3DES加密算法源码 c语言

以下是3DES加密算法的C语言源码实现：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define ENCRYPT 1
#define DECRYPT 0

typedef unsigned char BYTE;
typedef unsigned long DWORD;

/* 定义DES算法中使用的数据类型 */
typedef struct {
    BYTE key[8];
    BYTE encrypt;
    BYTE iv[8];
} des_context;

/* 定义3DES算法中使用的数据类型 */
typedef struct {
    des_context des1;
    des_context des2;
    des_context des3;
} des3_context;

/* 定义DES算法中使用的常量 */
static const BYTE odd_parity_table[256] = {
    1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31,
    32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59, 61, 62,
    64, 67, 69, 70, 73, 74, 76, 79, 81, 82, 84, 87, 88, 91, 93, 94,
    97, 98, 100, 103, 104, 107, 109, 110, 112, 115, 117, 118, 121, 122, 124, 127,
    128, 131, 133, 134, 137, 138, 140, 143, 145, 146, 148, 151, 152, 155, 157, 158,
    161, 162, 164, 167, 168, 171, 173, 174, 176, 179, 181, 182, 185, 186, 188, 191,
    193, 194, 196, 199, 200, 203, 205, 206, 208, 211, 213, 214, 217, 218, 220, 223,
    224, 227, 229, 230, 233, 234, 236, 239, 241, 242, 244, 247, 248, 251, 253, 254,
    1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 31,
    32, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59, 61, 62,
    64, 67, 69, 70, 73, 74, 76, 79, 81, 82, 84, 87, 88, 91, 93, 94,
    97, 98, 100, 103, 104, 107, 109, 110, 112, 115, 117, 118, 121, 122, 124, 127,
    128, 131, 133, 134, 137, 138, 140, 143, 145, 146, 148, 151, 152, 155, 157, 158,
    161, 162, 164, 167, 168, 171, 173, 174, 176, 179, 181, 182, 185, 186, 188, 191,
    193, 194, 196, 199, 200, 203, 205, 206, 208, 211, 213, 214, 217, 218, 220, 223,
    224, 227, 229, 230, 233, 234, 236, 239, 241, 242, 244, 247, 248, 251, 253, 254
};

static const BYTE bytebit[8] = {
    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80
};

static const DWORD bigbyte[24] = {
    0x800000L, 0x400000L, 0x200000L, 0x100000L,
    0x080000L, 0x040000L, 0x020000L, 0x010000L,
    0x008000L, 0x004000L, 0x002000L, 0x001000L,
    0x000800L, 0x000400L, 0x000200L, 0x000100L,
    0x000080L, 0x000040L, 0x000020L, 0x000010L,
    0x000008L, 0x000004L, 0x000002L, 0x000001L
};

static const BYTE pc1[56] = {
    56, 48, 40, 32, 24, 16, 8, 0, 57, 49, 41, 33, 25, 17, 9, 1,
    58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 62, 54, 46, 38,
    30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 60, 52, 44, 36,
    28, 20, 12, 4, 27, 19, 11, 3
};

static const BYTE totrot[16] = {
    1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, 28
};

static const BYTE pc2[48] = {
    13, 16, 10, 23, 0, 4, 2, 27, 14, 5, 20, 9, 22, 18, 11, 3,
    25, 7, 15, 6, 26, 19, 12, 1, 40, 51, 30, 36, 46, 54, 29, 39,
    50, 44, 32, 47, 43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31
};

static const DWORD SP1[64] = {
    0x01010400L, 0x00000000L, 0x00010000L, 0x01010404L,
    0x01010004L, 0x00010404L, 0x00000004L, 0x00010000L,
    0x00000400L, 0x01010400L, 0x01010404L, 0x00000400L,
    0x01000404L, 0x01010004L, 0x01000000L, 0x00000004L,
    0x00000404L, 0x01000400L, 0x01000400L, 0x00010400L,
    0x00010400L, 0x01010000L, 0x01010000L, 0x01000404L,
    0x00010004L, 0x01000004L, 0x01000004L, 0x00010004L,
    0x00000000L, 0x00000404L, 0x00010404L, 0x01000000L,
    0x00010000L, 0x01010404L, 0x00000004L, 0x01010000L,
    0x01010400L, 0x01000000L, 0x01000000L, 0x00000400L,
    0x01010004L, 0x00010000L, 0x00010400L, 0x01000004L,
    0x00000400L, 0x00000004L, 0x01000404L, 0x00010404L,
    0x01010404L, 0x00010004L, 0x01010000L, 0x01000404L,
    0x01000004L, 0x00000404L, 0x00010404L, 0x01010400L,
    0x00000404L, 0x01000400L, 0x01000400L, 0x00000000L,
    0x00010004L, 0x00010400L, 0x00000000L, 0x01010004L
};

static const DWORD SP2[64] = {
    0x80108020L, 0x80008000L, 0x00008000L, 0x00108020L,
    0x00100000L, 0x00000020L, 0x80100020L, 0x80008020L,
    0x80000020L, 0x80108020L, 0x80108000L, 0x80000000L,
    0x80008000L, 0x00100000L, 0x00000020L, 0x80100020L,
    0x00108000L, 0x00100020L, 0x80008020L, 0x00000000L,
    0x80000000L, 0x00008000L, 0x00108020L, 0x80100000L,
    0x00100020L, 0x80000020L, 0x00000000L, 0x00108000L,
    0x00008020L, 0x80108000L, 0x80100000L, 0x00008020L,
    0x00000000L, 0x00108020L, 0x80100020L, 0x00100000L,
    0x80008020L, 0x80100000L, 0x80108000L, 0x00008000L,
    0x80100000L, 0x80008000L, 0x00000020L, 0x80108020L,
    0x00108020L, 0x00000020L, 0x00008000L, 0x80000000L,
    0x00008020L, 0x80108000L, 0x00100000L, 0x80000020L,
    0x00100020L, 0x80008020L, 0x80000020L, 0x00100020L,
    0x00108000L, 0x00000000L, 0x80008000L, 0x00008020L,
    0x80000000L, 0x80100020L, 0x80108020L, 0x00108000L
};

static const DWORD SP3[64] = {
    0x00000208L, 0x08020200L, 0x00000000L, 0x08020008L,
    0x08000200L, 0x00000000L, 0x00020208L, 0x08000200L,
    0x00020008L, 0x08000008L, 0x08000008L, 0x00020000L,
    0x08020208L, 0x00020008L, 0x08020000L, 0x00000208L,
    0x08000000L, 0x00000008L, 0x08020200L, 0x00000200L,
    0x00020200L, 0x08020000L, 0x08020008L, 0x00020208L,
    0x08000208L, 0x00020200L, 0x00020000L, 0x08000208L,
    0x00000008L, 0x08020208L, 0x00000200L, 0x08000000L,
    0x08020200L, 0x08000000L, 0x00020008L, 0x00000208L,
    0x00020000L, 0x08020200L, 0x08000200L, 0x00000000L,
    0x00000200L, 0x00020008L, 0x08020208L, 0x08000200L,
    0x08000008L, 0x00000200L, 0x00000000L, 0x08020008L,
    0x08000208L, 0x00020000L, 0x08000000L, 0x08020208L,
    0x00000008L