10 advanced, yet digestible SSH techniques

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10 advanced, yet digestible SSH techniques Wil Moore III @wilmoore

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Full-Stack Web Application Craftsman, TDD and Devops Advocate. http://github.com/wilmoore

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Public/Private key refresher

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Key Generation Style Create multiple key pairs Don't share across networks

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Share Public Key Only Never share your "Private Key" Do share "Public Key" with trusted hosts Remote login: Provide your passphrase

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Github <3’s SSH Keys Github OAuth2 API http://developer.github.com/v3/oauth

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SSH Agent Set and Forget about it http://www.funtoo.org/wiki/Keychain

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(1) Change a private- key's pass-phrase

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Periodic Pass-Phrase Change

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(2) {Multiple,} Single- Use Keys

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Multiple Single-Use Keys Tedious... $HOME/.ssh/conﬁg You'll ♥ doing this:

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(3) Remove stale known_hosts entries

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Stale known_hosts entries No sed, awk, grep tricks needed We’ve all seen this fun message...

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(4) SSH Auto-Completion

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Hostname Completion Type a few characters...press tab https://github.com/wilmoore/ruby-version/blob/master/ruby-version.sh#L67 Completion is easy...see: https://github.com/wilmoore/php-version/blob/master/php-version.sh#L73 List ﬁltered based on preﬁx

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Remote Filename Completion Type a path preﬁx... The kestrel directory is expanded... Directory contents are expanded

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bash_completion_installed? You probably already have it If not, install it (if you have ZSH, DONE)

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Y-U-NO INIT COMPLETION? Use the source... Homebrew Much?

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(5) SSHFS

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Mount remote directory Mount Unmount Thousands of remote ﬁles == PAIN

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(6) Remote Commands

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Remote Commands Tailing a remote log-ﬁle Edit Remote Files Vim Edit Remote Files

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(7) Access Remote Resources Locally

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Forward local port to remote Access MongoDB as if local

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(8) Named Remote Screen Sessions

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Access a remote screen session Create a remote screen session Continue session in separate term

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4 terminal remote pairing

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(9) Multi-Line Remote Scripting

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SSH + HEREDOC % ssh -t … <

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(10) Tunnel browser traffic through a SOCKS proxy

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Hey Netflix, your country check is annoying; however, I didn’t watch anything so please don’t terminate my account.

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Y-U-NO NETFLIX IN CANADA? OH come on now Netﬂix!! Create the SOCKS proxy SOME-HOST-NOT-TELLING

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Browser Network Settings Firefox Chrome

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All good besides silverlight fail!

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Github SSH Key Generation Help https://help.github.com/articles/generating-ssh-keys Recover SSH key passphrase https://help.github.com/articles/how-do-i-recover- my-ssh-key-passphrase Resources

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on JoindIn https://joind.in/7991 on Twitter http://twitter.com/wilmoore on Github http://github.com/wilmoore Thanks for your feedback

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Thank You :)

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Intentionally blank?? :)

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Bonus Content because you are so awesome!!

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(11) Google Chrome SSH Client

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SSH Client in the browser

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(12) ~/.ssh/authorized_keys restrictions

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Restrict what clients can do ssh-rsa bbbbB3NzaC1yc2EAAEy0TOB0MTYhzKSaD//szJ9FFR0pY+G0M2pi/ Wcbcj55KtYzBpYPNz8uV3T2N24PU9jybUD+n5ge/nTBRVgGu6Rk/ 7Fu9jdhmwOfxGlfFme/ no-port-forwarding,no-pty ssh-rsa bbbbB3NzaC1yc2EAAEy0TOB0MTYhzKSaD/ szJ9FFR0pY+G0M2pi/Wcbcj55KtYzBpYPNz8uV3T2N247Fu9jdhmwOfxGlfFme/ COMMAND=”printf 'Unable to run %s\n' ${SSH_ORIGINAL_COMMAND}” ssh- rsa bbbbB3NzaC1yc2EAAEy0TOB0MTYhzKSaD/szJ9FFR0pY+G0M2pi/ git clone [email protected]:wilmoore/frontend-packagers.git

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(13) Fail2ban

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/etc/fail2ban/jail.local [ssh] enabled = true port = ssh filter = sshd logpath = /var/log/auth.log maxretry = 6 [ssh-ddos] enabled = true port = ssh filter = sshd-ddos logpath = /var/log/auth.log maxretry = 6