add CKM_EDDSA and CK_EDDSA_PARAMS support

[fuzzykat]

No description provided.

[LudovicRousseau]

Do yo know why the github action for tox does NOT finish?
https://github.com/LudovicRousseau/PyKCS11/actions/runs/16540031592/job/46779908617

It was working fine before your patch.

[fuzzykat]

Do yo know why the github action for tox does NOT finish? https://github.com/LudovicRousseau/PyKCS11/actions/runs/16540031592/job/46779908617

It was working fine before your patch.

I have no idea yet, I'll try to investigate, but I need some time to reproduce that workflow locally.

[coveralls]

coverage: 93.528% (+0.05%) from 93.474%
when pulling 60dbe73 on fuzzykat:feature/ckm_eddsa
into 2094a49 on LudovicRousseau:master.

[fuzzykat]

Here is what I discovered: the tox workflow likely hangs because of a deadlock caused presumably by a certain sequence of load() and unload() calls. The strange thing is that this only reproduces when I run tests with tox, while python -m unittest discover successfully finishes when invoked directly.

Next I investigated the code in load() and it seems to me that it executes with the lock more code than it really should. By trial and error method I found out that the snippet below is the one which leads to the deadlock:

    if pkcs11dll_filename is None:
        pkcs11dll_filename = os.getenv("PYKCS11LIB")
        if pkcs11dll_filename is None:
            raise PyKCS11Error(
                -1, "No PKCS11 library specified (set PYKCS11LIB env variable)"
            )

I didn't manage to figure out the exact cause of the problem but it appears to be connected with os.getenv("PYKCS11LIB"), since after I moved it outside of the _lock scope the tests don't hang anymore. Anyway the above code should not be placed in the scope of the lock in the first place, since it doesn't modify PyKCS11Lib._loaded_libs, which is protected by the mutex.

tl;dr; I managed to fix the problem by moving os.getenv("PYKCS11LIB") outside of the mutex scope in load(). The commit is included in this PR.

[LudovicRousseau]

God job.
Thanks