AWS-LC is a BoringSSL-based libcrypto implementation. SHA_CTX is declared with
the hash data specified as an array rather than as a field in upstream OpenSSL.
Since AWS-LC builds against C99, we are unable to handle this with anonymous
unions like BoringSSL. The workaround I propose is to add these conditional
macros around the accessors within openssl_sha1_prf. After this change,
everything builds successfully with AWS-LC headers.
Closesstrongswan/strongswan#2103
The old API has been deprecated with OpenSSL 3 and direct access to the
state isn't possible via EVP API. In the future we might just remove this
implementation but we'd probably have to implement EAP-AKA' first, which
uses HMAC-SHA-256 with IKEv2's prf+ construct to derive keys instead
of this weird construct (plus what fips-prf builds around it) that's used
by EAP-AKA.