libdes (which is still used out there) or other des implementations,
the OpenSSL DES functions are renamed to begin with DES_ instead of
des_. Compatibility routines are provided and declared by including
openssl/des_old.h. Those declarations are the same as were in des.h
when the OpenSSL project started, which is exactly how libdes looked
at that time, and hopefully still looks today.
The compatibility functions will be removed in some future release, at
the latest in version 1.0.
des_encrypt() and des_encrypt() defined on some systems (Solaris and
Unixware and maybe others), we rename des_encrypt() to des_encrypt1().
This should have very little impact on external software unless
someone has written a mode of DES, since that's all des_encrypt() is
meant for.
Never use des_set_key (it depends on the global variable des_check_key),
but usually des_set_key_unchecked.
Only destest.c bothered to look at the return values of des_set_key,
but it did not set des_check_key -- if it had done so,
most checks would have failed because of wrong parity and
because of weak keys.
