now i changed the “offset” in the functions f.e. aes_addRoundKey from 16 to zero, the same with the other functions, now it looks like good, the decoding buffer values are the same as before encoding :-)

I’m trying to change the code to 128Bit AES but I’m too stupid to modify it, always a different buffer :-(

Can you tell me, what i have to change? I changed void aes_expandEncKey(uint8_t *k, uint8_t *rc) like Dillip wrote but what is with void aes_expandDecKey(uint8_t *k, uint8_t *rc) ?

typedef struct is changed, and key size also to 16Byte.

What else i need to change?

Please help me….

Nice greetings, Manfred

Can you tell me changes to be made to your code available for hard code it to 128-bit Message Block and 128-bit Based Encryption Key for AES ?

i have tried to make some changes to it…
like :

1. Changing :

void aes_expandEncKey(uint8_t *k, uint8_t *rc)
{
register uint8_t i;

k[0] ^= rj_sbox(k[13]) ^ (*rc);
k[1] ^= rj_sbox(k[14]);
k[2] ^= rj_sbox(k[15]);
k[3] ^= rj_sbox(k[12]);
*rc = F( *rc);

for(i = 4; i < 16; i += 4) k[i] ^= k[i-4], k[i+1] ^= k[i-3],
k[i+2] ^= k[i-2], k[i+3] ^= k[i-1];
} /* aes_expandEncKey */

then similarly for:

2. void aes_expandDecKey(uint8_t *k, uint8_t *rc) ;

3. typedef struct {
uint8_t key[16];
uint8_t enckey[16];
uint8_t deckey[16];
} aes256_context;

4. uint8_t key[32]; to uint8_t key[16 ]; in demo.c file…
5. And few More changes…
6. but the input plain text with decrypted buffer varies totally….

I am using your license in my project report and bibliography too !! Dont mind for modification of work !! ;-)

And help me out !!

No, you do not need multiple inits. A demo is just a demo.

These would be a number of rounds and a key schedule.