AES Encryption/Decryption nRF91 and the CRYPTOCELL

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

jli157@intel — Tue, 14 Jan 2020 06:33:55 GMT

Thanks! I see the macro `MBEDTLS_CTR_DRBG_ENABLED` could be defined in pro.conf. However, I can't find its definition in your examples. Anyway, I see the whole examples and will take a try again. Thank you!

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

Einar Thorsrud — Mon, 06 Jan 2020 08:12:33 GMT

Hi,

Did you make any progress these last two weeks?

If not, the CONFIG_MBEDTLS_CTR_DRBG_ENABLED is set via Kconfig, so typically prj.conf, as is the case in the PR I linked to. You can see an example of usage of mbedtls_ctr_drbg_init() here.

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

Einar Thorsrud — Fri, 20 Dec 2019 14:03:30 GMT

Hi,

I need to look into this. The holiday season is upon us, so unfortunately I will probably not be able to get back to you regarding this until beginning of January.

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

jli157@intel — Fri, 20 Dec 2019 02:00:29 GMT

Hi Einar, one question about how to use the library: I'm trying to use entropy functions and I need to call the function `mbedtls_ctr_drbg_init`. However, I can't find the place for defining the macro `CONFIG_MBEDTLS_CTR_DRBG_ENABLED` in the test code. Also, it seems I need to define my mutex functions and call the function `mbedtls_threading_set_alt` to set them to the mbedtls library. However, I can't find a any code defining these mutex functions and calling the function `mbedtls_threading_set_alt`. Can you explain how I use the entropy functions? Thank you!

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

jli157@intel — Fri, 13 Dec 2019 21:10:32 GMT

The pull request is very helpful as a reference! I'll take a look and come back upon further questions. Thank you very much!

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

Einar Thorsrud — Fri, 13 Dec 2019 08:55:54 GMT

Hi,

I suggest you look at this pull request which has low-level crypto tests to see how to use the low-level API, which should show you how to do SHA256 etc.

Regarding the crypto components from the nRF5 SDK, these do not have any dependencies to the SoftDevice. However, there may be some issues using it together with Zephyr, since that is not tested.

You are right that there is support for nRF52840 in nRF Connect SDK and Zephyr, my point was just that it is not currently officially supported. So you should not make any assumptions about the quality etc.

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

jli157@intel — Thu, 12 Dec 2019 22:01:18 GMT

By reading the internal code, I didn't see the sdk excludes NRF52840 from being supported. Also, I tried a very simple sha256 hash example with mbedtls as the front-end and it works on NRF52840. So, I can assume the sdk still works for NRF52840 even though it doesn't get technical support, right?

Another way I can imagine is directly to use the crypto component from NRF52 sdk. However, I'm not sure if that component is independent from Soft Device since I'm using zephyr as the operating system for the device. Can you confirm if the crypto component is an independent one which doesn't need soft device?

Thank you!

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

Einar Thorsrud — Thu, 12 Dec 2019 08:08:06 GMT

Hi,

Please note that the nRF52 series is not officially supported in the nRF Connect SDK today.

The bootloader does not currently use the nrf_security module since that would increase the size, and we try to keep the bootloader size down. We are planning to add an example for using nrf_security along with improved documentation in the future, but it might take some time.

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

jli157@intel — Wed, 11 Dec 2019 01:32:42 GMT

Hi Einar, I'm also interested in how to use CC310 from NRF52840. However, by checking the documentation you mentioned, it is suggested to use `Nordic security module` instead of c310_mbedcrypto directly. Do you have any example showing how to use the module for a simple application, such as going through app configuration, initialization, using several functions, and de-initialization? I found the boot loader library in `nrf/subsys/bootloader` is using cc310 but it doesn't decently demonstrate how to use the APIs from Nordic Security module. So, any samples showing how to use the module will be much appreciated.

Thank you!

RE: AES Encryption/Decryption nRF91 and the CRYPTOCELL

Einar Thorsrud — Tue, 24 Sep 2019 11:40:07 GMT

Hi,

There are no examples specifically for the CC310 peripheral in nRF91 in nRF Connect SDK. However, it is supported, though the SW support lacks a bit in maturity. The CC310 should be used with mbed TLS as a frontend, via nrf_cc310_mbedcrypto (documentation here).