Using X509 certificates with RSA crypto

RE: Using X509 certificates with RSA crypto

Einar Thorsrud — Thu, 25 Sep 2025 09:17:04 GMT

Hi,

You can do that. ButI was wondering if you have removed this line in subsys/nrf_security/Kconfig.legacy as described in the post? Note that if you are using SDK 3.1 or newer(?), that fix is allready in place. (However, RSA certificates are stil not yet supported with PSA Crypto.)

RE: Using X509 certificates with RSA crypto

Portilha — Thu, 25 Sep 2025 08:07:25 GMT

Hello, I did not understood your suggestion. Should I post here my full proj.conf?

RE: Using X509 certificates with RSA crypto

Einar Thorsrud — Tue, 23 Sep 2025 14:02:20 GMT

Hi,

Have you doen the change suggested in this post (removing "depends on !MBEDTLS_USE_PSA_CRYPTO" for MBEDTLS_RSA_C)?

RE: Using X509 certificates with RSA crypto

Portilha — Tue, 23 Sep 2025 10:43:49 GMT

Hello,

I don´t know if I have expressed myself correctly. I want to use two different concepts, one is X509 DER certificates and another is RSA encryption. If I deactivate the CONFIG_MBEDTLS_LEGACY_CRYPTO_C, the RSA code block works correcly. However if I disable this option I cannot compile the mbedtls functions for x509 certificates. I wanted to know if there is some way to have both functionalities at the same time.

RE: Using X509 certificates with RSA crypto

Einar Thorsrud — Tue, 23 Sep 2025 10:28:49 GMT

Hi,

RSA certificates are not yet supported with PSA Crypto. There is ongoing work for this, but I not not have a timeline for now. Please see this thread for more details.