How to automate ktutil to immediately list keytab entries?
I use MIT ktutil a lot on Linux and I am fed up using the following sequence, even if command shortcuts and file name completion are here to help:
ktutil
rkt my.keytab
l
Isn’t there a way to get the same result in a “one-line” way from the shell? Either with an alias, a function, or just with another tool?
I found a way with a shell function, after guessing ktutil may accept commands from stdin:
rkt() { echo -e "read_kt $1nlistnquit" | ktutil | grep -v "^ktutil:"; }
And invoke with rkt my.keytab
Works as far as file name contains no space.
I always use klist instead to list the contents of keytab files out instead of ktutil.
Example #1 – klist
$ klist -kt /etc/somedir/conf/some.keytab
Keytab name: FILE:/etc/somedir/conf/some.keytab
KVNO Timestamp Principal
---- ----------------- --------------------------------------------------------
5 08/25/15 11:18:35 app/host1.dom.local@TD.COM
5 08/25/15 11:18:35 app/host1.dom.local@TD.COM
5 08/25/15 11:18:35 app/host1.dom.local@TD.COM
7 08/25/15 11:18:35 app/host2.dom.local@TD.COM
...
Example #2 – process substitution
You can also use a redirect to ktutil‘s STDIN like so:
$ ktutil < <(echo -e "rkt /etc/somedir/conf/some.keytabnlist")
ktutil: rkt /etc/somedir/conf/some.keytab
ktutil: list
slot KVNO Principal
---- ---- ---------------------------------------------------------------------
1 5 app/host1.dom.local@TD.COM
2 5 app/host1.dom.local@TD.COM
3 5 app/host1.dom.local@TD.COM
4 7 app/host1.dom.local@TD.COM
This can help to merge 2 keytab, using standad input to use in shell script
ktutil < <(echo -e "rkt/var/tmp/keytab/merge/krb5.keytab.server.keytab1n
rkt /var/tmp/keytab/merge/krb5.keytab.server.keytab1n
wkt /var/tmp/keytab/merge/krb5.keytabn
quit")
ktutil: rkt /var/tmp/keytab/merge/krb5.keytab.server.keytab1
ktutil: rkt /var/tmp/keytab/merge/krb5.keytab.server.keytab1
ktutil: wkt /var/tmp/keytab/merge/krb5.keytab
ktutil: quit
Other answers provide a way to run a series of ktutil commands and then exit.
It’s more difficult to do a series of commands and then get an interactive session, with full line editing capabilities.
You can achieve this with a script for the expect program, which should be available to install from your distro.
#!/usr/bin/env expect -f
spawn ktutil
send "read_kt [lrange $argv 0 1]nln"
set CTRLZ 32
interact {
-reset $CTRLZ {exec kill -STOP [pid]}
03 exit
}
Save as myktutil somewhere in your PATH and make it executable with chmod +x
Then you can do, for example:
$ myktutil foo.keytab
This will read in the keytab file foo.keytab, list the keys and then drop you into the interactive command at that point.
Extending the script to do non-trivial things will require familiarization with expect and the Tcl language.