Encrption, Decryption in STM32F417VG

sangilipandian · ‎2013-02-04

Posted on February 05, 2013 at 07:25

Hi Eveyone.

I'm newbie to this forum and I would expect a single response for this post. Actually i want to encrypt the data that is come from LCD Ram. The dats size would be 37kb when i pass this to for encrption i got no response in my Hyperterminal. Before that i've come accross the more errors like L6406E in Keil. That error related to size of RAM, I had increase the size in TARGET tab in keil compiler then error had gone. But i didn't get proper ouput. It's obivious one that i'm struggling in size of RAM. Here i would like to known cryptographic constrains. If i had increase the block size more than 100, not getting proper output.

I'm pleased if i got clear on this. Thanks in Advance.

#encryption #decrption #encryption

Tesla DeLorean · ‎2013-02-05

Posted on February 05, 2013 at 16:51

AES seemed to work fine on the 215, DMA is constrained by a 16-bit count length. Start with one of the firmware library examples if you can't get your own code working.

Why wouldn't you fire up your debugger and step into the code and observe what's going on with the chip and memory?

Add some more diagnostic output via the serial port until you know what it's doing, and where in your code it is.

Get yourself a better class of terminal program like Real Term or Tera Term, Hyper Terminal is about the worst

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sangilipandian · ‎2013-02-06

Posted on February 06, 2013 at 09:24

Thanks for your reply clive.

Yep, I've already choosen the firmware library (AES_ECBmode_DMA) and additinally modify the code for my requirements. I found where i was stuck in the code through terminal.

The following snippet will more helpful to understand my problem,

#define DATA_SIZE 120*160*2

__IO uint8_t AES128key[16]=''thiskeyforsecret'';

__IO uint8_t PlainData[DATA_SIZE]='' AES Demo Application '';

When i execute my application it got stuck with AES128_Encrypt_DMA() function . The result i got only plain text and key in terminal. I know its problem in DMA and it not accepting my required input. Am i doing wrong anything? . Please suggest me a answer to come out of this.

Thanks in Advance.