Samba supports using AES acceleration instructions (at least Intel's aesni). It can be enabled with './configure --accel-aes=aesni'.
This doesn't seem to be useful, actually. In this presentation [0], it's shown that gnutls + aesni if available is preferred, and there is a warning about using aesni in the source, so I'll close this. https://sambaxp.org/archive-data-samba/SambaXP2019-SLIDES/andreas_schneider_samba_in_love_with_gnutls.pdf