SSH - Revision history

Admin: /* Passwordless Login */

2018-03-09T23:15:09Z

Passwordless Login

← Older revision		Revision as of 23:15, 9 March 2018
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	'''DO THIS STEP ONCE:'''		'''DO THIS STEP ONCE:'''

	Generate a public and private key. Use the ~~DSA~~ encryption algorithm. To do this, execute the command:		Generate a public and private key. Use the RSA encryption algorithm. To do this, execute the command:

	<pre>		<pre>
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	</pre>		</pre>

	You'll be prompted for a passphrase that must be entered every time you use your public key. This operation will create two files, <code>~/.ssh/{~~id_dsa~~,~~id_dsa~~.pub}</code>.		You'll be prompted for a passphrase that must be entered every time you use your public key. This operation will create two files, <code>~/.ssh/{id_rsa,id_rsa.pub}</code>.

	The file id_rsa is your private key - ''DO NOT SHARE YOUR PRIVATE KEY WITH ANYONE!''		The file id_rsa is your private key - ''DO NOT SHARE YOUR PRIVATE KEY WITH ANYONE!''

Admin: /* Tunneling from local port to remote port */

2018-03-09T23:14:46Z

Tunneling from local port to remote port

← Older revision		Revision as of 23:14, 9 March 2018
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	<pre>		<pre>
	ssh -N -L 6432:host:5432 root@bastion		ssh -N -L 6432:host:5432 root@bastion
	<pre>		</pre>

	<code>-N</code> : Dot not execute remote command		<code>-N</code> : Dot not execute remote command
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	Unless you're using an ancient version of SSH, you'll be using version 2 (if you're not, you need to be, because version 1 has security flaws! For example, see http://nmap.org/movies.html, The Matrix Reloaded section, and http://packetstormsecurity.org/advisories/bindview/adv_ssh1crc.txt for more information).		Unless you're using an ancient version of SSH, you'll be using version 2 (if you're not, you need to be, because version 1 has security flaws! For example, see http://nmap.org/movies.html, The Matrix Reloaded section, and http://packetstormsecurity.org/advisories/bindview/adv_ssh1crc.txt for more information).




	== Passwordless Login ==		== Passwordless Login ==

Admin: /* References */

2018-01-27T03:19:53Z

References

@@ Line 329: / Line 329: @@
 http://www.soloport.com/iptables.html
 = References =
@@ Line 337: / Line 351: @@
 How to create a self signed certificate - http://www.akadia.com/services/ssh_test_certificate.html
 =Flags=

Admin: /* SSH Tunnels */

2018-01-07T09:10:02Z

SSH Tunnels

← Older revision		Revision as of 09:10, 7 January 2018
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	If you run the command <code>man ssh</code> you can see all of the different options you have for the -c flag. Arcfour is almost assured to be the fastest.		If you run the command <code>man ssh</code> you can see all of the different options you have for the -c flag. Arcfour is almost assured to be the fastest.

			===Tunneling from local port to remote port===

			To create a tunnel from a local port to a remote port:

			<pre>
			ssh -N -L 6432:host:5432 root@bastion
			<pre>

			<code>-N</code> : Dot not execute remote command

			<code>-L</code> : [bind_address:]port:host:hostport

	== Cypher Selection ==		== Cypher Selection ==

Admin: /* Port Knocking */

2017-08-16T20:29:37Z

Port Knocking

← Older revision		Revision as of 20:29, 16 August 2017
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	== Port Knocking ==		== Port Knocking ==

	http://en.~~wikipedia~~.~~org~~/~~wiki~~/~~Port_knocking~~		Port knocking is the idea that, in order to remotely connect to a machine via SSH, you can require a certain port-knocking pattern - kind of like if you had 65,536 front doors, and you would only open door number 22 if, FIRST, a person knocked on door 5000, then on door 4000, then on door 3000, then on door 2000, then on door 1000.

			Port knocking is security through obfuscation, which is a weak form of security on its own (since, once your secret port knocking pattern is known, it is trivial to bypass), but can lead to hackers giving up and moving on to find some other, easier machine.

			Fart Knocker vulnhub box: http://www.top-hat-sec.com/r4v3ns-blog/fartknocker-vm-challenge

	http://ubuntu-ky.ubuntuforums.org/showthread.php?s=7bc4f48f2cefe32872d40e97cc5848cb&t=812573		http://ubuntu-ky.ubuntuforums.org/showthread.php?s=7bc4f48f2cefe32872d40e97cc5848cb&t=812573

Admin: /* Handy SSH Tricks */

2017-08-16T20:26:09Z

Handy SSH Tricks

Show changes

Admin: /* SSH Shortcuts */

2017-03-31T02:51:50Z

SSH Shortcuts

← Older revision		Revision as of 02:51, 31 March 2017
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	Let's say you SSH into a machine like this:		Let's say you SSH into a machine like this:

	<~~source lang="bash"~~>		<pre>
	$ ssh -p9999 my_username@machine1.some.system.com		$ ssh -p9999 my_username@machine1.some.system.com
	</~~source~~>		</pre>

	You can shorten this by adding the following into your ssh config file:		You can shorten this by adding the following into your ssh config file:
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	Now, the ssh command can be shortened to:		Now, the ssh command can be shortened to:

	<~~source lang="bash"~~>		<pre>
	$ ssh machine1		$ ssh machine1
	</~~source~~>		</pre>


	== Port Knocking ==		== Port Knocking ==

Admin: /* Passwordless Login */

2017-03-31T02:05:34Z

Passwordless Login

← Older revision		Revision as of 02:05, 31 March 2017
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	<pre>		<pre>
	[MachineA] $ ssh-keygen -t ~~dsa~~		[MachineA] $ ssh-keygen -t rsa
	</pre>		</pre>

	You'll be prompted for a passphrase that must be entered every time you use your public key. This operation will create two files, <code>~/.ssh/{id_dsa,id_dsa.pub}</code>.		You'll be prompted for a passphrase that must be entered every time you use your public key. This operation will create two files, <code>~/.ssh/{id_dsa,id_dsa.pub}</code>.

	The file ~~id_dsa~~ is your private key - ''DO NOT SHARE YOUR PRIVATE KEY WITH ANYONE!''		The file id_rsa is your private key - ''DO NOT SHARE YOUR PRIVATE KEY WITH ANYONE!''

	First, print the public key for MachineA into a terminal on MachineA:		First, print the public key for MachineA into a terminal on MachineA:

	<pre>		<pre>
	cat ~/.ssh/~~id_dsa~~.pub		cat ~/.ssh/id_rsa.pub
	</pre>		</pre>

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	To login to MachineB from MachineA without entering your password, perform the following steps:		To login to MachineB from MachineA without entering your password, perform the following steps:

			Start the SSH agent in the background:

	<pre>		<pre>
	[MachineA] $ ssh-agent ~~# <~~-~~- copy and paste the output of this command into a terminal;~~		[MachineA] $ eval "$(ssh-agent -s)"
	~~# this will set 2 environmental variables~~		[MachineA] $ ssh-add -K ~/.ssh/id_rsa
	[MachineA] $ ssh-add
	</pre>		</pre>

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	alias MachineB="MachineB"		alias MachineB="MachineB"
	function MachineB() {		function MachineB() {
	~~# put environmental variables in~~ ssh~~.file~~		eval "$(ssh-agent -s)"
	ssh-~~agent > ~/ssh.file~~		ssh-add -K ~/.ssh/id_rsa

	~~# execute this file, sending output to /dev/null~~
	~~chmod +x~~ ~/~~ssh~~.~~file~~
	~/ssh~~.file > /dev/null~~
	~~# echo $SSH_AGENT_PID~~
	~~# echo $SSH_AUTH_SOCK~~
	~~rm -f ~~~/~~ssh.file~~

	# ssh to MachineB		# ssh to MachineB

Admin: /* Passwordless Login */

2017-03-31T02:02:52Z

Passwordless Login

← Older revision		Revision as of 02:02, 31 March 2017
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	Generate a public and private key. Use the DSA encryption algorithm. To do this, execute the command:		Generate a public and private key. Use the DSA encryption algorithm. To do this, execute the command:

	<~~syntaxhighlight lang="bash"~~>		<pre>
	[MachineA] $ ssh-keygen -t dsa		[MachineA] $ ssh-keygen -t dsa
	</~~syntaxhighlight~~>		</pre>

	You'll be prompted for a passphrase that must be entered every time you use your public key. This operation will create two files, <code>~/.ssh/{id_dsa,id_dsa.pub}</code>.		You'll be prompted for a passphrase that must be entered every time you use your public key. This operation will create two files, <code>~/.ssh/{id_dsa,id_dsa.pub}</code>.
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	Remote-login to MachineB and paste the public key for MachineA into MachineB's list of authorized keys, using your favorite (er, my favorite) text editor:		Remote-login to MachineB and paste the public key for MachineA into MachineB's list of authorized keys, using your favorite (er, my favorite) text editor:

	<~~syntaxhighlight lang="bash"~~>		<pre>
	[MachineB] $ vi ~/.ssh/authorized_keys		[MachineB] $ vi ~/.ssh/authorized_keys
	</~~syntaxhighlight~~>		</pre>

	and paste the contents of MachineA's public key.		and paste the contents of MachineA's public key.
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	To login to MachineB from MachineA without entering your password, perform the following steps:		To login to MachineB from MachineA without entering your password, perform the following steps:

	<~~syntaxhighlight lang="bash"~~>		<pre>
	[MachineA] $ ssh-agent # <-- copy and paste the output of this command into a terminal;		[MachineA] $ ssh-agent # <-- copy and paste the output of this command into a terminal;
	# this will set 2 environmental variables		# this will set 2 environmental variables
	[MachineA] $ ssh-add		[MachineA] $ ssh-add
	</~~syntaxhighlight~~>		</pre>

	You will be prompted for your public key passphrase once per session, and once you enter it, you will have passwordless access to MachineB from MachineA.		You will be prompted for your public key passphrase once per session, and once you enter it, you will have passwordless access to MachineB from MachineA.
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	These steps are somewhat cumbersome, and can be shortened to a much more convenient bash function as follows. I want to create a bash function on MachineA so that when I type:		These steps are somewhat cumbersome, and can be shortened to a much more convenient bash function as follows. I want to create a bash function on MachineA so that when I type:

	<~~syntaxhighlight lang="bash"~~>		<pre>
	[MachineA] $ MachineB		[MachineA] $ MachineB
	</~~syntaxhighlight~~>		</pre>

	I will instantaneously be logged in to MachineB. To do this, I will create a function in my <code>~/.bashrc</code> (or somewhere similar, I use a <code>~/.aliases</code> file). This will look as follows:		I will instantaneously be logged in to MachineB. To do this, I will create a function in my <code>~/.bashrc</code> (or somewhere similar, I use a <code>~/.aliases</code> file). This will look as follows:

	<~~syntaxhighlight lang="bash"~~>		<pre>
	alias MachineB="MachineB"		alias MachineB="MachineB"
	function MachineB() {		function MachineB() {
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	ssh -Y user@MachineB.com		ssh -Y user@MachineB.com
	}		}
	</~~syntaxhighlight~~>		</pre>

	And now you can log in to MachineB by simply typing:		And now you can log in to MachineB by simply typing:

	<~~syntaxhighlight lang="bash"~~>		<pre>
	$ MachineB		$ MachineB
	</~~syntaxhighlight~~>		</pre>

	How hard is that???		How hard is that???

Admin at 22:01, 25 March 2017

2017-03-25T22:01:20Z

← Older revision		Revision as of 22:01, 25 March 2017
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	[[Category:SSL]]		[[Category:SSL]]
			[[Category:Server]]
			[[Category:Encryption]]