The code was correctly selecting the mechanism to execute, but it was
improperly setting the mechanism type of the internal context when the
selected mechanism was that of an interposer and vice versa.

When an interposer is involved the internal context is that of the
interposer, so the mechanism type of the context needs to be the
interposer oid.  Conversely, when an interposer re-enters gssapi and
presents a token with a special oid, the mechanism called is the real
mechanism, and the context returned is a real mechanism context.  In
this case the mechanism type of the context needs to be that of the
real mechanism.

ticket: 7592
target_version: 1.11.2
tags: pullup

The caller of kg_unseal_v1 passes a gss_qop_t * for the qop_state
parameter, so make it use that type instead of an int *.  Noted by
David Benjamin <davidben@mit.edu>.

ticket: 7585

Rename the krb5int_buf_ family of functions to use the k5_ prefix for
brevity.  Reformat some k5buf implementation code to match current
practices.

Add a template-based array constructor for convenient marshalling of
structured values as JSON array values.  Use it to simplify
export_cred.c.

Return error codes (0, ENOMEM, or EINVAL) from JSON support functions
instead of returning results directly.  This makes error handling
simpler for functions which assemble JSON objects and then return a
krb5_error_code values.  Adjust all callers.  Use shims in
export_cred.c to minimize changes there; it will be redesigned
internally in a subsequent commit.

gss_const_ctx_id_t, gss_const_cred_id_t, and gss_const_name_t are
supposed to be const pointers to the appropriate structures, not the
structures themselves.  These are not used by any prototypes yet, and
no application would have any reason to use them as they are, so it
should be safe to change them within the public header.

ticket: 7567 (new)
target_version: 1.11.1
tags: pullup

Add k5-int.h static functions to duplicate byte ranges, optionally
with a trailing zero byte, and set an error code like k5alloc does.
Use them where they would shorten existing code.