HP C/iX Library Reference Manual (30026-90004)

Chapter 5 129

HP C/iX Library Function Descriptions

crypt

Provides one-way encryption of passwords.

Syntax

char *crypt (char *

key, char *salt

);

Parameters

key

A pointer to a character string to be encrypted.

salt

A pointer to a character string used as the initial value in the hashing

algorithm.

Return Values

x A pointer to a character string containing the encrypted password.

Description

The crypt function is the password encryption function based on the NBS Data

Encryption Standard (DES). It is a one-way algorithm that produces a scrambled

character string based upon the input string. It includes variations from the DES intended

to frustrate the use of hardware implementations of the DES for key search.

The

key

parameter is your typed password. The

salt

parameter is a two-character string

chosen from the set [a-zA-Z0-9./]; this string is used to set the hashing algorithm in one

of 4096 different ways, after which

key

is used to encrypt repeatedly a constant string. The

returned value points to the encrypted password; the ﬁrst two characters of the password

is the

salt

itself.

The return value points to static data that are overwritten by each call.