Support for ssh-ed25519 and curve25519 differs depending on the Maverick Synergy and Java version used.
The Maverick Synergy SSH API has a module that supports ed25519 public keys and the curve25519-sha256@libssh.org key exchange mechanism.
The core API libraries have zero third-party dependencies; as support for these algorithms is provided by third-party libraries, we do not impose this choice on the user. If you include these algorithms, you can include the maverick-ed25519 module.
The maverick-ed25519 module was replaced when we implemented ed25519 support using JCE standard interfaces. Support for ed25519 depends on the version of Java you are using. Java 15 introduced ed25519 key support; if you use a version earlier than this, you should consider using a third-party JCE such as BouncyCastle, which supports ed25519.
Curve25519 uses a public domain implementation included in our source and built into the core jar files.