Hello,
> Thanks for the reply. I have my sample test case like this.
>
> #define KEYSIZE 256
> #define AES_BLOCK_SIZE 32
AES block size for this implementation is 16 bytes
(of course AES standard talks about block size 24 and 32
bytes - Nb variable - but this implementation use
only 16 byte AES block)
> void test_main()
> {
> char key[KEYSIZE+1];
> int I,keylen;
> char data[AES_BLOCK_SIZE] ;
> char cbuf[AES_BLOCK_SIZE];
> char pbuf[AES_BLOCK_SIZE];
>
>
> strcpy(key,"2ea24d27bc6e40e70b0a2ab08b0831675cf1274834f98a58709edeeb56af
> f547");
>
> strcpy(data,"00000000000000000000000000000000000000000000000000000000000
> 00000");
I guess that this strings should be converted from hex form to
binary for using (something like 0x41 = 'A')
> keylen = strlen(key);
>
> {
> AES_KEY ctx;
> unsigned char iv[AES_BLOCK_SIZE];
> memset(cbuf, 0,AES_BLOCK_SIZE);
> AES_set_encrypt_key(key, KEYSIZE, &ctx);
> AES_cbc_encrypt(data, cbuf, AES_BLOCK_SIZE, &ctx, iv,
> AES_ENCRYPT);
iv is not initialized here and you should check return code of
AES_set_encrypt_key() - this function accept key length of 128,192,256.
Here this works good but checking error code is good practise.
>
> for (i =0 ; i <sizeof(data) ; i++)
> printf("%d...input = %d \n",data[i],i);
> printf("\n");
>
> for (i =0 ; i <sizeof(cbuf); i++)
> printf("%d...encoded data =%d \n",cbuf[i],i);
> printf("\n");
> }
>
> {
> AES_KEY ctx;
> int len,pad,flag =0;
> unsigned char iv[AES_BLOCK_SIZE];
> memset(pbuf, 0,AES_BLOCK_SIZE);
> memset(iv, 0, AES_BLOCK_SIZE);
iv should have the same value as in encrypting.
> AES_set_decrypt_key(key, KEYSIZE, &ctx);
check error code
> AES_cbc_encrypt(cbuf,pbuf, AES_BLOCK_SIZE, &ctx, iv,
> AES_DECRYPT);
> }
>
> }
>
> Please can any tell me what could be the problem with this code?
There are many problems with using AES_cbc*().
If we are talking of padding - this functions do not support
"normal" padding - i suggest add proper padding on encryption
yourself and remove padding after decryption.
This functions should take properly padded data rounded to
16 bytes.
Best regards,
--
Marek Marcola <[EMAIL PROTECTED]>
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