ocrypto supports the following cryptographic algorithms for  HomeKit:

Algorithm Specification
SRP-6 SHA512 (3072 bit keys) RFC2945
X25519 (Curve25519) RFC7748
Ed25519 RFC8032
AEAD-ChaCha20-Poly1305 RFC8439
AES FIPS-PUB-197
AES-CTR NIST SP 800-38A
SHA512 FIPS-PUB-180-4
SHA256 FIPS-PUB-180-4
SHA1 FIPS-PUB-180-4
HMAC-SHA512 RFC2104
HMAC-SHA256 RFC2104
HMAC-SHA1 RFC2104
HKDF-SHA512 RFC5869
HKDF-SHA256 RFC5869
HKDF-SHA1 RFC5869
PBKDF2-SHA1 RFC8018
SRTP RFC3711