[Ach] Thanks for the Logjam blog-post

Hanno Böck hanno at hboeck.de
Thu May 21 15:47:49 CEST 2015

On Thu, 21 May 2015 15:44:18 +0200
Axel Huebl <axel.huebl at plasma.ninja> wrote:

> server=bettercrypto.org && echo | openssl s_client -connect
> $server:443 -msg -cipher "DH" 2>/dev/null | grep -A 1
> "ServerKeyExchange" | tail -n1 | awk '{print strtonum("0x"$5$6)*8}'

if you add -servername $server it'll also work with SNI.

This is not as insignificant as it may sound. E.g. latest apache
versions try to align the DH group with the cert, so it's quite likely
that a server wil answer with different groups on different hosts. If
you have a 2048 bit rsa cert it'll use a 2048 bit group etc.

Hanno Böck

mail/jabber: hanno at hboeck.de
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