Firmware specification

Firmware overview

The Babylon A70CM demo firmware has been developed using A70CM Host API library and SCI2C library and performs RSA and AES-CBC encryption/decryption functions

It is designed only for evaluation purposes and to demonstrate how to use A70CM API functions.

End-user applications can use these examples to perform encryption/decryption functions, but it’s mandatory that customers follow standard specifications to improve security data exchange.

Some of these specification can be found, for example, at NIST National Institute of Standards and Techology, section Computer Security Resource Center CSRC

Firmware restrictions

The Babylon A70CM demo firmware assumes the following restrictions:

• Authentication Process assumes both Client than Server has same RSA certificate inside. No Certificate exchange is performed

• The demo program use default NXP Certificate for Autentication Process

• Authentication process is started from Client and uses a simple AES KeyA-KeyB exchange check.

• The AES session Key is exchanged after authentication success.

• AES key is generated using secure wrapping algoritm RFC3394

• The user’s text messages are sent from Server to Client (max lenght 64 char)

• All messages are 128 bytes fixed-length

• Signed user’s messages uses SHA1 digital signature, stored inside of last 20 bytes of each message (from position 109 to position 128). (more details at paragraph 19.2.3.1 - Secret Key Electronic Signatures on this link )

• To change AES session key, you must restart Authentication Process.

• AES key generation function is ONLY FOR DEBUG. Do not use for end-user application

• LAN mode has one board as Server and one board as Client, 3 terminal instance are needed

Main firmware features

By using two PC terminal software connected to Babylon board (see Hardware setup), you can perform:

• Main settings of application parameters
• Configure Man-In-The-Middle performance
• Launch Athentication Process
• Write plain custom messages (maximun 64 character) and send its to client
• Check results of sending

Operation mode macros

See at file “task_ac70.h” in project folder “\A70CM\inc” You can find these macros

#define AC70_TASK 0   //enable original main_task for A70CM Host Api demo application

#if AC70_TASK                  //if Host api demo, no other task can be enabled
 #define IP_TASK 0
 #define VCOMM_TASK 0
 #define BABYLON_TASK 0

#else                                  //not api demo, select operation mode
 #define VCOMM_TASK 1
 #define BABYLON_TASK 1
 #define IP_TASK 0             //IP task enable/disable

               #if IP_TASK
                       #define UDP_SERVER 1
                       #define UDP_CLIENT !UDP_SERVER
               #else
                       #define UDP_SERVER 0
                       #define UDP_CLIENT 0
               #endif
#endif

Macro AC70_TASK do not set to 1, only for A70CM API demo

Macro IP_TASK can be set 1 for LAN operation.

By default the firmware comes compiled in Stand-Alone operation mode (IP_TASK = 0).

To switch to LAN mode, you must set IP_TASK = 1, an then configure Server os Client compilation by setting:

UDP_SERVER 1 = Server application

or

UDP_SERVER 0 = Client application

You can also find these other macros:

#define LCD_TASK 1
#define POLL_TASK 0
#define JEN_TASK 0

LCD_TASK enable/disable GUI interface task

POLL_TASK and JEN_TASK must be set to 0

Project structure

The project “lwip_tcpecho_freertos” include the following specifing folders for A70CM application

• Babylon – main file folder

  • A70CM folder Host API and SCI2C library
  • board_dep folder SHA1 HostCrypto source files and other include file
  • babylon.c source file Main Application Tasks
  • AC70_enc_dec.c source file AC70 host API interface functions

• vcomm – Virtual Comm Port and Man-In-The-Middle file folder

  • VirtualSerial.c source file Main Application Task

Brief of firmware performance

The firmware will include a minimal example how to initialize the A70CM and use Host API functions.

It include also the source files of these Host API, the source files of SCI2C library and a layer to interface main application tasks with API functions.

In Stand Alone operation mode, there is only one Main Menu that will configure both Server and Client

Also the results of all operation (Settings, Authentication, Message exchange) are shown an same terminal window

As a demo of text messages, they are sent by Server Task to Client Task

Using LAN configuration, Server and Client are on two separate boards. Each board has your own terminal connection, and show same configuration menu.

In this case, only the needed selections from Server or Client menu gives your own effects. Unneeded parameters will ignored.

The LAN operation mode is designed for getting closer to real world- Client/Server interaction using 2 boards

For mode detail about LAN mode see Hardware setup LAN mode

Project and tools download

Instructions for tools and firmware installation can be found at Silica ArchiTech page under SerizII project section. Registration is needed to access at download section. Click here to go to ArchiTech main page.