Use keytab to select etypes in krb5_get_init_creds_keytab()

[Greg Hudson]

On 04/17/2012 12:53 PM, Stef Walter wrote:
> Here we go. I think the attached patch implements what you outlined.

This is committed (with changes).  The fix is associated with an
existing RT issue for the problem (#2131).

While working on this I noticed a DES interop issue uncovered by our
test suite.  If you have a keytab containing only a des-cbc-md5 key, you
really want to include des-cbc-crc in your request etypes, because MIT
KDCs unconditionally reject des-cbc-md5 (due to an age-old interop issue
involving salts).