThrow()
@@ -70,6 +70,18 @@ describe('Currency', function () {
     expect(Currency.from('USD').toJSON()).toBe('USD')
   })
 
+  test('Currency codes with no contiguous zeroes in first 96 type code & reserved bits', function () {
+    expect(
+      Currency.from('0000000023410000000000005852520000000000').iso(),
+    ).toBe(null)
+  })
+
+  test('Currency codes with no contiguous zeroes in last 40 reserved bits', function () {
+    expect(
+      Currency.from('0000000000000000000000005852527570656500').iso(),
+    ).toBe(null)
+  })
+
   test('can be constructed from a Buffer', function () {
     const xrp = new Currency(Buffer.alloc(20))
     expect(xrp.iso()).toBe('XRP')