Use EVP API instead of legacy APIs (s3 auth)

[maskit]

https://www.openssl.org/docs/manmaster/man3/SHA256_Init.html
https://www.openssl.org/docs/manmaster/man3/HMAC_Init_ex.html

SHA256 API and HMAC API are going to be deprecated.

[maskit]

[approve ci Clang-Analyzer]

[maskit]

Autest failure is because of OpenSSL on the box. It uses an old snapshot of OpenSSL master (+ QUIC patch) that has some new functions but not ones recently added. Although I could check availability of functions more strictly, that would not make much sense at the moment (until some incompatible changes happen in the future) because the new functions used on this PR are in the same series of OpenSSL API (EVP MAC). If one of them is available the others should be available at least on the next major release.

[maskit]

This is on hold because there's a discussion about heap allocation on #7447. We may prefer to use the old API as long as it's available.

Moved to WIP

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. Marking it stale to flag it for further consideration by the community.