AS replies can be spoofed as nothing in them authenticates the KDC to the client doing the AS request. Therefore something must be done to authenticate the AS reply or else you can't use Kerberos for password validation. The thing to do is this: use the TGT from the AS reply to get a TGT from the TGS (the KDC) for talking to a service corresponding to the client and for which the client knows the current key -- if the TGS response can be validated against such a key then the client knows that the AS reply must is valid, that it came from the correct KDC and was not spoofed. Cheers, Nico On Tue, Sep 18, 2001 at 03:03:14PM +0530, SRIDHAR BANDI wrote: > I am sorry if I had hit the wrong list . > can someone enlighten me about the PAM Kerberos authentication ( > downloaded from fcusack) validating the TGT that it obtained with the > host service principal's keytab entry (using the funciton > verify_krb_v5_tgt) , I dont understand the purpose of doing this because > the server machine is the one who gets the TGT on behalf of the client( > principal ) and its the one who is handling the host entry also . And > this call fails if the keytab file exists and there is no valid entry > for the host service principal and the authentication will be successful > if there is a valid entry for host principal or there is no keytab file > at all . > > thanks in advance for the help . > bandi > > > > > > _______________________________________________ > > Pam-list@redhat.com > https://listman.redhat.com/mailman/listinfo/pam-list -- Visit our website at http://www.ubswarburg.com This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as a solicitation or offer to buy or sell any securities or related financial instruments.
