/*      $NetBSD: des_setkey.c,v 1.10 2005/12/11 12:20:52 christos Exp $ */
/*      $KAME: des_setkey.c,v 1.6 2001/07/03 14:27:53 itojun Exp $      */

/* crypto/des/set_key.c */
/* Copyright (C) 1995-1996 Eric Young ([email protected])
* All rights reserved.
*
* This file is part of an SSL implementation written
* by Eric Young ([email protected]).
* The implementation was written so as to conform with Netscapes SSL
* specification.  This library and applications are
* FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
* as long as the following conditions are aheared to.
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.  If this code is used in a product,
* Eric Young should be given attribution as the author of the parts used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*    This product includes software developed by Eric Young ([email protected])
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed.  i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/

/* 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
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: des_setkey.c,v 1.10 2005/12/11 12:20:52 christos Exp $");

#include <sys/param.h>
#ifdef _KERNEL
#include <sys/systm.h>
#else
#include <string.h>
#endif
#include <crypto/des/des_locl.h>
#include <crypto/des/podd.h>
#include <crypto/des/sk.h>

int des_check_key=0;

void des_set_odd_parity(des_cblock *key)
{
       unsigned int i;

       for (i=0; i<DES_KEY_SZ; i++)
               (*key)[i]=odd_parity[(*key)[i]];
}

int des_check_key_parity(des_cblock *key)
{
       unsigned 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 [email protected] (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,0x0E,0x0E,0x0E,0x0E},
       {0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1},
       /* 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(des_cblock *key)
{
       int i;

       for (i=0; i<NUM_WEAK_KEY; i++)
               /* Added == 0 to comparison, I obviously don't run
                * this section very often :-(, thanks to
                * [email protected] for the fix
                * eay 93/06/29
                * Another problem, I was comparing only the first 4
                * bytes, 97/03/18 */
               if (memcmp(weak_keys[i],key,sizeof(des_cblock)) == 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))))

int des_set_key(des_cblock *key, des_key_schedule schedule)
{
       if (des_check_key)
       {
               return des_set_key_checked(key, schedule);
       }
       else
       {
               des_set_key_unchecked(key, schedule);
               return 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_checked(des_cblock *key, des_key_schedule schedule)
{
       if (!des_check_key_parity(key))
               return(-1);
       if (des_is_weak_key(key))
               return(-2);
       des_set_key_unchecked(key, schedule);
       return 0;
}

void des_set_key_unchecked(des_cblock *key, des_key_schedule schedule)
{
       static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
       register DES_LONG c,d,t,s,t2;
       register const unsigned char *in;
       register DES_LONG *k;
       register int i;

       k = &schedule->ks.deslong[0];
       in = &(*key)[0];

       c2l(in,c);
       c2l(in,d);

       /* do PC1 in 47 simple operations :-)
        * Thanks to John Fletcher ([email protected])
        * for the inspiration. :-) */
       PERM_OP (d,c,t,4,0x0f0f0f0fL);
       HPERM_OP(c,t,-2,0xcccc0000L);
       HPERM_OP(d,t,-2,0xcccc0000L);
       PERM_OP (d,c,t,1,0x55555555L);
       PERM_OP (c,d,t,8,0x00ff00ffL);
       PERM_OP (d,c,t,1,0x55555555L);
       d=      (((d&0x000000ffL)<<16L)| (d&0x0000ff00L)     |
                ((d&0x00ff0000L)>>16L)|((c&0xf0000000L)>>4L));
       c&=0x0fffffffL;

       for (i=0; i<ITERATIONS; i++)
       {
               if (shifts2[i])
                       { c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
               else
                       { c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
               c&=0x0fffffffL;
               d&=0x0fffffffL;
               /* 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>> 6L)&0x03)|((c>> 7L)&0x3c)]|
                       des_skb[2][((c>>13L)&0x0f)|((c>>14L)&0x30)]|
                       des_skb[3][((c>>20L)&0x01)|((c>>21L)&0x06) |
                                                       ((c>>22L)&0x38)];
               t=      des_skb[4][ (d    )&0x3f                ]|
                       des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
                       des_skb[6][ (d>>15L)&0x3f                ]|
                       des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];

               /* table contained 0213 4657 */
               t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
               *(k++)=ROTATE(t2,30)&0xffffffffL;

               t2=((s>>16L)|(t&0xffff0000L));
               *(k++)=ROTATE(t2,26)&0xffffffffL;
       }
}

int des_key_sched(des_cblock *key, des_key_schedule schedule)
{
       return(des_set_key(key,schedule));
}

void des_fixup_key_parity(des_cblock *key)
{
       des_set_odd_parity(key);
}

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