Fix issue with crypto library browser ripemd160 support.

lib/crypto/hash.js

@@ -1,6 +1,5 @@
 'use strict';
 
-var hashjs = require('hash.js');
 var sha512 = require('sha512');
 var crypto = require('crypto');
 var BufferUtil = require('../util/buffer');
@@ -29,19 +28,9 @@ Hash.sha256sha256 = function(buf) {
 
 Hash.ripemd160 = function(buf) {
   $.checkArgument(BufferUtil.isBuffer(buf));
-  return crypto.createHash('ripemd160').update(buf).digest();
+  return crypto.createHash('rmd160').update(buf).digest();
 };
 
-// Node.js crypto ripemd160 hashes are not supported in a browser
-// We'll replace with a (slower) version that does.
-if (process.browser) {
-  Hash.ripemd160 = function(buf) {
-    $.checkArgument(BufferUtil.isBuffer(buf));
-    var hash = (new hashjs.ripemd160()).update(buf).digest();
-    return new Buffer(hash);
-  };
-}
-
 Hash.sha256ripemd160 = function(buf) {
   $.checkArgument(BufferUtil.isBuffer(buf));
   return Hash.ripemd160(Hash.sha256(buf));