--- /dev/null
+# SSH configuration file.
+#
+# Some options are set even if they are default to prevent /etc/ssh/ssh_config
+# from overwriting them.
+
+# Copyright (C) 2011-2016 Simon Ruderich
+#
+# This file is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This file is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this file. If not, see <http://www.gnu.org/licenses/>.
+
+# Undocumented (and not very well tested) feature. This drops the connection
+# after 5 seconds of inactivity. Thanks to shad0VV in #openssh on Freenode
+# (2012-11-04 18:40 CET) for telling me about this undocumented feature.
+#
+# ServerAliveCountMax 0
+# ServerAliveInterval 5
+
+
+# Options are parsed top-to-bottom, the first matching option is used. Later
+# assignments to the same option are ignored, thanks to anonJD in #openssh on
+# Freenode (2011-05-18 21:40 CEST) for letting me know. Therefore put all
+# affected host specific rules here, before the global rules.
+#
+# For example to change the MACs option for a specific host, use:
+#
+# Host host
+# # Old SSH daemon which needs SHA1 (SHA-512 in case it gets updated).
+# MACs hmac-sha2-512,hmac-sha1
+
+
+# Rules for all hosts.
+Host *
+
+# Force protocol version 2 which is more secure (default).
+ Protocol 2
+
+# Use stronger algorithms. If some hosts require weaker versions then use Host
+# groups to enable them only for those specific machines.
+
+# Don't use SHA1 and disable elliptic curves whose security regarding the
+# parameters is still in debate.
+ KexAlgorithms diffie-hellman-group-exchange-sha256
+# Use stronger cipher versions. Disable CBC ciphers to prevent (unlikely)
+# plaintext recovery attack [1], disable RC4 because it's broken [2]; this
+# leaves only AES. No GCM ciphers yet because they are still very new.
+#
+# [1]: http://www.openssh.com/txt/cbc.adv
+# [2]: http://www.schneier.com/blog/archives/2013/03/new_rc4_attack.html
+ Ciphers aes256-ctr
+# Don't use weak MACs like MD5 or SHA1. However strong MACs are not as
+# important as strong ciphers because an attacker must be able to break a MAC
+# in real time to modify the data in transmit. Prefer "-etm" algorithms which
+# use encrypt-then-mac which is more secure than the default encrypt-and-mac
+# in SSH [1] (available since 6.2).
+#
+# [1]: http://cseweb.ucsd.edu/~mihir/papers/oem.html
+ MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-512
+# Disable DSA host keys because they are weak (only 1024 bit) and elliptic
+# curves. I don't need certificates, therefore disable those algorithms as
+# well (*-cert-*).
+ HostKeyAlgorithms ssh-rsa
+
+# Disable X11 and agent forwarding for security reasons (defaults).
+ ForwardX11 no
+ ForwardAgent no
+# Don't trust remote X11 clients. If enabled allows bad admins complete access
+# to local X11!
+ ForwardX11Trusted no
+
+# Disable authentication methods I don't use.
+ ChallengeResponseAuthentication no
+ GSSAPIAuthentication no
+ HostbasedAuthentication no
+ KbdInteractiveAuthentication no
+# Only enable those I need.
+ PasswordAuthentication yes
+ PubkeyAuthentication yes
+
+# Use only authentication identity files configured in ~/.ssh/config even if
+# ssh-agent offers more identities.
+ IdentitiesOnly yes
+
+# Bind local forwardings to loopback only. This way no remote hosts can access
+# them (default).
+ GatewayPorts no
+# Abort if not all requested port forwardings can be set up.
+ ExitOnForwardFailure yes
+
+# Allow using -M (ControlMaster) to create a master SSH session which
+# "tunnels" other connections to the same host, thus reducing the number of
+# authentications (which are relatively slow) and TCP connections. The master
+# sockets are stored in ~/.ssh (by default ControlPath is not set). Using %r
+# (remote user name) might leak information to other users on the current
+# system (e.g. via netstat or lsof).
+ ControlPath ~/.ssh/master/%l-%h-%p-%r
+# Automatically create a new master session if there's none yet or use an
+# existing one. This way the user doesn't have to use -M to enable a master
+# manually. Don't set this option to "yes" or all SSH commands try to become
+# the master session which is obviously not possible.
+ ControlMaster auto
+# When the connection for a master is closed (e.g. logout of remote shell),
+# move the master connection in the background. If there's no other active
+# connection using the master, close it after x seconds. This prevents the
+# client of the master connection from blocking because it waits for all
+# connections using it to terminate which is very annoying. The timeout
+# prevents stale master connections.
+ ControlPersist 10
+
+# Don't permit running local commands (default).
+ PermitLocalCommand no
+
+# Don't send any environment variables (default).
+ SendEnv
+
+# Don't hash any hosts in ~/.ssh/known_hosts. It doesn't help if the ssh hosts
+# are stored in the shell's history file or in this file as shortcut so it's
+# rather useless (default).
+ HashKnownHosts no
+
+# Check host IP in known_hosts when connecting to detect DNS spoofing
+# (default).
+ CheckHostIP yes
+# Ask before adding any host keys to ~/.ssh/known_hosts (default).
+ StrictHostKeyChecking ask
+# Check host keys from DNS' SSHFP resource records but ask apply
+# StrictHostKeyChecking before trusting them.
+ VerifyHostKeyDNS ask
ruderich.org/simon / config / dotfiles.git / blobdiff