/**
* \brief The AES interrupt handler.
*/
void AES_Handler(void)
{
uint32_t status = aes_read_interrupt_status(AES);
uint32_t mask = aes_read_interrupt_mask(AES);
if ((status & AES_ISR_DATRDY) && (mask & AES_IMR_DATRDY)) {
if(aes_callback_pointer[0]) {
aes_callback_pointer[0]();
}
}
if ((status & AES_ISR_URAD) && (mask & AES_IMR_URAD)) {
if(aes_callback_pointer[1]) {
aes_callback_pointer[1]();
}
}
}
/**
* \brief GCM mode decryption test.
*/
static void gcm_mode_decryption_test(void)
{
printf("\r\n-----------------------------------\r\n");
printf("- 256bit cryptographic key\r\n");
printf("- GCM Decryption\r\n");
printf("- Auto start mode\r\n");
printf("- input of 160-bit effective words\r\n");
printf("-----------------------------------\r\n");
/* Configure the AES. */
g_aes_cfg.encrypt_mode = AES_DECRYPTION;
g_aes_cfg.key_size = AES_KEY_SIZE_256;
g_aes_cfg.start_mode = AES_AUTO_START;
g_aes_cfg.opmode = AES_GCM_MODE;
g_aes_cfg.cfb_size = AES_CFB_SIZE_128;
g_aes_cfg.lod = false;
g_aes_cfg.gtag_en = false;
aes_set_config(AES, &g_aes_cfg);
/* AES-GCM Input Configuration */
gcm_input_data.key = aes_key;
gcm_input_data.key_len = AES_KEY_SIZE;
gcm_input_data.iv = aes_iv;
gcm_input_data.iv_len = AES_IV_SIZE;
gcm_input_data.input = aes_cipher_text;
gcm_input_data.text_len = AES_PDATA_EFFECTIVE_SIZE;
gcm_input_data.aad = aes_aad;
gcm_input_data.aad_len = AES_AAD_EFFECTIVE_SIZE;
gcm_input_data.output = output_data;
gcm_input_data.tag = tag_data;
/* Write the key to generate GCMH Subkey */
aes_write_key(AES, gcm_input_data.key);
/* Wait for the GCMH to generate */
while (!(aes_read_interrupt_status(AES) & AES_ISR_DATRDY)) {
}
/* Generate J0 using IV(96 Bits) */
uint32_t i;
/* J0 data array */
uint32_t j0[4];
for (i = 0; i < 3; i++) {
j0[i] = gcm_input_data.iv[i];
}
/* Write the j0 + 1 in IV register */
j0[3] = 0x02000000;
aes_write_initvector(AES, (uint32_t *)j0);
/* set AADLEN */
aes_write_authen_datalength(AES, gcm_input_data.aad_len);
/* Set CLEN */
aes_write_pctext_length(AES, gcm_input_data.text_len);
/* Write AAD Data for TAG generation */
uint32_t offset = 0;
for (i = 0; i < (AES_AAD_SIZE / 4); i++) {
/* write the input data */
aes_write_input_data(AES, (gcm_input_data.aad + offset));
/* Wait till TAG is ready */
while (!(aes_read_interrupt_status(AES) & AES_ISR_DATRDY)) {
}
/* 16-Byte Boundaries */
offset += 4;
}
/* Reset offset to zero */
offset = 0;
/* Write plain text for cipher text generation */
for (i = 0; i < (AES_PDATA_SIZE / 4); i++) {
/* write the input data */
aes_write_input_data(AES, (gcm_input_data.input + offset));
/* Wait for the operation to complete */
while (!(aes_read_interrupt_status(AES) & AES_ISR_DATRDY)) {
}
aes_read_output_data(AES,
(uint32_t *)(gcm_input_data.output + offset));
offset += 4;
}
if (memcmp(output_data, aes_plain_text,
AES_PDATA_EFFECTIVE_SIZE) != 0) {
printf("\n\rDEC COMPARE FAILED! ");
} else {
printf("\n\rDEC COMPARE SUCCESS! ");
}
}