diff --git a/auth-handler.go b/auth-handler.go
index 9d330b8dc..cf1d0638a 100644
--- a/auth-handler.go
+++ b/auth-handler.go
@@ -1,5 +1,5 @@
 /*
- * Minio Cloud Storage, (C) 2015 Minio, Inc.
+ * Minio Cloud Storage, (C) 2015, 2016 Minio, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -153,7 +153,7 @@ func isReqAuthenticated(r *http.Request) (s3Error APIErrorCode) {
 // is returned for unhandled auth type. Once the auth type is indentified
 // request headers and body are used to calculate the signature validating
 // the client signature present in request.
-func checkAuth(w http.ResponseWriter, r *http.Request) APIErrorCode {
+func checkAuth(r *http.Request) APIErrorCode {
 	authType := getRequestAuthType(r)
 	if authType != authTypePresigned && authType != authTypeSigned {
 		// For all unhandled auth types return error AccessDenied.
diff --git a/auth-handler_test.go b/auth-handler_test.go
new file mode 100644
index 000000000..5484168c6
--- /dev/null
+++ b/auth-handler_test.go
@@ -0,0 +1,93 @@
+/*
+ * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"testing"
+)
+
+// Provides a fully populated http request instance, fails otherwise.
+func mustNewRequest(method string, urlStr string, contentLength int64, body io.ReadSeeker, t *testing.T) *http.Request {
+	req, err := newTestRequest(method, urlStr, contentLength, body)
+	if err != nil {
+		t.Fatalf("Unable to initialize new http request %s", err)
+	}
+	return req
+}
+
+// This is similar to mustNewRequest but additionally the request
+// is signed with AWS Signature V4, fails if not able to do so.
+func mustNewSignedRequest(method string, urlStr string, contentLength int64, body io.ReadSeeker, t *testing.T) *http.Request {
+	req := mustNewRequest(method, urlStr, contentLength, body, t)
+	cred := serverConfig.GetCredential()
+	if err := signRequest(req, cred.AccessKeyID, cred.SecretAccessKey); err != nil {
+		t.Fatalf("Unable to inititalized new signed http request %s", err)
+	}
+	return req
+}
+
+// Tests is requested authenticated function, tests replies for s3 errors.
+func TestIsReqAuthenticated(t *testing.T) {
+	savedServerConfig := serverConfig
+	defer func() {
+		serverConfig = savedServerConfig
+	}()
+	serverConfig = nil
+
+	// Test initialized config file.
+	path, err := ioutil.TempDir("", "minio-")
+	if err != nil {
+		t.Fatalf("Unable to create a temporary directory, %s", err)
+	}
+	defer removeAll(path)
+
+	// Inititalize a new config.
+	setGlobalConfigPath(path)
+	if err := initConfig(); err != nil {
+		t.Fatalf("unable initialize config file, %s", err)
+	}
+	serverConfig.SetCredential(credential{"myuser", "mypassword"})
+
+	// List of test cases for validating http request authentication.
+	testCases := []struct {
+		req     *http.Request
+		s3Error APIErrorCode
+	}{
+		// When request is nil, internal error is returned.
+		{nil, ErrInternalError},
+		// When request is unsigned, access denied is returned.
+		{mustNewRequest("GET", "http://localhost:9000", 0, nil, t), ErrAccessDenied},
+		// When request is properly signed, but has bad Content-MD5 header.
+		{mustNewSignedRequest("PUT", "http://localhost:9000", 5, bytes.NewReader([]byte("hello")), t), ErrBadDigest},
+		// When request is properly signed, error is none.
+		{mustNewSignedRequest("GET", "http://localhost:9000", 0, nil, t), ErrNone},
+	}
+
+	// Validates all testcases.
+	for _, testCase := range testCases {
+		if testCase.s3Error == ErrBadDigest {
+			testCase.req.Header.Set("Content-Md5", "garbage")
+		}
+		if s3Error := isReqAuthenticated(testCase.req); s3Error != testCase.s3Error {
+			t.Fatalf("Unexpected s3error returned wanted %d, got %d", testCase.s3Error, s3Error)
+		}
+	}
+}
diff --git a/bucket-handlers.go b/bucket-handlers.go
index 9e122a441..504101915 100644
--- a/bucket-handlers.go
+++ b/bucket-handlers.go
@@ -199,7 +199,7 @@ func (api objectAPIHandlers) ListMultipartUploadsHandler(w http.ResponseWriter,
 // owned by the authenticated sender of the request.
 func (api objectAPIHandlers) ListBucketsHandler(w http.ResponseWriter, r *http.Request) {
 	// List buckets does not support bucket policies, no need to enforce it.
-	if s3Error := checkAuth(w, r); s3Error != ErrNone {
+	if s3Error := checkAuth(r); s3Error != ErrNone {
 		writeErrorResponse(w, r, s3Error, r.URL.Path)
 		return
 	}
@@ -306,27 +306,19 @@ func (api objectAPIHandlers) DeleteMultipleObjectsHandler(w http.ResponseWriter,
 // ----------
 // This implementation of the PUT operation creates a new bucket for authenticated request
 func (api objectAPIHandlers) PutBucketHandler(w http.ResponseWriter, r *http.Request) {
-	vars := mux.Vars(r)
-	bucket := vars["bucket"]
-
-	// Set http request for signature.
-	switch getRequestAuthType(r) {
-	default:
-		// For all unknown auth types return error.
-		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+	// PutBucket does not support policies, use checkAuth to validate signature.
+	if s3Error := checkAuth(r); s3Error != ErrNone {
+		writeErrorResponse(w, r, s3Error, r.URL.Path)
 		return
-	case authTypePresigned, authTypeSigned:
-		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
-			writeErrorResponse(w, r, s3Error, r.URL.Path)
-			return
-		}
 	}
 
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+
 	// Validate if incoming location constraint is valid, reject
 	// requests which do not follow valid region requirements.
-	errCode := isValidLocationConstraint(r)
-	if errCode != ErrNone {
-		writeErrorResponse(w, r, errCode, r.URL.Path)
+	if s3Error := isValidLocationConstraint(r); s3Error != ErrNone {
+		writeErrorResponse(w, r, s3Error, r.URL.Path)
 		return
 	}
 	// Make bucket.
@@ -463,21 +455,15 @@ func (api objectAPIHandlers) HeadBucketHandler(w http.ResponseWriter, r *http.Re
 
 // DeleteBucketHandler - Delete bucket
 func (api objectAPIHandlers) DeleteBucketHandler(w http.ResponseWriter, r *http.Request) {
-	vars := mux.Vars(r)
-	bucket := vars["bucket"]
-
-	switch getRequestAuthType(r) {
-	default:
-		// For all unknown auth types return error.
-		writeErrorResponse(w, r, ErrAccessDenied, r.URL.Path)
+	// DeleteBucket does not support bucket policies, use checkAuth to validate signature.
+	if s3Error := checkAuth(r); s3Error != ErrNone {
+		writeErrorResponse(w, r, s3Error, r.URL.Path)
 		return
-	case authTypePresigned, authTypeSigned:
-		if s3Error := isReqAuthenticated(r); s3Error != ErrNone {
-			writeErrorResponse(w, r, s3Error, r.URL.Path)
-			return
-		}
 	}
 
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+
 	if err := api.ObjectAPI.DeleteBucket(bucket); err != nil {
 		errorIf(err, "Unable to delete a bucket.")
 		writeErrorResponse(w, r, toAPIErrorCode(err), r.URL.Path)