CRYP api upgrade

[fermentedfly]

As far as I can tell the current HAL_CRYP_Encrypt (decrypt as well) provides an all-in-one solution for encryption. This is fine but my use case requires an API that can be initialized and then fed with multiple blocks of data, i.e. something like Init -> Encrypt Block 1 -> Encrypt Block 2 -> ... -> Finalize

Some other HAL implementations, e.g. STM32L4, provide functionality to do this. I've had a look in stm32h7xx_hal_cryp.c and it seems all the required functions are already present but have internal linkage. Please consider making those functions public.

Regards, Manuel

[TOUNSTM]

Hello @fermentedfly,

Thank you for this report. We will get back to you as soon as we analyze it further. This may take some time. Thank you for your comprehension.

With regards,

[HBOSTM]

Hello @fermentedfly,

Thank you for this contribution. Could you please give me more details about this issue, I need to know what internally linked functions you are talking about?

Best Regards,

[fermentedfly]

Hello @HBOSTM ,

I had a deeper look in stm32h7xx_hal_cryp.c and my initial estimate was a bit optimistic. I use AES CBC & GCM. For CBC, making static void CRYP_AES_ProcessData(CRYP_HandleTypeDef *hcryp, uint32_t Timeout) public is enough although a separate Init() would be very convenient.

For GCM, static HAL_StatusTypeDef CRYP_AESGCM_Process(CRYP_HandleTypeDef *hcryp, uint32_t Timeout) needs refactoring, i.e. the function needs to be split in it's three phases (header, data, finalize) in order to feed data multiple times.

For reference, please have a look in stm32l4xx_hal_cryp.c & stm32l4xx_hal_cryp_ex.c. It got my use case (both CBC & GCM) to work while using

• HAL_StatusTypeDef HAL_CRYP_Init(CRYP_HandleTypeDef *hcryp)
• HAL_StatusTypeDef HAL_CRYPEx_AES(CRYP_HandleTypeDef *hcryp, uint8_t *pInputData, uint16_t Size, uint8_t *pOutputData, uint32_t Timeout)
• HAL_StatusTypeDef HAL_CRYPEx_AES_Auth(CRYP_HandleTypeDef *hcryp, uint8_t *pInputData, uint64_t Size, uint8_t *pOutputData, uint32_t Timeout) (GCM only)

It would be superb if you can provide a similar API for STM32H7.

Regards, Manuel

[ALABSTM]

ST Internal Reference: 191062

[ALABSTM]

Hi @fermentedfly,

Your proposal has been forwarded to our development teams. I will get back to you once I have their feedback.

With regards,