How to use the command mosquitto_passwd (with examples)
Mosquitto_passwd is a command-line utility that is used to manage password files for Mosquitto, which is an MQTT server. This command allows you to add, delete, and upgrade user credentials in a password file, which is used for authentication purposes when connecting to a Mosquitto server.
Use case 1: Add a new user to a password file
Code:
mosquitto_passwd path/to/password_file username
Motivation: You may want to add a new user to a password file to grant them access to the Mosquitto server. By using this command, you can securely add the user’s credentials to the password file.
Explanation:
mosquitto_passwd: The command itself.path/to/password_file: The path to the password file. This is the file where user credentials are stored.username: The username of the new user being added to the password file. This username will be used for authentication.
Example output:
Enter password:
Reenter password:
Use case 2: Create the password file if it doesn’t already exist
Code:
mosquitto_passwd -c path/to/password_file username
Motivation: If the password file does not exist, you will need to create it before adding any user credentials. This command allows you to create the password file and add the first user simultaneously.
Explanation:
mosquitto_passwd: The command itself.-c: Specifies that a new password file should be created if it doesn’t already exist.path/to/password_file: The path to the password file. This is the file that will be created.username: The username of the first user being added to the newly created password file.
Example output:
Enter password:
Reenter password:
Use case 3: Delete the specified username
Code:
mosquitto_passwd -D path/to/password_file username
Motivation: If a user no longer requires access to the Mosquitto server, you can delete their username from the password file to revoke their access. This command allows you to easily remove user credentials from the password file.
Explanation:
mosquitto_passwd: The command itself.-D: Specifies that the specified username should be deleted from the password file.path/to/password_file: The path to the password file. This is the file from which the username will be deleted.username: The username that should be deleted from the password file.
Example output:
User removed successfully.
Use case 4: Upgrade an old plain-text password file to a hashed password file
Code:
mosquitto_passwd -U path/to/password_file
Motivation: In older versions of Mosquitto, password files used plain-text passwords. It is recommended to use hashed passwords for improved security. This command allows you to upgrade an old plain-text password file to a new hashed password file.
Explanation:
mosquitto_passwd: The command itself.-U: Specifies that the password file should be upgraded to use hashed passwords.path/to/password_file: The path to the password file that should be upgraded.
Example output:
Password file upgraded successfully.
Conclusion:
The mosquitto_passwd command is a powerful utility for managing password files for the Mosquitto MQTT server. It allows you to add, delete, and upgrade user credentials in the password file, providing a secure authentication mechanism for the server. By following the examples provided in this article, you can easily use this command to manage your Mosquitto password files effectively.
