evp-cmac: do not seg-fault when getting mac-size before init
Add null check to cmac_size(). This avoids a seg-fault encountered
with cmac when EVP_MAC_CTX_get_mac_size() is called before init.
Extend mac testing in evp_test.c to check that the sizes returned by
EVP_MAC_CTX_get_mac_size() before and after init make sense (this also
ensures that we no longer seg-fault).
Fixes #22842
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22858)
(cherry picked from commit
ff181969e28c1503b077b47a9ded3683524b3fd8)