/*
 * makeSP - build combination S and P tables for quick DES computation
 */

#include <stdio.h>
#include <sys/types.h>

#include "ntp_stdlib.h"

#define	STREQ(a, b)	(*(a) == *(b) && strcmp((a), (b)) == 0)

char *progname;
int debug;

static	void	selperm	P((int, int, u_int32 *));
static	void	doit	P((void));

/*
 * main - parse arguments and handle options
 */
void
main(argc, argv)
int argc;
char *argv[];
{
	int c;
	int errflg = 0;
	extern int ntp_optind;
	extern char *ntp_optarg;

	progname = argv[0];
	while ((c = ntp_getopt(argc, argv, "d")) != EOF)
		switch (c) {
		case 'd':
			++debug;
			break;
		default:
			errflg++;
			break;
		}
	if (errflg) {
		(void) fprintf(stderr, "usage: %s [-d]\n", progname);
		exit(2);
	}
	doit();
	exit(0);
}


/*
 * The cipher selection function tables.  These turn 6 bit data back
 * into 4 bit data.
 */
u_char S[8][64] = {
	14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7,
	 0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8,
	 4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0,
	15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13,

	15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10,
	 3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5,
	 0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15,
	13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9,
 
	10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8,
	13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1,
	13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7,
	 1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12,

	 7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15,
	13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9,
	10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4,
	 3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14,

	 2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9,
	14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6,
	 4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14,
	11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3,

	12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11,
	10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8,
	 9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6,
	 4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13,

	 4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1,
	13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6,
	 1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2,
	 6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12,

	13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7,
	 1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2,
	 7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8,
	 2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11
};

/*
 * Cipher function permutation table
 */
u_char PT[32] = {
	16,  7, 20, 21,
	29, 12, 28, 17,
	 1, 15, 23, 26,
	 5, 18, 31, 10,
	 2,  8, 24, 14,
	32, 27,  3,  9,
	19, 13, 30,  6,
	22, 11,  4, 25
};


/*
 * Bits array.  We keep this zeroed.
 */
u_char bits[32];


/*
 * selperm - run six bit data through the given selection table, then
 *           through the PT table to produce a long output.
 */
static void
selperm(selnumber, sixbits, resp)
	int selnumber;
	int sixbits;
	u_int32 *resp;
{
	register u_int32 res;
	register int selno;
	register int i;
	register int ind;

	selno = selnumber;
	i = sixbits;
	ind = (i & 0x20) | ((i >> 1) & 0xf) | ((i & 0x1) << 4);
	i = S[selno][ind];

	for (ind = 0; ind < 4; ind++) {
		if (i & 0x8)
			bits[4*selno + ind] = 1;
		i <<= 1;
	}

	res = 0;
	for (i = 0; i < 32; i++) {
		res <<= 1;
		if (bits[PT[i]-1])
			res |= 1;
	}

	*resp = res;
	bits[4*selno] = 0;
	bits[4*selno + 1] = 0;
	bits[4*selno + 2] = 0;
	bits[4*selno + 3] = 0;
}


/*
 * doit - compute and print the 8 SP tables
 */
static void
doit()
{
	int selno;
	u_int32 result;
	int sixbits;

	memset((char *)bits, 0, sizeof bits);
	printf("static u_int32 SP[8][64] = {");
	for (selno = 0; selno < 8; selno++) {
		for (sixbits = 0; sixbits < 64; sixbits++) {
			selperm(selno, sixbits, &result);
			if ((sixbits & 0x3) == 0)
				printf("\n\t0x%08x,", result);
			else if (sixbits == 63 && selno == 7)
				printf(" 0x%08x\n};\n", result);
			else if (sixbits == 63)
				printf(" 0x%08x,\n", result);
			else
				printf(" 0x%08x,", result);
		}
	}
}