Keytab Extraction

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Revision as of 12:44, 29 October 2010 by Wodin (talk | contribs) (→‎Samba4: Mention samba-tool for recent s4.)

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:


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:

dns_lookup_kdc = true

Then, to extract the keytab run

net export keytab PATH_TO_KEYAB


samba-tool export keytab PATH_TO_KEYAB

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


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.