AES
SIFLI has hardware implementation of AES encryption/decryption. It provides high performance on AES functions and is used in bootloader and DFU to decrypt received images.
It supports:
Encryption and decryption.
AES and SM4 algorithms.
128, 192 or 256 AES key length.
ECB, CTR and CBC AES cipher modes.
For API details, please refer to AES.
Note
The input and output memory used by AES cannot be ITCM RAM or Retention RAM, please refer to for addresses
Using AES Encryption/Decryption
Please refer to the following code as an example:
ALIGN(4) // Make sure g_key and g_nounce_counter 4bytes aligned
static uint8_t g_key[32] = // Key is defined by user, if use 256 AES length, it need to be 32 bytes
{
0x3D, 0xA5, 0xA4, 0x98, 0x6E, 0x90, 0xA7, 0x90,
0x1D, 0x97, 0x69, 0xAA, 0xF0, 0xDF, 0x32, 0xE4,
0x55, 0xE9, 0xFC, 0xD6, 0x75, 0x60, 0xBD, 0x33,
0x5E, 0x20, 0xD0, 0x78, 0x47, 0xF7, 0x8C, 0x4D,
};
static uint8_t g_nounce_counter[16]=
{
0xf0, 0xd7, 0x77, 0x7f, 0x61, 0x6f, 0x7c, 0x89,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
uint8_t input_data[BUFFER_SIZE];
uint8_t output_data[BUFFER_SIZE];
// Get input_data , this is not described in this code pieces.
// Encryption
HAL_AES_init(g_key, 32, g_nounce_counter, AES_MODE_CTR);
HAL_AES_run_IT(true, input_data, output_data, BUFFER_SIZE); // Run Async, interrupt will generate interrupt when done
rt_thread_delay(1000);
// Decryption
HAL_AES_init(g_key, 32, g_nounce_counter, AES_MODE_CTR); // Run Sync
HAL_AES_run(false, input_data, output_data, BUFFER_SIZE); // Function will block until Decryption finish.
....
void AES_IRQHandler(void)
{
printf("AES function finished");
HAL_AES_IRQHandler();
}