Remove a conditional imbrication level. Get rid of some minor overhead
for ECC public keys dating back from when they had ASN.1 wrapping.
No behavior change.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Move mbedtls_test_psa_exercise_key() (formerly exercise_key()) and
related functions to its own module. Export the few auxiliary
functions that are also called directly.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>