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一个简单的MD5加密算法C语言示例程序

2013-08-15 16:40 417 查看
#include   <stdio.h>
#include   <stdlib.h>
#include   <time.h>
#include   <string.h>

typedef   unsigned   char   *POINTER;
typedef   unsigned   short   int   UINT2;
typedef   unsigned   long   int   UINT4;

typedef   struct
{
UINT4   state[4];
UINT4   count[2];
unsigned   char   buffer[64];
}   MD5_CTX;

void   MD5Init(MD5_CTX   *);
void   MD5Update(MD5_CTX   *,   unsigned   char   *,   unsigned   int);
void   MD5Final(unsigned   char   [16],   MD5_CTX   *);

#define   S11   7
#define   S12   12
#define   S13   17
#define   S14   22
#define   S21   5
#define   S22   9
#define   S23   14
#define   S24   20
#define   S31   4
#define   S32   11
#define   S33   16
#define   S34   23
#define   S41   6
#define   S42   10
#define   S43   15
#define   S44   21

static   unsigned   char   PADDING[64]   =   {
0x80,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0
};

#define   F(x,   y,   z)   (((x)   &   (y))   |   ((~x)   &   (z)))
#define   G(x,   y,   z)   (((x)   &   (z))   |   ((y)   &   (~z)))
#define   H(x,   y,   z)   ((x)   ^   (y)   ^   (z))
#define   I(x,   y,   z)   ((y)   ^   ((x)   |   (~z)))

#define   ROTATE_LEFT(x,   n)   (((x)   <<   (n))   |   ((x)   >>   (32-(n))))

#define   FF(a,   b,   c,   d,   x,   s,   ac)   {     (a)   +=   F   ((b),   (c),   (d))   +   (x)   +   (UINT4)(ac);     (a)   =   ROTATE_LEFT   ((a),   (s));     (a)   +=   (b);       }
#define   GG(a,   b,   c,   d,   x,   s,   ac)   {     (a)   +=   G   ((b),   (c),   (d))   +   (x)   +   (UINT4)(ac);     (a)   =   ROTATE_LEFT   ((a),   (s));     (a)   +=   (b);       }
#define   HH(a,   b,   c,   d,   x,   s,   ac)   {     (a)   +=   H   ((b),   (c),   (d))   +   (x)   +   (UINT4)(ac);     (a)   =   ROTATE_LEFT   ((a),   (s));     (a)   +=   (b);       }
#define   II(a,   b,   c,   d,   x,   s,   ac)   {     (a)   +=   I   ((b),   (c),   (d))   +   (x)   +   (UINT4)(ac);     (a)   =   ROTATE_LEFT   ((a),   (s));     (a)   +=   (b);   }

inline   void   Encode(unsigned   char   *output,   UINT4   *input,   unsigned   int   len)
{
unsigned   int   i,   j;

for   (i   =   0,   j   =   0;   j   <   len;   i++,   j   +=   4)   {
output[j]   =   (unsigned   char)(input[i]   &   0xff);
output[j+1]   =   (unsigned   char)((input[i]   >>   8)   &   0xff);
output[j+2]   =   (unsigned   char)((input[i]   >>   16)   &   0xff);
output[j+3]   =   (unsigned   char)((input[i]   >>   24)   &   0xff);
}
}

inline   void   Decode(UINT4   *output,   unsigned   char   *input,   unsigned   int   len)
{
unsigned   int   i,   j;

for   (i   =   0,   j   =   0;   j   <   len;   i++,   j   +=   4)
output[i]   =   ((UINT4)input[j])   |   (((UINT4)input[j+1])   <<   8)   |
(((UINT4)input[j+2])   <<   16)   |   (((UINT4)input[j+3])   <<   24);
}

inline   void   MD5Transform   (UINT4   state[4],   unsigned   char   block[64])
{
UINT4   a   =   state[0],   b   =   state[1],   c   =   state[2],   d   =   state[3],   x[16];
Decode   (x,   block,   64);
FF   (a,   b,   c,   d,   x[   0],   S11,   0xd76aa478);   /*   1   */
FF   (d,   a,   b,   c,   x[   1],   S12,   0xe8c7b756);   /*   2   */
FF   (c,   d,   a,   b,   x[   2],   S13,   0x242070db);   /*   3   */
FF   (b,   c,   d,   a,   x[   3],   S14,   0xc1bdceee);   /*   4   */
FF   (a,   b,   c,   d,   x[   4],   S11,   0xf57c0faf);   /*   5   */
FF   (d,   a,   b,   c,   x[   5],   S12,   0x4787c62a);   /*   6   */
FF   (c,   d,   a,   b,   x[   6],   S13,   0xa8304613);   /*   7   */
FF   (b,   c,   d,   a,   x[   7],   S14,   0xfd469501);   /*   8   */
FF   (a,   b,   c,   d,   x[   8],   S11,   0x698098d8);   /*   9   */
FF   (d,   a,   b,   c,   x[   9],   S12,   0x8b44f7af);   /*   10   */
FF   (c,   d,   a,   b,   x[10],   S13,   0xffff5bb1);   /*   11   */
FF   (b,   c,   d,   a,   x[11],   S14,   0x895cd7be);   /*   12   */
FF   (a,   b,   c,   d,   x[12],   S11,   0x6b901122);   /*   13   */
FF   (d,   a,   b,   c,   x[13],   S12,   0xfd987193);   /*   14   */
FF   (c,   d,   a,   b,   x[14],   S13,   0xa679438e);   /*   15   */
FF   (b,   c,   d,   a,   x[15],   S14,   0x49b40821);   /*   16   */
GG   (a,   b,   c,   d,   x[   1],   S21,   0xf61e2562);   /*   17   */
GG   (d,   a,   b,   c,   x[   6],   S22,   0xc040b340);   /*   18   */
GG   (c,   d,   a,   b,   x[11],   S23,   0x265e5a51);   /*   19   */
GG   (b,   c,   d,   a,   x[   0],   S24,   0xe9b6c7aa);   /*   20   */
GG   (a,   b,   c,   d,   x[   5],   S21,   0xd62f105d);   /*   21   */
GG   (d,   a,   b,   c,   x[10],   S22,     0x2441453);   /*   22   */
GG   (c,   d,   a,   b,   x[15],   S23,   0xd8a1e681);   /*   23   */
GG   (b,   c,   d,   a,   x[   4],   S24,   0xe7d3fbc8);   /*   24   */
GG   (a,   b,   c,   d,   x[   9],   S21,   0x21e1cde6);   /*   25   */
GG   (d,   a,   b,   c,   x[14],   S22,   0xc33707d6);   /*   26   */
GG   (c,   d,   a,   b,   x[   3],   S23,   0xf4d50d87);   /*   27   */
GG   (b,   c,   d,   a,   x[   8],   S24,   0x455a14ed);   /*   28   */
GG   (a,   b,   c,   d,   x[13],   S21,   0xa9e3e905);   /*   29   */
GG   (d,   a,   b,   c,   x[   2],   S22,   0xfcefa3f8);   /*   30   */
GG   (c,   d,   a,   b,   x[   7],   S23,   0x676f02d9);   /*   31   */
GG   (b,   c,   d,   a,   x[12],   S24,   0x8d2a4c8a);   /*   32   */
HH   (a,   b,   c,   d,   x[   5],   S31,   0xfffa3942);   /*   33   */
HH   (d,   a,   b,   c,   x[   8],   S32,   0x8771f681);   /*   34   */
HH   (c,   d,   a,   b,   x[11],   S33,   0x6d9d6122);   /*   35   */
HH   (b,   c,   d,   a,   x[14],   S34,   0xfde5380c);   /*   36   */
HH   (a,   b,   c,   d,   x[   1],   S31,   0xa4beea44);   /*   37   */
HH   (d,   a,   b,   c,   x[   4],   S32,   0x4bdecfa9);   /*   38   */
HH   (c,   d,   a,   b,   x[   7],   S33,   0xf6bb4b60);   /*   39   */
HH   (b,   c,   d,   a,   x[10],   S34,   0xbebfbc70);   /*   40   */
HH   (a,   b,   c,   d,   x[13],   S31,   0x289b7ec6);   /*   41   */
HH   (d,   a,   b,   c,   x[   0],   S32,   0xeaa127fa);   /*   42   */
HH   (c,   d,   a,   b,   x[   3],   S33,   0xd4ef3085);   /*   43   */
HH   (b,   c,   d,   a,   x[   6],   S34,     0x4881d05);   /*   44   */
HH   (a,   b,   c,   d,   x[   9],   S31,   0xd9d4d039);   /*   45   */
HH   (d,   a,   b,   c,   x[12],   S32,   0xe6db99e5);   /*   46   */
HH   (c,   d,   a,   b,   x[15],   S33,   0x1fa27cf8);   /*   47   */
HH   (b,   c,   d,   a,   x[   2],   S34,   0xc4ac5665);   /*   48   */
II   (a,   b,   c,   d,   x[   0],   S41,   0xf4292244);   /*   49   */
II   (d,   a,   b,   c,   x[   7],   S42,   0x432aff97);   /*   50   */
II   (c,   d,   a,   b,   x[14],   S43,   0xab9423a7);   /*   51   */
II   (b,   c,   d,   a,   x[   5],   S44,   0xfc93a039);   /*   52   */
II   (a,   b,   c,   d,   x[12],   S41,   0x655b59c3);   /*   53   */
II   (d,   a,   b,   c,   x[   3],   S42,   0x8f0ccc92);   /*   54   */
II   (c,   d,   a,   b,   x[10],   S43,   0xffeff47d);   /*   55   */
II   (b,   c,   d,   a,   x[   1],   S44,   0x85845dd1);   /*   56   */
II   (a,   b,   c,   d,   x[   8],   S41,   0x6fa87e4f);   /*   57   */
II   (d,   a,   b,   c,   x[15],   S42,   0xfe2ce6e0);   /*   58   */
II   (c,   d,   a,   b,   x[   6],   S43,   0xa3014314);   /*   59   */
II   (b,   c,   d,   a,   x[13],   S44,   0x4e0811a1);   /*   60   */
II   (a,   b,   c,   d,   x[   4],   S41,   0xf7537e82);   /*   61   */
II   (d,   a,   b,   c,   x[11],   S42,   0xbd3af235);   /*   62   */
II   (c,   d,   a,   b,   x[   2],   S43,   0x2ad7d2bb);   /*   63   */
II   (b,   c,   d,   a,   x[   9],   S44,   0xeb86d391);   /*   64   */
state[0]   +=   a;
state[1]   +=   b;
state[2]   +=   c;
state[3]   +=   d;
memset   ((POINTER)x,   0,   sizeof   (x));
}

inline   void   MD5Init(MD5_CTX   *context)
{
context->count[0]   =   context->count[1]   =   0;
context->state[0]   =   0x67452301;
context->state[1]   =   0xefcdab89;
context->state[2]   =   0x98badcfe;
context->state[3]   =   0x10325476;
}

inline   void   MD5Update(MD5_CTX   *context,   unsigned   char   *input,   unsigned   int   inputLen)
{
unsigned   int   i,   index,   partLen;

index   =   (unsigned   int)((context->count[0]   >>   3)   &   0x3F);
if   ((context->count[0]   +=   ((UINT4)inputLen   <<   3))
<   ((UINT4)inputLen   <<   3))
context->count[1]++;
context->count[1]   +=   ((UINT4)inputLen   >>   29);

partLen   =   64   -   index;

if   (inputLen   >=   partLen)   {
memcpy((POINTER)&context->buffer[index],   (POINTER)input,   partLen);
MD5Transform(context->state,   context->buffer);

for   (i   =   partLen;   i   +   63   <   inputLen;   i   +=   64)
MD5Transform   (context->state,   &input[i]);
index   =   0;
}
else
i   =   0;

memcpy((POINTER)&context->buffer[index],   (POINTER)&input[i],   inputLen-i);
}

inline   void   MD5Final(unsigned   char   digest[16],   MD5_CTX   *context)
{
unsigned   char   bits[8];
unsigned   int   index,   padLen;

Encode   (bits,   context->count,   8);
index   =   (unsigned   int)((context->count[0]   >>   3)   &   0x3f);
padLen   =   (index   <   56)   ?   (56   -   index)   :   (120   -   index);
MD5Update   (context,   PADDING,   padLen);
MD5Update   (context,   bits,   8);
Encode   (digest,   context->state,   16);
memset   ((POINTER)context,   0,   sizeof   (*context));
}

void   MD5Digest(char   *pszInput,   unsigned   long   nInputSize,   char   *pszOutPut)
{
MD5_CTX   context;
unsigned   int   len   =   strlen   (pszInput);

MD5Init   (&context);
MD5Update   (&context,   (unsigned   char   *)pszInput,   len);
MD5Final   ((unsigned   char   *)pszOutPut,   &context);
}

main()
{ char szDigest[16];
char encrypt[200];
printf("请输入要计算MD5值的字符串:");
gets(encrypt);
printf("\n加密结果:");
MD5Digest(encrypt,strlen(encrypt),szDigest);
int i;
for (i=0;i<16;i++) printf ("%02X",(unsigned char)szDigest[i]);
getchar();
}

//直接gcc 编译即可,无需添加任何库。


将买呢封装下:

char* md5encrypt(char* encrypt)
{
char szDigest[16]; char *Addr= szDigest ;

MD5Digest(encrypt,strlen(encrypt),szDigest);

printf("md5:%s\n",szDigest);

return Addr;
}
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