[openssl-users] Selection of DHE ciphers based on modulus size of DH

[Matt Caswell]

On 07/06/18 04:10, Viktor Dukhovni wrote:
> 
> 
>> On Jun 6, 2018, at 7:15 PM, Salz, Rich via openssl-users <openssl-users at openssl.org> wrote:
>>
>> Without commenting on whether or not your understanding is correct (the client gets the params and can see how big the key is, no?), I will point out that the way DHE works is defined by the IETF RFC’s, and they have not changed.
> 
> However, in TLS 1.3, the FFDHE groups are pre-defined, and the server
> does not get to choose ad-hoc (p, g) pairs.

Although OpenSSL does not currently support FFDHE groups in TLSv1.3.

Matt