Remove deprecated things in psa/crypto_compat.h

[mpg]

There are a number of deprecated types and constants in include/psa/crypto_compat.h which seem to be for compatibility with previous version and should be removed. (For a list, search for DEPRECATED in that file.)

[mpg]

@gilles-peskine-arm Can you double-check that this makes sense? Also, I see that scripts/generate_psa_constant.py has provisions for skipping deprecated constants - can these be removed once the deprecated things in psa/crypto_compat.h or should support remain in the script?

[gilles-peskine-arm]

Yes, we should remove everything from crypto_compat.h in 3.0. We might as well remove that header file altogether.

There are two kinds of things in crypto_compat.h: old constants, and support for open/close.

Old constants can just go away, removing any reference to them in tests.

Removing open/close means removing more tests and code and there's a requested feature (#4218) that may reuse some of the code that's currently specific to open/close, so I suggest deferring that: just remove the declarations of psa_open_key and psa_close_key and supporting macros/funtions from public APIs, but keep the code and tests until after the 3.0 release.

I recommend not touching generate_psa_constants.py. I'm heavily refactoring it as part of my work to generate test cases for storage format stability; the code is now in scripts/mbedtls_dev/macro_collector.py, and it's just 3 lines of code: not worth the trouble of merge conflicts.

[TRodziewicz]

The issue has been fixed by: "Remove deprecated things from crypto_compat.h and dependent tests. #4344" so I'm closing it.