1 files changed, 8 insertions, 8 deletions

diff --git a/lib/crypto.js b/lib/crypto.js
index f8efffda4..42564c79e 100644
--- a/lib/crypto.js
+++ b/lib/crypto.js
@@ -25,7 +25,7 @@ const DH_GENERATOR = 2;
 // to break them unnecessarily.
 function toBuf(str, encoding) {
   encoding = encoding || 'binary';
-  if (util.isString(str)) {
+  if (typeof str === 'string') {
     if (encoding === 'buffer')
       encoding = 'binary';
     str = new Buffer(str, encoding);
@@ -92,7 +92,7 @@ Hash.prototype._flush = function(callback) {
 
 Hash.prototype.update = function(data, encoding) {
   encoding = encoding || exports.DEFAULT_ENCODING;
-  if (encoding === 'buffer' && util.isString(data))
+  if (encoding === 'buffer' && typeof data === 'string')
     encoding = 'binary';
   this._handle.update(data, encoding);
   return this;
@@ -369,7 +369,7 @@ function DiffieHellman(sizeOrKey, keyEncoding, generator, genEncoding) {
   if (!(this instanceof DiffieHellman))
     return new DiffieHellman(sizeOrKey, keyEncoding, generator, genEncoding);
 
-  if (!util.isBuffer(sizeOrKey) &&
+  if (!(sizeOrKey instanceof Buffer) &&
       typeof sizeOrKey !== 'number' &&
       typeof sizeOrKey !== 'string')
     throw new TypeError('First argument should be number, string or Buffer');
@@ -513,7 +513,7 @@ DiffieHellman.prototype.setPrivateKey = function(key, encoding) {
 
 
 function ECDH(curve) {
-  if (!util.isString(curve))
+  if (typeof curve !== 'string')
     throw new TypeError('curve should be a string');
 
   this._handle = new binding.ECDH(curve);
@@ -566,12 +566,12 @@ exports.pbkdf2 = function(password,
                           keylen,
                           digest,
                           callback) {
-  if (util.isFunction(digest)) {
+  if (typeof digest === 'function') {
     callback = digest;
     digest = undefined;
   }
 
-  if (!util.isFunction(callback))
+  if (typeof callback !== 'function')
     throw new Error('No callback provided to pbkdf2');
 
   return pbkdf2(password, salt, iterations, keylen, digest, callback);
@@ -632,10 +632,10 @@ Certificate.prototype.exportChallenge = function(object, encoding) {
 
 
 exports.setEngine = function setEngine(id, flags) {
-  if (!util.isString(id))
+  if (typeof id !== 'string')
     throw new TypeError('id should be a string');
 
-  if (flags && !util.isNumber(flags))
+  if (flags && typeof flags !== 'number')
     throw new TypeError('flags should be a number, if present');
   flags = flags >>> 0;