nrf_crypto chacha20 cipher only examples

[Hiihtaja]

Hello !

As part of nrf_crypto it is no any examples how-to use chacha20 without poly e.g only stream cipher.

Would be nice to use it via nrf_crypto and evaluate hw accelerated version ( cc310) and software one ( It is not clear if SW implementation is part of mbedtls or oberon back end).

Direct examples at /nRF5_SDK_17.1.0_ddde560/examples/crypto/nrf_cc310/chacha_poly work fine and chacha and chacha+poly examples are there.

Regards,

Eugene

[Edvin]

Hello,

I don't understand exactly what you were missing? Can you please clarify? As you said, the chacha_poly contains both chacha+poly and chacha without poly, which was what you needed, right?

Best regards,

Edvin

[Hiihtaja]

Hello !

I would like to use nrf_crypto APIs  only and would like to try Chacha as HW accelerated and SW implementation of it.

Regards,

Eugene

[Edvin]

I asked a colleague who came back today. He explained to me that Chacha without Poly is supported by CC310, but not in the nrf_crypto libraries, and hence, we don't have any examples for it.

You can find the API for it in SDK\external\nrf_cc310\include\crys_chacha.h. I have not tested, but I think everything should be there.

You can also do chacha without poly using oberon or mbed TLS (for SW implementation), but again we don't have any examples, and it is not supported by nrf_crypto. You can look at:

SDK\external\nrf_oberon_include\ocrypto_chacha20.h

SDK\external\mbedtls\include\mbedtls\chacha20.h

Best regards,

Edvin