Ssh keys - Revision history

Daniel-schurhoff-de23@rwth-aachen.de at 13:51, 3 September 2019

2019-09-03T13:51:08Z

Nina-loseke-fd7a@rwth-aachen.de at 13:37, 20 April 2018

2018-04-20T13:37:10Z

Nina-loseke-fd7a@rwth-aachen.de at 13:34, 20 April 2018

2018-04-20T13:34:45Z

Christian-wassermann-e30b@rwth-aachen.de: /* How-to-use-it */

2018-04-17T06:30:16Z

How-to-use-it

Christian-wassermann-e30b@rwth-aachen.de at 12:24, 16 April 2018

2018-04-16T12:24:29Z

Christian-wassermann-e30b@rwth-aachen.de at 12:23, 16 April 2018

2018-04-16T12:23:55Z

Christian-wassermann-e30b@rwth-aachen.de at 12:11, 16 April 2018

2018-04-16T12:11:24Z

Christian-wassermann-e30b@rwth-aachen.de at 12:00, 16 April 2018

2018-04-16T12:00:21Z

Christian-wassermann-e30b@rwth-aachen.de: /* How-it-works */

2018-04-10T13:00:12Z

How-it-works

Christian-wassermann-e30b@rwth-aachen.de: /* Copy the public key to the server */

2018-04-10T12:56:38Z

Copy the public key to the server

← Older revision		Revision as of 13:51, 3 September 2019
Line 1:		Line 1:
		+	[[Category:Basics]]
	An ssh key is a way of identifying (authenticating) yourself when connecting to a server via [[ssh]]. A different popular authentication method is entering a password.		An ssh key is a way of identifying (authenticating) yourself when connecting to a server via [[ssh]]. A different popular authentication method is entering a password.

@@ Line 1: / Line 1: @@
 An ssh key is a way of identifying (authenticating) yourself when connecting to a server via [[ssh]]. A different popular authentication method is entering a password.
 __TOC__
 == Why should I use it?==

← Older revision		Revision as of 13:34, 20 April 2018
Line 1:		Line 1:
	An ssh key is a way of identifying (authenticating) yourself when connecting to a server via [[ssh]]. A different popular authentication method is entering a password.		An ssh key is a way of identifying (authenticating) yourself when connecting to a server via [[ssh]]. A different popular authentication method is entering a password.
		+
		+	__TOC__

	== Why should I use it?==		== Why should I use it?==

@@ Line 44: / Line 44: @@
 You should also make sure, that correct file access permission are set. If unsure, execute:
   $ chmod 600 ~/.ssh/id_rsa
   $ chmod 640 ~/.ssh/id_rsa.pub
 == How-it-works ==

@@ Line 21: / Line 21: @@
 === Copy the public key to the server ===
-==== Method 1 ====
+==== Method A ====
 This public key now has to be copied to the server into the <code>~/.ssh/authorized_keys</code> file. This can be done, by opening an [[ssh]] connection via password and then using an editor (e.g. [[vim]]) to paste the key into the file (creating the '''.ssh''' directory beforehand if it does not exist):
@@ Line 27: / Line 27: @@
   $ vim ~/.ssh/authorized_keys
-==== Method 2 ====
+==== Method B ====
 Instead of performing the copying of the ssh key to the server manually, you can use the program <code>ssh-copy-id</code> to achieve the same goal:

@@ Line 1: / Line 1: @@
-An ssh key is a way of identifying (authenticating) yourself when connecting to a server per [[ssh]]. A different popular authentication method is via a password.
+An ssh key is a way of identifying (authenticating) yourself when connecting to a server via [[ssh]]. A different popular authentication method is entering a password.
 == Why should I use it?==
@@ Line 7: / Line 7: @@
 == How-to-use-it ==
 === Generate a key ===
 You should start by generating a key pair:
@@ Line 19: / Line 20: @@
 === Copy the public key to the server ===
-This public key now has to be copied to the server to the
- ~/.ssh/authorized_keys
+==== Method 1 ====
 file. This can be done, by opening an [[ssh]] connection via password and then using an editor (e.g. [[vim]]) to paste the key into the file (creating the '''.ssh''' directory if it does not exist):
-  $ mkdir ~/.ssh
+This public key now has to be copied to the server into the <code>~/.ssh/authorized_keys</code> file. This can be done, by opening an [[ssh]] connection via password and then using an editor (e.g. [[vim]]) to paste the key into the file (creating the '''.ssh''' directory beforehand if it does not exist):
   $ vim ~/.ssh/authorized_keys
-The next time you [[ssh]] to the server, it should use the key and instead of prompting for the user's pass'''word''', prompt for the pass'''phrase''' of the key (if you chose to employ a passphrase).
+==== Method 2 ====
 === Troubleshooting ===
 If it still asks for your password, something went wrong. In that case you should check, whether the '''authorized_keys''' file really contains the key by executing:
   $ cat ~/.ssh/authorized_keys
 on the '''server''' and
   $ cat ~/.ssh/id_rsa.pub
-on '''your local machine'''. If the key of your local machine is not contained in the '''authorized_keys''' on the server, repeat the steps of copying the key to the server. You should also make sure, that correct file access permission are set. If unsure, execute:
+on '''your local machine'''. If the key of your local machine is not contained in the '''authorized_keys''' on the server, repeat the steps of copying the key to the server.
   $ chmod 600 ~/.ssh/id_rsa
   $ chmod 640 ~/.ssh/id_rsa.pub
 == How-it-works ==
 The basic principle is that of asymmetrical cryptography being employed by using a public-private-key-pair. A public key is like an indestructible piggy bank: Everybody can put something (data) into it, but nobody can get it back out again. A private key is the key for this. In this way you can distribute all the piggy banks you like and if someone put something in there and sends it back, only you can open it with your private key.
@@ Line 44: / Line 56: @@
 == References ==
 [https://wiki.archlinux.de/title/SSH-Authentifizierung_mit_Schl%C3%BCsselpaaren SSH keys on the archlinux wiki]

@@ Line 35: / Line 35: @@
 == How-it-works ==
-The basic principle is that of asymmetrical cryptography being employed by using a public-private-key-pair. A public key is like an indestructible piggy bank: Everybody can put something (data) into it and nobody can get it back out again. A private key is the key for this. In this way you can distribute all the piggy banks you like and if someone put something in there and sends it back, only you can open it with your private key.
+The basic principle is that of asymmetrical cryptography being employed by using a public-private-key-pair. A public key is like an indestructible piggy bank: Everybody can put something (data) into it, but nobody can get it back out again. A private key is the key for this. In this way you can distribute all the piggy banks you like and if someone put something in there and sends it back, only you can open it with your private key.
 Now since you gave the server the public key (=piggy bank), it can encrypt something (say a random number), send it back and only you can decrypt this number, since only you have the private key.