How to use the command 'systemd-ask-password' (with examples)

This article will explain how to use the ‘systemd-ask-password’ command with various use cases. The ‘systemd-ask-password’ command is used to query the user for a system password.

Use case 1: Query a system password with a specific message

Code:

systemd-ask-password "Please enter the system password:"

Motivation: This use case is useful when you need to prompt the user to enter a system password with a specific message. This can be used to securely retrieve sensitive information from the user.

Explanation: The command ‘systemd-ask-password’ is called with the specific message as a parameter. The user will be prompted to enter the system password in a secure manner.

Example output:

Please enter the system password:

Use case 2: Specify an identifier for the password query

Code:

systemd-ask-password --id=identifier "Please enter the system password:"

Motivation: This use case allows you to specify an identifier for the password query. This can be useful if you need to uniquely identify the password query for future reference.

Explanation: The ‘–id’ option is used to specify an identifier for the password query. The identifier can be any string value that you want to associate with the password query.

Example output:

Please enter the system password:

Use case 3: Use a kernel keyring key name as a cache for the password

Code:

systemd-ask-password --keyname=key_name "Please enter the system password:"

Motivation: This use case allows you to cache the password in the kernel keyring using a specific key name. This can be useful if you need to retrieve the password later without prompting the user again.

Explanation: The ‘–keyname’ option is used to specify a key name for caching the password in the kernel keyring. The key name can be any string value that you want to associate with the password.

Example output:

Please enter the system password:

Use case 4: Set a custom timeout for the password query

Code:

systemd-ask-password --timeout=10 "Please enter the system password:"

Motivation: This use case allows you to set a custom timeout for the password query. This can be useful if you want to automatically proceed with a default action if the user doesn’t enter the password within a specific time.

Explanation: The ‘–timeout’ option is used to set a custom timeout value in seconds for the password query. If the user doesn’t enter the password within the specified timeout, the command will exit and the default action can be taken.

Example output:

Please enter the system password:

Use case 5: Force the use of an agent system and never ask on current TTY

Code:

systemd-ask-password --no-tty "Please enter the system password:"

Motivation: This use case allows you to force the use of an agent system and never ask the user to enter the password on the current TTY. This can be useful in automated scripts or non-interactive environments where there is no TTY.

Explanation: The ‘–no-tty’ option is used to disable the password prompt on the current TTY and force the use of an agent system. This is useful when the command needs to run in a non-interactive mode without requiring user input.

Example output:

Please enter the system password:

Use case 6: Store a password in the kernel keyring without displaying it

Code:

systemd-ask-password --no-output --keyname=key_name "Please enter the system password:"

Motivation: This use case allows you to store a password in the kernel keyring without displaying it on the terminal. This can be useful if you want to securely store the password for later use without exposing it to the user.

Explanation: The ‘–no-output’ option is used to disable the display of the password on the terminal. The password will still be stored in the kernel keyring using the specified key name.

Example output:

Please enter the system password:

Conclusion:

The ‘systemd-ask-password’ command provides a convenient way to query the user for a system password. By using different options and parameters, you can customize the behavior of the command according to your requirements. Whether you need to prompt the user for a password, set a timeout, or store the password securely, the ‘systemd-ask-password’ command has you covered.