Imported config file examples, improved ssh's

examples/ssh/ssh_config

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+################################################################################
+## ~/.ssh/config
+##
+## Gotchas:
+## - options are applied first-come-first-served, so:
+##   - specific and higher priority settings go on top, generic and lower ones
+##     go on the bottom
+##   - user defaults MUST come last to be treated as such
+## - host specificity is NOT a factor of priority
+## - multiple host names (and aliases) may be specified per section
+## - targets may match multiple host sections and have settings applied in order
+## - host sections only apply to the matched names
+## - canonicalization forces a configuration reload to check the now canonical
+##   host name against the configuration
+################################################################################
+
+# Canonicalize host names as first thing
+# Forces a configuration reload so that only the canonical host name is matched
+# against the rest of the configuration
+CanonicalizeHostname  yes
+CanonicalDomains      lan localdomain my.org
+
+# 'special' devices
+# E.g. work ones
+Host  net?a?-fw? org?-h?-sw?
+	CanonicalDomains     that.org
+	CanonicalizeMaxDots  0
+Host  !bastion* *.brt*.my.org *.brs? *.brs??
+	AddressFamily  inet6
+	ProxyCommand   ssh -W %h:%p `host bastion.my.org | awk '/address/ {print $4; exit}' | xargs host | cut -d\  -f5`
+
+# Connect to secured hosts
+# E.g. targets using non-default configuration
+Host  *-bastion-* *-fw
+	IdentitiesOnly  yes
+	IdentityFile    ~/.ssh/id_rsa
+	Port            2222
+
+# Avoid OS incompatibility nuisances
+# E.g. LANG not set when connecting to Linux from Darwin
+Host  linux-* raspberrypi?
+	SendEnv  -LC_* PAGER
+	SetEnv   LANG=C LANGUAGE=en LC_ALL=C
+
+# Connect to unresolvable host names
+# E.g. home routers
+Host  router fixed-ip
+	HostName  192.168.50.1
+	User      root
+
+# Enable connections to old SSH server versions
+# E.g. legacy targets using old key algorithms
+Host  legacy-hosts azure-vm-* oci-bastion-*
+	HostKeyAlgorithms         +ssh-dss +ssh-rsa
+	PubkeyAcceptedAlgorithms  +ssh-rsa
+
+# Avoid nuisances with ephemeral hosts and localhost
+# E.g. preemptible or testing virtual machines which are often recreated
+Host  localhost *-vm-*
+	StrictHostKeyChecking  no
+	UserKnownHostsFile     /dev/null
+
+# User-specific settings
+# E.g. programmatic accesses
+Match  user  robots
+	AddKeysToAgent       no
+	BatchMode            yes
+	ForwardAgent         no
+	IdentitiesOnly       yes
+	IdentityFile         ~/.ssh/robots.id_ed25519
+	ServerAliveCountMax  1
+	ServerAliveInterval  30
+	UseKeyChain          no
+
+# Keep connections open for some time to reuse them
+# %C returns a hash of different information and is useful as socket identifier
+ControlMaster   auto
+ControlPersist  30s
+ControlPath     ~/.ssh/control-%C
+
+# User defaults
+AddKeysToAgent       yes
+Compression          yes
+ForwardAgent         yes
+HashKnownHosts       no
+ServerAliveCountMax  2
+ServerAliveInterval  300
+UseKeyChain          yes

examples/ssh/sshd_config

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+#	$OpenBSD: sshd_config,v 1.103 2018/04/09 20:41:22 tj Exp $
+
+# This is the sshd server system-wide configuration file.  See
+# sshd_config(5) for more information.
+
+# This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin
+
+# The strategy used for options in the default sshd_config shipped with
+# OpenSSH is to specify options with their default value where
+# possible, but leave them commented.  Uncommented options override the
+# default value.
+
+#Port 22
+#AddressFamily any
+#ListenAddress 0.0.0.0
+#ListenAddress ::
+
+#HostKey /etc/ssh/ssh_host_rsa_key
+#HostKey /etc/ssh/ssh_host_ecdsa_key
+#HostKey /etc/ssh/ssh_host_ed25519_key
+
+# Ciphers and keying
+#RekeyLimit default none
+
+# Logging
+#SyslogFacility AUTH
+#LogLevel INFO
+
+# Authentication:
+
+#LoginGraceTime 2m
+PermitRootLogin yes
+#StrictModes yes
+#MaxAuthTries 6
+#MaxSessions 10
+
+#PubkeyAuthentication yes
+
+# The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2
+# but this is overridden so installations will only check .ssh/authorized_keys
+AuthorizedKeysFile	.ssh/authorized_keys
+
+#AuthorizedPrincipalsFile none
+
+#AuthorizedKeysCommand none
+#AuthorizedKeysCommandUser nobody
+
+# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
+#HostbasedAuthentication no
+# Change to yes if you don't trust ~/.ssh/known_hosts for
+# HostbasedAuthentication
+#IgnoreUserKnownHosts no
+# Don't read the user's ~/.rhosts and ~/.shosts files
+#IgnoreRhosts yes
+
+# To disable tunneled clear text passwords, change to no here!
+#PasswordAuthentication yes
+#PermitEmptyPasswords no
+
+# Change to no to disable s/key passwords
+#ChallengeResponseAuthentication yes
+
+# Kerberos options
+#KerberosAuthentication no
+#KerberosOrLocalPasswd yes
+#KerberosTicketCleanup yes
+#KerberosGetAFSToken no
+
+# GSSAPI options
+#GSSAPIAuthentication no
+#GSSAPICleanupCredentials yes
+#GSSAPIStrictAcceptorCheck yes
+#GSSAPIKeyExchange no
+
+# Set this to 'yes' to enable PAM authentication, account processing,
+# and session processing. If this is enabled, PAM authentication will
+# be allowed through the ChallengeResponseAuthentication and
+# PasswordAuthentication.  Depending on your PAM configuration,
+# PAM authentication via ChallengeResponseAuthentication may bypass
+# the setting of "PermitRootLogin without-password".
+# If you just want the PAM account and session checks to run without
+# PAM authentication, then enable this but set PasswordAuthentication
+# and ChallengeResponseAuthentication to 'no'.
+UsePAM yes
+
+#AllowAgentForwarding yes
+#AllowTcpForwarding yes
+#GatewayPorts no
+X11Forwarding yes
+#X11DisplayOffset 10
+#X11UseLocalhost yes
+#PermitTTY yes
+#PrintMotd yes
+#PrintLastLog yes
+#TCPKeepAlive yes
+#PermitUserEnvironment no
+#Compression delayed
+#ClientAliveInterval 0
+#ClientAliveCountMax 3
+#UseDNS no
+#PidFile /run/sshd.pid
+#MaxStartups 10:30:100
+#PermitTunnel no
+#ChrootDirectory none
+#VersionAddendum none
+
+# no default banner path
+#Banner none
+
+# override default of no subsystems
+Subsystem	sftp	/usr/lib/ssh/sftp-server
+
+# This enables accepting locale enviroment variables LC_* LANG, see sshd_config(5).
+AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
+AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
+AcceptEnv LC_IDENTIFICATION LC_ALL
+
+# Example of overriding settings on a per-user basis
+#Match User anoncvs
+#	X11Forwarding no
+#	AllowTcpForwarding no
+#	PermitTTY no
+#	ForceCommand cvs server