/* * $Source: /mit/kerberos/src/lib/des/RCS/random_key.c,v $ * $Author: jtkohl $ * * 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[] = "$Header: random_key.c,v 4.8 89/01/21 16:50:39 jtkohl Exp $"; #endif lint #include <mit-copyright.h> #include <stdio.h> #include <des.h> #include "des_internal.h" #ifdef BSDUNIX #include <sys/time.h> #endif extern int des_debug; extern int des_debug_print(); /* 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; long gethostid(), random(); int i,j; #ifdef BSDUNIX static struct timeval time; if (!p) { p = getpid(); p ^= gethostid(); } (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++; } /* **** */ #else dont know how to do random numbers for this machine; #endif return 0; }