Make struct k5buf less opaque and get rid of k5buf-int.h.  Make it
easy to initialize a k5buf in an error state so that it can be freed
in a cleanup handler.  Add a function k5_buf_status which returns 0 or
ENOMEM.  Remove k5_buf_data and k5_buf_len.  Rename k5_free_buf to
k5_buf_free.  Adjust all callers to match.

In prng_fortuna.c, if krb5_c_random_make_octets detects that we do not
have entropy, set an error message saying that the random number
generator could not be seeded, as we likely failed previously to read
from /dev/urandom or the Windows equivalent.

ticket: 7968 (new)

When krb5int_c_combine_keys was updated to use the new crypto
interface, a small bug was introduced.  It turns out the temporary
keyblock created needs to have its enctype set; otherwise, when
krb5int_derive_keyblock() is called later, it will fail with
KRB5_BAD_ENCTYPE.

ticket: 7914
target_version: 1.12.2
tags: pullup

Use alloc_data() and empty_data() where appropriate.  Keep mainline
logic to the left where possible.  Name the output parameter of
krb5int_des_init_state with an _out suffix.  Use a professional tone
in comments.  Partly based on a patch from Alok Menghrajani.

Directly use stdint.h names for integer types in preference to the
various internal names we have made up for them.

Remove uitypes.h and just include stdint.h; all we need from it is
uint{8,16,32}_t.

On 32-bit platforms, the code to translate an iteration count of 0 to
2^32 can trigger a compiler warning.  Since we will basically never
accept an iteration count that high (right now we reject anything
above 2^24), just reject it out of hand.

Also add a testing interface to allow weak iteration counts.
(Published test vectors use weak iteration counts.)

ticket: 7465
target_version: 1.12
tags: pullup

Wherever we use k5alloc with a multiplication in the size parameter,,
use the new k5calloc helper function instead.