In the SunJSSE provider, if the Signature is available in crypto for a certain signature algorithm, the algorithm will be requested in the signature_algorithms extension. With the integration of ed25519 and ed448, the signature algorithm are now available in crypto, and thus is activated in JSSE. Ed25519 and Ed448 are present in handshake messages, which is not the expected behavior before JDK-8166596 get addressed.

    "signature_algorithms (13)": {
      "signature schemes": [ed25519, ed448, ecdsa_secp256r1_sha256, ecdsa_secp38
4r1_sha384, ecdsa_secp521r1_sha512, rsa_pss_rsae_sha256, rsa_pss_rsae_sha384, rs
a_pss_rsae_sha512, rsa_pss_pss_sha256, rsa_pss_pss_sha384, rsa_pss_pss_sha512, r
sa_pkcs1_sha256, rsa_pkcs1_sha384, rsa_pkcs1_sha512, dsa_sha256, ecdsa_sha1, rsa
_pkcs1_sha1, dsa_sha1]
    },
    "signature_algorithms_cert (50)": {
      "signature schemes": [ed25519, ed448, ecdsa_secp256r1_sha256, ecdsa_secp38
4r1_sha384, ecdsa_secp521r1_sha512, rsa_pss_rsae_sha256, rsa_pss_rsae_sha384, rs
a_pss_rsae_sha512, rsa_pss_pss_sha256, rsa_pss_pss_sha384, rsa_pss_pss_sha512, r
sa_pkcs1_sha256, rsa_pkcs1_sha384, rsa_pkcs1_sha512, dsa_sha256, ecdsa_sha1, rsa
_pkcs1_sha1, dsa_sha1]