Remove unused code from HMAC implementation

src/platform/web/lib/util/bufferutils.ts

@@ -1,7 +1,7 @@
 import WordArray from 'crypto-js/build/lib-typedarrays';
 import Platform from 'common/platform';
 import IBufferUtils from 'common/types/IBufferUtils';
-import { sign as hmacSha256 } from './hmac-sha256';
+import { hmac as hmacSha256 } from './hmac-sha256';
 
 /* Most BufferUtils methods that return a binary object return an ArrayBuffer
  * The exception is toBuffer, which returns a Uint8Array (and won't work on

src/platform/web/lib/util/hmac-sha256.ts

@@ -185,7 +185,7 @@ function sha256(data: Uint8Array) {
   );
 }
 
-function hmac(key: Uint8Array, data: Uint8Array) {
+export function hmac(key: Uint8Array, data: Uint8Array) {
   if (key.length > 64) key = sha256(key);
 
   if (key.length < 64) {
@@ -215,20 +215,3 @@ function hmac(key: Uint8Array, data: Uint8Array) {
   // Hash the previous message
   return sha256(result);
 }
-
-// Convert a string to a Uint8Array, SHA-256 it, and convert back to string
-const encoder = new TextEncoder();
-
-export function sign(inputKey: string | Uint8Array, inputData: string | Uint8Array) {
-  const key = typeof inputKey === 'string' ? encoder.encode(inputKey) : inputKey;
-  const data = typeof inputData === 'string' ? encoder.encode(inputData) : inputData;
-  return hmac(key, data);
-}
-
-export function hash(str: string) {
-  return hex(sha256(encoder.encode(str)));
-}
-
-export function hex(bin: Uint8Array) {
-  return bin.reduce((acc, val) => acc + ('00' + val.toString(16)).substr(-2), '');
-}