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      How to Set Up SSH Keys on Debian 11


      Not using Debian 11?


      Choose a different version or distribution.

      Introduction

      SSH, or secure shell, is an encrypted protocol used to administer and communicate with servers. When working with a Debian server, chances are you will spend most of your time in a terminal session connected to your server through SSH.

      In this guide, we’ll focus on setting up SSH keys for a vanilla Debian 11 installation. SSH keys provide an easy, secure way of logging into your server and are recommended for all users.

      Step 1 — Create the RSA Key Pair

      The first step is to create a key pair on the client machine (usually your computer):

      By default ssh-keygen will create a 3072-bit RSA key pair, which is secure enough for most use cases (you may optionally pass in the -b 4096 flag to create a larger 4096-bit key).

      After entering the command, you should see the following output:

      Output

      Generating public/private rsa key pair. Enter file in which to save the key (/your_home/.ssh/id_rsa):

      Press enter to save the key pair into the .ssh/ subdirectory in your home directory, or specify an alternate path.

      If you had previously generated an SSH key pair, you may see the following prompt:

      Output

      /home/your_home/.ssh/id_rsa already exists. Overwrite (y/n)?

      Warning: If you choose to overwrite the key on disk, you will not be able to authenticate using the previous key anymore. Be very careful when selecting yes, as this is a destructive process that cannot be reversed.

      You should then see the following prompt:

      Output

      Enter passphrase (empty for no passphrase):

      Here you optionally may enter a secure passphrase, which is highly recommended. A passphrase adds an additional layer of security to prevent unauthorized users from logging in. To learn more about security, consult our tutorial on How To Configure SSH Key-Based Authentication on a Linux Server.

      You should then see the following output:

      Output

      Your identification has been saved in /your_home/.ssh/id_rsa. Your public key has been saved in /your_home/.ssh/id_rsa.pub. The key fingerprint is: SHA256:5E2BtTN9FHPBNoRXAB/EdjtHNYOHzTBzG5qUv7S3hyM root@debian-suricata The key's randomart image is: +---[RSA 3072]----+ | oo .O^XB| | . +.BO%B| | . = .+B+o| | o o o . =.| | S . . =| | o.| | .o| | E o..| | . ..| +----[SHA256]-----+

      You now have a public and private key that you can use to authenticate. The next step is to place the public key on your server so that you can use SSH-key-based authentication to log in.

      Step 2 — Copy the Public Key to Debian Server

      The quickest way to copy your public key to the Debian host is to use a utility called ssh-copy-id. Due to its simplicity, this method is highly recommended if available. If you do not have ssh-copy-id available to you on your client machine, you may use one of the two alternate methods provided in this section (copying via password-based SSH, or manually copying the key).

      Copying Public Key Using ssh-copy-id

      The ssh-copy-id tool is included by default in many operating systems, so you may have it available on your local system. For this method to work, you must already have password-based SSH access to your server.

      To use the utility, you simply need to specify the remote host that you would like to connect to and the user account that you have password SSH access to. This is the account to which your public SSH key will be copied.

      The syntax is:

      • ssh-copy-id username@remote_host

      You may see the following message:

      Output

      The authenticity of host '203.0.113.1 (203.0.113.1)' can't be established. ECDSA key fingerprint is fd:fd:d4:f9:77:fe:73:84:e1:55:00:ad:d6:6d:22:fe. Are you sure you want to continue connecting (yes/no)? yes

      This means that your local computer does not recognize the remote host. This will happen the first time you connect to a new host. Type “yes” and press ENTER to continue.

      Next, the utility will scan your local account for the id_rsa.pub key that we created earlier. When it finds the key, it will prompt you for the password of the remote user’s account:

      Output

      /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys username@203.0.113.1's password:

      Type in the password (your typing will not be displayed for security purposes) and press ENTER. The utility will connect to the account on the remote host using the password you provided. It will then copy the contents of your ~/.ssh/id_rsa.pub key into a file in the remote account’s home ~/.ssh directory called authorized_keys.

      You should see the following output:

      Output

      Number of key(s) added: 1 Now try logging into the machine, with: "ssh 'username@203.0.113.1'" and check to make sure that only the key(s) you wanted were added.

      At this point, your id_rsa.pub key has been uploaded to the remote account. You can continue on to Step 3.

      Copying Public Key Using SSH

      If you do not have ssh-copy-id available, but you have password-based SSH access to an account on your server, you can upload your keys using a conventional SSH method.

      We can do this by using the cat command to read the contents of the public SSH key on our local computer and piping that through an SSH connection to the remote server.

      On the other side, we can make sure that the ~/.ssh directory exists and has the correct permissions under the account we’re using.

      We can then output the content we piped over into a file called authorized_keys within this directory. We’ll use the >> redirect symbol to append the content instead of overwriting it. This will let us add keys without destroying previously added keys.

      The full command looks like this:

      • cat ~/.ssh/id_rsa.pub | ssh username@remote_host "mkdir -p ~/.ssh && touch ~/.ssh/authorized_keys && chmod -R go= ~/.ssh && cat >> ~/.ssh/authorized_keys"

      You may see the following message:

      Output

      The authenticity of host '203.0.113.1 (203.0.113.1)' can't be established. ECDSA key fingerprint is fd:fd:d4:f9:77:fe:73:84:e1:55:00:ad:d6:6d:22:fe. Are you sure you want to continue connecting (yes/no)? yes

      This means that your local computer does not recognize the remote host. This will happen the first time you connect to a new host. Type “yes” and press ENTER to continue.

      Afterwards, you should be prompted to enter the remote user account password:

      Output

      username@203.0.113.1's password:

      After entering your password, the content of your id_rsa.pub key will be copied to the end of the authorized_keys file of the remote user’s account. Continue on to Step 3 if this was successful.

      Copying Public Key Manually

      If you do not have password-based SSH access to your server available, you will have to complete the above process manually.

      We will manually append the content of your id_rsa.pub file to the ~/.ssh/authorized_keys file on your remote machine.

      To display the content of your id_rsa.pub key, type this into your local computer:

      You will see the key’s content, which should look something like this:

      Output

      ssh-rsa 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 demo@test

      Access your remote host using whichever method you have available.

      Once you have access to your account on the remote server, you should make sure the ~/.ssh directory exists. This command will create the directory if necessary, or do nothing if it already exists:

      Now, you can create or modify the authorized_keys file within this directory. You can add the contents of your id_rsa.pub file to the end of the authorized_keys file, creating it if necessary, using this command:

      • echo public_key_string >> ~/.ssh/authorized_keys

      In the above command, substitute the public_key_string with the output from the cat ~/.ssh/id_rsa.pub command that you executed on your local system. It should start with ssh-rsa AAAA....

      Finally, we’ll ensure that the ~/.ssh directory and authorized_keys file have the appropriate permissions set:

      This recursively removes all “group” and “other” permissions for the ~/.ssh/ directory.

      If you’re using the root account to set up keys for a user account, it’s also important that the ~/.ssh directory belongs to the user and not to root:

      • chown -R sammy:sammy ~/.ssh

      In this tutorial our user is named sammy but you should substitute the appropriate username into the above command.

      You can now attempt passwordless authentication with your Debian server.

      Step 3 — Authenticate to Debian Server Using SSH Keys

      If you have successfully completed one of the procedures above, you should be able to log into the remote host without the remote account’s password.

      The general process is the same:

      If this is your first time connecting to this host (if you used the last method above), you may see something like this:

      Output

      The authenticity of host '203.0.113.1 (203.0.113.1)' can't be established. ECDSA key fingerprint is fd:fd:d4:f9:77:fe:73:84:e1:55:00:ad:d6:6d:22:fe. Are you sure you want to continue connecting (yes/no)? yes

      This means that your local computer does not recognize the remote host. Type “yes” and then press ENTER to continue.

      If you did not supply a passphrase for your private key, you will be logged in immediately. If you supplied a passphrase for the private key when you created the key, you will be prompted to enter it now (note that your keystrokes will not display in the terminal session for security). After authenticating, a new shell session should open for you with the configured account on the Debian server.

      If key-based authentication was successful, continue on to learn how to further secure your system by disabling password authentication.

      Step 4 — Disable Password Authentication on your Server

      If you were able to log into your account using SSH without a password, you have successfully configured SSH-key-based authentication to your account. However, your password-based authentication mechanism is still active, meaning that your server is still exposed to brute-force attacks.

      Before completing the steps in this section, make sure that you either have SSH-key-based authentication configured for the root account on this server, or preferably, that you have SSH-key-based authentication configured for a non-root account on this server with sudo privileges. This step will lock down password-based logins, so ensuring that you will still be able to get administrative access is crucial.

      Once you’ve confirmed that your remote account has administrative privileges, log into your remote server with SSH keys, either as root or with an account with sudo privileges. Then, open up the SSH daemon’s configuration file:

      • sudo nano /etc/ssh/sshd_config

      Inside the file, search for a directive called PasswordAuthentication. This may be commented out. Uncomment the line and set the value to “no”. This will disable your ability to log in via SSH using account passwords:

      /etc/ssh/sshd_config

      ...
      PasswordAuthentication no
      ...
      

      Save and close the file when you are finished by pressing CTRL + X, then Y to confirm saving the file, and finally ENTER to exit nano. To actually implement these changes, we need to restart the sshd service:

      • sudo systemctl restart ssh

      As a precaution, open up a new terminal window and test that the SSH service is functioning correctly before closing this session:

      Once you have verified your SSH service, you can safely close all current server sessions.

      The SSH daemon on your Debian server now only responds to SSH keys. Password-based authentication has successfully been disabled.

      Conclusion

      You should now have SSH-key-based authentication configured on your server, allowing you to sign in without providing an account password.

      If you’d like to learn more about working with SSH, take a look at our SSH Essentials Guide.



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      How To Set Up SSH Keys on Rocky Linux 8


      Not using Rocky Linux 8?


      Choose a different version or distribution.

      Introduction

      SSH, or secure shell, is an encrypted protocol used to administer and communicate with servers. When working with a Rocky Linux server, chances are you will spend most of your time in a terminal session connected to your server through SSH.

      In this guide, we’ll focus on setting up SSH keys for a Rocky Linux 8 server. SSH keys provide a straightforward, secure method of logging into your server and are recommended for all users.

      Step 1 — Creating the RSA Key Pair

      The first step is to create a key pair on the client machine (usually your local computer):

      By default, ssh-keygen will create a 2048-bit RSA key pair, which is secure enough for most use cases (you may optionally pass in the -b 4096 flag to create a larger 4096-bit key).

      After entering the command, you should see the following prompt:

      Output

      Generating public/private rsa key pair. Enter file in which to save the key (/your_home/.ssh/id_rsa):

      Press ENTER to save the key pair into the .ssh/ subdirectory in your home directory, or specify an alternate path.

      If you had previously generated an SSH key pair, you may see the following prompt:

      Output

      /home/your_home/.ssh/id_rsa already exists. Overwrite (y/n)?

      If you choose to overwrite the key on disk, you will not be able to authenticate using the previous key anymore. Be very careful when selecting yes, as this is a destructive process that cannot be reversed.

      You should then see the following prompt:

      Output

      Enter passphrase (empty for no passphrase):

      Here you may optionally enter a secure passphrase, which is highly recommended. A passphrase adds an additional layer of security to your key, to prevent unauthorized users from logging in.

      You should then see the following output:

      Output

      Your identification has been saved in /your_home/.ssh/id_rsa. Your public key has been saved in /your_home/.ssh/id_rsa.pub. The key fingerprint is: a9:49:2e:2a:5e:33:3e:a9:de:4e:77:11:58:b6:90:26 username@remote_host The key's randomart image is: +--[ RSA 2048]----+ | ..o | | E o= . | | o. o | | .. | | ..S | | o o. | | =o.+. | |. =++.. | |o=++. | +-----------------+

      You now have a public and private key that you can use to authenticate. The next step is to get the public key onto your server so that you can use SSH-key-based authentication to log in.

      Step 2 — Copying the Public Key to Your Rocky Linux Server

      The quickest way to copy your public key to the Rocky Linux host is to use a utility called ssh-copy-id. This method is highly recommended if available. If you do not have ssh-copy-id available to you on your client machine, you may use one of the two alternate methods that follow (copying via password-based SSH, or manually copying the key).

      Copying your Public Key Using ssh-copy-id

      The ssh-copy-id tool is included by default in many operating systems, so you may have it available on your local system. For this method to work, you must already have password-based SSH access to your server.

      To use the utility, you need only specify the remote host that you would like to connect to and the user account that you have password SSH access to. This is the account to which your public SSH key will be copied:

      • ssh-copy-id username@remote_host

      You may see the following message:

      Output

      The authenticity of host '203.0.113.1 (203.0.113.1)' can't be established. ECDSA key fingerprint is fd:fd:d4:f9:77:fe:73:84:e1:55:00:ad:d6:6d:22:fe. Are you sure you want to continue connecting (yes/no)? yes

      This means that your local computer does not recognize the remote host. This will happen the first time you connect to a new host. Type yes and press ENTER to continue.

      Next, the utility will scan your local account for the id_rsa.pub key that we created earlier. When it finds the key, it will prompt you for the password of the remote user’s account:

      Output

      /usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed /usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys username@203.0.113.1's password:

      Type in the password (your typing will not be displayed for security purposes) and press ENTER. The utility will connect to the account on the remote host using the password you provided. It will then copy the contents of your ~/.ssh/id_rsa.pub key into the remote account’s ~/.ssh/authorized_keys file.

      You should see the following output:

      Output

      Number of key(s) added: 1 Now try logging into the machine, with: "ssh 'username@203.0.113.1'" and check to make sure that only the key(s) you wanted were added.

      At this point, your id_rsa.pub key has been uploaded to the remote account. You can continue on to Step 3.

      Copying Public Key Using SSH

      If you do not have ssh-copy-id available, but you have password-based SSH access to an account on your server, you can upload your keys using a more conventional SSH method.

      We can do this by using the cat command to read the contents of the public SSH key on our local computer and piping that through an SSH connection to the remote server.

      On the other side, we can make sure that the ~/.ssh directory exists and has the correct permissions under the account we’re using.

      We can then output the content we piped over into a file called authorized_keys within this directory. We’ll use the >> redirect symbol to append the content instead of overwriting it. This will let us add keys without destroying any previously added keys.

      The full command looks like this:

      • cat ~/.ssh/id_rsa.pub | ssh username@remote_host "mkdir -p ~/.ssh && touch ~/.ssh/authorized_keys && chmod -R go= ~/.ssh && cat >> ~/.ssh/authorized_keys"

      You may see the following message:

      Output

      The authenticity of host '203.0.113.1 (203.0.113.1)' can't be established. ECDSA key fingerprint is fd:fd:d4:f9:77:fe:73:84:e1:55:00:ad:d6:6d:22:fe. Are you sure you want to continue connecting (yes/no)? yes

      This means that your local computer does not recognize the remote host. This will happen the first time you connect to a new host. Type yes and press ENTER to continue.

      Afterwards, you should be prompted to enter the remote user account password:

      Output

      username@203.0.113.1's password:

      After entering your password, the content of your id_rsa.pub key will be copied to the end of the authorized_keys file of the remote user’s account. Continue on to Step 3 if this was successful.

      Copying Public Key Manually

      If you do not have password-based SSH access to your server available, you will have to complete the above process manually.

      We will manually append the content of your id_rsa.pub file to the ~/.ssh/authorized_keys file on your remote machine.

      To display the content of your id_rsa.pub key, type this into your local computer:

      You will see the key’s content, which should look something like this:

      Output

      ssh-rsa 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 sammy@host

      Log in to your remote host using whichever method you have available.

      Once you have access to your account on the remote server, you should make sure the ~/.ssh directory exists. This command will create the directory if necessary, or do nothing if it already exists:

      Now, you can create or modify the authorized_keys file within this directory. You can add the contents of your id_rsa.pub file to the end of the authorized_keys file, creating it if necessary, using this command:

      • echo public_key_string >> ~/.ssh/authorized_keys

      In the above command, substitute the public_key_string with the output from the cat ~/.ssh/id_rsa.pub command that you executed on your local system. It should start with ssh-rsa AAAA....

      Finally, we’ll ensure that the ~/.ssh directory and authorized_keys file have the appropriate permissions set:

      This recursively removes all “group” and “other” permissions for the ~/.ssh/ directory.

      If you’re using the root account to set up keys for a user account, it’s also important that the ~/.ssh directory belongs to the user and not to root:

      • chown -R sammy:sammy ~/.ssh

      In this tutorial our user is named sammy but you should substitute the appropriate username into the above command.

      We can now attempt key-based authentication with our Rocky Linux server.

      Step 3 — Logging In to Your Rocky Linux Server Using SSH Keys

      If you have successfully completed one of the procedures above, you should now be able to log into the remote host without the remote account’s password.

      The initial process is the same as with password-based authentication:

      If this is your first time connecting to this host (if you used the last method above), you may see something like this:

      Output

      The authenticity of host '203.0.113.1 (203.0.113.1)' can't be established. ECDSA key fingerprint is fd:fd:d4:f9:77:fe:73:84:e1:55:00:ad:d6:6d:22:fe. Are you sure you want to continue connecting (yes/no)? yes

      This means that your local computer does not recognize the remote host. Type yes and then press ENTER to continue.

      If you did not supply a passphrase when creating your key pair in step 1, you will be logged in immediately. If you supplied a passphrase you will be prompted to enter it now. After authenticating, a new shell session should open for you with the configured account on the Rocky Linux server.

      If key-based authentication was successful, continue on to learn how to further secure your system by disabling your SSH server’s password-based authentication.

      Step 4 — Disabling Password Authentication on your Server

      If you were able to log in to your account using SSH without a password, you have successfully configured SSH-key-based authentication to your account. However, your password-based authentication mechanism is still active, meaning that your server is still exposed to brute-force attacks.

      Before completing the steps in this section, make sure that you either have SSH-key-based authentication configured for the root account on this server, or preferably, that you have SSH-key-based authentication configured for a non-root account on this server with sudo privileges. This step will lock down password-based logins, so ensuring that you will still be able to get administrative access is crucial.

      Once you’ve confirmed that your remote account has administrative privileges, log into your remote server with SSH keys, either as root or with an account with sudo privileges. Then, open up the SSH daemon’s configuration file:

      • sudo vi /etc/ssh/sshd_config

      Inside the file, search for a directive called PasswordAuthentication. This may be commented out with a # hash. Press i to put vi into insertion mode, and then uncomment the line and set the value to no. This will disable your ability to log in via SSH using account passwords:

      /etc/ssh/sshd_config

      ...
      PasswordAuthentication no
      ...
      

      When you are finished making changes, press ESC and then :wq to write the changes to the file and quit. To actually implement these changes, we need to restart the sshd service:

      • sudo systemctl restart sshd

      As a precaution, open up a new terminal window and test that the SSH service is functioning correctly before closing your current session:

      Once you have verified your SSH service is still working properly, you can safely close all current server sessions.

      The SSH daemon on your Rocky Linux server now only responds to SSH keys. Password-based authentication has successfully been disabled.

      Conclusion

      You should now have SSH-key-based authentication configured on your server, allowing you to sign in without providing an account password.

      If you’d like to learn more about working with SSH, take a look at our SSH Essentials Guide.



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      How to Create an SSH Shortcut


      While this tutorial has content that we believe is of great benefit to our community, we have not yet tested or
      edited it to ensure you have an error-free learning experience. It’s on our list, and we’re working on it!
      You can help us out by using the “report an issue” button at the bottom of the tutorial.

      If you are constantly needing to SSH into multiple servers, it can real daunting to remember all the different usernames, hostnames, IP addresses, and even sometimes custom private keys to connect to them. It’s actually extremely easy to create command line shortcuts to solve this problem. There’s two major ways to do it, and we’ll discuss the pros and cons of each.

      Method 1: Using SSH Config

      SSH on *NIX machines, such as Linux or Mac, have default shortcut functionality right out of the box. It’s very straight forward to setup, too. For those two reasons, this is my preferred way of setting up SSH shortcuts. The first step is to navigate to your .ssh folder:

      cd ~/.ssh
      

      Following this, you’ll need to create a file called config. Here’s how to do it with Vim:

      vim config
      

      From here, you can now create shortcuts. You can specify the hostname, username, port, and the private key. For a full list of options, please visit the official docs. Here’s an example of how to structure the file:

      Host scotch
          HostName scotch.io
          User nick
      
      Host example2
          HostName example.com
          User root
      
      Host example3
          HostName 64.233.160.0
          User userxyz123
          Port 56000
      
      Host droplet1
          HostName droplet1.digitalocean.com
          User ec2-user
          IdentityFile /path/to/special/privatekey/droplet1.pem
      

      Now, you can simply SSH into any of these servers with these simple commands:

      ssh scotch
      ssh example2
      ssh example3
      ssh droplet1
      

      If this isn’t working for you, trying changing the permissions of the config file like this:

      chmod 600 ~/.ssh/config
      

      Method 2: Create aliases for your shell

      This method involves creating an alias for your shell (or terminal). You can use this for creating any type of shortcut you want, but a lot of people use them for SSH shortcuts. To set this up, you’ll need to navigate to your .bash_aliases file (or some people do this in .bashrc or .bash_profile). The following command will create the .bash_aliases file if it doesn’t exist or just edit it if it already does using Vim.

      vim ~/.bash_aliases
      

      Here you can add as many shortcuts as you want. Here’s how to add the same SSH shortcuts from above:

      alias scotch="ssh nick@scotch.io"
      alias example2='ssh root@example.com'
      alias example3='ssh userxyz123@64.233.160.0 -p 56000'
      alias droplet1='ssh ec2-user@droplet1.digitalocean.com -i /path/to/special/privatekey/droplet1.pem'
      

      After you add those and save the file, you’ll need to “reboot” the aliases file with:

      source ~/.bash_aliases
      

      Once that is completed, you can now SSH into all of those same boxes by just typing the following:

      scotch
      example2
      example3
      droplet1
      

      This method provides additional flexibility that the first method might not be able to provide, but it really comes down to a matter of preference for most use cases.



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