Example Summary

This example shows how to use the AESCBC driver. The target expects the user to enter 1 or 2 and press Enter. The predefined plaintext is first encrypted and displayed to the user. Then, the encrypted message is decrypted to get back the original plaintext. After decryption, plaintext is displayed back to the user. ‘1’ is to select 16 byte plaintext and ‘2’ is for 128 byte plaintext. The user can interact with the target until the application is ended. Note that Loki AES-128 (LAES) engine will be used on CC23XX devices and Hardware Security Module (HSM) will be used on CC27XX devices. CC27XX has LAES engine as well, which can be used as an alternative.

Peripherals & Pin Assignments

When this project is built, the SysConfig tool will generate the TI-Driver configurations into the ti_drivers_config.c and ti_drivers_config.h files. Information on pins and resources used is present in both generated files. Additionally, the System Configuration file (*.syscfg) present in the project may be opened with SysConfig’s graphical user interface to determine pins and resources used.

BoosterPacks, Board Resources & Jumper Settings

For board specific jumper settings, resources and BoosterPack modifications, refer to the Board.html file.

If you’re using an IDE such as Code Composer Studio (CCS) or IAR, please refer to Board.html in your project directory for resources used and board-specific jumper settings.

The Board.html can also be found in your SDK installation:

<SDK_INSTALL_DIR>/source/ti/boards/<BOARD>

Example Usage

• Open a serial session (e.g. PuTTY, etc.) to the appropriate COM port.
  • The COM port can be determined via Device Manager in Windows or via ls /dev/tty* in Linux.

The connection should have the following settings

    Baud-rate:  115200
    Data bits:       8
    Stop bits:       1
    Parity:       None
    Flow Control: None

The console application also needs to be setup to send the carriage return (CR) character when Enter is pressed. This is because it is used as the termination character in this demo. If the demo is not working properly, check the default configuration of the console application in question and make sure that it is sending the carriage return character as expected.

• Run the example.

• Enter 1 or 2 and press Enter.

• Enter q to exit the application.

• The target will encrypt predefined plaintext and displays ciphertext. Then, it will decrypt the ciphertext to get the original plaintext back. Initial plaintext and decrypted ciphertext should match.

Application Design Details

This application waits for an input from the user (1 or 2) in a thread, mainThread. It performs an encryption on a predefined message using AESCBC_oneStepEncrypt and displays the encrypted message to the console. Then, it performs a decryption using AESCBC_oneStepDecrypt on the encrypted message. Decrypted message is also displayed to the console. Both the predefined plaintext message and the decrypted ciphertext message should be the same.