Linux下C语言计算文件的md5值（转）

代码直接可用，更改一下文件路径及名称即可

如果是字符串，则只需调用MD5Update这个函数即可

感谢原创作者
http://www.tuicool.com/articles/jYB77n

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <memory.h>#define READ_DATA_SIZE  1024#define MD5_SIZE        16#define MD5_STR_LEN     (MD5_SIZE * 2)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; \}  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 MD5Decode(unsigned int *output, unsigned char *input, unsigned int len){  unsigned int i = 0;  unsigned int 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;}void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputlen){  unsigned int i = 0;  unsigned int index = 0;  unsigned int 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 MD5Encode(unsigned char *output,unsigned int *input,unsigned int len){  unsigned int i = 0;  unsigned int 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 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);}int Compute_file_md5(const char *file_path, char *md5_str){  int i;  int fd;  int ret;  unsigned char data[READ_DATA_SIZE];  unsigned char md5_value[MD5_SIZE];  MD5_CTX md5;  fd = open(file_path, O_RDONLY);  if (-1 == fd)  {    perror("open");    return -1;  }  // init md5  MD5Init(&md5);  while (1)  {    ret = read(fd, data, READ_DATA_SIZE);    if (-1 == ret)    {      perror("read");      return -1;    }    MD5Update(&md5, data, ret);    if (0 == ret || ret < READ_DATA_SIZE)    {      break;    }  }  close(fd);  MD5Final(&md5, md5_value);  for(i = 0; i < MD5_SIZE; i++)  {    snprintf(md5_str + i*2, 2+1, "%02x", md5_value[i]);  }  md5_str[MD5_STR_LEN] = '\0'; // add end  return 0;}int main(int argc, char *argv[]){  int ret;  const char *file_path = "xshell-1.1.exe";  char md5_str[MD5_STR_LEN + 1];  ret = Compute_file_md5(file_path, md5_str);  if (0 == ret)  {    printf("[file - %s] md5 value:\n", file_path);    printf("%s\n", md5_str);  }  return 0;}

该代码与md5sum及openssl md5 进行比较