Tutorial A8 32bit AES
Most of our previous tutorials were running on 8-bit modes of operation. We can target typical implementation on ARM devices which actually looks a little different.
This tutorial is ONLY possible if you have an ARM target. For example the UFO Board with the STM32F3 target (or similar).
Background
A 32-bit machine can operate on 32-bit words, so it seems wasteful to use the same 8-bit operations. Indeed we can speed up the AES operation considerably by generating several tables (called T-Tables), as was described in the book The Design of Rijndael which was published by the authors of AES.
Building Firmware
You will have to build with the PLATFORM set to one of the ARM targets (such as CW308_STM32F0 for the STM32F0 victim, or CW308_STM32F3 for the STM32F3 victim). If you haven't setup the ARM build environment see the page CW308T-STM32F#Example_Projects. Assuming your build environment is OK, you can build it as follows:
cd chipwhisperer\hardware\victims\firmware\simpleserial-aes make PLATFORM=CW308_STM32F3 CRYPTO_TARGET=MBEDTLS
If this works you should get something like the following:
Creating Symbol Table: simpleserial-aes-CW308_STM32F3.sym
arm-none-eabi-nm -n simpleserial-aes-CW308_STM32F3.elf > simpleserial-aes-CW308_
STM32F3.sym
Size after:
text data bss dec hex filename
8440 1076 10320 19836 4d7c simpleserial-aes-CW308_STM32F3.elf
+--------------------------------------------------------
+ Built for platform CW308T: STM32F3 Target
+--------------------------------------------------------