is no function called md5()
as discussed with jmc

with different magic numbers, so we need to add some functions instead
of just asking the user to truncate as desired. Sigh.
SHA512 is quite a bit faster than SHA256 on 64 bit CPUs,
but 256 bit hashes are usually quite sufficient. Best of both.
ok deraadt tom

correctly - logically complete that now by removing MLINKS from base;
authors need only to ensure there is an entry in NAME for any function/
util being added. MLINKS will still work, and remain for perl to ease
upgrades;
ok nicm (curses) bcook (ssl)
ok schwarze, who provided a lot of feedback and assistance
ok tb natano jung

"A collision attack published in 2007 can find collisions for full
MD4 in less than two hash operations."
ok deraadt@, man pages ok jmc@

later revision of FIPS-180.  OK miod@ jmc@ guenther@ djm@

forthcoming OpenSSL update.
Function names lose their underscore (SHA256_Init => SHA256Init) and
the various SHA256_CTX, SHA512_CTX are merged into a single SHA2_CTX
that is used for all these hashes.
ok millert@ manpage bits jmc@ "please commit" deraadt@

The Pad function does padding like in Final but does not finish processing.
The FileChunk function creates a digest from a portion of a file.
Also made the length parameters consistent (and size_t).

previously lived in foohl.c.  The foohl.c files are now generated
via sed, though perhaps cpp could be used in the future.
Use u_int8_t instead of unsigned char for the buffers struct fooContext.
Add constants for buffer lengths and use them in function prototypes
and the man pages.
This is basically cosmetic surgery; there should be no functional changes.
OK deraadt@

massaging and a man page by me.  I used the phk-derived stuff for
sha2hl.c instead of Aaron's for consistency with our other hash
routines.

doesn't blow up.  This is a hack but is better than compiling sha1.c
with -O0 on sparc64.  From NetBSD (mrg).
deraadt@ OK

ok jason@

All POSIX libc api now there (to P1003.1c/D10)
(more md stuff is needed for other libc/arch/*)
(setlogin is no longer a special syscall)
Add -pthread option to gcc (that makes it use -lc_r and -D_POSIX_THREADS).
Doc some re-entrant routines
Add libc_r to intro(3)
dig() uses some libc srcs and an extra -I was needed there.
Add more md stuff to libc_r.
Update includes for the pthreads api
Update libc_r TODO

Antoon Bosselaers and massaged by me to fit the mdX(3) API.