Maxim Integrated / Mbed OS MAXREFDES155#

DeepCover Embedded Security in IoT: Public-key Secured Data Paths

Dependencies:   MaximInterface

The MAXREFDES155# is an internet-of-things (IoT) embedded-security reference design, built to authenticate and control a sensing node using elliptic-curve-based public-key cryptography with control and notification from a web server.

The hardware includes an ARM® mbed™ shield and attached sensor endpoint. The shield contains a DS2476 DeepCover® ECDSA/SHA-2 coprocessor, Wifi communication, LCD push-button controls, and status LEDs. The sensor endpoint is attached to the shield using a 300mm cable and contains a DS28C36 DeepCover ECDSA/SHA-2 authenticator, IR-thermal sensor, and aiming laser for the IR sensor. The MAXREFDES155# is equipped with a standard Arduino® form-factor shield connector for immediate testing using an mbed board such as the MAX32600MBED#. The combination of these two devices represent an IoT device. Communication to the web server is accomplished with the shield Wifi circuitry. Communication from the shield to the attached sensor module is accomplished over I2C . The sensor module represents an IoT endpoint that generates small data with a requirement for message authenticity/integrity and secure on/off operational control.

The design is hierarchical with each mbed platform and shield communicating data from the sensor node to a web server that maintains a centralized log and dispatches notifications as necessary. The simplicity of this design enables rapid integration into any star-topology IoT network to provide security with the low overhead and cost provided by the ECDSA-P256 asymmetric-key and SHA-256 symmetric-key algorithms.

More information about the MAXREFDES155# is available on the Maxim Integrated website.

--- a/WindowManager.hpp	Thu Mar 09 11:38:33 2017 -0600
+++ b/WindowManager.hpp	Thu Apr 06 15:16:30 2017 -0500
@@ -39,13 +39,15 @@
 #include "Keys.hpp"
 #include "Window.hpp"
 
+class Display;
+
 /// Stack based window manager.
 class WindowManager
 {
 public:
     /// @param width Width of the windows to render.
     /// @param height Height of the windows to render.
-    WindowManager(int width, int height) : m_width(width), m_height(height) { }
+    WindowManager() { }
     ~WindowManager();
     
     /// Push a window onto the top of the stack.
@@ -56,14 +58,10 @@
     /// Pop a window from the top of the stack.
     /// @details The operation will be queued until the next update. The popped window will be deleted.
     void pop();
-    
-    /// Renders the top window as a bitmap.
-    Bitmap render() const;
-    
-    /// Updates all windows.
-    /// @returns True if the screen should be redrawn or false if it does not need to be redrawn.
-    /// Only the top window can request a screen redraw.
-    bool update();
+        
+    /// Updates all windows and redraws the top window if invalid.
+    /// @param display Display used for rendering.
+    void update(Display & display);
     
     /// Forwards a key-press input event to the top window for processing.
     void processKey(Key key);
@@ -71,8 +69,6 @@
 private:
     void processAction(Window * window);
 
-    int m_width;
-    int m_height;
     std::vector<Window *> m_windowStack;
     std::vector<Window *> m_actionQueue;