[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Support for multiple GSS libs
- To: Simon Wilkinson <email@example.com>, "Douglas E. Engert" <firstname.lastname@example.org>, Daniel Kouril <email@example.com>, firstname.lastname@example.org, Heimdal discussion list <email@example.com>, krbdev@MIT.EDU
- Subject: Re: Support for multiple GSS libs
- From: Nicolas Williams <Nicolas.Williams@ubsw.com>
- Date: Thu, 8 Nov 2001 08:40:15 -0500
- In-Reply-To: <firstname.lastname@example.org>; from Simon Wilkinson on Wed, Nov 07, 2001 at 11:05:23PM +0000
- Mail-Followup-To: Simon Wilkinson <email@example.com>,"Douglas E. Engert" <firstname.lastname@example.org>,Daniel Kouril <email@example.com>, firstname.lastname@example.org,Heimdal discussion list <email@example.com>, firstname.lastname@example.org
- References: <20011107160728.D7279@durin.ics.muni.cz> <3BE9B7B1.255FDCFA@anl.gov> <email@example.com>
- Sender: firstname.lastname@example.org
On Wed, Nov 07, 2001 at 11:05:23PM +0000, Simon Wilkinson wrote:
> On Wednesday 07 November 2001 22:37, Douglas E. Engert wrote:
> > Another problem is that the GSSAPI does not define how delegated
> > credentials are to be saved. It is left up to the implementation to provide
> > extra implementation specific routines to handle the delegated credentials.
> > The gss_krb5_* and Kerberos routines are called to do this from the openssh
> > for the Kerberos credentials, where there is a
> > ssh_gssapi_krb5_storecreds().
> There's actually two points where the GSSAPI doesn't provide the necessary
> hooks. The first, as you have noted, is in storing delegated credentials. The
> second is in checking to see if the given principal is allowed to connect as
> a particular user (the kuserok check). Both of these are implemented by means
> of a mechanism dependent switch, and some helper code, within the OpenSSH GSS
With respect to the userok() check, the named-keys-in-auth_keys patch I
posted helps: instead of relying on the krb5 or GSI specific userok()
you can rely on authorized_keys.
This is how GSS-API was meant to be used in authorization: get the
initiator's name, export it, compare it to an ACL built using the
My named-keys-in-auth_keys patch gets pretty close to that... And
authorized_keys is way superior to .k5login...
> The code is in ssh_gssapi_do_child() and ssh_gssapi_userok() within
> gss_serv.c. Fortunately, these complications appear to be server only.
Well, the initiator might want to authorize the aceptor too.
Say, if you have Kerberos principal name canonicalization.
-DISCLAIMER: an automatically appended disclaimer may follow. By posting-
-to a public e-mail mailing list I hereby grant permission to distribute-
-and copy this message.-
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.