C语言 MD5的源码实例详解

C语言 MD5源码

md5c.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 *context); 
void MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen); 
void MD5UpdaterString(MD5_CTX *context,const char *string); 
int MD5FileUpdateFile (MD5_CTX *context,char *filename); 
void MD5Final (unsigned char digest[16], MD5_CTX *context); 
void MDString (char *string,unsigned char digest[16]); 
int MD5File (char *filename,unsigned char digest[16]); 

md5c.c:

 
 
 
#include "md5c.h" 
#include  
#include  
 
 
 
 
#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 void MD5_memcpy (POINTER output, POINTER input, unsigned int len); 
static void MD5Transform (UINT4 state[4], unsigned char block[64]); 
static void Encode (unsigned char *output, UINT4 *input, unsigned int len); 
static void MD5_memset (POINTER output, int value, unsigned int len); 
static void Decode (UINT4 *output, unsigned char *input, unsigned int len); 
 
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);  
 } 
 
 
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; 
} 
 
 
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) { 
  MD5_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; 
 
  
 MD5_memcpy((POINTER)&context->buffer[index], (POINTER)&input[i],inputLen-i); 
} 
 
 
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); 
 
  
 MD5_memset ((POINTER)context, 0, sizeof (*context)); 
} 
 
 
static 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);  
 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756);  
 FF (c, d, a, b, x[ 2], S13, 0x242070db);  
 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee);  
 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf);  
 FF (d, a, b, c, x[ 5], S12, 0x4787c62a);  
 FF (c, d, a, b, x[ 6], S13, 0xa8304613);  
 FF (b, c, d, a, x[ 7], S14, 0xfd469501);  
 FF (a, b, c, d, x[ 8], S11, 0x698098d8);  
 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af);  
 FF (c, d, a, b, x[10], S13, 0xffff5bb1);  
 FF (b, c, d, a, x[11], S14, 0x895cd7be);  
 FF (a, b, c, d, x[12], S11, 0x6b901122);  
 FF (d, a, b, c, x[13], S12, 0xfd987193);  
 FF (c, d, a, b, x[14], S13, 0xa679438e);  
 FF (b, c, d, a, x[15], S14, 0x49b40821);  
 
  
 GG (a, b, c, d, x[ 1], S21, 0xf61e2562);  
 GG (d, a, b, c, x[ 6], S22, 0xc040b340);  
 GG (c, d, a, b, x[11], S23, 0x265e5a51);  
 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa);  
 GG (a, b, c, d, x[ 5], S21, 0xd62f105d);  
 GG (d, a, b, c, x[10], S22, 0x2441453);  
 GG (c, d, a, b, x[15], S23, 0xd8a1e681);  
 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8);  
 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6);  
 GG (d, a, b, c, x[14], S22, 0xc33707d6);  
 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87);  
 GG (b, c, d, a, x[ 8], S24, 0x455a14ed);  
 GG (a, b, c, d, x[13], S21, 0xa9e3e905);  
 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8);  
 GG (c, d, a, b, x[ 7], S23, 0x676f02d9);  
 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a);  
 
  
 HH (a, b, c, d, x[ 5], S31, 0xfffa3942);  
 HH (d, a, b, c, x[ 8], S32, 0x8771f681);  
 HH (c, d, a, b, x[11], S33, 0x6d9d6122);  
 HH (b, c, d, a, x[14], S34, 0xfde5380c);  
 HH (a, b, c, d, x[ 1], S31, 0xa4beea44);  
 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9);  
 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60);  
 HH (b, c, d, a, x[10], S34, 0xbebfbc70);  
 HH (a, b, c, d, x[13], S31, 0x289b7ec6);  
 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa);  
 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085);  
 HH (b, c, d, a, x[ 6], S34, 0x4881d05);  
 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039);  
 HH (d, a, b, c, x[12], S32, 0xe6db99e5);  
 HH (c, d, a, b, x[15], S33, 0x1fa27cf8);  
 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665);  
 
  
 II (a, b, c, d, x[ 0], S41, 0xf4292244);  
 II (d, a, b, c, x[ 7], S42, 0x432aff97);  
 II (c, d, a, b, x[14], S43, 0xab9423a7);  
 II (b, c, d, a, x[ 5], S44, 0xfc93a039);  
 II (a, b, c, d, x[12], S41, 0x655b59c3);  
 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92);  
 II (c, d, a, b, x[10], S43, 0xffeff47d);  
 II (b, c, d, a, x[ 1], S44, 0x85845dd1);  
 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f);  
 II (d, a, b, c, x[15], S42, 0xfe2ce6e0);  
 II (c, d, a, b, x[ 6], S43, 0xa3014314);  
 II (b, c, d, a, x[13], S44, 0x4e0811a1);  
 II (a, b, c, d, x[ 4], S41, 0xf7537e82);  
 II (d, a, b, c, x[11], S42, 0xbd3af235);  
 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb);  
 II (b, c, d, a, x[ 9], S44, 0xeb86d391);  
 
 state[0] += a; 
 state[1] += b; 
 state[2] += c; 
 state[3] += d; 
 
  
 MD5_memset ((POINTER)x, 0, sizeof (x)); 
} 
 
 
static 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); 
 } 
} 
 
 
static 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); 
} 
 
 
 
static void MD5_memcpy (POINTER output, POINTER input, unsigned int len) 
{ 
 unsigned int i; 
 
 for (i = 0; i < len; i++) 
  output[i] = input[i]; 
} 
 
 
static void MD5_memset (POINTER output, int value, unsigned int len) 
{ 
 unsigned int i; 
 
 for (i = 0; i < len; i++) 
  ((char *)output)[i] = (char)value; 
} 
 
void MDString (char *string,unsigned char digest[16]) 
{ 
 MD5_CTX context; 
 unsigned int len = strlen (string); 
 
 MD5Init (&context); 
 MD5Update (&context, (unsigned char *)string, len); 
 MD5Final (digest, &context); 
} 
 
int MD5File (char *filename,unsigned char digest[16]) 
{ 
 FILE *file; 
 MD5_CTX context; 
 int len; 
 unsigned char buffer[1024]; 
 
 if ((file = fopen (filename, "rb")) == NULL) 
  return -1; 
 else { 
  MD5Init (&context); 
  while (len = fread (buffer, 1, 1024, file)) 
   MD5Update (&context, buffer, len); 
  MD5Final (digest, &context); 
 
  fclose (file); 
 } 
 return 0; 
} 
void MD5UpdaterString(MD5_CTX *context,const char *string) 
{ 
 unsigned int len = strlen (string); 
 MD5Update (context, (unsigned char *)string, len); 
} 
int MD5FileUpdateFile (MD5_CTX *context,char *filename) 
{ 
 FILE *file; 
 int len; 
 unsigned char buffer[1024]; 
 
 if ((file = fopen (filename, "rb")) == NULL) 
  return -1; 
 else { 
  while (len = fread (buffer, 1, 1024, file)) 
   MD5Update (context, buffer, len); 
  fclose (file); 
 } 
 return 0; 
} 

用法:

void main(void) 
{ 
  unsigned char digest[16]; //存放结果 
 
  //第一种用法: 
 
  MD5_CTX md5c; 
  MD5Init(&md5c); //初始化 
  MD5UpdaterString(&md5c,"你要测试的字符串"); 
  MD5FileUpdateFile(&md5c,"你要测试的文件路径"); 
  MD5Final(digest,&md5c); 
 
  //第二种用法: 
  MDString("你要测试的字符串",digest); //直接输入字符串并得出结果 
 
 //第三种用法: 
 MD5File("你要测试的文件路径",digest); //直接输入文件路径并得出结果 
} 

相关文章：

C++ MD5源码：https://www.jb51.net/article/103113.htm

C语言 MD5源码：https://www.jb51.net/article/103108.htm

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