[openssl-dev] Calculating DTLS payload MTU

[David Woodhouse]

>
>
> On 05/10/16 15:37, David Woodhouse wrote:
>> On Wed, 2016-10-05 at 14:40 +0100, David Woodhouse wrote:
>>> How's this for a start...
>>
>> Now I think I have it right for CCM too, although having to use
>> strstr() for that makes me *very* sad. Next up, Chacha20-Poly1305...
>> and then maybe I can stop worrying about new modes and ciphersuites
>> because those won't be added in OpenSSL 1.1 and we can get OpenSSL do
>> to this for itself before 1.2? :)
>
> Or even 1.1.1! Why don't you pull this together into a github PR?

Sure. Any thoughts on what you want it to look like? Not just
SSL_CIPHER_get_overhead() because it'seems not constant -- you have to
account for blocksize rounding and padding in CBC ciphers. So just
SSL_CIPHER_get_data_mtu(int link_mtu)?

Or are there other use cases we want it for, and we *should* try returning
a full set of three "add this, round up to this, add this" integers?

As for the actual numbers... am I on the right track so far?

-- 
dwmw2