AC68 - Merlin 378.56 - OPENVPN - ECDHE/ECDSA support

[winter]

Hi, I am trying to set up openvpn server on AC68 with Merlin 378.56 that uses tls-cipher TLS-ECDHE-ECDSA-catergory (such as TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256).

When I listed it in the server option, the server starts fine but give out following error when a client tries to connect to it.

TLS: Initial packet from [AF_INET] IPport sid=76bde0df 30689078
Oct 31 18:48:23 openvpn[1417]: IPort TLS_ERROR: BIO read tls_read_plaintext error: error:1408A0C1:SSL routines:ssl3_get_client_hello:no shared cipher
Oct 31 18:48:23 openvpn[1417]: IPport TLS Error: TLS object -> incoming plaintext read error
Oct 31 18:48:23 openvpn[1417]: IPport TLS Error: TLS handshake failed


All CA, Server, and Client certs & keys are generated by easyrsa3 with EC and secp384r1.
vpn client is 2.3.8 on windows.

so far the highest tls-cipher I can pair up the server and client is DHE-RSA-AES256-GCM-SHA384 with RSA.

Is ECDHE/ECDSA supported so far? base on my reading, it should work for tls handshake part.

 

[RMerlin]

I'm not sure if it's still needed with 2.3.8, but try adding this to the server and client configuration:

tls-version-min 1.0

This will allow it to use TLS 1.2.

 

[winter]

tried tls-version-min 1.0 & tls-version-min 1.2 on both server & client, didn't make any difference.
actually, by able to use DHE-RSA-AES256-GCM-SHA384, it is already using version 1.2, as I read somewhere this cipher is part of the v1.2. Yes, server message also said v1.2 when the connection is made.

I tried verb 5 on the client side and there is no error message coming out. Also tried a different desktop with 2.3.8, there is no difference.

since I don't have a different server to try, can't tell if the client has a problem or the server has. so far only server side give error message as listed above.

just want to add, also tried EC with secp256k1 on all key and cert, same error message.

wondering if anyone has experience with EC in OpeVPN. All I am swapping here is just cert & key in server & client. with RSA, it all works, with EC, they are not.

searching on internet didn't give out anything useful. base on all the piece of information all over the place, EC supposes to work for tls handshake part, not the data channel......