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/*
* $Source$
* $Author$
*
* Copyright 1985, 1988,1990 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
*
* This routine generates the P permutation code for the DES.
*/
#if !defined(lint) && !defined(SABER)
static char rcsid_make_p_c[] =
"$Id$";
#endif /* !lint & !SABER */
#include <krb5/krb5.h>
#include <stdio.h>
#include "des_int.h"
#include "tables.h"
void gen(stream)
FILE *stream;
{
/* P permutes 32 bit input R1 into 32 bit output R2 */
/* clear the output */
fprintf(stream," L2 = 0;\n");
#ifndef BIG
fprintf(stream," R2 = 0;\n");
fprintf(stream,
"/* P operations */\n/* from right to right */\n");
/* first list mapping from left to left */
for (i = 0; i <=31; i++)
if (P[i] < 32)
fprintf(stream,
" if (R1 & (1<<%d)) R2 |= 1<<%d;\n",P[i],i);
#else /* BIG */
/* flip p into p_temp */
fprintf(stream," P_temp = R1;\n");
fprintf(stream," P_temp_p = (unsigned char *) &P_temp;\n");
#ifdef LSBFIRST
fprintf(stream," R2 = P_prime[0][*P_temp_p++];\n");
fprintf(stream," R2 |= P_prime[1][*P_temp_p++];\n");
fprintf(stream," R2 |= P_prime[2][*P_temp_p++];\n");
fprintf(stream," R2 |= P_prime[3][*P_temp_p];\n");
#else /* MSBFIRST */
fprintf(stream," R2 = P_prime[3][*P_temp_p++];\n");
fprintf(stream," R2 |= P_prime[2][*P_temp_p++];\n");
fprintf(stream," R2 |= P_prime[1][*P_temp_p++];\n");
fprintf(stream," R2 |= P_prime[0][*P_temp_p];\n");
#endif /* MSBFIRST */
#endif /* BIG */
}
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