des.c

外国开源的硬盘加密软件

/* Deprecated/legacy */
// des.cpp - modified by Wei Dai from Phil Karn's des.c
// The original code and all modifications are in the public domain.

/*
 * This is a major rewrite of my old public domain DES code written
 * circa 1987, which in turn borrowed heavily from Jim Gillogly's 1977
 * public domain code. I pretty much kept my key scheduling code, but
 * the actual encrypt/decrypt routines are taken from from Richard
 * Outerbridge's DES code as printed in Schneier's "Applied Cryptography."
 *
 * This code is in the public domain. I would appreciate bug reports and
 * enhancements.
 *
 * Phil Karn KA9Q, [e-mail], August 1994.
 */

/* Adapted for TrueCrypt by the TrueCrypt Foundation */

#include <memory.h>
#include "Common/Tcdefs.h"
#include "Common/Endian.h"
#include "Des.h"

#define word32 unsigned __int32
#define byte unsigned __int8

static word32 rotlFixed (word32 x, unsigned int y)
{
	return (word32)((x<<y) | (x>>(sizeof(word32)*8-y)));
}

static word32 rotrFixed (word32 x, unsigned int y)
{
	return (word32)((x>>y) | (x<<(sizeof(word32)*8-y)));
}


/* Tables defined in the Data Encryption Standard documents
 * Three of these tables, the initial permutation, the final
 * permutation and the expansion operator, are regular enough that
 * for speed, we hard-code them. They're here for reference only.
 * Also, the S and P boxes are used by a separate program, gensp.c,
 * to build the combined SP box, Spbox[]. They're also here just
 * for reference.
 */
#ifdef notdef
/* initial permutation IP */
static byte ip[] = {
	   58, 50, 42, 34, 26, 18, 10,  2,
	   60, 52, 44, 36, 28, 20, 12,  4,
	   62, 54, 46, 38, 30, 22, 14,  6,
	   64, 56, 48, 40, 32, 24, 16,  8,
	   57, 49, 41, 33, 25, 17,  9,  1,
	   59, 51, 43, 35, 27, 19, 11,  3,
	   61, 53, 45, 37, 29, 21, 13,  5,
	   63, 55, 47, 39, 31, 23, 15,  7
};

/* final permutation IP^-1 */
static byte fp[] = {
	   40,  8, 48, 16, 56, 24, 64, 32,
	   39,  7, 47, 15, 55, 23, 63, 31,
	   38,  6, 46, 14, 54, 22, 62, 30,
	   37,  5, 45, 13, 53, 21, 61, 29,
	   36,  4, 44, 12, 52, 20, 60, 28,
	   35,  3, 43, 11, 51, 19, 59, 27,
	   34,  2, 42, 10, 50, 18, 58, 26,
	   33,  1, 41,  9, 49, 17, 57, 25
};
/* expansion operation matrix */
static byte ei[] = {
	   32,  1,  2,  3,  4,  5,
		4,  5,  6,  7,  8,  9,
		8,  9, 10, 11, 12, 13,
	   12, 13, 14, 15, 16, 17,
	   16, 17, 18, 19, 20, 21,
	   20, 21, 22, 23, 24, 25,
	   24, 25, 26, 27, 28, 29,
	   28, 29, 30, 31, 32,  1
};
/* The (in)famous S-boxes */
static byte sbox[8][64] = {
	   /* S1 */
	   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,

	   /* S2 */
	   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,

	   /* S3 */
	   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,

	   /* S4 */
		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,

	   /* S5 */
		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,

	   /* S6 */
	   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,

	   /* S7 */
		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,

	   /* S8 */
	   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
};

/* 32-bit permutation function P used on the output of the S-boxes */
static byte p32i[] = {
	   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
};
#endif

/* permuted choice table (key) */
static const byte pc1[] = {
	   57, 49, 41, 33, 25, 17,  9,
		1, 58, 50, 42, 34, 26, 18,
	   10,  2, 59, 51, 43, 35, 27,
	   19, 11,  3, 60, 52, 44, 36,

	   63, 55, 47, 39, 31, 23, 15,
		7, 62, 54, 46, 38, 30, 22,
	   14,  6, 61, 53, 45, 37, 29,
	   21, 13,  5, 28, 20, 12,  4
};

/* number left rotations of pc1 */
static const byte totrot[] = {
	   1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28
};

/* permuted choice key (table) */
static const byte pc2[] = {
	   14, 17, 11, 24,  1,  5,
		3, 28, 15,  6, 21, 10,
	   23, 19, 12,  4, 26,  8,
	   16,  7, 27, 20, 13,  2,
	   41, 52, 31, 37, 47, 55,
	   30, 40, 51, 45, 33, 48,
	   44, 49, 39, 56, 34, 53,
	   46, 42, 50, 36, 29, 32
};

/* End of DES-defined tables */

/* bit 0 is left-most in byte */
static const int bytebit[] = {
	   0200,0100,040,020,010,04,02,01
};

static const word32 Spbox[8][64] = {
{
0x01010400,0x00000000,0x00010000,0x01010404, 0x01010004,0x00010404,0x00000004,0x00010000,
0x00000400,0x01010400,0x01010404,0x00000400, 0x01000404,0x01010004,0x01000000,0x00000004,
0x00000404,0x01000400,0x01000400,0x00010400, 0x00010400,0x01010000,0x01010000,0x01000404,
0x00010004,0x01000004,0x01000004,0x00010004, 0x00000000,0x00000404,0x00010404,0x01000000,
0x00010000,0x01010404,0x00000004,0x01010000, 0x01010400,0x01000000,0x01000000,0x00000400,
0x01010004,0x00010000,0x00010400,0x01000004, 0x00000400,0x00000004,0x01000404,0x00010404,
0x01010404,0x00010004,0x01010000,0x01000404, 0x01000004,0x00000404,0x00010404,0x01010400,
0x00000404,0x01000400,0x01000400,0x00000000, 0x00010004,0x00010400,0x00000000,0x01010004},
{
0x80108020,0x80008000,0x00008000,0x00108020, 0x00100000,0x00000020,0x80100020,0x80008020,
0x80000020,0x80108020,0x80108000,0x80000000, 0x80008000,0x00100000,0x00000020,0x80100020,
0x00108000,0x00100020,0x80008020,0x00000000, 0x80000000,0x00008000,0x00108020,0x80100000,
0x00100020,0x80000020,0x00000000,0x00108000, 0x00008020,0x80108000,0x80100000,0x00008020,
0x00000000,0x00108020,0x80100020,0x00100000, 0x80008020,0x80100000,0x80108000,0x00008000,
0x80100000,0x80008000,0x00000020,0x80108020, 0x00108020,0x00000020,0x00008000,0x80000000,
0x00008020,0x80108000,0x00100000,0x80000020, 0x00100020,0x80008020,0x80000020,0x00100020,
0x00108000,0x00000000,0x80008000,0x00008020, 0x80000000,0x80100020,0x80108020,0x00108000},
{
0x00000208,0x08020200,0x00000000,0x08020008, 0x08000200,0x00000000,0x00020208,0x08000200,