create-cracklib-dict

create-cracklib-dict

The create-cracklib-dict command is used to generate a dictionary file in the format required by cracklib. Cracklib is a library used to test the strength of passwords. This command reads a list of words from standard input (usually a wordlist) and creates a hashed dictionary file suitable for use with password checking programs. The resulting dictionary file efficiently stores the wordlist and their derivatives, allowing for rapid checking to prevent users from choosing easily guessable passwords. This prevents the most common, frequently used, or easily deduced passwords from being used. The command is primarily intended for system administrators who want to enhance password security on their systems. The generated dictionary files are consulted by programs using cracklib such as passwd or other authentication tools.

This command reads the wordlist from standard input. Ensure that the input wordlist is clean and contains only relevant words. Large input files can take a significant amount of time to process. The output dictionary file will be created in the directory where the command is executed. Ensure sufficient disk space is available.

The output of the command is a set of dictionary files in a special binary format. These files are usually named pw_dict.pwd, pw_dict.hwm and etc. and are stored in a directory that cracklib is configured to use. The actual name and location can vary depending on system configuration.

To create a dictionary from a wordlist file named 'words.txt', you would use the following command:
cat words.txt | create-cracklib-dict
This will read the content of words.txt from standard input and build a dictionary file from it.

Cracklib was originally designed to strengthen security by preventing users from using weak passwords. create-cracklib-dict is a crucial component, allowing admins to build customized dictionaries that reflect the specific language and patterns they want to discourage.

cracklib(3), passwd(1)