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/*
* $Source$
* $Author$
*
* Copyright 1988, 1990 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* For copying and distribution information, please see the file
* <krb5/copyright.h>.
*
* This file contains a generation routine for source code
* implementing the final permutation of the DES.
*/
#if !defined(lint) && !defined(SABER)
static char rcsid_make_fp_c[] =
"$Id$";
#endif /* !lint & !SABER */
#include <krb5/krb5.h>
#include <stdio.h>
#include <krb5/ext-proto.h>
#include "des_int.h"
#include "tables.h"
void gen (stream)
FILE * stream;
{
register i;
/* clear the output */
fprintf(stream," L2 = 0; R2 = 0;\n");
/*
* NOTE: As part of the final permutation, we also have to adjust
* for host bit order via "swap_bit_pos_0()". Since L2,R2 are
* the output from this, we adjust the bit positions written into
* L2,R2.
*/
#define SWAP(i,j) \
swap_long_bytes_bit_number(swap_bit_pos_0_to_ansi((unsigned)i)-j)
/* first setup FP */
fprintf(stream,
"/* FP operations */\n/* first left to left */\n");
/* first list mapping from left to left */
for (i = 0; i <= 31; i++)
if (FP[i] < 32)
test_set(stream, "L1", FP[i], "L2", SWAP(i,0));
/* now mapping from right to left */
fprintf(stream,"\n\n/* now from right to left */\n");
for (i = 0; i <= 31; i++)
if (FP[i] >= 32)
test_set(stream, "R1", FP[i]-32, "L2", SWAP(i,0));
fprintf(stream,"\n/* now from left to right */\n");
/* list mapping from left to right */
for (i = 32; i <= 63; i++)
if (FP[i] <32)
test_set(stream, "L1", FP[i], "R2", SWAP(i,32));
/* now mapping from right to right */
fprintf(stream,"\n/* last from right to right */\n");
for (i = 32; i <= 63; i++)
if (FP[i] >= 32)
test_set(stream, "R1", FP[i]-32, "R2", SWAP(i,32));
}
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