static void random_gen(void)
{
uint8_t ciphertext[16];
AES_SETMODE(ECB);
AESLoadKeyOrIV(entropy_buf, TRUE); // IV = entropy_buf
AESEncDec(prng_buf, 16, ciphertext, prng_buf, FALSE, FALSE); // encrypt prng_buf with itself
memcpy(prng_buf, ciphertext, 16); // prng_buf = ciphertext
prng_buf_len = 16; // 16 prng bytes now available
}
/******************************************************************************
* @fn sspAesEncryptHW
*
* @brief Encrypts 16 byte block using AES encryption engine
*
* input parameters
*
* @param AesKey - Pointer to AES Key.
* @param Cstate - Pointer to input data.
*
* output parameters
*
* @param Cstate - Pointer to encrypted data.
*
* @return None
*
*/
void sspAesEncryptHW( uint8 *AesKey, uint8 *Cstate )
{
(void)AesKey;
#if (defined HAL_AES_DMA) && (HAL_AES_DMA == TRUE)
/* Setup DMA for AES encryption */
AesDmaSetup( Cstate, STATE_BLENGTH, Cstate, STATE_BLENGTH );
AES_SET_ENCR_DECR_KEY_IV( AES_ENCRYPT );
/* Kick it off, block until DMA is done */
AES_START();
while( !HAL_DMA_CHECK_IRQ( HAL_DMA_AES_OUT ) );
#else
/* Set ECB mode for AES encryption */
AES_SETMODE(ECB);
AES_SET_ENCR_DECR_KEY_IV( AES_ENCRYPT );
/* Load and start the block */
AesStartBlock( Cstate, Cstate );
#endif
}
/******************************************************************************
* @fn ssp_HW_KeyInit
*
* @brief Writes the key into AES engine
*
* input parameters
*
* @param AesKey - Pointer to AES Key.
*
* @return None
*/
void ssp_HW_KeyInit( uint8 *AesKey )
{
AES_SETMODE(ECB);
AesLoadKey( AesKey );
}