Engine with ed25519/ed448 support

[Bengt Warnemyr]

Hi OpenSSL team.

I did subscribe to openssl-users on December 2 or 3 but haven't got
any response.
Sending my question again to this address.

I'm developing an engine using an hsm for key storage and the
cryptographic operations when setting up a tls session with libssl.
I have it working for RSA and EC keys by implementing
  ENGINE_set_load_pubkey_function(e, my_load_pub_key_function)
  ENGINE_set_load_privkey_function(e, my_load_priv_key_function)
  ENGINE_set_pkey_meths(e, my_pmeths_function)

When my engine instantiates a EVP_PKEY the public part of RSA/EC_KEY
is set with data from the hsm
and gives it my RSA_METHOD/EC_KEY_METHOD.
Then I use RSA_set_ex_data/EC_KEY_set_ex_data to store information
about the hsm key to use.

However ECX_KEY isn't public nor does it have any METHOD or ex data.

My question is how to support ed25519/ed448 keys?

/Bengt