2.10.9. SSH key authentication

• Windows 10 with the update installed Fall Creators Update.
• macOS.
• Linux.

To generate a key pair in the console, do the following:

1. Open your console:
   • Windows command line.
   • Terminal macOS or Linux.
2. Go to the directory .sshby running the command:
   • On Windows:

     cd %userprofile%\.ssh

     If the directory does not exist, create it with the command:

     mkdir %userprofile%\.ssh

   • On Linux and macOS:

     cd ~/.ssh

     If the directory does not exist, create it with the command:

     mkdir ~/.ssh

3. Generate a key pair by running the command:

   ssh-keygen -t rsa -b 2048

   The program will ask you to specify a file name for saving keys and ask you to enter a secret phrase. Click on Enterto use the default options and the default filename id_rsa (if you give your filename, use it in all subsequent commands instead of id_rsa). Remember the output of the line “The key fingerprint is:».
   With default parameters, the keys will be saved in a subdirectory .ssh the user's home directory. These will be two files:

   • id_rsa - private key.
   • id_rsa.pub - public key.
4. Display the contents of the public key by running the command:
   • On Windows:

     type %userprofile%\.ssh\id_rsa.pub

   • On Linux and macOS:

     cat ~/.ssh/id_rsa.pub

5. Copy the displayed key content and add it on the server.

1. Generate a private key in PuTTY format using the PuTTYgen utility:
   1. Run puttygen.exe.
   2. Opposite "Generate a public/private key pair»Click«Generate».
   3. Save the generated private key by clicking "Save private key».
   4. Copy the contents of the public key from the "Public key for pasting into OpenSSH authorized_keys file"And add it on the server.
2. Start PuTTY.
3. Open the settings section “Connection → SSH → Auth».
4. Next to the field "Private key for Authentification»Click«Browse»And select the generated private key file.
5. Save the settings and connect to the server.