SSH

SSH - Signing Files

Signing Files with SSH 8.0 unsigned file $ cat hosts 127.0.0.1 localhost ::1 localhost 1.2.3.4 egal sign $ ssh-keygen -Y sign -f id_rsa -n file hosts Signing file hosts Write signature to hosts.sig signed file $ cat hosts.sig -----BEGIN SSH SIGNATURE----- U1NIU0lHAAAAAQAAAZcAAAAHc3NoLXJzYQAAAAMBAAEAAAGBALJB+O4WCOM7V56H1xigpd uJem52Izwltl2cG9GQOO94HClebcr7C5aD24iI4wDcT9Ajv5/fu9cDVEXku83I/U0blUZe oMd8qCIH+4O+RVYyCvKFyEkcZ6n+RRH1G5EgcP0UXtmo4J3p8Hyo/6jtPA/r28+idi84A6 7yW1cmC5GpIw24Vr5aqA3e3rCJdFBZThzsTrwu/DHzIueQstEQdldycUit4X9UPBaCVnov +nhyijO9b8adzkTMxjcJAl65fdLUmwuJ5h3z0owdKOmrcNlbWxqTIuGU0in25ZDQVxLssc WI8oW7vR5F7+cXSV7fYliTG/XPsCkD1KpWc/xSOr35bALRQpxD1+T48mrbKToZuzu4hage cUSOvRI3R0hKIvcXYyf2SQoBfLNlpvl5CRcatlw2fMhFQPrVz0Bh543chEFsF4nxKQw8yq riJbqkvhW8tzKCnMA7vyTRxey6uSDJrw0YchXIJdprNUlgM1t+z9J3AwC4ugpvhgVd6H0v 9QAAAAxob3N0cy5zaWduZWQAAAAAAAAABnNoYTUxMgAAAZQAAAAMcnNhLXNoYTItNTEyAA ABgAB9zAZStPsSvPIBh66lAgGLE/JWPk0voZjTUz9pO5wl81aM6Kn1clY9n4jysEkiQ0xy yy/tWgFzKi10mVfh/SJ34L2Mdo8t+vBnha1KNlkFwXZl+GXiCLlVl+ei6xpRfp9knheoIh LyEHoxgkuI6lO0c8pi4ymNnrlfvkg9SvvZfSdXWUMfTWHDlHvFIGqMg3BWQu7ylTEgQVDF obpqDInU3hkisfsywQRQh6KVVe8eSUc0qVH/FSSLoG8X/IX9Vh3g4tT/2FJPrE4k464yie GdnLkp5edcnnE+jjoSQroMs52QWy2a3XXZC5KTaDL6w4mcry1RpavhXb5aJQ7o0852Pkc9 wDkwX/11JZhMmxNZbDlg+tHsWy12KUubKAxAjJ1HUFXMjTFI6HMu8WyU989e3dOTt/bL3W l7sDo5P8SGv3/6+tJxugz9shz8WaN9Xz6Oh2AfCM6+IROXaeUgWMXtDmGS5bUZxUOSxHa1 ww7wzYR0NKXuOk3IeJMSQ2f97g== -----END SSH SIGNATURE----- verify file allowed signers $ cat /etc/allowed_signers mail@world.net ssh-rsa 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 verify

Honeypot

i like to run honeypots … ok, to be honest, it’s not a honeypot. It’s a productive maschine for me, but all the bots trying to get in get’s redirected to a Honeypot, the credentials were captured and last but not least, you can watch them live in your browser :) http://honeypot.nolink.ch btw. 100k failed login attempts in 10 Day … have fun ! Any Comments ? sha256: 8ae49e2283f894d5ab59ec16309f4f1d4aa547c0fd90705f969bae0d20d3b6f2

SSH Server behind Firewall

got a Server behing NAT / Firewall ? Need Shell access to … ? Server behind NAT/FW user@server$ ssh -R 1234:localhost:22 my.public.jumpbox Access Server ssh my.public.jumpbox user@jumpbox$ ssh -p 1234 localhost user@server$ and you’re in :) Any Comments ? sha256: 81b4dc1d84f9f8bcbf5060f382853759fffa1e5824e2ae98ad5508a082db5dfd

Ed25519

like ssh and secure keys ? Generate Secure Key ssh-keygen -o -a 100 -t ed25519 -C "MyFamousComment" ssh-keygen -o -a 100 -t ed25519 -C "$(whoami)@$(hostname)" ssh-keygen -o -a 100 -t ed25519 -C "$(whoami)@$(hostname) at $(date \"+%Y-%m-%d\")" ssh-keygen -o -a 100 -t ed25519 -C "$(whoami)@$(hostname) at $(date \"+%Y-%m-%d %H:%M\")" What’s ed25519 ? Wikipedia about Curve25519 Distribute Key ssh-copy-id user@remotehost Connect to Remote Connect to Remove without Agent Forwarding (use this unless you know what you’re dooing …)