Creating a principal using the kadmin C API

[Teo Klestrup Röijezon]

Hey, I'm a coworker of Lars' and working on this project.

On Friday, 8 April 2022 06.35.29 CEST Greg Hudson wrote:
> krb5_init_context_profile() lets you supply a profile object.  If this
> is created with profile_init_path(), the application should be able to
> strictly control which file is used.
> 
> It is possible to create an in-memory profile with
> profile_init_vtable().  Perhaps it would be nicer if one could create an
> empty in-memory profile object and populate it with
> profile_add_relation(), but that is not currently implemented.

profile_init_vtable() (or building it with profile_add_relation()) would be 
ideal, yes. Our current prototype uses krb5_init_context_profile() for the sake 
of simplicity (vtables are annoying to build up and maintain across the Rust-C 
border, so I didn't want to go there until we could confirm that the rest 
works).

However, the kadm5_init_*() family of functions (via init_any()) calls 
kadm5_get_config_params(), which in turn always loads its own profile by calling 
krb5_aprof_init() with a hard-coded choice of either DEFAULT_PROFILE_PATH or 
DEFAULT_KDC_PROFILE. This _is_ possible to override with environment 
variables, but that's a pretty big ask when linking to the library in-process.