Example of Using AES Functions¶
AES Encryption and Decryption
// use of the CTR mode
int AES_sample(void)
{
// secret key
Ipp8u key[] = "\x00\x01\x02\x03\x04\x05\x06\x07"
"\x08\x09\x10\x11\x12\x13\x14\x15";
// define and setup AES cipher
int ctxSize;
ippsAESGetSize(&ctxSize);
IppsAESSpec* pAES = (IppsAESSpec*)( new Ipp8u [ctxSize] );
ippsAESInit(key, sizeof(key)-1, pAES, ctxSize);
// message to be encrypted
Ipp8u msg[] = "the quick brown fox jumps over the lazy dog";
// and initial counter
Ipp8u ctr0[] = "\xff\xee\xdd\xcc\xbb\xaa\x99\x88"
"\x77\x66\x55\x44\x33\x22\x11\x00";
// counter
Ipp8u ctr[16];
// init counter before encryption
memcpy(ctr, ctr0, sizeof(ctr));
// encrypted message
Ipp8u ctext[sizeof(msg)];
// encryption
ippsAESEncryptCTR(msg, ctext, sizeof(msg), pAES, ctr, 64);
// init counter before decryption
memcpy(ctr, ctr0, sizeof(ctr));
// decrypted message
Ipp8u rtext[sizeof(ctext)];
// decryption
ippsAESDecryptCTR(ctext, rtext, sizeof(ctext), pAES, ctr, 64);
// remove secret and release resource
ippsAESInit(0, sizeof(key)-1, pAES, ctxSize);
delete [] (Ipp8u*)pAES;
int error = memcmp(rtext, msg, sizeof(msg));
return 0==error;
}