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T.I. AES Library usage. (slaa397a)

Jimmy Sfaelos
Prodigy 10 points
Other Parts Discussed in Thread: MSP430F5418A

Hello All:

Is there anyone with experience using the I.I. AES library (slaa397a)?

I am interested in the aes_cbc_encrypt(. . .) && aes_cbc_decrypt(. . .) && aes_set_key(. . .)

I am attempting to verify my understanding of these functions by applying these functions to the

NIST Special Publication 800-38A 2001 edition.

http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf

I have built the TI aes.c & aes.h, along with a main.c to exercise the NIST CBC Example Vectors of Section

F.2 CBC Example Vectors

F.2.1 CBC-AES128.Encrypt

I am running the code on a MSP430F5418A target.

(If there are other CBC Test Vectors people are aware of, that would also help.)

I am attempting to generate the vectors for the 4 Blocks listed in

F.2.1 CBC-AES128.Encrypt

so far, I can generated only the numbers for Block 1, so I know I am "missing something".

Thanks

Jimmy

  • 0
    Prodigy 130 points

    Jimmy,

    Did you compile under Code Composer or IAR Workbench?  I compiled with both; however, only the IAR Workbench compiled and executed properly.  The document SLAA397a, the IAR Compiler was used with an optimization setting in the compiler (see Section 4).  I suspect this is only half the story. 

    Running with the Code Composer executable through the debugger on a 2410 and a 5515,  I found I could encrypt but not decrypt. 

    More details as I move through this exercise as well.

     

    Dan

     

     

  • 0 in reply to Dan Trembley
    TI__Guru 56650 points

    Hi,

    i just made a CCS project (i use the latest version of CCS - V4.2.4.00033) and run the example code, and it works without any problem.

    However i made a small change that i switch off the watchdog timer at the beginning of the program (in case the excryption and decryption takes longer time as the watchdog timer expires in between).

    Attached you can find the CCS project file:

    5672.TEST_AES.zip

    Here are the screenshot of the test result:

    - Encrypt:

     

    - Decrypt:

     

    Hope this helps.

    -Leo-

  • 0 in reply to Leo Hendrawan

    Hi. Does this code only work for msp430? I'm asking this because I've tried the code using C55x (TI simulator, cpu cycle accurate c55x ver2) and I didn't get the expected answer. Thank you for any help.

  • 0 in reply to Leo Hendrawan
    Prodigy 10 points

    Hi Leo!

    I am implementing the AES-256 encryption and would like to know if your example is 256? Or 128?

    I made a compilation of your code and it worked perfectly.

    Thank you!    ,

    Jorge

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