RFC 3961 says the simplified profile PRF should truncate the hash
output to "multiple of m", which MIT krb5 interprets as the largest
possible multiple of m. RFC 6113 appendix A also uses that
interpretation for the KRB-FX-CF2 test vector. So the DES3 PRF should
truncate the 20-byte SHA-1 result to 16 bytes, not 8. Also make
krb5_crypto_prf_length work with DES3 by giving the DES3 enctype a
non-zero PRF length.
Signed-off-by: Nicolas Williams <nico@cryptonector.com>
lib/krb5/crypto.c was a large, monolithic block of code which made
it very difficult to selectively enable and disable particular
alogrithms.
Reorganise crypto.c into individual files for each encryption and
salt time, and place the structures which tie everything together
into their own file (crypto-algs.c)
Add a non-installed library (librfc3961) and test program
(test_rfc3961) which builds a minimal rfc3961 crypto library, and
checks that it is usable.
