Hi @BLEuser ,
It exists a specific API for this :
tBleStatus hci_le_encrypt(uint8_t Key[16],
uint8_t Plaintext_Data[16],
uint8_t Encrypted_Data[16]);
This API can be used to request controller to encrypt Plaintext_Data iusing the Key given in the command
* and returns the Encrypted_Data to the Host
Here below is a copy/past of a code example where data is encrypted using AES engine with hci_le_encrypt and then decrypted with sw decryption using crypo lib.
Particular attention must be paid to the endianness: hci_le_encrypt uses data in little endian format, while cryptolib uses big endian format.
uint8_t key_le[16] = {0x0f,0x0e,0x0d,0x0c,0x0b,0x0a,0x09,0x08,0x07,0x06,0x05,0x04,0x03,0x02,0x01,0x00};
uint8_t key_be[16];
uint8_t plaintext_data_le[16] = {0x0f,0x0e,0x0d,0x0c,0x0b,0x0a,0x09,0x08,0x07,0x06,0x05,0x04,0x03,0x02,0x01,0x00};
uint8_t plaintext_data_be[16];
uint8_t encrypted_data_le[16];
uint8_t encrypted_data_be[16];
int32_t length;
int32_t ret_val;
AESECBctx_stt AESECBctx;
AESECBctx.mKeySize = CRL_AES128_KEY;
AESECBctx.mFlags = E_SK_DEFAULT;
hci_le_encrypt(key_le, plaintext_data_le, encrypted_data_le);
for(int i = 0; i < 16; i++)
{
key_be[i] = key_le[15 - i];
}
for(int i = 0; i < 16; i++)
{
plaintext_data_be[i] = plaintext_data_le[15-i];
}
for(int i = 0; i < 16; i++)
{
encrypted_data_be[i] = encrypted_data_le[15-i];
}
for(int i = 0; i < sizeof(encrypted_data_le); i++)
printf("%02X ",encrypted_data_be[i]);
printf("\n");
ret_val = AES_ECB_Decrypt_Init(&AESECBctx, key_be, NULL);
if(ret_val != AES_SUCCESS)
{
printf("AES_ECB_Decrypt_Init 0x%02X\n",ret_val);
while(1);
}
ret_val = AES_ECB_Decrypt_Append(&AESECBctx, encrypted_data_be, sizeof(encrypted_data_be), plaintext_data_be, &length);
if(ret_val != AES_SUCCESS)
{
printf("AES_ECB_Decrypt_Append 0x%02X\n",ret_val);
while(1);
}
for(int i = 0; i < sizeof(plaintext_data_be); i++)
printf("%02X ",plaintext_data_be[i]);
printf("\n");
ret_val = AES_ECB_Decrypt_Finish(&AESECBctx, plaintext_data_be, &length);
if(ret_val != AES_SUCCESS)
{
printf("AES_ECB_Decrypt_Finish 0x%02X\n",ret_val);
while(1);
}
Hope it helps.
Regards,
Sebastien.
