SSH

mv /etc/ssh/ssh_config /etc/ssh/ssh_config-$(date "+%s")

# add go
pkg_add go

# add user 'sshchat'
adduser

# switch user
su - sshchat
ftp https://github.com/shazow/ssh-chat/archive/v1.10.tar.gz
tar zxf v1.10.tar.gz
cd ssh-chat-1.10/
make build

# back to root
exit
cp /home/sshchat/ssh-chat-1.10/ssh-chat /usr/local/bin/

# create folder
mkdir -p /etc/pf.d

# sample file
echo "127.0.0.1" > /etc/pf.d/sshchat

# set permission
chmod 600 /etc/pf.d/sshchat

# get Version
brew info xz

# Cleanup Cache
brew cleanup -v -s --prune=all

# Downgrade
brew reinstall xz

# Update
brew update

# Upgrade
brew upgrade

# reboot
reboot

# confirm, 5.4.6 should be fine
xz -V

# get & convert public key
pubkey=$(cat ~/.ssh/id_rsa.pub |cut -d' ' -f 2 |fold -b -w 72)

# Username Switch
username=root

# Password for User
password=$(openssl rand -hex 12)

# Full Line
echo "username $username privilege 15 password $password"

# Build Config
cat  << EOF


############################################
# Copy/Paste to your Cisco Devices - START #
############################################

conf t

# Set Version
ip ssh version 2
no aaa new-model

# Set User
username $username privilege 15 password $password

# Set Key
ip ssh pubkey-chain 
username $username 
key-string
$pubkey
exit
exit
exit

# vty Stuff
line vty 0 15
 login local
 transport input ssh

end
write
exit

############################################
# Copy/Paste to your Cisco Devices - END   #
############################################


EOF

In SSH, the LogLevel option allows you to control the level of logging information generated by the SSH client and server.
There are several log levels you can use to adjust the verbosity of SSH logging. Here are the most commonly used log levels:

QUIET:
Suppresses all log messages, except for fatal errors. It provides the least amount of information.
FATAL:
Logs only fatal errors, indicating severe issues that may prevent the SSH session from being established.
ERROR:
Logs error messages, which are issues that might cause problems but don't necessarily prevent the session from being established.
INFO:
Logs informational messages, such as connection status and key exchange details. This is the default log level.
VERBOSE:
Provides more detailed logging than INFO, including additional debugging information.
DEBUG:
Generates detailed debugging messages. This level is useful when diagnosing connection and authentication issues.
DEBUG1, DEBUG2, DEBUG3:
Provides even more verbose debugging output, with DEBUG3 being the most detailed.

cat ~/.ssh/config
  Host *
    LogLevel QUIET
    LogLevel FATAL
    LogLevel ERROR
    LogLevel INFO
    LogLevel VERBOSE
    LogLevel DEBUG
    LogLevel DEBUG1
    LogLevel DEBUG2
    LogLevel DEBUG3
    ...

echo "net.inet.ip.forwarding=1" >> /etc/sysctl.conf
sysctl net.inet.ip.forwarding=1

echo "inet 10.0.0.1 255.255.255.0 10.0.0.2" >> /etc/hostname.tun0
sh /etc/netstart tun0

sed -i '/PermitTunnel .*/PermitTunnel                      yes/' /etc/ssh/sshd_config
rcctl restart sshd

ssh-copy-id root@host2

echo "net.inet.ip.forwarding=1" >> /etc/sysctl.conf
sysctl net.inet.ip.forwarding=1

echo "inet 10.0.0.2 255.255.255.0 10.0.0.1" >> /etc/hostname.tun0
sh /etc/netstart tun0

sed -i '/PermitTunnel .*/PermitTunnel                      yes/' /etc/ssh/sshd_config
rcctl restart sshd

ssh-copy-id root@host1

cat << 'EOF' > /tmp/ssh-key-generator.sh
#!/usr/bin/env bash

# File
f=/tmp/id_ed25519

# Cleanup
test -f $f && rm $f $f.pub

# Gen Key
ssh-keygen -o -a 100 -t ed25519 -N "" -f ${f}

# Extact Password (last 8 Char from PubKey)
pw=$(cat ${f}.pub |cut -d" " -f 2 |gsed -E 's/^.{60}//')
pw2=$(echo $pw |gsed -E 's/\//x/g')
id=$(echo $pw2 |gsed -E 's/^....//')

# Rename
mv ${f}     ${f}-${id}
mv ${f}.pub ${f}-${id}.pub

# Set Var
x="${f}-${id}"
f="$x"

# Prepare Password
cat << EOF2 > ${f}.x
#!/bin/sh
echo $pw2
EOF2
chmod +x ${f}.x

# Set Comment
ssh-keygen -c -C "Password: $pw2" -f ${f}

# Set Password
ssh-keygen -p -N "$pw2" -f ${f}

# Show Key
cat ${f}.pub

# Add to Agent
DISPLAY=1 SSH_ASKPASS="${f}.x" ssh-add ${f} < /dev/null

# Cleanup
rm ${f}.x

exit 0
EOF

cd /tmp
chmod +x /tmp/ssh-key-generator.sh
./ssh-key-generator.sh; ls -la /tmp/id*

pkg_add yubikey-manager-3.1.2p4

rcctl enable pcscd
rcctl start pcscd