/**
* \brief Test AES state interface functions
*
* This test verifies that the functions used to check the state of the module
* are working, and that the clear functions work correctly.
*
* \param test Current test case
*/
static void run_aes_state_interface_test(const struct test_case *test)
{
/* We first reset the module */
aes_software_reset();
/* The module should not be busy or in error */
test_assert_true(test, aes_is_busy(), "Module should not be busy!");
test_assert_true(test, !aes_is_error(), "Module should not be in error!");
/* Get the module into error by trying to start the module before loading
* values into state memory */
aes_start();
/* Module should now be in error */
test_assert_true(test, aes_is_error(), "Module should be in error!");
/* Clear the flag and check that it has been cleared */
aes_clear_error_flag();
test_assert_true(test, !aes_is_error(),
"Module error flag should have been cleared!");
/* Load up dummy data into the module and do a cycle, then check that
* the aes_is_busy() function actually works */
aes_software_reset();
aes_configure(AES_ENCRYPT, AES_MANUAL, AES_XOR_OFF);
aes_set_key(encryption_key);
aes_write_inputdata(dummy_data);
aes_start();
/* Check that the module is busy, the module uses more CPU cycles to
* complete than it takes to see if it is busy */
test_assert_true(test, aes_is_busy(), "AES module should be busy!");
do {
/* Wait until the module is finished */
} while(aes_is_busy());
/* The module now has data in the status register. We want to clear the
* flag without reading the data. First verify that the flag is set */
test_assert_true(test, AES.STATUS & AES_SRIF_bm,
"State ready interrupt flag is not set!");
aes_clear_interrupt_flag();
/* Now, check that we have cleared the flag */
test_assert_true(test, !(AES.STATUS & AES_SRIF_bm),
"State ready interrupt flag should not be set!");
}
/**
* \brief Test AES decryption function.
*
* This test decrypts the pre-encrypted data and checks
* whether it is correct.
*
* \param test Current test case.
*/
static void run_aes_decryption_test(const struct test_case *test)
{
t_key decrypted_data;
bool success;
set_buffer(decrypted_data, 0x00);
set_buffer(lastsubkey, 0x00);
/* Call helper function to generate a last subkey for decryption */
if (!aes_lastsubkey_generate(encryption_key, lastsubkey)) {
success = false;
test_assert_true(test, !success,
"Could not generate last subkey");
} else {
/* Configure module for manual decryption */
aes_software_reset();
aes_set_key(lastsubkey);
aes_configure(AES_DECRYPT, AES_MANUAL, AES_XOR_OFF);
aes_write_inputdata(pre_encrypted_data);
aes_start();
do {
/* Wait until AES is finished or an error occurs. */
} while (aes_is_busy());
aes_read_outputdata(decrypted_data);
/* Verify that the decrypted data is correct */
success = compare_data_block(decrypted_data, encryption_data);
test_assert_true(test, success,
"Decrypted values do not match excepted values");
}
}
/**
* \brief Generate AES sub key
*
* Get AES sub key by encryption of dummy data.
*
* \param key Pointer to AES key input.
* \param last_sub_key Pointer to AES sub key output.
*
*/
static bool aes_lastsubkey_generate(t_key key, t_key last_sub_key)
{
bool keygen_ok;
aes_software_reset();
/* Set AES encryption of a single block in manual mode. */
aes_configure(AES_ENCRYPT, AES_MANUAL, AES_XOR_OFF);
/* Load key into AES key memory. */
aes_set_key(key);
/* Load dummy data into AES state memory. It isn't important what is
* written, just that a write cycle occurs. */
aes_write_inputdata(dummy_data);
/* Start encryption. */
aes_start();
do {
/* Wait until AES is finished or an error occurs. */
} while (aes_is_busy());
/* If not error. */
if (!aes_is_error()) {
/* Store the last subkey. */
aes_get_key(last_sub_key);
aes_clear_interrupt_flag();
keygen_ok = true;
} else {
aes_clear_error_flag();
keygen_ok = false;
}
return keygen_ok;
}
/**
* \brief Generate AES sub key
*
* \note Get AES sub key by encryption of dummy data.
*
* \param key Pointer to AES key input.
* \param last_sub_key Pointer to AES sub key output.
*
*/
static bool aes_lastsubkey_generate(t_key key, t_key last_sub_key)
{
bool keygen_ok;
uint8_t i;
/* Before using the AES it is recommended to do an AES software reset to
* put the module in known state, in case other parts of your code has
* accessed the AES module. */
aes_software_reset();
/* Set AES encryption of a single block in manual mode. */
aes_configure(AES_ENCRYPT, AES_MANUAL, AES_XOR_OFF);
/* Load key into AES key memory. */
aes_set_key(key);
/* Load dummy data into AES state memory. */
for (i = 0; i < BLOCK_LENGTH; i++) {
AES.STATE = 0x00;
}
/* Start encryption. */
aes_start();
do {
/* Wait until AES is finished or an error occurs. */
} while (aes_is_busy());
/* If not error. */
if (!aes_is_error()) {
/* Store the last subkey. */
aes_get_key(last_sub_key);
aes_clear_interrupt_flag();
keygen_ok = true;
} else {
aes_clear_error_flag();
keygen_ok = false;
}
return keygen_ok;
}
/**
* \brief Test AES encryption function
*
* This test generates an encrypted byte string from a key and input,
* and compares it to a pre-encrypted value.
*
* \param test Current test case.
*/
static void run_aes_encryption_test(const struct test_case *test)
{
t_data encrypted_data;
bool success;
/* Zero out the output data storage */
set_buffer(encrypted_data, 0x00);
/* Reset the module */
aes_software_reset();
/*
* Configure AES module to encrypt, triggered by software,
* with no XOR
*/
aes_configure(AES_ENCRYPT, AES_MANUAL, AES_XOR_OFF);
aes_set_key(encryption_key);
aes_write_inputdata(encryption_data);
aes_start();
do {
/* Wait until AES is finished or an error occurs. */
} while (aes_is_busy());
aes_read_outputdata(encrypted_data);
/* Verify that this data is correct by comparing it
* to our pre-encrypted value
*/
success = compare_data_block(encrypted_data, pre_encrypted_data);
test_assert_true(test, success,
"Encrypted values do not match pre-encrypted"
" values");
}
int main( void )
{
uint8_t i;
board_init();
sysclk_init();
sleepmgr_init();
/* Assume that everything is ok*/
success = true;
/* Enable the AES clock. */
sysclk_enable_module(SYSCLK_PORT_GEN, SYSCLK_AES);
/* Do AES encryption of a single block with DMA support. */
//********************************************************
// CIPHER IN MANUAL MODE:
// - 128bit cryptographic key and data
// - ECB cipher mode
// - XOR disable
// - DMA support for AES input and output
//********************************************************
/* Before using the AES it is recommended to do an AES software reset to
* put the module in known state, in case other parts of your code has
* accessed the AES module. */
aes_software_reset();
/* Set AES encryption of a single block in manual mode. */
aes_configure(AES_ENCRYPT, AES_MANUAL, AES_XOR_OFF);
/* Disable the AES interrupt. */
aes_isr_configure(AES_INTLVL_OFF);
/* Set KEY and write STATE using DMA channel 0. */
aes_dma_input();
/* Start encryption. */
aes_start();
do {
/* Wait until AES is finished or an error occurs. */
} while (aes_is_busy());
/* Store the result if not error. */
if (!aes_is_error()){
/* Read STATE using DMA channel 0. */
aes_dma_output();
} else {
success = false;
}
/* Check if encrypted answer is equal to cipher result. */
for (i = 0; i < BLOCK_LENGTH ; i++ ) {
if (cipher_text[i] != single_ans[i]) {
success = false;
}
}
/* Disable the AES clock. */
sysclk_disable_module(SYSCLK_PORT_GEN, SYSCLK_AES);
/* Indicate final result by lighting LED. */
if (success) {
/* If the example ends up here every thing is ok. */
ioport_set_pin_low(LED0_GPIO);
} else {
/* If the example ends up here something is wrong. */
ioport_set_pin_low(LED1_GPIO);
}
while (true) {
/* Go to sleep. */
sleepmgr_enter_sleep();
}
}
int main( void )
{
uint8_t i;
board_init();
sysclk_init();
sleepmgr_init();
/* Assume that everything is ok */
success = true;
/* Enable the AES clock. */
sysclk_enable_module(SYSCLK_PORT_GEN, SYSCLK_AES);
/* Do AES encryption and decryption of a single block. */
//********************************************************
// CIPHER IN MANUAL MODE:
// - 128bit cryptographic key and data
// - ECB cipher mode
// - XOR disable
// - Polling AES State Ready Interrupt flag
//********************************************************
/* Before using the AES it is recommended to do an AES software reset to
* put the module in known state, in case other parts of your code has
* accessed the AES module. */
aes_software_reset();
/* Set AES encryption of a single block in manual mode. */
aes_configure(AES_ENCRYPT, AES_MANUAL, AES_XOR_OFF);
/* Disable the AES interrupt. */
aes_isr_configure(AES_INTLVL_OFF);
/* Load key into AES key memory. */
aes_set_key(key);
/* Load data into AES state memory. */
aes_write_inputdata(plain_text);
/* Start encryption. */
aes_start();
do {
/* Wait until AES is finished or an error occurs. */
} while (aes_is_busy());
/* Store the result if not error. */
if (!aes_is_error()) {
aes_read_outputdata(single_ans);
} else {
success = false;
}
/* Check if encrypted answer is equal to cipher result. */
for (i = 0; i < BLOCK_LENGTH ; i++ ) {
if (cipher_text[i] != single_ans[i]) {
success = false;
}
}
//********************************************************
// DECIPHER IN AUTO MODE:
// - 128bit cryptographic key and data
// - ECB cipher mode
// - XOR disable
// - Polling AES State Ready Interrupt flag
//********************************************************
/* Generate last subkey. */
if (!aes_lastsubkey_generate(key, lastsubkey)) {
success = false;
}
/* Before using the AES it is recommended to do an AES software reset to
* put the module in known state, in case other parts of your code has
* accessed the AES module. */
aes_software_reset();
/* Set AES decryption of a single block in auto mode. */
aes_configure(AES_DECRYPT, AES_AUTO, AES_XOR_OFF);
/* Disable the AES interrupt. */
aes_isr_configure(AES_INTLVL_OFF);
/* Load key into AES key memory. */
aes_set_key(lastsubkey);
/* Load data into AES state memory. */
aes_write_inputdata(cipher_text);
// NOTE: since we're in auto mode, the ciphering process will start as soon
// as the correct number of input data is written. In this case, the
// process should start when we write the sixteenth byte.
do {
/* Wait until AES is finished or an error occurs. */
} while (aes_is_busy());
/* Store the result if not error. */
if (!aes_is_error()) {
aes_read_outputdata(single_ans);
} else {
success = false;
}
/* Check if decrypted answer is equal to plaintext. */
for (i = 0; i < BLOCK_LENGTH ; i++ ) {
if (plain_text[i] != single_ans[i]) {
success = false;
}
}
/* Disable the AES clock. */
sysclk_disable_module(SYSCLK_PORT_GEN, SYSCLK_AES);
/* Indicate final result by lighting LED. */
if (success) {
/* If the example ends up here every thing is ok. */
ioport_set_pin_low(LED0_GPIO);
} else {
/* If the example ends up here something is wrong. */
ioport_set_pin_low(LED1_GPIO);
}
while (true) {
/* Go to sleep. */
sleepmgr_enter_sleep();
}
}
/**
* \brief CTR mode encryption and decryption test.
*/
static void ctr_mode_test(void)
{
printf("\r\n-----------------------------------\r\n");
printf("- 128bit cryptographic key\r\n");
printf("- CTR cipher mode\r\n");
printf("- Auto start mode\r\n");
printf("- 4 32bit words\r\n");
printf("-----------------------------------\r\n");
state = false;
/* Configure the AES. */
g_aes_cfg.encrypt_mode = AES_ENCRYPTION;
g_aes_cfg.key_size = AES_KEY_SIZE_128;
g_aes_cfg.start_mode = AES_AUTO_START;
g_aes_cfg.opmode = AES_CTR_MODE;
g_aes_cfg.cfb_size = AES_CFB_SIZE_128;
g_aes_cfg.lod = false;
aes_set_config(&aes_instance,AES, &g_aes_cfg);
/* Set the cryptographic key. */
aes_write_key(&aes_instance, key128);
/* Set the initialization vector. */
aes_write_init_vector(&aes_instance, init_vector_ctr);
aes_set_new_message(&aes_instance);
/* Write the data to be ciphered to the input data registers. */
aes_write_input_data(&aes_instance, ref_plain_text);
aes_clear_new_message(&aes_instance);
/* Wait for the end of the encryption process. */
while (false == state) {
}
/* check the result. */
if ((ref_cipher_text_ctr[0] != output_data[0]) ||
(ref_cipher_text_ctr[1] != output_data[1]) ||
(ref_cipher_text_ctr[2] != output_data[2]) ||
(ref_cipher_text_ctr[3] != output_data[3])) {
printf("\r\nKO!!!\r\n");
} else {
printf("\r\nOK!!!\r\n");
}
printf("\r\n-----------------------------------\r\n");
printf("- 128bit cryptographic key\r\n");
printf("- CTR decipher mode\r\n");
printf("- Auto start mode\r\n");
printf("- 4 32bit words\r\n");
printf("-----------------------------------\r\n");
state = false;
/* Configure the AES. */
g_aes_cfg.encrypt_mode = AES_DECRYPTION;
g_aes_cfg.key_size = AES_KEY_SIZE_128;
g_aes_cfg.start_mode = AES_MANUAL_START;
g_aes_cfg.opmode = AES_CTR_MODE;
g_aes_cfg.cfb_size = AES_CFB_SIZE_128;
g_aes_cfg.lod = false;
aes_set_config(&aes_instance,AES, &g_aes_cfg);
/* Set the cryptographic key. */
aes_write_key(&aes_instance, key128);
/* Set the initialization vector. */
aes_write_init_vector(&aes_instance, init_vector_ctr);
/* Write the data to be deciphered to the input data registers. */
aes_write_input_data(&aes_instance, ref_cipher_text_ctr);
aes_set_new_message(&aes_instance);
aes_start(&aes_instance);
aes_clear_new_message(&aes_instance);
/* Wait for the end of the decryption process. */
while (false == state) {
}
/* check the result. */
if ((ref_plain_text[0] != output_data[0]) ||
(ref_plain_text[1] != output_data[1]) ||
(ref_plain_text[2] != output_data[2]) ||
(ref_plain_text[3] != output_data[3])) {
printf("\r\nKO!!!\r\n");
} else {
printf("\r\nOK!!!\r\n");
}
}
int main( void )
{
uint16_t i;
/* Enable all three interrupt levels of the PMIC. */
pmic_init();
board_init();
sysclk_init();
sleepmgr_init();
/* Assume that everything is ok*/
success = true;
/* Enable the AES clock. */
sysclk_enable_module(SYSCLK_PORT_GEN, SYSCLK_AES);
/* Do AES decryption of a single block with AES interrupt handler. */
//********************************************************
// DECIPHER IN MANUAL MODE:
// - 128bit cryptographic key and data
// - ECB cipher mode
// - XOR disable
// - Interrupt call back handler
//********************************************************
/* Generate last subkey. */
if (!aes_lastsubkey_generate(key, lastsubkey)) {
success = false;
}
/* Enable global interrupts. */
cpu_irq_enable();
/* Assume no interrupt is finished. */
int_end = false;
byte_count = 0;
/* Set AES interrupt call back function. */
aes_set_callback(&aes_isr_handler);
/* Before using the AES it is recommended to do an AES software reset to
* put the module in known state, in case other parts of your code has
* accessed the AES module. */
aes_software_reset();
/* Set AES encryption of a single block in manual mode. */
aes_configure(AES_DECRYPT, AES_MANUAL, AES_XOR_OFF);
/* Enable the AES low level interrupt. */
aes_isr_configure(AES_INTLVL_LO);
/* Load key into AES key memory. */
aes_set_key(lastsubkey);
/* Load data into AES state memory. */
aes_write_inputdata(cipher_text);
/* Start encryption. */
aes_start();
do{
/* Wait until the AES interrupt is finished. */
} while (!int_end);
/* Do AES encryption and decryption of multi blocks. */
//********************************************************
// CIPHER IN AUTO MODE:
// - 128bit cryptographic key and data
// - CBC cipher mode
// - XOR on
// - Interrupt call back handler
//********************************************************
/* Assume no interrupt is finished. */
int_end = false;
byte_count = 0;
/* Set AES interrupt call back function. */
aes_set_callback(&aes_isr_cbc_encrypt_handler);
/* Before using the AES it is recommended to do an AES software reset to
* put the module in known state, in case other parts of your code has
* accessed the AES module. */
aes_software_reset();
/* Load initial vector into AES state memory. */
aes_write_inputdata(init);
/* Set AES encryption of a single block in auto mode. */
aes_configure(AES_ENCRYPT, AES_AUTO, AES_XOR_ON);
/* Enable the AES low level interrupt. */
aes_isr_configure(AES_INTLVL_LO);
/* Load key into AES key memory. */
aes_set_key(key);
/* Load data into AES state memory. */
aes_write_inputdata(data_block);
// NOTE: since we're in auto mode, the ciphering process will start as soon
// as the correct number of input data is written. In this case, the
// process should start when we write the sixteenth byte.
do{
/* Wait until the AES interrupt is finished. */
} while (!int_end);
//********************************************************
// DECIPHER IN AUTO MODE:
// - 128bit cryptographic key and data
// - CBC cipher mode
// - XOR off
// - Interrupt call back handler
//********************************************************
/* Generate last subkey. */
if (!aes_lastsubkey_generate(key, lastsubkey)) {
success = false;
}
/* Assume no interrupt is finished. */
int_end = false;
byte_count = 0;
/* Set AES interrupt call back function. */
aes_set_callback(&aes_isr_cbc_decrypt_handler);
/* Before using the AES it is recommended to do an AES software reset to
* put the module in known state, in case other parts of your code has
* accessed the AES module. */
aes_software_reset();
/* Set AES decryption of a single block in auto mode. */
aes_configure(AES_DECRYPT, AES_AUTO, AES_XOR_OFF);
/* Enable the AES low level interrupt. */
aes_isr_configure(AES_INTLVL_LO);
/* Load key into AES key memory. */
aes_set_key(lastsubkey);
/* Load data into AES state memory. */
aes_write_inputdata(cipher_block_ans);
// NOTE: since we're in auto mode, the ciphering process will start as soon
// as the correct number of input data is written. In this case, the
// process should start when we write the sixteenth byte.
do{
/* Wait until the AES interrupt is finished. */
} while (!int_end);
/* Check if decrypted answer is equal to plaintext. */
for (i = 0; i < BLOCK_LENGTH * BLOCK_COUNT ; i++) {
if (data_block[i] != plain_block_ans[i]){
success = false;
}
}
/* Disable the AES clock. */
sysclk_disable_module(SYSCLK_PORT_GEN, SYSCLK_AES);
/* Indicate final result by lighting LED. */
if (success) {
/* If the example ends up here every thing is ok. */
ioport_set_pin_low(LED0_GPIO);
} else {
/* If the example ends up here something is wrong. */
ioport_set_pin_low(LED1_GPIO);
}
while (true) {
/* Go to sleep. */
sleepmgr_enter_sleep();
}
}