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/*
* $Source$
* $Author$
*
* Copyright 1988 by the Massachusetts Institute of Technology.
*
* For copying and distribution information, please see the file
* <mit-copyright.h>.
*
* These routines perform encryption and decryption using the DES
* private key algorithm, or else a subset of it-- fewer inner loops.
* ( AUTH_DES_ITER defaults to 16, may be less)
*
* Under U.S. law, this software may not be exported outside the US
* without license from the U.S. Commerce department.
*
* The key schedule is passed as an arg, as well as the cleartext or
* ciphertext. The cleartext and ciphertext should be in host order.
*
* These routines form the library interface to the des facilities.
*
* spm 8/85 MIT project athena
*/
#ifndef lint
static char rcsid_random_key_c[] =
"$Id$";
#endif
#include <mit-copyright.h>
#include <stdio.h>
#include <time.h>
#include <sys/time.h>
#include <des.h>
#ifdef USE_RAND48
#define random lrand48
#define srandom srand48
#endif
/* random_key */
int
des_random_key(key)
des_cblock *key;
{
/*
* create a random des key; should force odd parity per byte;
* parity is bits 8,16,...64 in des order, implies 0, 8, 16, ...
* vax order
*/
register unsigned int temp;
register int odd;
register unsigned char *c = (unsigned char *) key;
unsigned long *k = (unsigned long *) key;
static long p = 0;
static long n = 0;
int i,j;
static struct timeval time;
if (!p) {
p = getpid();
#ifndef SOLARIS
p ^= gethostid();
#endif
}
(void) gettimeofday(&time,(struct timezone *)0);
/* randomize start */
srandom(time.tv_usec ^ time.tv_sec ^ p ^ n++);
*k++ = random();
*k = random();
/* make each byte parity odd */
for (i = 0; i <= 7; i++) {
odd = 0;
temp = (unsigned int) *c;
/* ignore bit 0, lsb, it will be parity (on vax) */
/* should do this with a table lookup */
for (j = 0; j <= 6; j++) {
temp = temp >> 1;
odd ^= temp & 01;
}
/* set odd parity in lsb */
if (!odd)
*c |= 1;
else
*c &= ~1;
c++;
}
return 0;
}
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