An implementation of draft-zhu-negoex-04 for MIT Kerberos was developed in
2011. This has been recently integrated, with many fixes from Greg Hudson. This
commit ports it to Heimdal. The implementation has been interoperability tested
with MIT Kerberos and Windows, using the GSS EAP mechanism developed as part of
the Moonshot project.
The SPNEGO code was also updated to import the state machine from Apple which
improves mechListMIC processing and avoids discarding initial context tokens
generated during mechanism probing, that can be used for optimistic tokens.
Finally, to aid in testing, the GSS-API mechanism glue configuration file can
be changed using the environment variable GSS_MECH_CONFIG. This environment
variable name, along with the format of the configuration file, is compatible
with MIT (although it would be difficult for a single mechanism binary to
support both implementations).
Add helper APIs to the mechanism glue from the Apple implementation.
gss_mg_export_name() can be used by a mechanism to create an exported name
(this is used by the future SAnon implementation). _gss_mech_import_name()
allows the mechanism to pass in a list of parsing functions for specific name
tiypes. This commit only adds support to the mechanism glue itself.
The GSS mechglue uses singly linked lists for mechanisms and mechanism objects,
to which new entries are inserted at the head. This breaks ordering of
mechanisms specified in OID sets and in /etc/gss/mech, as they will be back to
front. Use a tail queue instead so that new entries are inserted at the end.
Apple's Heimdal impelmentation uses a number of utility functions for
allocating names and credentials, to avoid calling malloc or calloc directly.
Import them.
gss_init_sec_context() with input_cred_handle != GSS_C_NO_CREDENTIAL
should NOT proceed if there is no element in the given credential for
the requested mechanism.
