Is TFM-M currently able to verify the signature of the image downloaded by
the 'untrusted client'?
I mean, are there needed methods exposed to 'untrusted app'? If so, what
methods need to be used?
Kind regards,
Tomasz
Hi,
It appears that ITS encryption would be required for PSA Certified Level 3. I'm seeing that this would required a platform specific HAL implementation. Is there some reason PSA Crypto APIs were not used like they were for attestation?
Encryption in ITS
=================
The ITS can optionally be configured to encrypt the internal trusted storage
data.
To support encryption in ITS the target platform must provide an
implementation of the APIs defined in ``platform/include/tfm_hal_its_encryption.h``::
enum tfm_hal_status_t tfm_hal_its_aead_generate_nonce(uint8_t *nonce,
const size_t nonce_size);
enum tfm_hal_status_t tfm_hal_its_aead_encrypt(
struct tfm_hal_its_auth_crypt_ctx *ctx,
const uint8_t *plaintext,
const size_t plaintext_size,
uint8_t *ciphertext,
const size_t ciphertext_size,
uint8_t *tag,
const size_t tag_size);
enum tfm_hal_status_t tfm_hal_its_aead_decrypt(
struct tfm_hal_its_auth_crypt_ctx *ctx,
const uint8_t *ciphertext,
const size_t ciphertext_size,
uint8_t *tag,
const size_t tag_size,
uint8_t *plaintext,
const size_t plaintext_size);
Regards,
Brian Quach
SimpleLink MCU
Texas Instruments Inc.
12500 TI Blvd, MS F-4000
Dallas, TX 75243
214-479-4076