object: PutObjectHandler should set the md5Sum properly. (#1604)

Additionally add a test case as well for validating for us
to reply BadDigest properly.

Fixes #1603

object-handlers.go

@@ -603,7 +603,7 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 		// Save metadata.
 		metadata := make(map[string]string)
 		// Make sure we hex encode here.
-		metadata["md5"] = hex.EncodeToString(md5Bytes)
+		metadata["md5Sum"] = hex.EncodeToString(md5Bytes)
 		// Create object.
 		md5Sum, err = api.ObjectAPI.PutObject(bucket, object, size, reader, metadata)
 	}

server_test.go

@@ -117,8 +117,10 @@ func (s *MyAPISuite) newRequest(method, urlStr string, contentLength int64, body
 			return nil, e
 		}
 		hashedPayload = hex.EncodeToString(sum256(payloadBytes))
-		md5base64 := base64.StdEncoding.EncodeToString(sumMD5(payloadBytes))
-		req.Header.Set("Content-Md5", md5base64)
+		if req.Header.Get("Content-Md5") != "" {
+			md5base64 := base64.StdEncoding.EncodeToString(sumMD5(payloadBytes))
+			req.Header.Set("Content-Md5", md5base64)
+		}
 	}
 	req.Header.Set("x-amz-content-sha256", hashedPayload)
 
@@ -1219,6 +1221,43 @@ func (s *MyAPISuite) TestObjectMultipartList(c *C) {
 	verifyError(c, response4, "InvalidArgument", "Argument maxParts must be an integer between 1 and 10000.", http.StatusBadRequest)
 }
 
+// Tests if valid md5 was set while uploading and server replies back
+// with BadDigest.
+func (s *MyAPISuite) TestObjectValidMD5(c *C) {
+	request, err := s.newRequest("PUT", testAPIFSCacheServer.URL+"/object-valid-md5", 0, nil)
+	c.Assert(err, IsNil)
+
+	client := http.Client{}
+	response, err := client.Do(request)
+	c.Assert(err, IsNil)
+	c.Assert(response.StatusCode, Equals, 200)
+
+	// Create a byte array of 5MB.
+	data := bytes.Repeat([]byte("0123456789abcdef"), 5*1024*1024/16)
+
+	hasher := md5.New()
+	hasher.Write(data)
+	md5Sum := hasher.Sum(nil)
+
+	buffer1 := bytes.NewReader(data)
+	request, err = s.newRequest("PUT", testAPIFSCacheServer.URL+"/object-valid-md5/object", int64(buffer1.Len()), buffer1)
+	c.Assert(err, IsNil)
+	request.Header.Set("Content-Md5", base64.StdEncoding.EncodeToString(md5Sum))
+	client = http.Client{}
+	response, err = client.Do(request)
+	c.Assert(err, IsNil)
+	c.Assert(response.StatusCode, Equals, http.StatusOK)
+
+	buffer1 = bytes.NewReader(data)
+	request, err = s.newRequest("PUT", testAPIFSCacheServer.URL+"/object-valid-md5/object1", int64(buffer1.Len()), buffer1)
+	c.Assert(err, IsNil)
+	request.Header.Set("Content-Md5", "WvLTlMrX9NpYDQlEIFlnDw==")
+	client = http.Client{}
+	response, err = client.Do(request)
+	c.Assert(err, IsNil)
+	verifyError(c, response, "BadDigest", "The Content-Md5 you specified did not match what we received.", http.StatusBadRequest)
+}
+
 func (s *MyAPISuite) TestObjectMultipart(c *C) {
 	request, err := s.newRequest("PUT", testAPIFSCacheServer.URL+"/objectmultiparts", 0, nil)
 	c.Assert(err, IsNil)