KEM algorithms encap and decap with oqsprovider

[NarjasHadjer]

Hi,
I'm attempting to encapsulate a private key generated with Kyber512 on my Raspberry Pi 3B+ using Pi OS, but I'm encountering the error: "Operation not supported for this key type."
Could you advise on how to resolve this issue?

Thanks.

[baentsch]

I assume you have built oqsprovider with OQS_KEM_ENCODERS? If it then still doesn't work, I'm afraid you're out of luck: The openssl pkeyutil app has not been tested with oqsprovider and I'm not sure it's fully wired up for provider support. Maybe a question worth while asking in the OpenSSL forum? If you are convinced it should work, please consider contributing a PR to the oqsprovider test scripts.

[NarjasHadjer]

Effectively, i have built oqsprovider with OQS_KEM_ENCODERS,I am unable to either encrypt a text file or encapsulate the secret key. I am trying to apply OpenSSL commands and adapt them for PQC algorithms, but it's not working. When using RSA, for example, I am able to encrypt data, encapsulate, and decapsulate a secret key. However, when I try to do the same with Kyber512 by simply changing the algorithm name as shown in the screenshots, it does not work. I have also, upgraded OpenSSL to version 3.3.0, but i get the same errors. I have also noticed that with OQS_KEM_ENCODERS enabled, I encounter errors with DS algorithms, even though I tested the digital signature algorithms normally before enabling it.

[beldmit]

You want to encapsulate, not encrypt. Encapsulation was recently added by me to the OpenSSL master branch and will be a part of the upcoming 3.4 release

[NarjasHadjer]

Could you Sir please check if there is any error in the syntax of my command? I am unable to either encrypt a text file or encapsulate the secret key. I am trying to apply OpenSSL commands and adapt them for PQC algorithms, but it's not working. Could you kindly correct the encryption command, as the encapsulation is currently not supported?

[beldmit]

openssl/openssl#25127 is the PR, you can cherry-pick it, rebuild openssl, and use the syntax from the tests

#Encap/decap tests
$ openssl pkeyutl -encap -pubin -inkey rsa_pub.pem -secret secret.bin -out encap_out.bin
$ openssl pkeyutl -decap -inkey rsa_priv.pem -in encap_out.bin -out decap_out.bin
// decap_out is equal to secret

[NarjasHadjer]

I now understand what you meant in your previous comment, sir. Indeed, I know that I need to use the encap option instead of encrypt, but the encap and decap options are not available with the openssl pkeyutl command. I thought this might have been a change in OpenSSL 3.3.0.

[baentsch]

Thanks for pointing out the new/3.4.0 encap/decap feature, @beldmit . Worth while adding a comment at https://github.com/open-quantum-safe/oqs-provider?tab=readme-ov-file#note-on-openssl-versions and maybe a (openssl version-dependent) test in https://github.com/open-quantum-safe/oqs-provider/blob/main/scripts/runtests.sh?

[beldmit]

@NarjasHadjer to get this feature here and now, you'll have to apply code from the PR to openssl code (or wait till, I think, October 2024 for the 3.4 release).

@baentsch yes, it probably is worth a test and mentioning.