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

306 Chapter5

HP C/iX Library Function Descriptions

setkey

Deﬁnes the key used for encrypting blocks of text.

Syntax

void setkey (

key

)

char *

key

;

Parameters

key A pointer to a character string that contains the encryption key.

Return Values

None.

Description

The setkey function provides primitive access to the hashing algorithm used by crypt().

It is used in conjunction with encrypt to ﬁrst prime the machine and then encrypt a block

of text.

The argument of setkey is an 8-byte character array treated as a 64-bit binary number.

The string is divided into groups of 8 bits, and the low-order bit in each group is ignored.

This gives a 56-bit key that is used to prime the NBS Data Encryption Standard

encryption algorithm. This is the key that is used with the hashing algorithm to encrypt

the string

block

with the encrypt function.