Edwards curves are not compatible with ECDH

[Sarkoxed]

After trying to initialize ECDH with Ed25519 and compute a shared secret it returns the following error:

AttributeError: 'PrivateKey' object has no attribute 'secret_multiplier'

I believe it's called __s in eddsa.PrivateKey class.

[tomato42]

yes, because that's Ed25519, ECDH operation over Curve25519 is X25519, that's not implemented.

it's documented in the README.md:

Key generation, siging and verifying is also supported for Ed25519 and Ed448 curves.