Regarding Credential Cache

Benjamin Kaduk kaduk at MIT.EDU
Tue May 28 15:29:49 EDT 2013

On Mon, 27 May 2013, Mohit Aggrawal wrote:

> I am using Kerberos 1.11 build using Visual Studio 2010 . In our code we
> are calling krb5_cc_default after calling krb5_init_context .  The call to
> krb5_init_context  is successful while the call to krb5_cc_default is
> failing i.e. the return value is not zero.
> Please let us know if I need to modify or change the value of parameters so
> that the call to krb5_cc_default is successful. I am sending  the code
> snippet and the value of parametres .

The interesting bits of krb5_cc_Defeault are in 
src/lib/krb5/os/ccdefname.c .  The windows behavior is rather different 
from the Unix behavior.
I wonder, what is the value of the HKCU\Software\MIT\Kerberos5\ccname 
registry entry?  The KfW installer should set it to "API:"; I am not 
entirely sure offhand what behavior to expect if it is not set at all.
(The HKLM version of that entry is also checked.)

> krb5_context context value is
> - context 0x1ab152d8 {magic=-1760647388 in_tkt_etypes=0x00000000
> tgs_etypes=0x00000000 ...} _krb5_context *
> magic -1760647388 int
> + in_tkt_etypes 0x00000000 int *
> + tgs_etypes 0x00000000 int *
> + os_context {magic=-1760647387 time_offset=0 usec_offset=0 ...}
> _krb5_os_context

Probably, the call to krb5_cc_default_name is falling back to 
os_context->default_ccname, you might look at that in the debugger.

-Ben Kaduk

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