Need SHA 256 Support for Micro ECC library

[Srinivas V]

Hi Team,

We are using the Micro ECC functionalities , for that we need the SHA 256 Library,Micro ECC library won't have inbuilt SHA.So how to enable the SHA for Micro ECC library.

    1. Which back end library is best for crypto functionalities with respect to time and current consumption(like mbed TLS, Oberon,Cifra)

    2. How to enable the RNG functionalities for Micro ECC library.

Regards,

Srinivas.V

[Jared]

Hi,

SHA256 is implemented in multiple backends in the SDK, µECC has it but we don't support the µECC HASH backend part. The alternative would be to use one of the other implementations that are supported in the SDK such as nrf_oberon. That is also the best library based on performance. To use RNG you need a entropy source which is available in either the RNG peripheral or the CC310 peripheral. 

best regards

Jared

[Srinivas V]

Hi Jared,

Thanks for your reply.

1.In between "nrf_oberon" and "mbed TLS" which one is best one, for normal cryptography(AES) we are using the mbed TLS library already, so in that can we enable the SHA256 functionality is that ok ? or we can use the oberon library for SHA Functionality.

2. We are using the nrf52832 soc, in that we dont have cc310 for RNG functionalities.How to enable the RNG peripheral alone without impacting the other crypto engines, some times crypto engines also using the RNG module, like mbed TLS and uECC as well.

3. What are the specific macros we need to enable for RNG peripheral in sdk_config.h file.

Regards,

Srinivas.V

[Jared]

Hi,

1. I would expect nrf_oberon to have the best performance. 
2. You should use the nRF Crypto API instead of accessing the peripheral directly. 
3. See the crypto examples from the SDK.