Ensure null termination of AFS salts

Use krb5int_copy_data_contents_add0 when copying a pa-pw-salt or
pa-afs3-salt value in pa_salt().  If it's an afs3-salt, we're going to
throw away the length and use strcspn in krb5int_des_string_to_key,
which isn't safe if the value is unterminated.

(cherry picked from commit f566fee75f2455d6e5e7ee4fcdf5a0d327808639)

ticket: 7537 (new)
version_fixed: 1.10.4
status: resolved
Make verify_init_creds work with existing ccache

As the file ccache implementation currently stands, we don't want to
turn off TC_OPENCLOSE on a file cache we're writing to, or it will be
opened read-only and stores to it will fail.  Reported by Russ
Allbery.

(cherry picked from commit 0ae663d35b7dcbf2c469ad0688a67f4d1c0e425e)

ticket: 7538 (new)
version_fixed: 1.10.4
status: resolved