From f2d7b52e1b53b8e7266d3d82f8c8f68281b25d61 Mon Sep 17 00:00:00 2001
From: Cristian Maglie <c.maglie@arduino.cc>
Date: Thu, 8 Oct 2015 16:38:57 +0200
Subject: [PATCH] [HID] Improved checks in getDescriptor() method

---
 cores/arduino/USBCore.h | 5 +++--
 libraries/HID/HID.cpp   | 9 ++++++---
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/cores/arduino/USBCore.h b/cores/arduino/USBCore.h
index 806fa60..530abec 100644
--- a/cores/arduino/USBCore.h
+++ b/cores/arduino/USBCore.h
@@ -49,8 +49,9 @@
 #define REQUEST_OTHER			0x03
 #define REQUEST_RECIPIENT		0x03
 
-#define REQUEST_DEVICETOHOST_CLASS_INTERFACE  (REQUEST_DEVICETOHOST + REQUEST_CLASS + REQUEST_INTERFACE)
-#define REQUEST_HOSTTODEVICE_CLASS_INTERFACE  (REQUEST_HOSTTODEVICE + REQUEST_CLASS + REQUEST_INTERFACE)
+#define REQUEST_DEVICETOHOST_CLASS_INTERFACE    (REQUEST_DEVICETOHOST + REQUEST_CLASS + REQUEST_INTERFACE)
+#define REQUEST_HOSTTODEVICE_CLASS_INTERFACE    (REQUEST_HOSTTODEVICE + REQUEST_CLASS + REQUEST_INTERFACE)
+#define REQUEST_DEVICETOHOST_STANDARD_INTERFACE (REQUEST_DEVICETOHOST + REQUEST_STANDARD + REQUEST_INTERFACE)
 
 //	Class requests
 
diff --git a/libraries/HID/HID.cpp b/libraries/HID/HID.cpp
index 762d170..bff00e3 100644
--- a/libraries/HID/HID.cpp
+++ b/libraries/HID/HID.cpp
@@ -40,9 +40,12 @@ int HID_::getInterface(uint8_t* interfaceCount)
 
 int HID_::getDescriptor(USBSetup& setup)
 {
-	if (pluggedInterface != setup.wIndex) {
-		return 0;
-	}
+	// Check if this is a HID Class Descriptor request
+	if (setup.bmRequestType != REQUEST_DEVICETOHOST_STANDARD_INTERFACE) { return 0; }
+	if (setup.wValueH != HID_REPORT_DESCRIPTOR_TYPE) { return 0; }
+
+	// In a HID Class Descriptor wIndex cointains the interface number
+	if (setup.wIndex != pluggedInterface) { return 0; }
 
 	int total = 0;
 	HIDDescriptorListNode* node;