Linux password policies
Sunday, August 31st, 2008
Lets start with some basics….
“/etc/passwd” file: the password database
Our Linux system stores its usernames and passwords in a special file : ‘/etc/password’. The passwords in this file are one way encrypted (hash-ed) through a password encryption function called ‘crypt’ using DES as the encryption algorithm. The good thing about ‘hashing’ is that you can not ‘decrypt’ the hashed passwords because the function used for hashing cannot be reversed (one-way traffic). DES generally uses keys (symmetric key cryptography) in which case things can be either encrypted or decrypted, but for encrypting passwords in Linux, only the ‘hashing’ implementation of DES is used.