Wireshark-users: Re: [Wireshark-users] Can't decrypt "snakeoil2" sample SSL session from wiki

From: Sake Blok <sake@xxxxxxxxxx>
Date: Mon, 10 Sep 2012 22:32:43 +0200
On 10 sep 2012, at 22:02, Grant Edwards wrote:

> I've been trying (and failing) to decrypt an SSL session using my
> server and key.  So, I backed up a step and downloaded the
> snakeoil2_070531.tgz sample file from the wiki:
> 
>  http://wiki.wireshark.org/SampleCaptures?action=AttachFile&do=view&target=snakeoil2_070531.tgz
> 
> I can't get that to decrypt either
[...]
> Below is the ssl debug log that gets created when I run
> 
> $ wireshark rsasnakeoil2.cap
> 
> One line that looks suspicious is where it says
> 
> ssl_decrypt_pre_master_secret wrong pre_master_secret length (128, expected 48)
> 
> Any ideas on what's wrong?

Usually that means that you are using a private key that does not match the certificate. But it is the 3rd time I hear problems (on Linux) with decrypting the traffic with a key that is indeed matching the certificate. It might be the version of your SSL libraries that has a bug. Or Wireshark has a bug in the linux version. Could you file a bugreport on https://bugs.wireshark.org?

Cheers,
Sake