Forbid requests generated at least 15 min in the past or in the future (#2648)

cmd/globals.go

@@ -17,6 +17,8 @@
 package cmd
 
 import (
+	"time"
+
 	"github.com/fatih/color"
 	"github.com/minio/minio/pkg/objcache"
 )
@@ -58,6 +60,11 @@ var (
 	maxFormFieldSize = int64(1024 * 1024)
 )
 
+var (
+	// The maximum allowed difference between the request generation time and the server processing time
+	maxSkewTime = 15 * time.Minute
+)
+
 // global colors.
 var (
 	colorBlue = color.New(color.FgBlue).SprintfFunc()