How to debug encode_krb5_error?

[Benjamin Kaduk]

On Wed, 12 Jun 2013, Weijun Wang wrote:

> Hi All
>
> I am trying to get a KRB-ERROR output on the acceptor side when the
> AP-REQ is a replay. This is inside lib/gssapi/krb5/accept_sec_context.c.
>
> When a replay is received, the kg_accept_krb5() function calls
> krb5_mk_error(), which then calls encode_krb5_error() inside
> lib/krb5/krb/mk_error.c. The last function returns 1859794433 (or
> 6eda3601). What does it mean? It is automatically generated by some
> ASN.1 parser and I cannot debug into it.

1859794433 is ASN1_MISSING_FIELD (see lib/krb5/error_tables/asn1_err.h in 
a build tree).
The file src/lib/krb5/asn.1/README.asn1 has some tips for debugging 
encoder/decoder issues at the end, though it seems more focused on crashes 
than failure returns.  Stepping through encode_krb5_error in the debugger 
might still be helpful, though.  I am not sure whether your "cannot debug 
into it" is for source inspection or a live debugger such as gdb.

-Ben Kaduk