2.3.2.1 - EC keys suppport?

[ѽ҉ᶬḳ℠]

>>>> I did some local testing and it seems that you are using a curve
>>>> that is not acceptable for openssl as a server key.
>>>> I tested with openssl s_server -cert ec-cert.pem -key ec-key.pem
>>>> -port 5555
>>>> using cert generated with brainpool. Everything works if I use
>>>> prime256v1 or secp521r1. This is a limitation in OpenSSL and not
>>>> something we can really do anything about.
>>>> Aki Tuomi
>>>> Open-Xchange Oy
>>> Which openssl version you are using? This end it is OpenSSL 1.1.0h.
>>> There are no issues creating private keys, issuing csr, signing certs
>>> with that particular curve. Printing certs and verifying certs against
>>> keys is panning out too, comparing md5 hashes also no errors. So why
>>> would openssl not accept (limit) keys is has generated and verified with
>>> no error?
>>>
>>>
>> try
>>
>> openssl s_server -cert /path/to/cert -key /path/to/key -port 5555
>>
>> openssl s_client -connect localhost:5555
>>
> Uhum, I see now. What a strange thing (bug?) openssl is doing. Thank you
> for valuable time/effort having debug this. Seems I have to start the CA
> all over...

Perhaps for whose interested - IETF RFC 7027 specifies for TLS use:

[ brainpoolP256r1 | brainpoolP384r1 | brainpoolP512r1 ]

And thus t1 would not work anyway. However, having tested r1 the result
was just the same.

A tcpdump during the openssl test [ s_server | s_client ] then revealed
(TLSv1.2 Record Layer: Handshake Protocol: Client Hello) :

Extension: supported_groups (len=10)
    Type: supported_groups (10)
    Length: 10
    Supported Groups List Length: 8
    Supported Groups (4 groups)
        Supported Group: x25519 (0x001d)
        Supported Group: secp256r1 (0x0017)
        Supported Group: secp521r1 (0x0019)
        Supported Group: secp384r1 (0x0018)

Apparently [ brainpool ] would apparently not fit into any of those
groups. Perhaps a bug in OpenSSL 1.1.0h thus.