SSH Stuff
ssh - Secure Shell for remote system access
ssh is used to securely log into remote systems, execute commands on remote machines, and create encrypted tunnels for various network services.
Examples:
- ssh user@example.com: Connect to example.com as "user"
- ssh -p 2222 user@example.com: Connect using a non-standard port (2222)
- ssh -i ~/.ssh/my_key user@example.com: Use a specific private key for authentication
- ssh user@example.com 'ls -l /tmp': Execute a command on the remote system without entering interactive mode
- ssh -X user@example.com: Enable X11 forwarding for GUI applications
scp - Secure Copy for file transfer
scp uses SSH to securely copy files between local and remote systems or between two remote systems.
Examples:
- scp file.txt user@example.com:/home/user/: Copy a local file to a remote system
- scp user@example.com:/home/user/file.txt .: Copy a remote file to the local system
- scp -r directory/ user@example.com:/home/user/: Recursively copy a directory to a remote system
- scp -P 2222 file.txt user@example.com:/home/user/: Use a non-standard SSH port
- scp user1@host1:/file user2@host2:/directory/: Copy a file from one remote host to another
ssh-keygen - Generate SSH key pairs
ssh-keygen creates public/private key pairs for SSH authentication, offering a more secure alternative to password-based logins.
Examples:
- ssh-keygen -t rsa: Generate an RSA key pair
- ssh-keygen -t ed25519: Generate an Ed25519 key pair (more secure and efficient)
- ssh-keygen -t rsa -b 4096: Generate an RSA key with 4096-bit strength
- ssh-keygen -f ~/.ssh/my_key: Specify a custom filename and path for the key
- ssh-keygen -p -f ~/.ssh/id_rsa: Change the passphrase of an existing private key
ssh-copy-id - Install SSH key on a remote server
ssh-copy-id securely copies your public key to a remote server's authorized_keys file, enabling key-based authentication.
Examples:
- ssh-copy-id user@example.com: Copy the default public key to the remote server
- ssh-copy-id -i ~/.ssh/my_key.pub user@example.com: Specify a particular public key to copy
- ssh-copy-id -p 2222 user@example.com: Use a non-standard SSH port
ssh-agent - Manage SSH keys
ssh-agent is a program that holds private keys used for public key authentication, allowing you to use SSH without re-entering your passphrase.
Examples:
- eval $(ssh-agent): Start the SSH agent
- ssh-add: Add the default private key to the agent
- ssh-add ~/.ssh/my_key: Add a specific private key to the agent
- ssh-add -l: List fingerprints of all identities currently represented by the agent
- ssh-add -D: Delete all identities from the agent
sftp - Secure File Transfer Protocol
sftp provides an interactive file transfer session with an interface similar to FTP but using SSH for security.
Examples:
- sftp user@example.com: Start an SFTP session
- sftp> get remote_file: Download a file from the remote system
- sftp> put local_file: Upload a file to the remote system
- sftp> ls: List directory contents on the remote system
- sftp> !ls: Execute a local command (list local directory contents)
