[Bug]: iotsafe_hkdf_extract only works for SHA256_DIGEST about wolfssl HOT 4 OPEN

Hello @bolons
Thank you for testing our IoT-Safe module. The current implementation indeed only supports SHA256, as we had not tested the code against an applet supporting different hash sizes. The API documentation mentions this when describing the interface.

As the changes you introduced are currently working with your applet I will work on a patch to support other sizes as suggested, and update the docs.

from wolfssl.

Hi again @bolons

Could you please confirm that PR #7176 works with different hash sizes in your applet so I can go ahead and submit for reviews?

Thanks,

--
Daniele, wolfSSL

from wolfssl.

hello @danielinux

Thank you for the reply.
I can confirm that SHA384 worked in my applet. TLS 1.3 was established between woflssl-iotsafe and openssl in the server.
As for SHA512, haven't tested yet. My iotsafe applet supports SHA512 but don't know how to 'force' wolfssl and openssl server agree to use SHA512.

If you know how to configure either wolfssl or openssl in the server so that they use SHA512, let me know. I want to test SHA512 too.

from wolfssl.

Hi,
Thanks for your feedback. I am not sure how to force SHA512, it does not seem to be in any of the supported TLS 1.3 ciphersuites.

I'll go ahead with the PR. I'll ask around if there is a way to activate SHA512 with a TLS 1.3 ciphersuite.

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