Merge pull request #130 from ltonetwork/binary-methods

Add `dataview` property and `hmac` method to binary.

src/Binary.ts

@@ -1,5 +1,6 @@
 import { IBinary } from './types';
 import { sha256 } from '@noble/hashes/sha256';
+import { hmac } from '@noble/hashes/hmac';
 import { int16ToBytes, int32ToBytes } from './utils/bytes';
 import { bytesToHex, hexToBytes } from '@noble/hashes/utils';
 import { base58 } from '@scure/base';
@@ -27,11 +28,20 @@ export default class Binary extends Uint8Array implements IBinary {
     return bytesToHex(this);
   }
 
+  get dataView(): DataView {
+    return new DataView(this.buffer);
+  }
+
   /** Create a SHA256 hash */
   hash(): Binary {
     return new Binary(sha256(new Uint8Array(this)));
   }
 
+  /** Create HMAC SHA256 hash */
+  hmac(key: string | Uint8Array): Binary {
+    return new Binary(hmac(sha256, key, this));
+  }
+
   toString(): string {
     return new TextDecoder().decode(this);
   }

src/types/binary.d.ts

@@ -4,8 +4,10 @@ export interface IBinary extends Uint8Array {
   readonly base58: string;
   readonly base64: string;
   readonly hex: string;
+  readonly dataView: DataView;
   toString(): string;
   hash(): IBinary;
+  hmac(key: string | Uint8Array): IBinary;
   slice(start?: number, end?: number): IBinary;
   reverse(): IBinary;
   toReversed(): IBinary;

src/utils/convert.ts

@@ -25,7 +25,7 @@ export function bytesToByteArrayWithSize(input: TBinary): Uint8Array {
 
   if (!(input instanceof Array)) input = Array.prototype.slice.call(input);
 
-  const lengthBytes = int16ToBytes(input.length);
+  const lengthBytes = shortToByteArray(input.length);
   return Uint8Array.from([...lengthBytes, ...(input as Array<number>)]);
 }
 

test/Binary.spec.ts

@@ -1,6 +1,7 @@
 import { expect } from 'chai';
 import { Binary } from '../src';
 import { sha256 } from '@noble/hashes/sha256';
+import { hmac } from '@noble/hashes/hmac';
 
 describe('Binary', () => {
   const testString = 'test';
@@ -69,6 +70,18 @@ describe('Binary', () => {
     });
   });
 
+  describe('dataview', () => {
+    it('should return correct dataview', () => {
+      const binary = Binary.concat(Binary.fromInt32(123), Binary.fromInt16(45));
+      expect(binary.dataView).to.be.instanceOf(DataView);
+      expect(binary.dataView.byteLength).to.equal(6);
+      expect(binary.dataView.byteOffset).to.equal(0);
+
+      expect(binary.dataView.getInt32(0)).to.be.deep.equal(123);
+      expect(binary.dataView.getInt16(4)).to.be.deep.equal(45);
+    });
+  });
+
   describe('fromBase58', () => {
     it('should return correct Binary from base58 string', () => {
       const binary = Binary.fromBase58(base58String);
@@ -177,4 +190,22 @@ describe('Binary', () => {
       expect(hash).to.deep.equal(sha256(testString));
     });
   });
+
+  describe('hmac', () => {
+    it('should return a Binary with the hmac sha256 hash with a string key', () => {
+      const binary = new Binary(testString);
+      const hash = binary.hmac('some_key');
+
+      expect(hash).to.be.instanceOf(Binary);
+      expect(hash).to.deep.equal(hmac(sha256, 'some_key', testString));
+    });
+
+    it('should return a Binary with the hmac sha256 hash with a binary key', () => {
+      const binary = new Binary(testString);
+      const hash = binary.hmac(new Binary('some_key'));
+
+      expect(hash).to.be.instanceOf(Binary);
+      expect(hash).to.deep.equal(hmac(sha256, 'some_key', testString));
+    });
+  });
 });