2.3.2.1 - EC keys suppport?

[Aki Tuomi]

On 31.07.2018 09:30, ѽ҉ᶬḳ℠ wrote:
>>>> 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.
>>>>
>>>>
>>> Turned out not being a bug in OpenSSL after all. From the cli it works
>>> with no issues this way:
>>>
>>> [ openssl s_server -cert ec.cert.pem -key ec.key.pem -port 5555 -curves
>>> brainpoolP512r1 ]
>>> [ openssl s_client -connect localhost:5555 -curves brainpoolP512r1 ]
>>>
>>> I am not familiar really with the OpenSSL API and only roughly gather
>>> that the app (dovecot) would have to make the API call [
>>> SSL_CTX_set1_groups_list ]
>>> (https://www.openssl.org/docs/manmaster/man3/SSL_CTX_set1_groups.html)
>>> in order to support those curves.
>>>
>>>
>> Whoops.
>>
>> We have a setting called `ssl_curve_list` in dovecot, and I tried using
>> that when I was testing. Turns out that there is a bug preventing that
>> setting from being used. If you are compiling yourself, you can use the
>> attached patch to fix this.
>>
>> After applying, you can set
>>
>> ssl_curve_list = brainpoolP512r1
>>
>> And then you can connect again.
>>
>> Aki
> Meantime I stumbled over that setting and was like 'yeah - what are you
> blubbering about when dovecot caters for it already'. That stopped when
> testing the setting ... like you said it is a bug apparently.
>
> Now about compiling... that is not really my turf unless it is
> absolutely necessary. Time being I will (have to) work around with [ 
> ssl_alt_key/cert ] and will notify the downstream repo maintainer about
> the patch, assuming that needs all that compiling I cannot just modify
> some file manually.
>
>
>

Yeah, it needs to be recompiled to fix.

Aki