# DES和3DES加密算法C语言实现【转】

DES和3DES加密算法C语言实现 记录DES和3DES加密算法最简洁易懂的C语言源码 主要是要用到CBC这部分的算法，后边也有一个工具可以提供验证，因为网上的工具含有CBC的很少，也方便大家吧

```#define MBEDTLS_DES_ENCRYPT     1
#define MBEDTLS_DES_DECRYPT     0

#define MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH              -0x0002 /**< The data input has an invalid length. */

#define MBEDTLS_DES_KEY_SIZE    8
#define DES_KEY_SIZE         (8)
#define DES3_KEY2_SIZE       (16)
#define DES3_KEY3_SIZE       (24)

typedef struct
{
uint32_t sk[32];            /*!<  DES subkeys       */
}des_context;

/**
* \brief          Triple-DES context structure
*/
typedef struct
{
uint32_t sk[96];            /*!<  3DES subkeys      */
}des3_context;

#define DES_C

#if defined(DES_C)

#include "des.h"

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

#if !defined(DES_ALT)

/* Implementation that should never be optimized out by the compiler */
static void zeroize( void *v, size_t n ) {
volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
}

/*
* 32-bit integer manipulation macros (big endian)
*/
#ifndef GET_UINT32_BE
#define GET_UINT32_BE(n,b,i)                            \
{                                                       \
(n) = ( (uint32_t) (b)[(i)    ] << 24 )             \
| ( (uint32_t) (b)[(i) + 1] << 16 )             \
| ( (uint32_t) (b)[(i) + 2] <<  8 )             \
| ( (uint32_t) (b)[(i) + 3]       );            \
}
#endif

#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n,b,i)                            \
{                                                       \
(b)[(i)    ] = (unsigned char) ( (n) >> 24 );       \
(b)[(i) + 1] = (unsigned char) ( (n) >> 16 );       \
(b)[(i) + 2] = (unsigned char) ( (n) >>  8 );       \
(b)[(i) + 3] = (unsigned char) ( (n)       );       \
}
#endif

/*
* Expanded DES S-boxes
*/
static const uint32_t SB1[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
};

static const uint32_t SB2[64] =
{
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
};

static const uint32_t SB3[64] =
{
0x00000208, 0x08020200, 0x00000000, 0x08020008,
0x08000200, 0x00000000, 0x00020208, 0x08000200,
0x00020008, 0x08000008, 0x08000008, 0x00020000,
0x08020208, 0x00020008, 0x08020000, 0x00000208,
0x08000000, 0x00000008, 0x08020200, 0x00000200,
0x00020200, 0x08020000, 0x08020008, 0x00020208,
0x08000208, 0x00020200, 0x00020000, 0x08000208,
0x00000008, 0x08020208, 0x00000200, 0x08000000,
0x08020200, 0x08000000, 0x00020008, 0x00000208,
0x00020000, 0x08020200, 0x08000200, 0x00000000,
0x00000200, 0x00020008, 0x08020208, 0x08000200,
0x08000008, 0x00000200, 0x00000000, 0x08020008,
0x08000208, 0x00020000, 0x08000000, 0x08020208,
0x00000008, 0x00020208, 0x00020200, 0x08000008,
0x08020000, 0x08000208, 0x00000208, 0x08020000,
0x00020208, 0x00000008, 0x08020008, 0x00020200
};

static const uint32_t SB4[64] =
{
0x00802001, 0x00002081, 0x00002081, 0x00000080,
0x00802080, 0x00800081, 0x00800001, 0x00002001,
0x00000000, 0x00802000, 0x00802000, 0x00802081,
0x00000081, 0x00000000, 0x00800080, 0x00800001,
0x00000001, 0x00002000, 0x00800000, 0x00802001,
0x00000080, 0x00800000, 0x00002001, 0x00002080,
0x00800081, 0x00000001, 0x00002080, 0x00800080,
0x00002000, 0x00802080, 0x00802081, 0x00000081,
0x00800080, 0x00800001, 0x00802000, 0x00802081,
0x00000081, 0x00000000, 0x00000000, 0x00802000,
0x00002080, 0x00800080, 0x00800081, 0x00000001,
0x00802001, 0x00002081, 0x00002081, 0x00000080,
0x00802081, 0x00000081, 0x00000001, 0x00002000,
0x00800001, 0x00002001, 0x00802080, 0x00800081,
0x00002001, 0x00002080, 0x00800000, 0x00802001,
0x00000080, 0x00800000, 0x00002000, 0x00802080
};

static const uint32_t SB5[64] =
{
0x00000100, 0x02080100, 0x02080000, 0x42000100,
0x00080000, 0x00000100, 0x40000000, 0x02080000,
0x40080100, 0x00080000, 0x02000100, 0x40080100,
0x42000100, 0x42080000, 0x00080100, 0x40000000,
0x02000000, 0x40080000, 0x40080000, 0x00000000,
0x40000100, 0x42080100, 0x42080100, 0x02000100,
0x42080000, 0x40000100, 0x00000000, 0x42000000,
0x02080100, 0x02000000, 0x42000000, 0x00080100,
0x00080000, 0x42000100, 0x00000100, 0x02000000,
0x40000000, 0x02080000, 0x42000100, 0x40080100,
0x02000100, 0x40000000, 0x42080000, 0x02080100,
0x40080100, 0x00000100, 0x02000000, 0x42080000,
0x42080100, 0x00080100, 0x42000000, 0x42080100,
0x02080000, 0x00000000, 0x40080000, 0x42000000,
0x00080100, 0x02000100, 0x40000100, 0x00080000,
0x00000000, 0x40080000, 0x02080100, 0x40000100
};

static const uint32_t SB6[64] =
{
0x20000010, 0x20400000, 0x00004000, 0x20404010,
0x20400000, 0x00000010, 0x20404010, 0x00400000,
0x20004000, 0x00404010, 0x00400000, 0x20000010,
0x00400010, 0x20004000, 0x20000000, 0x00004010,
0x00000000, 0x00400010, 0x20004010, 0x00004000,
0x00404000, 0x20004010, 0x00000010, 0x20400010,
0x20400010, 0x00000000, 0x00404010, 0x20404000,
0x00004010, 0x00404000, 0x20404000, 0x20000000,
0x20004000, 0x00000010, 0x20400010, 0x00404000,
0x20404010, 0x00400000, 0x00004010, 0x20000010,
0x00400000, 0x20004000, 0x20000000, 0x00004010,
0x20000010, 0x20404010, 0x00404000, 0x20400000,
0x00404010, 0x20404000, 0x00000000, 0x20400010,
0x00000010, 0x00004000, 0x20400000, 0x00404010,
0x00004000, 0x00400010, 0x20004010, 0x00000000,
0x20404000, 0x20000000, 0x00400010, 0x20004010
};

static const uint32_t SB7[64] =
{
0x00200000, 0x04200002, 0x04000802, 0x00000000,
0x00000800, 0x04000802, 0x00200802, 0x04200800,
0x04200802, 0x00200000, 0x00000000, 0x04000002,
0x00000002, 0x04000000, 0x04200002, 0x00000802,
0x04000800, 0x00200802, 0x00200002, 0x04000800,
0x04000002, 0x04200000, 0x04200800, 0x00200002,
0x04200000, 0x00000800, 0x00000802, 0x04200802,
0x00200800, 0x00000002, 0x04000000, 0x00200800,
0x04000000, 0x00200800, 0x00200000, 0x04000802,
0x04000802, 0x04200002, 0x04200002, 0x00000002,
0x00200002, 0x04000000, 0x04000800, 0x00200000,
0x04200800, 0x00000802, 0x00200802, 0x04200800,
0x00000802, 0x04000002, 0x04200802, 0x04200000,
0x00200800, 0x00000000, 0x00000002, 0x04200802,
0x00000000, 0x00200802, 0x04200000, 0x00000800,
0x04000002, 0x04000800, 0x00000800, 0x00200002
};

static const uint32_t SB8[64] =
{
0x10001040, 0x00001000, 0x00040000, 0x10041040,
0x10000000, 0x10001040, 0x00000040, 0x10000000,
0x00040040, 0x10040000, 0x10041040, 0x00041000,
0x10041000, 0x00041040, 0x00001000, 0x00000040,
0x10040000, 0x10000040, 0x10001000, 0x00001040,
0x00041000, 0x00040040, 0x10040040, 0x10041000,
0x00001040, 0x00000000, 0x00000000, 0x10040040,
0x10000040, 0x10001000, 0x00041040, 0x00040000,
0x00041040, 0x00040000, 0x10041000, 0x00001000,
0x00000040, 0x10040040, 0x00001000, 0x00041040,
0x10001000, 0x00000040, 0x10000040, 0x10040000,
0x10040040, 0x10000000, 0x00040000, 0x10001040,
0x00000000, 0x10041040, 0x00040040, 0x10000040,
0x10040000, 0x10001000, 0x10001040, 0x00000000,
0x10041040, 0x00041000, 0x00041000, 0x00001040,
0x00001040, 0x00040040, 0x10000000, 0x10041000
};

/*
* PC1: left and right halves bit-swap
*/
static const uint32_t LHs[16] =
{
0x00000000, 0x00000001, 0x00000100, 0x00000101,
0x00010000, 0x00010001, 0x00010100, 0x00010101,
0x01000000, 0x01000001, 0x01000100, 0x01000101,
0x01010000, 0x01010001, 0x01010100, 0x01010101
};

static const uint32_t RHs[16] =
{
0x00000000, 0x01000000, 0x00010000, 0x01010000,
0x00000100, 0x01000100, 0x00010100, 0x01010100,
0x00000001, 0x01000001, 0x00010001, 0x01010001,
0x00000101, 0x01000101, 0x00010101, 0x01010101,
};

/*
* Initial Permutation macro
*/
#define DES_IP(X,Y)                                             \
{                                                               \
T = ((X >>  4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T <<  4);   \
T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16);   \
T = ((Y >>  2) ^ X) & 0x33333333; X ^= T; Y ^= (T <<  2);   \
T = ((Y >>  8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T <<  8);   \
Y = ((Y << 1) | (Y >> 31)) & 0xFFFFFFFF;                    \
T = (X ^ Y) & 0xAAAAAAAA; Y ^= T; X ^= T;                   \
X = ((X << 1) | (X >> 31)) & 0xFFFFFFFF;                    \
}

/*
* Final Permutation macro
*/
#define DES_FP(X,Y)                                             \
{                                                               \
X = ((X << 31) | (X >> 1)) & 0xFFFFFFFF;                    \
T = (X ^ Y) & 0xAAAAAAAA; X ^= T; Y ^= T;                   \
Y = ((Y << 31) | (Y >> 1)) & 0xFFFFFFFF;                    \
T = ((Y >>  8) ^ X) & 0x00FF00FF; X ^= T; Y ^= (T <<  8);   \
T = ((Y >>  2) ^ X) & 0x33333333; X ^= T; Y ^= (T <<  2);   \
T = ((X >> 16) ^ Y) & 0x0000FFFF; Y ^= T; X ^= (T << 16);   \
T = ((X >>  4) ^ Y) & 0x0F0F0F0F; Y ^= T; X ^= (T <<  4);   \
}

/*
* DES round macro
*/
#define DES_ROUND(X,Y)                          \
{                                               \
T = *SK++ ^ X;                              \
Y ^= SB8[ (T      ) & 0x3F ] ^              \
SB6[ (T >>  8) & 0x3F ] ^              \
SB4[ (T >> 16) & 0x3F ] ^              \
SB2[ (T >> 24) & 0x3F ];               \
\
T = *SK++ ^ ((X << 28) | (X >> 4));         \
Y ^= SB7[ (T      ) & 0x3F ] ^              \
SB5[ (T >>  8) & 0x3F ] ^              \
SB3[ (T >> 16) & 0x3F ] ^              \
SB1[ (T >> 24) & 0x3F ];               \
}

#define SWAP(a,b) { uint32_t t = a; a = b; b = t; t = 0; }

void des_init( des_context *ctx )
{
memset( ctx, 0, sizeof( des_context ) );
}

void des_free( des_context *ctx )
{
if( ctx == NULL )
return;

zeroize( ctx, sizeof( des_context ) );
}

void des3_init( des3_context *ctx )
{
memset( ctx, 0, sizeof( des3_context ) );
}

void des3_free( des3_context *ctx )
{
if( ctx == NULL )
return;

zeroize( ctx, sizeof( des3_context ) );
}

static const unsigned char odd_parity_table[128] = { 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 };

void des_key_set_parity( unsigned char key[DES_KEY_SIZE] )
{
int i;

for( i = 0; i < DES_KEY_SIZE; i++ )
key[i] = odd_parity_table[key[i] / 2];
}

/*
* Check the given key's parity, returns 1 on failure, 0 on SUCCESS
*/
int des_key_check_key_parity( const unsigned char key[DES_KEY_SIZE] )
{
int i;

for( i = 0; i < DES_KEY_SIZE; i++ )
if( key[i] != odd_parity_table[key[i] / 2] )
return( 1 );

return( 0 );
}

/*
* Table of weak and semi-weak keys
*
* Source: http://en.wikipedia.org/wiki/Weak_key
*
* Weak:
* Alternating ones + zeros (0x0101010101010101)
* Alternating 'F' + 'E' (0xFEFEFEFEFEFEFEFE)
* '0xE0E0E0E0F1F1F1F1'
* '0x1F1F1F1F0E0E0E0E'
*
* Semi-weak:
* 0x011F011F010E010E and 0x1F011F010E010E01
* 0x01E001E001F101F1 and 0xE001E001F101F101
* 0x01FE01FE01FE01FE and 0xFE01FE01FE01FE01
* 0x1FE01FE00EF10EF1 and 0xE01FE01FF10EF10E
* 0x1FFE1FFE0EFE0EFE and 0xFE1FFE1FFE0EFE0E
* 0xE0FEE0FEF1FEF1FE and 0xFEE0FEE0FEF1FEF1
*
*/

#define WEAK_KEY_COUNT 16

static const unsigned char weak_key_table[WEAK_KEY_COUNT][DES_KEY_SIZE] =
{
{ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01 },
{ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE },
{ 0x1F, 0x1F, 0x1F, 0x1F, 0x0E, 0x0E, 0x0E, 0x0E },
{ 0xE0, 0xE0, 0xE0, 0xE0, 0xF1, 0xF1, 0xF1, 0xF1 },

{ 0x01, 0x1F, 0x01, 0x1F, 0x01, 0x0E, 0x01, 0x0E },
{ 0x1F, 0x01, 0x1F, 0x01, 0x0E, 0x01, 0x0E, 0x01 },
{ 0x01, 0xE0, 0x01, 0xE0, 0x01, 0xF1, 0x01, 0xF1 },
{ 0xE0, 0x01, 0xE0, 0x01, 0xF1, 0x01, 0xF1, 0x01 },
{ 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE },
{ 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01 },
{ 0x1F, 0xE0, 0x1F, 0xE0, 0x0E, 0xF1, 0x0E, 0xF1 },
{ 0xE0, 0x1F, 0xE0, 0x1F, 0xF1, 0x0E, 0xF1, 0x0E },
{ 0x1F, 0xFE, 0x1F, 0xFE, 0x0E, 0xFE, 0x0E, 0xFE },
{ 0xFE, 0x1F, 0xFE, 0x1F, 0xFE, 0x0E, 0xFE, 0x0E },
{ 0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1, 0xFE },
{ 0xFE, 0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1 }
};

int des_key_check_weak( const unsigned char key[DES_KEY_SIZE] )
{
int i;

for( i = 0; i < WEAK_KEY_COUNT; i++ )
if( memcmp( weak_key_table[i], key, DES_KEY_SIZE) == 0 )
return( 1 );

return( 0 );
}

void des_setkey( uint32_t SK[32], const unsigned char key[DES_KEY_SIZE] )
{
int i;
uint32_t X, Y, T;

GET_UINT32_BE( X, key, 0 );
GET_UINT32_BE( Y, key, 4 );

/*
* Permuted Choice 1
*/
T =  ((Y >>  4) ^ X) & 0x0F0F0F0F;  X ^= T; Y ^= (T <<  4);
T =  ((Y      ) ^ X) & 0x10101010;  X ^= T; Y ^= (T      );

X =   (LHs[ (X      ) & 0xF] << 3) | (LHs[ (X >>  8) & 0xF ] << 2)
| (LHs[ (X >> 16) & 0xF] << 1) | (LHs[ (X >> 24) & 0xF ]     )
| (LHs[ (X >>  5) & 0xF] << 7) | (LHs[ (X >> 13) & 0xF ] << 6)
| (LHs[ (X >> 21) & 0xF] << 5) | (LHs[ (X >> 29) & 0xF ] << 4);

Y =   (RHs[ (Y >>  1) & 0xF] << 3) | (RHs[ (Y >>  9) & 0xF ] << 2)
| (RHs[ (Y >> 17) & 0xF] << 1) | (RHs[ (Y >> 25) & 0xF ]     )
| (RHs[ (Y >>  4) & 0xF] << 7) | (RHs[ (Y >> 12) & 0xF ] << 6)
| (RHs[ (Y >> 20) & 0xF] << 5) | (RHs[ (Y >> 28) & 0xF ] << 4);

X &= 0x0FFFFFFF;
Y &= 0x0FFFFFFF;

/*
* calculate subkeys
*/
for( i = 0; i < 16; i++ )
{
if( i < 2 || i == 8 || i == 15 )
{
X = ((X <<  1) | (X >> 27)) & 0x0FFFFFFF;
Y = ((Y <<  1) | (Y >> 27)) & 0x0FFFFFFF;
}
else
{
X = ((X <<  2) | (X >> 26)) & 0x0FFFFFFF;
Y = ((Y <<  2) | (Y >> 26)) & 0x0FFFFFFF;
}

*SK++ =   ((X <<  4) & 0x24000000) | ((X << 28) & 0x10000000)
| ((X << 14) & 0x08000000) | ((X << 18) & 0x02080000)
| ((X <<  6) & 0x01000000) | ((X <<  9) & 0x00200000)
| ((X >>  1) & 0x00100000) | ((X << 10) & 0x00040000)
| ((X <<  2) & 0x00020000) | ((X >> 10) & 0x00010000)
| ((Y >> 13) & 0x00002000) | ((Y >>  4) & 0x00001000)
| ((Y <<  6) & 0x00000800) | ((Y >>  1) & 0x00000400)
| ((Y >> 14) & 0x00000200) | ((Y      ) & 0x00000100)
| ((Y >>  5) & 0x00000020) | ((Y >> 10) & 0x00000010)
| ((Y >>  3) & 0x00000008) | ((Y >> 18) & 0x00000004)
| ((Y >> 26) & 0x00000002) | ((Y >> 24) & 0x00000001);

*SK++ =   ((X << 15) & 0x20000000) | ((X << 17) & 0x10000000)
| ((X << 10) & 0x08000000) | ((X << 22) & 0x04000000)
| ((X >>  2) & 0x02000000) | ((X <<  1) & 0x01000000)
| ((X << 16) & 0x00200000) | ((X << 11) & 0x00100000)
| ((X <<  3) & 0x00080000) | ((X >>  6) & 0x00040000)
| ((X << 15) & 0x00020000) | ((X >>  4) & 0x00010000)
| ((Y >>  2) & 0x00002000) | ((Y <<  8) & 0x00001000)
| ((Y >> 14) & 0x00000808) | ((Y >>  9) & 0x00000400)
| ((Y      ) & 0x00000200) | ((Y <<  7) & 0x00000100)
| ((Y >>  7) & 0x00000020) | ((Y >>  3) & 0x00000011)
| ((Y <<  2) & 0x00000004) | ((Y >> 21) & 0x00000002);
}
}

/*
* DES key schedule (56-bit, encryption)
*/
int des_setkey_enc( des_context *ctx, const unsigned char key[DES_KEY_SIZE] )
{
des_setkey( ctx->sk, key );

return( 0 );
}

/*
* DES key schedule (56-bit, decryption)
*/
int des_setkey_dec( des_context *ctx, const unsigned char key[DES_KEY_SIZE] )
{
int i;

des_setkey( ctx->sk, key );

for( i = 0; i < 16; i += 2 )
{
SWAP( ctx->sk[i    ], ctx->sk[30 - i] );
SWAP( ctx->sk[i + 1], ctx->sk[31 - i] );
}

return( 0 );
}

static void des3_set2key( uint32_t esk[96],
uint32_t dsk[96],
const unsigned char key[DES_KEY_SIZE*2] )
{
int i;

des_setkey( esk, key );
des_setkey( dsk + 32, key + 8 );

for( i = 0; i < 32; i += 2 )
{
dsk[i     ] = esk[30 - i];
dsk[i +  1] = esk[31 - i];

esk[i + 32] = dsk[62 - i];
esk[i + 33] = dsk[63 - i];

esk[i + 64] = esk[i    ];
esk[i + 65] = esk[i + 1];

dsk[i + 64] = dsk[i    ];
dsk[i + 65] = dsk[i + 1];
}
}

/*
* Triple-DES key schedule (112-bit, encryption)
*/
int des3_set2key_enc( des3_context *ctx,
const unsigned char key[DES_KEY_SIZE * 2] )
{
uint32_t sk[96];

des3_set2key( ctx->sk, sk, key );
zeroize( sk,  sizeof( sk ) );

return( 0 );
}

/*
* Triple-DES key schedule (112-bit, decryption)
*/
int des3_set2key_dec( des3_context *ctx,
const unsigned char key[DES_KEY_SIZE * 2] )
{
uint32_t sk[96];

des3_set2key( sk, ctx->sk, key );
zeroize( sk,  sizeof( sk ) );

return( 0 );
}

static void des3_set3key( uint32_t esk[96],
uint32_t dsk[96],
const unsigned char key[24] )
{
int i;

des_setkey( esk, key );
des_setkey( dsk + 32, key +  8 );
des_setkey( esk + 64, key + 16 );

for( i = 0; i < 32; i += 2 )
{
dsk[i     ] = esk[94 - i];
dsk[i +  1] = esk[95 - i];

esk[i + 32] = dsk[62 - i];
esk[i + 33] = dsk[63 - i];

dsk[i + 64] = esk[30 - i];
dsk[i + 65] = esk[31 - i];
}
}

/*
* Triple-DES key schedule (168-bit, encryption)
*/
int des3_set3key_enc( des3_context *ctx,
const unsigned char key[DES_KEY_SIZE * 3] )
{
uint32_t sk[96];

des3_set3key( ctx->sk, sk, key );
zeroize( sk,  sizeof( sk ) );

return( 0 );
}

/*
* Triple-DES key schedule (168-bit, decryption)
*/
int des3_set3key_dec( des3_context *ctx,
const unsigned char key[DES_KEY_SIZE * 3] )
{
uint32_t sk[96];

des3_set3key( sk, ctx->sk, key );
zeroize( sk,  sizeof( sk ) );

return( 0 );
}

/*
* DES-ECB block encryption/decryption
*/

int des_crypt_ecb( des_context *ctx,
const unsigned char input[8],
unsigned char output[8] )
{
int i;
uint32_t X, Y, T, *SK;

SK = ctx->sk;

GET_UINT32_BE( X, input, 0 );
GET_UINT32_BE( Y, input, 4 );

DES_IP( X, Y );

for( i = 0; i < 8; i++ )
{
DES_ROUND( Y, X );
DES_ROUND( X, Y );
}

DES_FP( Y, X );

PUT_UINT32_BE( Y, output, 0 );
PUT_UINT32_BE( X, output, 4 );

return( 0 );
}

/*
* DES-CBC buffer encryption/decryption
*/
int des_crypt_cbc( des_context *ctx,
int mode,
size_t length,
unsigned char iv[8],
const unsigned char *input,
unsigned char *output )
{
int i;
unsigned char temp[8];

if( length % 8 )
return( ERR_DES_INVALID_INPUT_LENGTH );

if( mode == DES_ENCRYPT )
{
while( length > 0 )
{
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( input[i] ^ iv[i] );

des_crypt_ecb( ctx, output, output );
memcpy( iv, output, 8 );

input  += 8;
output += 8;
length -= 8;
}
}
else /* DES_DECRYPT */
{
while( length > 0 )
{
memcpy( temp, input, 8 );
des_crypt_ecb( ctx, input, output );

for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( output[i] ^ iv[i] );

memcpy( iv, temp, 8 );

input  += 8;
output += 8;
length -= 8;
}
}

return( 0 );
}

/*
* 3DES-ECB block encryption/decryption
*/

int des3_crypt_ecb( des3_context *ctx,
const unsigned char input[8],
unsigned char output[8] )
{
int i;
uint32_t X, Y, T, *SK;

SK = ctx->sk;

GET_UINT32_BE( X, input, 0 );
GET_UINT32_BE( Y, input, 4 );

DES_IP( X, Y );

for( i = 0; i < 8; i++ )
{
DES_ROUND( Y, X );
DES_ROUND( X, Y );
}

for( i = 0; i < 8; i++ )
{
DES_ROUND( X, Y );
DES_ROUND( Y, X );
}

for( i = 0; i < 8; i++ )
{
DES_ROUND( Y, X );
DES_ROUND( X, Y );
}

DES_FP( Y, X );

PUT_UINT32_BE( Y, output, 0 );
PUT_UINT32_BE( X, output, 4 );

return( 0 );
}

/*
* 3DES-CBC buffer encryption/decryption
*/
int des3_crypt_cbc( des3_context *ctx,
int mode,
size_t length,
unsigned char iv[8],
const unsigned char *input,
unsigned char *output )
{
int i;
unsigned char temp[8];

if( length % 8 )
return( ERR_DES_INVALID_INPUT_LENGTH );

if( mode == DES_ENCRYPT )
{
while( length > 0 )
{
for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( input[i] ^ iv[i] );

des3_crypt_ecb( ctx, output, output );
memcpy( iv, output, 8 );

input  += 8;
output += 8;
length -= 8;
}
}
else /* DES_DECRYPT */
{
while( length > 0 )
{
memcpy( temp, input, 8 );
des3_crypt_ecb( ctx, input, output );

for( i = 0; i < 8; i++ )
output[i] = (unsigned char)( output[i] ^ iv[i] );

memcpy( iv, temp, 8 );

input  += 8;
output += 8;
length -= 8;
}
}

return( 0 );
}

#endif /* !DES_ALT */

#endif /* DES_C */

/*
* DES-ECB buffer encryption API
*/
unsigned int des_ecb_encrypt(unsigned char *pout,
unsigned char *pdata,
unsigned int nlen,
unsigned char *pkey)
{
unsigned char *tmp;
unsigned int len,i;
unsigned char ch = '\0';
des_context ctx;

des_setkey_enc( &ctx, pkey );

len = (nlen / 8 + (nlen % 8 ? 1: 0)) * 8;

//ch = 8 - nlen % 8;
for(i = 0;i < nlen;i += 8)
{
des_crypt_ecb( &ctx, (pdata + i), (pout + i) );
}
if(len > nlen)
{
tmp = (unsigned char *)malloc(len);
i -= 8;
memcpy(tmp,pdata + i,nlen - i);
memset(tmp + nlen % 8, ch, (8 - nlen % 8) % 8);
des_crypt_ecb( &ctx, tmp, (pout + i));
free(tmp);
}

des_free( &ctx );
return len;

}
/*
* DES-ECB buffer decryption API
*/
unsigned int des_ecb_decrypt(unsigned char *pout,
unsigned char *pdata,
unsigned int nlen,
unsigned char *pkey)
{

unsigned int i;
des_context ctx;

if(nlen % 8)
return 1;

des_setkey_dec( &ctx, pkey );

for(i = 0;i < nlen;i += 8)
{
des_crypt_ecb(&ctx, (pdata + i), (pout + i));
}
des_free( &ctx );
return 0;

}

/*
* DES-CBC buffer encryption API
*/
unsigned int des_cbc_encrypt(unsigned char *pout,
unsigned char *pdata,
unsigned int nlen,
unsigned char *pkey,
unsigned char *piv)
{
des_context ctx;
unsigned char iv[8] = {0};
unsigned char *pivb;

if(piv == NULL)
pivb = iv;
else
pivb = piv;

des_setkey_enc( &ctx, pkey );

des_crypt_cbc( &ctx, 1, nlen, pivb, pdata, (pout));

des_free( &ctx );

return nlen;

}
/*
* DES-CBC buffer decryption API
*/
unsigned int des_cbc_decrypt(unsigned char *pout,
unsigned char *pdata,
unsigned int nlen,
unsigned char *pkey,
unsigned char *piv)
{

des_context ctx;
unsigned char iv[8] = {0};
unsigned char *pivb;

if(piv == NULL)
pivb = iv;
else
pivb = piv;

des_setkey_dec( &ctx, pkey );

des_crypt_cbc( &ctx, 0, nlen, pivb, pdata, (pout));

des_free( &ctx );

return 0;

}
/*
* 3DES-ECB buffer encryption API
*/
unsigned int des3_ecb_encrypt(unsigned char *pout,
unsigned char *pdata,
unsigned int nlen,
unsigned char *pkey,
unsigned int klen)
{
unsigned char *tmp;
unsigned int len,i;
unsigned char ch = '\0';
des3_context ctx3;

if(klen == DES3_KEY2_SIZE)//16字节
des3_set2key_enc( &ctx3, pkey );//根据长度设置key
else if(klen == DES3_KEY3_SIZE)//24字节
des3_set3key_enc( &ctx3, pkey );

len = (nlen / 8 + (nlen % 8 ? 1: 0)) * 8;

//ch = 8 - nlen % 8;//可以设置补齐内容，常用0或0xFF
for(i = 0;i < nlen;i += 8)
{
des3_crypt_ecb( &ctx3, (pdata + i), (pout + i) );
}
if(len > nlen)//不足8字节补齐
{
tmp = (unsigned char *)malloc(len);
i -= 8;
memcpy(tmp,pdata + i,nlen - i);
memset(tmp + nlen % 8, ch, (8 - nlen % 8) % 8);
des3_crypt_ecb( &ctx3, tmp, (pout + i));
free(tmp);
}

des3_free( &ctx3 );
return len;

}
/*
* 3DES-ECB buffer decryption API
*/
unsigned int des3_ecb_decrypt(unsigned char *pout,
unsigned char *pdata,
unsigned int nlen,
unsigned char *pkey,
unsigned int klen)
{

unsigned int i;
des3_context ctx3;

if(nlen % 8)
return 1;

if(klen == DES3_KEY2_SIZE)
des3_set2key_dec( &ctx3, pkey );
else if(klen == DES3_KEY3_SIZE)
des3_set3key_dec( &ctx3, pkey );

for(i = 0;i < nlen;i += 8)
{
des3_crypt_ecb(&ctx3, (pdata + i), (pout + i));
}
des3_free( &ctx3 );
return 0;

}
/*
* 3DES-CBC buffer encryption API
*/
unsigned int des3_cbc_encrypt(unsigned char *pout,
unsigned char *pdata,
unsigned int nlen,
unsigned char *pkey,
unsigned int klen,
unsigned char *piv)
{
des3_context ctx;
unsigned char iv[8] = {0};
unsigned char *pivb;
unsigned int len;

if(piv == NULL)
pivb = iv;
else
pivb = piv;

if(klen == DES3_KEY2_SIZE)
des3_set2key_enc( &ctx, pkey );
else if(klen == DES3_KEY3_SIZE)
des3_set3key_enc( &ctx, pkey );

if(nlen % 8)
{
len = nlen + 8 - nlen % 8;
tmp = (unsigned char *)calloc(1, len);
memcpy(tmp, pdata, nlen);
des3_crypt_cbc( &ctx, 1, len, pivb, tmp, (pout));
free(tmp);
}
else
{
des3_crypt_cbc( &ctx, 1, nlen, pivb, pdata, (pout));
}

des3_free( &ctx );

return nlen;

}
/*
* 3DES-CBC buffer decryption API
*/
unsigned int des3_cbc_decrypt(unsigned char *pout,
unsigned char *pdata,
unsigned int nlen,
unsigned char *pkey,
unsigned int klen,
unsigned char *piv)
{

des3_context ctx;
unsigned char iv[8] = {0};
unsigned char *pivb;

if(nlen % 8)
return 1;

if(piv == NULL)
pivb = iv;
else
pivb = piv;

if(klen == DES3_KEY2_SIZE)
des3_set2key_dec( &ctx, pkey );
else if(klen == DES3_KEY3_SIZE)
des3_set3key_dec( &ctx, pkey );

des3_crypt_cbc( &ctx, 0, nlen, pivb, pdata, (pout));

des3_free( &ctx );

return 0;

}```

```//main函数测试
int des_test_self()
{
unsigned char buff[1024] = {0};
unsigned char data[1024] = {0x3F,0x12,0xE7,0xC0,0x2D,0x66,0x5A,0xB0,0xC4,0x2E,0x58,0xF1};
int ret,len,i;

//  len = MyStrToHex("3F12E7C02D665AB0C42E58F1", data);//不满8字节
len = strlen((char*)data);
for(i = 0;i < len;i++)
{
printf("%02X",data[i]);
}
printf("\r\n");

unsigned char key[16] = {0x11,0x22,0x33,0x44,0x55,0x66,0x77,0x88,0x99,0x00,0xAA,0xBB,0xCC,0xDD,0xEE,0xFF};
//DES ECB 加密
printf("DES ECB ENC::\r\n");
ret = des_ecb_encrypt(buff,data,len,key);
for(i = 0;i < ret;i++)
{
printf("%02X",buff[i]);
}
printf("\r\n");
//DES ECB 解密
printf("DES ECB DEC::\r\n");
memset(data,0,sizeof(data));
des_ecb_decrypt(data,buff,ret,key);
for(i = 0;i < ret;i++)
{
printf("%02X",data[i]);
}
printf("\r\n");

//DES CBC 加密
printf("DES CBC ENC::\r\n");
memset(buff,0,sizeof(buff));
des_cbc_encrypt(buff,data,ret,key,NULL);
for(i = 0;i < ret;i++)
{
printf("%02X",buff[i]);
}
printf("\r\n");

//DES CBC 解密
printf("DES CBC DEC::\r\n");
memset(data,0,sizeof(data));
des_cbc_decrypt(data,buff,ret,key,NULL);
for(i = 0;i < ret;i++)
{
printf("%02X",data[i]);
}
printf("\r\n");
printf("\r\n");

//3DES ECB 加密
printf("3DES ECB ENC::\r\n");
ret = des3_ecb_encrypt(buff,data,len,key,16);
for(i = 0;i < ret;i++)
{
printf("%02X",buff[i]);
}
printf("\r\n");
//3DES ECB 解密
printf("3DES ECB DEC::\r\n");
memset(data,0,sizeof(data));
des3_ecb_decrypt(data,buff,ret,key,16);
for(i = 0;i < ret;i++)
{
printf("%02X",data[i]);
}
printf("\r\n");

//3DES CBC 加密
printf("3DES CBC ENC::\r\n");
memset(buff,0,sizeof(buff));
des3_cbc_encrypt(buff,data,ret,key,16,NULL);
for(i = 0;i < ret;i++)
{
printf("%02X",buff[i]);
}
printf("\r\n");

//3DES CBC 解密
printf("3DES CBC DEC::\r\n");
memset(data,0,sizeof(data));
des3_cbc_decrypt(data,buff,ret,key,16,NULL);
for(i = 0;i < ret;i++)
{
printf("%02X",data[i]);
}
printf("\r\n");

return 0;
}```

--------------------- 作者：leumber 来源：CSDN 原文：https://blog.csdn.net/leumber/article/details/78043675?utm_source=copy 版权声明：本文为博主原创文章，转载请附上博文链接！

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