Difference between revisions of "Keytab Extraction"

(Samba4: Mention samba-tool for recent s4.)
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Once you have [[Capture Packets|captured packets]] you can use Wireshark to analyze them in many case decryption of traffic is needed in order to analyze correctly an exchange.
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=How to Extract a keytab containing your domain's passwords=
 
=How to Extract a keytab containing your domain's passwords=
 
The keytab, a standard format for the storage of Kerberos keys, is also the input required by Wireshark to decrypt encrypted traffic
 
The keytab, a standard format for the storage of Kerberos keys, is also the input required by Wireshark to decrypt encrypted traffic

Revision as of 14:34, 19 June 2011

Once you have captured packets you can use Wireshark to analyze them in many case decryption of traffic is needed in order to analyze correctly an exchange.

How to Extract a keytab containing your domain's passwords

The keytab, a standard format for the storage of Kerberos keys, is also the input required by Wireshark to decrypt encrypted traffic

There are two ways to obtain a keytab from a Windows domain, with Samba:

Samba4

To join the domain, run:

net vampire NETBIOS_DOMAIN_NAME --realm=REALM -Uadministrator

Or, for a recent GIT checkout (later than 2010/10/23):

samba-tool vampire NETBIOS_DOMAIN_NAME --realm=REALM -Uadministrator

If everything is set up correctly, it should just work. If not, check /etc/krb5.conf in particular - ensure it can reach the KDC by setting:

[libdefaults]
dns_lookup_kdc = true

Then, to extract the keytab run

net export keytab PATH_TO_KEYAB

or:

samba-tool export keytab PATH_TO_KEYAB

It will write out a keytab in the path specified, containing the current keys for every host.

Samba3

To dump a keytab, join the domain and then run:

net rpc vampire keytab /path/to/keytab/file

Note that the path to the keytab file needs to be an absolute path.