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What causes SIGHUP?
If a command is executed inside a terminal window and the terminal window is closed while the command process is still running, it receives SIGHUP. Daemon programs sometimes use SIGHUP as a signal to restart themselves, the most common reason for this being to re-read a configuration file that has been changed.
What happens when a handler is set up and the process returns from the handler?
When the handler returns, the set of blocked signals is restored to the value it had before the handler ran. So using sigprocmask inside the handler only affects what signals can arrive during the execution of the handler itself, not what signals can arrive once the handler returns.
How does a client know which SSH key to use?
When a client connects to the host, wishing to use SSH key authentication, it will inform the server of this intent and will tell the server which public key to use. The server then checks its authorized_keys file for the public key, generates a random string, and encrypts it using the public key.
Which is the best cryptographic algorithm to generate SSH keys?
A number of cryptographic algorithms can be used to generate SSH keys, including RSA, DSA, and ECDSA. RSA keys are generally preferred and are the default key type. To generate an RSA key pair on your local computer, type:
What’s the difference between public and private SSH keys?
Each set contains a public and a private key. The public key can be shared freely without concern, while the private key must be vigilantly guarded and never exposed to anyone. To authenticate using SSH keys, a user must have an SSH key pair on their local computer.
What happens when you connect to a SSH server?
How SSH Works. When you connect through SSH, you will be dropped into a shell session, which is a text-based interface where you can interact with your server. For the duration of your SSH session, any commands that you type into your local terminal are sent through an encrypted SSH tunnel and executed on your server.