mmCAU library, AES Initialization vector

[emilien]

Hi,

     I'm using the mmCAU library, and I'm able to run cau_aes_set_key, cau_aes_encrypt, cau_aes_decrypt with a 16bytes key. It worked and I could retrieve the original plaintext on my Kinetis K60. However, the documentation says it's CBC and I don't get how the Initilization vector is picked (This I cannot decrypt on my desktop when I receive it from the network)

Where can I set this initilization vector ?

I'm using "CAU and mmCAU version 2.3".

Best regards,

--

Emilien

[emilien]

Hi again,

     I've figured out it's not CBC mode, but ECB mode which is used in the mmCAU library... which is weird because in the AN4307 I can read "All the crypto algorithms are executed in Cipher-block chaining (CBC) block cipher mode to increase block encryption and decryption security". Any idea about how to use CBC? Anyway I guess until nanoSSL comes with a Kinetis implementation, I have only poor encryption solutions...

[PaoloRenzo · Accepted solution]

Hi Emilien

mmCAu library implements ECB mode (no initialization vector). AN4307 implements CBC wrapping mmCAU libray for this feature. You can get more details in AN4307SW.zip from freescale web page:

Go to:

K60_100 Product Summary Page ---> Run-time Software (18) ---> Lab and Test Software (1)

More details here:

Block cipher modes of operation - Wikipedia, the free encyclopedia

Hope this helps

Paolo

[edwardcullen]

Hi Paolo, I need  AN4307SW.zip to implement mmCAU in my thesis.I followed your instruction to get software AN4307 but require some info :"Export Compliance Project Inquiry", and I also provided info about my project but I haven't received Freescale's answer yet. Could you help me ?