HPN-SSH 18.1.0 for OpenSSH 9.4

This is the 18.1.0 release of HPN-SSH based on OpenSSH 9.4. The major changes
included in this release are the introduction of a parallel ChaCha20-Poly1305 cipher
called chacha20-poly1305-mt@hpnssh.org. This is now the default cipher used by
HPN-SSH. You may use the serial version of the cipher by explicitly calling it
with -cchacha20-poly1035@openssh.com if you prefer. However, this will only have
an impact on the local instantiation of hpnssh or hpnsshd. To use serial ChaCha20
on both ends of the connection you must run both the server and client with the
serial version.

We have also improved the efficacy of the Poly1305 MAC by using OpenSSL functions
to compute the MAC instead of the portable C implementation included in OpenSSH. Our
implementation of Poly1305 will fall back to the portable implementation if the OpenSSL
EVP is not available.

There have been other minor changes to improve code readability, improve compatibility
with LibreSSL, support Alpine more gracefully, and so forth.

Lastly, the versioning scheme as been normalize to Major.Minor.Fix. For example,
this version is 18.1.0 meaning that it is the 18th Major release, the 1st minor
release, and there 0 fixes/patches applied. In this scheme a minor bug fix will
increment the Fix value. A forward port to a new version of OpenSSH or a performance
improvement will increment the Minor value (and reset the Fix value). The introduction
of a major change or functionality will increment the Major value while resetting
both Minor and Fix to 1 and 0 respectively.

Okayed by mwd@psc.edu and rapier@psc.edu

What's Changed

• Fix deadlocks in cipher ctr mt by @chutz in #7
• Use an exit flag as well as pthread_cancel to tell worker threads to terminate by @chutz in #8
• fix typos in HPN-README by @allanjude in #12
• HPN-README: Mention correct OpenSSH buffer size by @nh2 in #24
• Create FUNDING.yml by @rapier1 in #33
• cipher-ctr-mt: Fix fscanf() on FILE *fp == NULL on non-SMT machines by @S-trace in #34
• Reorder user creation and install steps in install instructions by @mpounsett in #43

New Contributors

• @chutz made their first contribution in #7
• @allanjude made their first contribution in #12
• @nh2 made their first contribution in #24
• @fscheiner made their first contribution in #28
• @rapier1 made their first contribution in #33
• @S-trace made their first contribution in #34
• @mpounsett made their first contribution in #43

Full Changelog: https://github.com/rapier1/openssh-portable/commits/hpn-18.1.0