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/* set_key.c */
/* Copyright (C) 1993 Eric Young - see README for more details */
/* set_key.c v 1.4 eay 24/9/91
* 1.4 Speed up by 400% :-)
* 1.3 added register declarations.
* 1.2 unrolled make_key_sched a bit more
* 1.1 added norm_expand_bits
* 1.0 First working version
*/
/*-
* $Id: set_key.c,v 1.2 1994/07/19 19:22:07 g89r4222 Exp $
*/
#include "des_locl.h"
#include "podd.h"
#include "sk.h"
static int check_parity();
int des_check_key=0;
void des_set_odd_parity(key)
des_cblock *key;
{
int i;
for (i=0; i<DES_KEY_SZ; i++)
(*key)[i]=odd_parity[(*key)[i]];
}
static int check_parity(key)
des_cblock *key;
{
int i;
for (i=0; i<DES_KEY_SZ; i++)
{
if ((*key)[i] != odd_parity[(*key)[i]])
return(0);
}
return(1);
}
/* Weak and semi week keys as take from
* %A D.W. Davies
* %A W.L. Price
* %T Security for Computer Networks
* %I John Wiley & Sons
* %D 1984
* Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
* (and actual cblock values).
*/
#define NUM_WEAK_KEY 16
static des_cblock weak_keys[NUM_WEAK_KEY]={
/* weak keys */
0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,
0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,
0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,
0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,
/* semi-weak keys */
0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,
0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,
0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1,
0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E,
0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,
0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01,
0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE,
0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,
0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,
0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01,
0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE,
0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1};
int des_is_weak_key(key)
des_cblock *key;
{
int i;
for (i=0; i<NUM_WEAK_KEY; i++)
/* Added == 0 to comparision, I obviously don't run
* this section very often :-(, thanks to
* engineering@MorningStar.Com for the fix
* eay 93/06/29 */
if (memcmp(weak_keys[i],key,sizeof(key)) == 0) return(1);
return(0);
}
/* NOW DEFINED IN des_local.h
* See ecb_encrypt.c for a pseudo description of these macros.
* #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
* (b)^=(t),\
* (a)=((a)^((t)<<(n))))
*/
#define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
(a)=(a)^(t)^(t>>(16-(n))))
static char shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
/* return 0 if key parity is odd (correct),
* return -1 if key parity error,
* return -2 if illegal weak key.
*/
int des_set__key(key,schedule)
des_cblock *key;
des_key_schedule schedule;
{
register unsigned long c,d,t,s;
register unsigned char *in;
register unsigned long *k;
register int i;
if (des_check_key)
{
if (!check_parity(key))
return(-1);
if (des_is_weak_key(key))
return(-2);
}
k=(unsigned long *)schedule;
in=(unsigned char *)key;
c2l(in,c);
c2l(in,d);
/* do PC1 in 60 simple operations */
/* PERM_OP(d,c,t,4,0x0f0f0f0f);
HPERM_OP(c,t,-2, 0xcccc0000);
HPERM_OP(c,t,-1, 0xaaaa0000);
HPERM_OP(c,t, 8, 0x00ff0000);
HPERM_OP(c,t,-1, 0xaaaa0000);
HPERM_OP(d,t,-8, 0xff000000);
HPERM_OP(d,t, 8, 0x00ff0000);
HPERM_OP(d,t, 2, 0x33330000);
d=((d&0x00aa00aa)<<7)|((d&0x55005500)>>7)|(d&0xaa55aa55);
d=(d>>8)|((c&0xf0000000)>>4);
c&=0x0fffffff; */
/* I now do it in 47 simple operations :-)
* Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
* for the inspiration. :-) */
PERM_OP (d,c,t,4,0x0f0f0f0f);
HPERM_OP(c,t,-2,0xcccc0000);
HPERM_OP(d,t,-2,0xcccc0000);
PERM_OP (d,c,t,1,0x55555555);
PERM_OP (c,d,t,8,0x00ff00ff);
PERM_OP (d,c,t,1,0x55555555);
d= (((d&0x000000ff)<<16)| (d&0x0000ff00) |
((d&0x00ff0000)>>16)|((c&0xf0000000)>>4));
c&=0x0fffffff;
for (i=0; i<ITERATIONS; i++)
{
if (shifts2[i])
{ c=((c>>2)|(c<<26)); d=((d>>2)|(d<<26)); }
else
{ c=((c>>1)|(c<<27)); d=((d>>1)|(d<<27)); }
c&=0x0fffffff;
d&=0x0fffffff;
/* could be a few less shifts but I am to lazy at this
* point in time to investigate */
s= des_skb[0][ (c )&0x3f ]|
des_skb[1][((c>> 6)&0x03)|((c>> 7)&0x3c)]|
des_skb[2][((c>>13)&0x0f)|((c>>14)&0x30)]|
des_skb[3][((c>>20)&0x01)|((c>>21)&0x06) |
((c>>22)&0x38)];
t= des_skb[4][ (d )&0x3f ]|
des_skb[5][((d>> 7)&0x03)|((d>> 8)&0x3c)]|
des_skb[6][ (d>>15)&0x3f ]|
des_skb[7][((d>>21)&0x0f)|((d>>22)&0x30)];
/* table contained 0213 4657 */
*(k++)=((t<<16)|(s&0x0000ffff))&0xffffffff;
s= ((s>>16)|(t&0xffff0000));
s=(s<<4)|(s>>28);
*(k++)=s&0xffffffff;
}
return(0);
}
int des_key_sched(key,schedule)
des_cblock *key;
des_key_schedule schedule;
{
return(des_set__key(key,schedule));
}
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