amauryval · July 7, 2022 22:25 · Mar 12, 2014 · Mar 12, 2014 · Mar 12, 2014 · Mar 12, 2014
diff --git a/how_to_set_up_ssh_keys.md b/how_to_set_up_ssh_keys.md
@@ -34,7 +34,7 @@ Your identification has been saved in /home/demo/.ssh/id_rsa.
 Your public key has been saved in /home/demo/.ssh/id_rsa.pub.
 The key fingerprint is:
 4a:dd:0a:c6:35:4e:3f:ed:27:38:8c:74:44:4d:93:67 demo@a
-The key\'s randomart image is:
+The key's randomart image is:
 +--[ RSA 2048]----+
 |          .oo.   |
 |         .  o.E  |
@@ -58,35 +58,35 @@ Once the key pair is generated, it's time to place the public key on the virtual
 You can copy the public key into the new machine's authorized_keys file with the ssh-copy-id command. Make sure 
 to replace the example username and IP address below.
 
-```bash
+```
 ssh-copy-id [email protected]
 ```
 
 Alternatively, you can paste in the keys using SSH:
 
-```bash
-cat ~/.ssh/id_rsa.pub | ssh [email protected] '"cat >> ~/.ssh/authorized_keys"'
+```
+cat ~/.ssh/id_rsa.pub | ssh [email protected] "cat >> ~/.ssh/authorized_keys"
 ```
 
 No matter which command you chose, you should see something like:
 
-```bash
-The authenticity of host \'12.34.56.78 (12.34.56.78)\' can\'t be established.
+```
+The authenticity of host '12.34.56.78 (12.34.56.78)' can't be established.
 RSA key fingerprint is b1:2d:33:67:ce:35:4d:5f:f3:a8:cd:c0:c4:48:86:12.
 Are you sure you want to continue connecting (yes/no)? yes
 Warning: Permanently added '12.34.56.78' (RSA) to the list of known hosts.
-[email protected]\'s password:
+[email protected]'s password:
 ```
  
 Now try logging into the machine, with:
 
-```bash
+```
 ssh [email protected]
 ```
 
 and check in:
 
-```bash
+```
 ~/.ssh/authorized_keys
 ```
 
@@ -100,19 +100,19 @@ Once you have copied your SSH keys unto your server and ensured that you can log
 
 In order to do this, open up the SSH config file:
 
-```bash
+```
 sudo nano /etc/ssh/sshd_config
 ```
 
 Within that file, find the line that includes PermitRootLogin and modify it to ensure that users can only connect with their SSH key:
 
-```bash
+```
 PermitRootLogin without-password
 ```
 
 Put the changes into effect:
 
-```bash
+```
 sudo /etc/init.d/ssh restart
 ```
 
diff --git a/how_to_set_up_ssh_keys.md b/how_to_set_up_ssh_keys.md
@@ -65,7 +65,7 @@ ssh-copy-id [email protected]
 Alternatively, you can paste in the keys using SSH:
 
 ```bash
-cat ~/.ssh/id_rsa.pub | ssh [email protected] \"cat >> ~/.ssh/authorized_keys\"
+cat ~/.ssh/id_rsa.pub | ssh [email protected] '"cat >> ~/.ssh/authorized_keys"'
 ```
 
 No matter which command you chose, you should see something like:

diff --git a/how_to_set_up_ssh_keys.md b/how_to_set_up_ssh_keys.md
@@ -34,7 +34,7 @@ Your identification has been saved in /home/demo/.ssh/id_rsa.
 Your public key has been saved in /home/demo/.ssh/id_rsa.pub.
 The key fingerprint is:
 4a:dd:0a:c6:35:4e:3f:ed:27:38:8c:74:44:4d:93:67 demo@a
-The key's randomart image is:
+The key\'s randomart image is:
 +--[ RSA 2048]----+
 |          .oo.   |
 |         .  o.E  |
@@ -65,17 +65,17 @@ ssh-copy-id [email protected]
 Alternatively, you can paste in the keys using SSH:
 
 ```bash
-cat ~/.ssh/id_rsa.pub | ssh [email protected] "cat >> ~/.ssh/authorized_keys"
+cat ~/.ssh/id_rsa.pub | ssh [email protected] \"cat >> ~/.ssh/authorized_keys\"
 ```
 
 No matter which command you chose, you should see something like:
 
 ```bash
-The authenticity of host '12.34.56.78 (12.34.56.78)' can't be established.
+The authenticity of host \'12.34.56.78 (12.34.56.78)\' can\'t be established.
 RSA key fingerprint is b1:2d:33:67:ce:35:4d:5f:f3:a8:cd:c0:c4:48:86:12.
 Are you sure you want to continue connecting (yes/no)? yes
 Warning: Permanently added '12.34.56.78' (RSA) to the list of known hosts.
-[email protected]'s password:
+[email protected]\'s password:
 ```
 
 Now try logging into the machine, with:

diff --git a/how_to_set_up_ssh_keys.md b/how_to_set_up_ssh_keys.md
@@ -0,0 +1,118 @@
+# How to Set up SSH Keys
+### Create the RSA Key Pair
+
+```bash
+ssh-keygen -t rsa
+```
+
+### Store the Keys and Passphrase
+Once you have entered the Gen Key command, you will get a few more questions:
+
+```bash
+Enter file in which to save the key (/home/demo/.ssh/id_rsa):
+```
+
+You can press enter here, saving the file to the user home (in this case, my example user is called demo).
+
+```bash
+Enter passphrase (empty for no passphrase):
+```
+
+It's up to you whether you want to use a passphrase. 
+
+Entering a passphrase does have its benefits: the security of a key, no matter how encrypted, still depends on the fact that it is not visible to anyone else. Should a passphrase-protected private key fall into an unauthorized users possession, they will be unable to log in to its associated accounts until they figure out the passphrase, buying the hacked user some extra time. The only downside, of course, to having a passphrase, is then having to type it in each time you use the Key Pair. 
+
+The entire key generation process looks like this:
+
+```bash
+ssh-keygen -t rsa
+Generating public/private rsa key pair.
+Enter file in which to save the key (/home/demo/.ssh/id_rsa): 
+Enter passphrase (empty for no passphrase): 
+Enter same passphrase again: 
+Your identification has been saved in /home/demo/.ssh/id_rsa.
+Your public key has been saved in /home/demo/.ssh/id_rsa.pub.
+The key fingerprint is:
+4a:dd:0a:c6:35:4e:3f:ed:27:38:8c:74:44:4d:93:67 demo@a
+The key's randomart image is:
++--[ RSA 2048]----+
+|          .oo.   |
+|         .  o.E  |
+|        + .  o   |
+|     . = = .     |
+|      = S = .    |
+|     o + = +     |
+|      . o + o .  |
+|           . o   |
+|                 |
++-----------------+
+```
+
+The public key is now located in /home/demo/.ssh/id_rsa.pub 
+
+The private key (identification) is now located in /home/demo/.ssh/id_rsa 
+
+### Copy the Public Key
+Once the key pair is generated, it's time to place the public key on the virtual server that we want to use. 
+
+You can copy the public key into the new machine's authorized_keys file with the ssh-copy-id command. Make sure 
+to replace the example username and IP address below.
+
+```bash
+ssh-copy-id [email protected]
+```
+
+Alternatively, you can paste in the keys using SSH:
+
+```bash
+cat ~/.ssh/id_rsa.pub | ssh [email protected] "cat >> ~/.ssh/authorized_keys"
+```
+
+No matter which command you chose, you should see something like:
+
+```bash
+The authenticity of host '12.34.56.78 (12.34.56.78)' can't be established.
+RSA key fingerprint is b1:2d:33:67:ce:35:4d:5f:f3:a8:cd:c0:c4:48:86:12.
+Are you sure you want to continue connecting (yes/no)? yes
+Warning: Permanently added '12.34.56.78' (RSA) to the list of known hosts.
+[email protected]'s password:
+```
+ 
+Now try logging into the machine, with:
+
+```bash
+ssh [email protected]
+```
+
+and check in:
+
+```bash
+~/.ssh/authorized_keys
+```
+
+to make sure we haven't added extra keys that you weren't expecting.
+
+Now you can go ahead and log into [email protected] and you will not be prompted for a password. However, if you set a passphrase, you will be asked to enter the passphrase at that time (and whenever else you log in in the future).
+
+### Disable the Password for Root Login
+
+Once you have copied your SSH keys unto your server and ensured that you can log in with the SSH keys alone, you can go ahead and restrict the root login to only be permitted via SSH keys.
+
+In order to do this, open up the SSH config file:
+
+```bash
+sudo nano /etc/ssh/sshd_config
+```
+
+Within that file, find the line that includes PermitRootLogin and modify it to ensure that users can only connect with their SSH key:
+
+```bash
+PermitRootLogin without-password
+```
+
+Put the changes into effect:
+
+```bash
+sudo /etc/init.d/ssh restart
+```
+