Reference: crypt
Author: Ellen Siever, Stephen Spainhour & Nathan Patwardhan
Date: 1999-07-02T01:34:28Z

#

| Chapter 5 Function Reference |

## crypt

    crypt string, salt

Used by the `passwd` function on Unix systems to produce a unique 13-character string (stored in the system's password file) from the first 8 characters of the given string and the 2-character salt. The Perl function operates the same way, and returns a 13-character string with the first 2 characters being the salt. `crypt` uses a modified version of the Data Encryption Standard, which produces a one-way encryption; the resulting string cannot be decrypted to determine the original string. `crypt` can be used to check that a password is correct by comparing the string from the function to the string found in /etc/passwd (if you have permission to do this):

>     if (crypt ($guess, $pass) eq $pass) {
>            # guess is correct
>        }

The variable `$pass` is the password string from the password file. `crypt` merely uses the first two characters from this string for the salt argument.

Reference: cos |  | Reference: dbmclose