Re: configuration kerberos in Postgre sql

Hi Rahimeh,

Is PG on the same box as the kadmind?

rahimeh khodadadi wrote:

have never been worked  with krb5 in postgresql?

On 10/12/09, rahimeh khodadadi <rahimeh.khodadadi@gmail.com> wrote:

nobody could help me?

On Sun, Oct 11, 2009 at 5:06 PM, rahimeh khodadadi <
rahimeh.khodadadi@gmail.com> wrote:

Hi,

after compling the postgresql --with-krb5  and setting up the krb5-server
in centos, I configured the *postgresql.conf* as bellow:

*krb_server_keyfile = '/var/kerberos/krb5kdc/kadm5.keytab'*
*krb_srvname = 'POSTGRES' *       # (Kerberos only)
#krb_caseins_users = off

I like to specify my krb_server_hostname explicitly here.

and

my *pg_hba.conf* is :

# "local" is for Unix domain socket connections only
local   all         postgres                         trust
# IPv4 local connections:
host   all         *frank*       0.0.0.0/0            krb5
#host    all         all         127.0.0.1/32      trust
# IPv6 local connections:
host    all         all         ::1/128               trust


,and kdc.conf

kdcdefaults]
 v4_mode = nopreauth
 kdc_tcp_ports = 88

[realms]
 EXAMPLE.COM = {
 #master_key_type = des3-hmac-sha1
 * acl_file = /var/kerberos/krb5kdc/kadm5.acl*
 dict_file = /usr/share/dict/words
 admin_keytab = /var/kerberos/krb5kdc/kadm5.keytab

If this is the same machine as PG, I'm not sure why you have the same file here as for the keytab to keep the PG service principal in.  My manpage for kdc.conf says that admin_keytab specifies the keytab to be used by kadmin to authenticate to the database, so really shouldn't be kept very distinct from the keytab with the PG service principal.

 supported_enctypes = des3-hmac-sha1:normal arcfour-hmac:normal
des-hmac-sha1:normal des-cbc-md5:normal des-cbc-crc:normal des-cbc-crc:v4
des-cbc-crc:afs3
 }

Then, I created the user frank  as :

 kadmin.local
Authenticating as principal rahimeh/admin@EXAMPLE.COM with password.
kadmin.local: * ank frank*
WARNING: no policy specified for frank@EXAMPLE.COM; defaulting to no
policy
Enter password for principal "frank@EXAMPLE.COM":
Re-enter password for principal "frank@EXAMPLE.COM":

*kadmin.local: ktadd -k /var/kerberos/krb5kdc/kadm5.keytab frank*
Entry for principal frank with kvno 2, encryption type Triple DES cbc
mode
with HMAC/sha1 added to keytab WRFILE:/var/kerberos/krb5kdc/kadm5.keytab.
Entry for principal frank with kvno 2, encryption type ArcFour with
HMAC/md5 added to keytab WRFILE:/var/kerberos/krb5kdc/kadm5.keytab.
Entry for principal frank with kvno 2, encryption type DES with HMAC/sha1
added to keytab WRFILE:/var/kerberos/krb5kdc/kadm5.keytab.
Entry for principal frank with kvno 2, encryption type DES cbc mode with
RSA-MD5 added to keytab WRFILE:/var/kerberos/krb5kdc/kadm5.keytab.

But for PG you'll need a keytab with the service principal you've defined to be POSTGRES/<hostname>@EXAMPLE.COM in it.

Finally, it gives error like:

[root@localhost ~]# *kinit frank* -t /var/kerberos/krb5kdc/kadm5.keytab
Password for frank@EXAMPLE.COM:
*kinit(v5): Password incorrect while getting initial credentials*

I've never had much joy myself when getting tickets from a -t keytab, I usually just kinit and enter a password instead.

or

in cmd when I run this instruction the below error is shown.

[root@localhost bin]# ./psql -h 127.0.0.1  -U frank
*psql: krb5_sendauth: Bad application version was sent (via sendauth)*

To construct the service principal the library takes the the -h argument, then gets the A record for it (if applicable), then gets the PTR record for the A record to get the hostname for the service principal name (unless you're using Windows I have found, in which case it just stops and takes the originally given hostname if an A record exists).  Just use a non-127 address instead, it'll make things a lot easier to keep straight.  For that matter, /etc/hostname and /etc/resolv.conf would be good to see too because of their importance here.

HTH,
Geoff


---------
Geoff Tolley
DBA/Systems Administrator

YouGovPolimetrix
285 Hamilton Avenue Suite 200
Palo Alto, CA 94301
geoff.tolley@yougov.com
http://www.yougov.com/