md5加密C

md5.c

#include<stdio.h>

#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 RL(x, y) (((x) << (y)) | ((x) >> (32 - (y))))  //x向左循环移y位

#define PP(x) (x<<24)|((x<<8)&0xff0000)|((x>>8)&0xff00)|(x>>24)  //将x高低位互换,例如PP(aabbccdd)=ddccbbaa

#define FF(a, b, c, d, x, s, ac) a = b + (RL((a + F(b,c,d) + x + ac),s))
#define GG(a, b, c, d, x, s, ac) a = b + (RL((a + G(b,c,d) + x + ac),s))
#define HH(a, b, c, d, x, s, ac) a = b + (RL((a + H(b,c,d) + x + ac),s))
#define II(a, b, c, d, x, s, ac) a = b + (RL((a + I(b,c,d) + x + ac),s))

unsigned A,B,C,D,a,b,c,d,i,len,flen[2],x[16];   //i临时变量,len文件长,flen[2]为64位二进制表示的文件初始长度
char filename[200];   //文件名
FILE *fp;

void md5(){                 //MD5核心算法,供64轮

  a=A,b=B,c=C,d=D;
  /**//* Round 1 */
  FF (a, b, c, d, x[ 0],  7, 0xd76aa478); /**//* 1 */
  FF (d, a, b, c, x[ 1], 12, 0xe8c7b756); /**//* 2 */
  FF (c, d, a, b, x[ 2], 17, 0x242070db); /**//* 3 */
  FF (b, c, d, a, x[ 3], 22, 0xc1bdceee); /**//* 4 */
  FF (a, b, c, d, x[ 4],  7, 0xf57c0faf); /**//* 5 */
  FF (d, a, b, c, x[ 5], 12, 0x4787c62a); /**//* 6 */
  FF (c, d, a, b, x[ 6], 17, 0xa8304613); /**//* 7 */
  FF (b, c, d, a, x[ 7], 22, 0xfd469501); /**//* 8 */
  FF (a, b, c, d, x[ 8],  7, 0x698098d8); /**//* 9 */
  FF (d, a, b, c, x[ 9], 12, 0x8b44f7af); /**//* 10 */
  FF (c, d, a, b, x[10], 17, 0xffff5bb1); /**//* 11 */
  FF (b, c, d, a, x[11], 22, 0x895cd7be); /**//* 12 */
  FF (a, b, c, d, x[12],  7, 0x6b901122); /**//* 13 */
  FF (d, a, b, c, x[13], 12, 0xfd987193); /**//* 14 */
  FF (c, d, a, b, x[14], 17, 0xa679438e); /**//* 15 */
  FF (b, c, d, a, x[15], 22, 0x49b40821); /**//* 16 */

/**//* Round 2 */
  GG (a, b, c, d, x[ 1],  5, 0xf61e2562); /**//* 17 */
  GG (d, a, b, c, x[ 6],  9, 0xc040b340); /**//* 18 */
  GG (c, d, a, b, x[11], 14, 0x265e5a51); /**//* 19 */
  GG (b, c, d, a, x[ 0], 20, 0xe9b6c7aa); /**//* 20 */
  GG (a, b, c, d, x[ 5],  5, 0xd62f105d); /**//* 21 */
  GG (d, a, b, c, x[10],  9, 0x02441453); /**//* 22 */
  GG (c, d, a, b, x[15], 14, 0xd8a1e681); /**//* 23 */
  GG (b, c, d, a, x[ 4], 20, 0xe7d3fbc8); /**//* 24 */
  GG (a, b, c, d, x[ 9],  5, 0x21e1cde6); /**//* 25 */
  GG (d, a, b, c, x[14],  9, 0xc33707d6); /**//* 26 */
  GG (c, d, a, b, x[ 3], 14, 0xf4d50d87); /**//* 27 */
  GG (b, c, d, a, x[ 8], 20, 0x455a14ed); /**//* 28 */
  GG (a, b, c, d, x[13],  5, 0xa9e3e905); /**//* 29 */
  GG (d, a, b, c, x[ 2],  9, 0xfcefa3f8); /**//* 30 */
  GG (c, d, a, b, x[ 7], 14, 0x676f02d9); /**//* 31 */
  GG (b, c, d, a, x[12], 20, 0x8d2a4c8a); /**//* 32 */

  /**//* Round 3 */
  HH (a, b, c, d, x[ 5],  4, 0xfffa3942); /**//* 33 */
  HH (d, a, b, c, x[ 8], 11, 0x8771f681); /**//* 34 */
  HH (c, d, a, b, x[11], 16, 0x6d9d6122); /**//* 35 */
  HH (b, c, d, a, x[14], 23, 0xfde5380c); /**//* 36 */
  HH (a, b, c, d, x[ 1],  4, 0xa4beea44); /**//* 37 */
  HH (d, a, b, c, x[ 4], 11, 0x4bdecfa9); /**//* 38 */
  HH (c, d, a, b, x[ 7], 16, 0xf6bb4b60); /**//* 39 */
  HH (b, c, d, a, x[10], 23, 0xbebfbc70); /**//* 40 */
  HH (a, b, c, d, x[13],  4, 0x289b7ec6); /**//* 41 */
  HH (d, a, b, c, x[ 0], 11, 0xeaa127fa); /**//* 42 */
  HH (c, d, a, b, x[ 3], 16, 0xd4ef3085); /**//* 43 */
  HH (b, c, d, a, x[ 6], 23, 0x04881d05); /**//* 44 */
  HH (a, b, c, d, x[ 9],  4, 0xd9d4d039); /**//* 45 */
  HH (d, a, b, c, x[12], 11, 0xe6db99e5); /**//* 46 */
  HH (c, d, a, b, x[15], 16, 0x1fa27cf8); /**//* 47 */
  HH (b, c, d, a, x[ 2], 23, 0xc4ac5665); /**//* 48 */

  /**//* Round 4 */
  II (a, b, c, d, x[ 0],  6, 0xf4292244); /**//* 49 */
  II (d, a, b, c, x[ 7], 10, 0x432aff97); /**//* 50 */
  II (c, d, a, b, x[14], 15, 0xab9423a7); /**//* 51 */
  II (b, c, d, a, x[ 5], 21, 0xfc93a039); /**//* 52 */
  II (a, b, c, d, x[12],  6, 0x655b59c3); /**//* 53 */
  II (d, a, b, c, x[ 3], 10, 0x8f0ccc92); /**//* 54 */
  II (c, d, a, b, x[10], 15, 0xffeff47d); /**//* 55 */
  II (b, c, d, a, x[ 1], 21, 0x85845dd1); /**//* 56 */
  II (a, b, c, d, x[ 8],  6, 0x6fa87e4f); /**//* 57 */
  II (d, a, b, c, x[15], 10, 0xfe2ce6e0); /**//* 58 */
  II (c, d, a, b, x[ 6], 15, 0xa3014314); /**//* 59 */
  II (b, c, d, a, x[13], 21, 0x4e0811a1); /**//* 60 */
  II (a, b, c, d, x[ 4],  6, 0xf7537e82); /**//* 61 */
  II (d, a, b, c, x[11], 10, 0xbd3af235); /**//* 62 */
  II (c, d, a, b, x[ 2], 15, 0x2ad7d2bb); /**//* 63 */
  II (b, c, d, a, x[ 9], 21, 0xeb86d391); /**//* 64 */

  A += a;
  B += b;
  C += c;
  D += d;

}

main(){
  while(1){
    printf("Input file:");
    gets(filename);    //用get函数,避免scanf以空格分割数据,
    if (filename[0]==34) filename[strlen(filename)-1]=0,strcpy(filename,filename+1);  //支持文件拖曳,但会多出双引号,这里是处理多余的双引号
    if (!strcmp(filename,"exit")) exit(0);  //输入exit退出
    if (!(fp=fopen(filename,"rb"))) {printf("Can not open this file!\n");continue;}  //以二进制打开文件
    fseek(fp, 0, SEEK_END);  //文件指针转到文件末尾
    if((len=ftell(fp))==-1) {printf("Sorry! Can not calculate files which larger than 2 GB!\n");fclose(fp);continue;}  //ftell函数返回long,最大为2GB,超出返回-1
    rewind(fp);  //文件指针复位到文件头
    A=0x67452301,B=0xefcdab89,C=0x98badcfe,D=0x10325476; //初始化链接变量
    flen[1]=len/0x20000000;     //flen单位是bit
    flen[0]=(len%0x20000000)*8;
    memset(x,0,64);   //初始化x数组为0
    fread(&x,4,16,fp);  //以4字节为一组,读取16组数据
    for(i=0;i<len/64;i++){    //循环运算直至文件结束
      md5();
      memset(x,0,64);
      fread(&x,4,16,fp);
    }
    ((char*)x)[len%64]=128;  //文件结束补1,补0操作,128二进制即10000000
    if(len%64>55) md5(),memset(x,0,64);
    memcpy(x+14,flen,8);    //文件末尾加入原文件的bit长度
    md5();
    fclose(fp);
    printf("MD5 Code:%08x%08x%08x%08x\n",PP(A),PP(B),PP(C),PP(D));  //高低位逆反输出
  }
}

 

 -----------------------------------------------  一分为二  -------------------------------------------------------------

 

网上找到的实现md5函数代码,包括一个头文件md5.h和一个源文件md5.c,用下面的测试代码test.c测试通过,各文件依次如下:

头文件md5.h

#ifndef MD5_H
#define MD5_H

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


#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 + ac; \
  a = ROTATE_LEFT(a,s); \
  a += b; \
}
#define GG(a,b,c,d,x,s,ac) \
{ \
  a += G(b,c,d) + x + ac; \
  a = ROTATE_LEFT(a,s); \
  a += b; \
}
#define HH(a,b,c,d,x,s,ac) \
{ \
  a += H(b,c,d) + x + ac; \
  a = ROTATE_LEFT(a,s); \
  a += b; \
}
#define II(a,b,c,d,x,s,ac) \
{ \
  a += I(b,c,d) + x + ac; \
  a = ROTATE_LEFT(a,s); \
  a += b; \
}
void MD5Init(MD5_CTX *context);
void MD5Update(MD5_CTX *context,unsigned char *input,unsigned int inputlen);
void MD5Final(MD5_CTX *context,unsigned char digest[16]);
void MD5Transform(unsigned int state[4],unsigned char block[64]);
void MD5Encode(unsigned char *output,unsigned int *input,unsigned int len);
void MD5Decode(unsigned int *output,unsigned char *input,unsigned int len);

#endif

 

源文件md5.c

#include <memory.h>
#include "md5.h"

unsigned char PADDING[]={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};

void MD5Init(MD5_CTX *context)
{
  context->count[0] = 0;
  context->count[1] = 0;
  context->state[0] = 0x67452301;
  context->state[1] = 0xEFCDAB89;
  context->state[2] = 0x98BADCFE;
  context->state[3] = 0x10325476;
}
void MD5Update(MD5_CTX *context,unsigned char *input,unsigned int inputlen)
{
  unsigned int i = 0,index = 0,partlen = 0;
  index = (context->count[0] >> 3) & 0x3F;
  partlen = 64 - index;
  context->count[0] += inputlen << 3;
  if(context->count[0] < (inputlen << 3))
  context->count[1]++;
  context->count[1] += inputlen >> 29;

  if(inputlen >= partlen)
  {
    memcpy(&context->buffer[index],input,partlen);
    MD5Transform(context->state,context->buffer);
    for(i = partlen;i+64 <= inputlen;i+=64)
    MD5Transform(context->state,&input[i]);
    index = 0;
  }
  else
  {
    i = 0;
  }
   memcpy(&context->buffer[index],&input[i],inputlen-i);
}
void MD5Final(MD5_CTX *context,unsigned char digest[16])
{
  unsigned int index = 0,padlen = 0;
  unsigned char bits[8];
  index = (context->count[0] >> 3) & 0x3F;
  padlen = (index < 56)?(56-index):(120-index);
  MD5Encode(bits,context->count,8);
  MD5Update(context,PADDING,padlen);
  MD5Update(context,bits,8);
  MD5Encode(digest,context->state,16);
}
void MD5Encode(unsigned char *output,unsigned int *input,unsigned int len)
{
  unsigned int i = 0,j = 0;
  while(j < len)
  {
    output[j] = input[i] & 0xFF;
    output[j+1] = (input[i] >> 8) & 0xFF;
    output[j+2] = (input[i] >> 16) & 0xFF;
    output[j+3] = (input[i] >> 24) & 0xFF;
    i++;
    j+=4;
  }
}
void MD5Decode(unsigned int *output,unsigned char *input,unsigned int len)
{
  unsigned int i = 0,j = 0;
  while(j < len)
  {
    output[i] = (input[j]) |
    (input[j+1] << 8) |
    (input[j+2] << 16) |
    (input[j+3] << 24);
    i++;
    j+=4;
   }
}
void MD5Transform(unsigned int state[4],unsigned char block[64])
{
  unsigned int a = state[0];
  unsigned int b = state[1];
  unsigned int c = state[2];
  unsigned int d = state[3];
  unsigned int x[64];
  MD5Decode(x,block,64);
  FF(a, b, c, d, x[ 0], 7, 0xd76aa478); /* 1 */
  FF(d, a, b, c, x[ 1], 12, 0xe8c7b756); /* 2 */
  FF(c, d, a, b, x[ 2], 17, 0x242070db); /* 3 */
  FF(b, c, d, a, x[ 3], 22, 0xc1bdceee); /* 4 */
  FF(a, b, c, d, x[ 4], 7, 0xf57c0faf); /* 5 */
  FF(d, a, b, c, x[ 5], 12, 0x4787c62a); /* 6 */
  FF(c, d, a, b, x[ 6], 17, 0xa8304613); /* 7 */
  FF(b, c, d, a, x[ 7], 22, 0xfd469501); /* 8 */
  FF(a, b, c, d, x[ 8], 7, 0x698098d8); /* 9 */
  FF(d, a, b, c, x[ 9], 12, 0x8b44f7af); /* 10 */
  FF(c, d, a, b, x[10], 17, 0xffff5bb1); /* 11 */
  FF(b, c, d, a, x[11], 22, 0x895cd7be); /* 12 */
  FF(a, b, c, d, x[12], 7, 0x6b901122); /* 13 */
  FF(d, a, b, c, x[13], 12, 0xfd987193); /* 14 */
  FF(c, d, a, b, x[14], 17, 0xa679438e); /* 15 */
  FF(b, c, d, a, x[15], 22, 0x49b40821); /* 16 */

  /* Round 2 */
  GG(a, b, c, d, x[ 1], 5, 0xf61e2562); /* 17 */
  GG(d, a, b, c, x[ 6], 9, 0xc040b340); /* 18 */
  GG(c, d, a, b, x[11], 14, 0x265e5a51); /* 19 */
  GG(b, c, d, a, x[ 0], 20, 0xe9b6c7aa); /* 20 */
  GG(a, b, c, d, x[ 5], 5, 0xd62f105d); /* 21 */
  GG(d, a, b, c, x[10], 9, 0x2441453); /* 22 */
  GG(c, d, a, b, x[15], 14, 0xd8a1e681); /* 23 */
  GG(b, c, d, a, x[ 4], 20, 0xe7d3fbc8); /* 24 */
  GG(a, b, c, d, x[ 9], 5, 0x21e1cde6); /* 25 */
  GG(d, a, b, c, x[14], 9, 0xc33707d6); /* 26 */
  GG(c, d, a, b, x[ 3], 14, 0xf4d50d87); /* 27 */
  GG(b, c, d, a, x[ 8], 20, 0x455a14ed); /* 28 */
  GG(a, b, c, d, x[13], 5, 0xa9e3e905); /* 29 */
  GG(d, a, b, c, x[ 2], 9, 0xfcefa3f8); /* 30 */
  GG(c, d, a, b, x[ 7], 14, 0x676f02d9); /* 31 */
  GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); /* 32 */

  /* Round 3 */
  HH(a, b, c, d, x[ 5], 4, 0xfffa3942); /* 33 */
  HH(d, a, b, c, x[ 8], 11, 0x8771f681); /* 34 */
  HH(c, d, a, b, x[11], 16, 0x6d9d6122); /* 35 */
  HH(b, c, d, a, x[14], 23, 0xfde5380c); /* 36 */
  HH(a, b, c, d, x[ 1], 4, 0xa4beea44); /* 37 */
  HH(d, a, b, c, x[ 4], 11, 0x4bdecfa9); /* 38 */
  HH(c, d, a, b, x[ 7], 16, 0xf6bb4b60); /* 39 */
  HH(b, c, d, a, x[10], 23, 0xbebfbc70); /* 40 */
  HH(a, b, c, d, x[13], 4, 0x289b7ec6); /* 41 */
  HH(d, a, b, c, x[ 0], 11, 0xeaa127fa); /* 42 */
  HH(c, d, a, b, x[ 3], 16, 0xd4ef3085); /* 43 */
  HH(b, c, d, a, x[ 6], 23, 0x4881d05); /* 44 */
  HH(a, b, c, d, x[ 9], 4, 0xd9d4d039); /* 45 */
  HH(d, a, b, c, x[12], 11, 0xe6db99e5); /* 46 */
  HH(c, d, a, b, x[15], 16, 0x1fa27cf8); /* 47 */
  HH(b, c, d, a, x[ 2], 23, 0xc4ac5665); /* 48 */

  /* Round 4 */
  II(a, b, c, d, x[ 0], 6, 0xf4292244); /* 49 */
  II(d, a, b, c, x[ 7], 10, 0x432aff97); /* 50 */
  II(c, d, a, b, x[14], 15, 0xab9423a7); /* 51 */
  II(b, c, d, a, x[ 5], 21, 0xfc93a039); /* 52 */
  II(a, b, c, d, x[12], 6, 0x655b59c3); /* 53 */
  II(d, a, b, c, x[ 3], 10, 0x8f0ccc92); /* 54 */
  II(c, d, a, b, x[10], 15, 0xffeff47d); /* 55 */
  II(b, c, d, a, x[ 1], 21, 0x85845dd1); /* 56 */
  II(a, b, c, d, x[ 8], 6, 0x6fa87e4f); /* 57 */
  II(d, a, b, c, x[15], 10, 0xfe2ce6e0); /* 58 */
  II(c, d, a, b, x[ 6], 15, 0xa3014314); /* 59 */
  II(b, c, d, a, x[13], 21, 0x4e0811a1); /* 60 */
  II(a, b, c, d, x[ 4], 6, 0xf7537e82); /* 61 */
  II(d, a, b, c, x[11], 10, 0xbd3af235); /* 62 */
  II(c, d, a, b, x[ 2], 15, 0x2ad7d2bb); /* 63 */
  II(b, c, d, a, x[ 9], 21, 0xeb86d391); /* 64 */
  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;
}

 

测试代码test.c

#include <stdio.h>
#include <stdlib.h>
#include "md5.h"

int main(int argc, char *argv[])
{
  int i;
  unsigned char encrypt[] ="admin";//21232f297a57a5a743894a0e4a801fc3
  unsigned char decrypt[16];
  MD5_CTX md5;
  MD5Init(&md5);
  MD5Update(&md5,encrypt,strlen((char *)encrypt));
  MD5Final(&md5,decrypt);
  printf("加密前:%s\n加密后:",encrypt);
  for(i=0;i<16;i++)
  {
    printf("%02x",decrypt[i]);
  }

  getchar();

  return 0;
}

 

posted on 2015-06-26 15:22  DayAfterDay  阅读(262)  评论(0编辑  收藏  举报

导航