A key selection algorithm is similar to a key derivation algorithm in
that it takes a secret input and produces a secret output stream.
However, unlike key derivation algorithms, there is no expectation
that the input cannot be reconstructed from the output. Key selection
algorithms are exclusively meant to be used on the output of a key
agreement algorithm to select chunks of the shared secret.
For all key types, validate feature test macros (PSA_KEY_TYPE_IS_xxx).
For asymmetric keys (public key or key pair), validate the
corresponding public/pair type.
For ECC keys, validate GET_CURVE.
For all algorithms, validate feature test macros (PSA_ALG_IS_xxx).
For hash algorithms, validate the exact hash size, and validate
xxx_GET_HASH macros on dependent algorithms.
For MAC algorithms, validate the MAC size. For AEAD algorithms,
validate the tag size.
There is a separate test case for each HMAC algorithm, which is
necessary because each has its own MAC size. For other hash-dependent
algorithms, there is no interesting variation to test here, so only
one hash gets tested.
