Generating an SSH Key Pair

Linux/MacOS

1. Open a terminal and use the ssh-keygen utility to create your key. For a 2048-bit RSA key:

   bashCopy codessh-keygen -t rsa

   For increased security, generate a 4096-bit RSA key:

   bashCopy codessh-keygen -t rsa -b 4096

   Note: RSA is recommended over DSA because DSA keys are limited to 1024 bits.

2. When prompted, press Enter to use the default location (e.g., /home/your_username/.ssh/id_rsa on Linux or /Users/your_username/.ssh/id_rsa on Mac), or specify a custom location if needed (e.g., creating a second key).

3. Enter a secure passphrase.

   • This passphrase is required to unlock your private key, adding an extra layer of security.

   • Without a passphrase, someone with your private key could access accounts tied to that key.

4. Confirm your passphrase when prompted.

5. Once complete, ssh-keygen will generate:

   • A private key (e.g., id_rsa) in the specified location.

   • A public key (e.g., id_rsa.pub) in the same location.

6. To use the public key:

   • For remote access, copy and paste the contents of the public key file into the ~/.ssh/authorized_keys file on the server.

   • To share with a team, send the public key (never share the private key).

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Windows (Using PuTTY)

1. Download and start the puttygen.exe key generator.

2. In the Key section, select SSH-2 RSA, then click Generate.

3. Move your mouse randomly in the small window to generate entropy for the key pair.

4. Add a key comment to identify the key (useful when managing multiple keys).

5. Enter and confirm a passphrase to protect your key.

6. Save your keys:

   • Click Save private key to store your private key securely.

   • Click Save public key to save your public key.

7. To use the key with PuTTY:

   • Open PuTTY and navigate to Connection -> SSH -> Auth.

   • Browse and select your private key file.

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Important Notes

• Always keep your private key secure and never share it.

• Use the public key to:

  • Add to ~/.ssh/authorized_keys for servers you control.

  • Share with teams or projects requiring access.

By following these steps, you ensure secure and efficient SSH access for your use cases.