Remove $FreeBSD$: one-line nroff pattern

Remove /^\.\\"\s*\$FreeBSD\$$\n/

libmd / md5: Add SHA-512/224.

While there, remove .Tn from man pages.

Also remove an obsolete comment about the 80386.

MFC after: 1 week
Sponsored by: Klara, Inc.
Reviewed by: kevans, allanjude
Differential Revision: https://reviews.freebsd.org/D38373

Fix wrong section number in man page cross references.

Fix a few mandoc issues

- skipping paragraph macro: Pp after Sh
- sections out of conventional order: Sh EXAMPLES
- whitespace at end of input line
- normalizing date format

Add missing errors section to md[2-5], ripemd160, sha*, and skein* manpages

PR: 148987
Submitted by: Dan Lukes <dan@obluda.cz> (original version)
MFC after: 1 week
Sponsored by: Klara Systems
Event: Waterloo Hackathon 2019

libmd: Always erase context in _Final method, and when doing
it, consistently use explicit_bzero().

Update manual pages to match the behavior.

Reviewed by: pfg, allanjude, jmg
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D16316

Fix formatting errors that resulted in apropos(1) output looking weird.

MFC after: 2 weeks

Implement SHA-512 truncated (224 and 256 bits)

This implements SHA-512/256, which generates a 256 bit hash by
calculating the SHA-512 then truncating the result. A different initial
value is used, making the result different from the first 256 bits of
the SHA-512 of the same input. SHA-512 is ~50% faster than SHA-256 on
64bit platforms, so the result is a faster 256 bit hash.

The main goal of this implementation is to enable support for this
faster hashing algorithm in ZFS. The feature was introduced into ZFS
in r289422, but is disconnected because SHA-512/256 support was missing.
A further commit will enable it in ZFS.

This is the follow on to r292782

Reviewed by: cem
Sponsored by: ScaleEngine Inc.
Differential Revision: https://reviews.freebsd.org/D6061

Replace sys/crypto/sha2/sha2.c with lib/libmd/sha512c.c

cperciva's libmd implementation is 5-30% faster

The same was done for SHA256 previously in r263218

cperciva's implementation was lacking SHA-384 which I implemented, validated against OpenSSL and the NIST documentation

Extend sbin/md5 to create sha384(1)

Chase dependancies on sys/crypto/sha2/sha2.{c,h} and replace them with sha512{c.c,.h}

Reviewed by: cperciva, des, delphij
Approved by: secteam, bapt (mentor)
MFC after: 2 weeks
Sponsored by: ScaleEngine Inc.
Differential Revision: https://reviews.freebsd.org/D3929

Dereference nonexistent md2(3) manual.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Rewrite HISTORY: The SHA256 code first appeared in 6.0, and the SHA512
code in 9.0; neither existed in FreeBSD 4.0.

Add SHA512 (Actually, this is Colin Percival's code for SHA256, with
relevant constants changed).

While I'm here clean up the tests and Makefile.

PR: misc/124164
Submitted by: KIMURA Yasuhiro < yasu utahime org >
MFC after: 1 month