redhat man page for setkey

ENCRYPT(3)						     Linux Programmer's Manual							ENCRYPT(3)

NAME
       encrypt - Encrypt 64 bits messages

SYNOPSIS
       #define _XOPEN_SOURCE

       #include <unistd.h>

       void encrypt(char block[64], int edflag);
       void setkey(const char *key);

DESCRIPTION
       These  functions encrypt and decrypt 64 bit messages.  The setkey() function sets the key used by encrypt(). The key parameter used here is
       an array of bytes, having each byte the numerical value 1 or 0. The key[n] byte, where n=8*q-1, is ignored consisting the key  used  of	56
       bits.

       The setkey() function modifies the passed buffer, encoding if edflag is 0, and decoding if 1 is being passed.

       These functions are not reentrant.

RETURN VALUE
       These functions do not return any value.

CONFORMING TO
       SVID, SUSv2

SEE ALSO
       crypt(3)

GNU
								    2000-07-22								ENCRYPT(3)