C语言实现MD5校验

根据网上资料，整理验证C程序代码。

接口函数：

1 /******************************************************
2 *函数名称:Compute_data_md5
3 *输   入:data 校验数据首地址
4         len 校验数据长度
5         md5_str 字符串形式的MD5值
6 *输   出:无
7 *功   能:计算数据MD5值，并以字符串形式返回
8 *******************************************************/
9 int Compute_data_md5(unsigned char *data, unsigned int len,unsigned char *md5_str)
View Code

MD5.h 的内容：

 1 #ifndef _MD5_H_
 2 #define _MD5_H_
 3 
 4 #define MD5_SIZE        16
 5 #define MD5_STR_LEN        (MD5_SIZE * 2)
 6 
 7 typedef struct
 8 {
 9   unsigned int count[2];
10   unsigned int state[4];
11   unsigned char buffer[64];   
12 } MD5_CTX;
13 
14 #define F(x,y,z) ((x & y) | (~x & z))
15 #define G(x,y,z) ((x & z) | (y & ~z))
16 #define H(x,y,z) (x^y^z)
17 #define I(x,y,z) (y ^ (x | ~z))
18 #define ROTATE_LEFT(x,n) ((x << n) | (x >> (32-n)))
19 
20 #define FF(a,b,c,d,x,s,ac) \
21 { \
22   a += F(b,c,d) + x + ac; \
23   a = ROTATE_LEFT(a,s); \
24   a += b; \
25 }
26 #define GG(a,b,c,d,x,s,ac) \
27 { \
28   a += G(b,c,d) + x + ac; \
29   a = ROTATE_LEFT(a,s); \
30   a += b; \
31 }
32 #define HH(a,b,c,d,x,s,ac) \
33 { \
34   a += H(b,c,d) + x + ac; \
35   a = ROTATE_LEFT(a,s); \
36   a += b; \
37 }
38 #define II(a,b,c,d,x,s,ac) \
39 { \
40   a += I(b,c,d) + x + ac; \
41   a = ROTATE_LEFT(a,s); \
42   a += b; \
43 }                                            
44 void MD5Init(MD5_CTX *context);
45 void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputlen);
46 void MD5Final(MD5_CTX *context, unsigned char digest[16]);
47 void MD5Transform(unsigned int state[4], unsigned char block[64]);
48 void MD5Encode(unsigned char *output, unsigned int *input, unsigned int len);
49 void MD5Decode(unsigned int *output, unsigned char *input, unsigned int len);
50 
51 int Compute_data_md5(unsigned char *data, unsigned int len,unsigned char *md5_str);
52 
53 #endif
View Code

MD5.c 的内容：

  1 #include "md5.h"
  2 #include <memory.h>
  3 #include <stdio.h>
  4 
  5 unsigned char PADDING[] =
  6 {
  7   0x80,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  8   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  9   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 10   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 11 };
 12 
 13 void MD5Init(MD5_CTX *context)
 14 {
 15   context->count[0] = 0;
 16   context->count[1] = 0;
 17   context->state[0] = 0x67452301;
 18   context->state[1] = 0xEFCDAB89;
 19   context->state[2] = 0x98BADCFE;
 20   context->state[3] = 0x10325476;
 21 }
 22 
 23 void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputlen)
 24 {
 25   unsigned int i = 0;
 26   unsigned int index = 0;
 27   unsigned int partlen = 0;
 28 
 29   index = (context->count[0] >> 3) & 0x3F;
 30   partlen = 64 - index;
 31   context->count[0] += inputlen << 3;
 32 
 33   if(context->count[0] < (inputlen << 3))
 34     context->count[1]++;
 35   context->count[1] += inputlen >> 29;
 36 
 37   if(inputlen >= partlen)
 38   {
 39     memcpy(&context->buffer[index], input,partlen);
 40     MD5Transform(context->state, context->buffer);
 41 
 42     for(i = partlen; i+64 <= inputlen; i+=64)
 43       MD5Transform(context->state, &input[i]);
 44 
 45     index = 0;        
 46   }  
 47   else
 48   {
 49     i = 0;
 50   }
 51   memcpy(&context->buffer[index], &input[i], inputlen-i);
 52 }
 53 
 54 void MD5Final(MD5_CTX *context, unsigned char digest[16])
 55 {
 56   unsigned int index = 0,padlen = 0;
 57   unsigned char bits[8];
 58 
 59   index = (context->count[0] >> 3) & 0x3F;
 60   padlen = (index < 56)?(56-index):(120-index);
 61   MD5Encode(bits, context->count, 8);
 62   MD5Update(context, PADDING, padlen);
 63   MD5Update(context, bits, 8);
 64   MD5Encode(digest, context->state, 16);
 65 }
 66 
 67 void MD5Encode(unsigned char *output,unsigned int *input,unsigned int len)
 68 {
 69   unsigned int i = 0;
 70   unsigned int j = 0;
 71 
 72   while(j < len)
 73   {
 74     output[j] = input[i] & 0xFF;  
 75     output[j+1] = (input[i] >> 8) & 0xFF;
 76     output[j+2] = (input[i] >> 16) & 0xFF;
 77     output[j+3] = (input[i] >> 24) & 0xFF;
 78     i++;
 79     j += 4;
 80   }
 81 }
 82 
 83 void MD5Decode(unsigned int *output, unsigned char *input, unsigned int len)
 84 {
 85   unsigned int i = 0;
 86   unsigned int j = 0;
 87 
 88   while(j < len)
 89   {
 90     output[i] = (input[j]) |
 91       (input[j+1] << 8) |
 92       (input[j+2] << 16) |
 93       (input[j+3] << 24);
 94     i++;
 95     j += 4; 
 96   }
 97 }
 98 
 99 void MD5Transform(unsigned int state[4], unsigned char block[64])
100 {
101   unsigned int a = state[0];
102   unsigned int b = state[1];
103   unsigned int c = state[2];
104   unsigned int d = state[3];
105   unsigned int x[64];
106 
107   MD5Decode(x,block,64);
108 
109   FF(a, b, c, d, x[ 0], 7, 0xd76aa478); /* 1 */
110   FF(d, a, b, c, x[ 1], 12, 0xe8c7b756); /* 2 */
111   FF(c, d, a, b, x[ 2], 17, 0x242070db); /* 3 */
112   FF(b, c, d, a, x[ 3], 22, 0xc1bdceee); /* 4 */
113   FF(a, b, c, d, x[ 4], 7, 0xf57c0faf); /* 5 */
114   FF(d, a, b, c, x[ 5], 12, 0x4787c62a); /* 6 */
115   FF(c, d, a, b, x[ 6], 17, 0xa8304613); /* 7 */
116   FF(b, c, d, a, x[ 7], 22, 0xfd469501); /* 8 */
117   FF(a, b, c, d, x[ 8], 7, 0x698098d8); /* 9 */
118   FF(d, a, b, c, x[ 9], 12, 0x8b44f7af); /* 10 */
119   FF(c, d, a, b, x[10], 17, 0xffff5bb1); /* 11 */
120   FF(b, c, d, a, x[11], 22, 0x895cd7be); /* 12 */
121   FF(a, b, c, d, x[12], 7, 0x6b901122); /* 13 */
122   FF(d, a, b, c, x[13], 12, 0xfd987193); /* 14 */
123   FF(c, d, a, b, x[14], 17, 0xa679438e); /* 15 */
124   FF(b, c, d, a, x[15], 22, 0x49b40821); /* 16 */
125 
126   /* Round 2 */
127   GG(a, b, c, d, x[ 1], 5, 0xf61e2562); /* 17 */
128   GG(d, a, b, c, x[ 6], 9, 0xc040b340); /* 18 */
129   GG(c, d, a, b, x[11], 14, 0x265e5a51); /* 19 */
130   GG(b, c, d, a, x[ 0], 20, 0xe9b6c7aa); /* 20 */
131   GG(a, b, c, d, x[ 5], 5, 0xd62f105d); /* 21 */
132   GG(d, a, b, c, x[10], 9,  0x2441453); /* 22 */
133   GG(c, d, a, b, x[15], 14, 0xd8a1e681); /* 23 */
134   GG(b, c, d, a, x[ 4], 20, 0xe7d3fbc8); /* 24 */
135   GG(a, b, c, d, x[ 9], 5, 0x21e1cde6); /* 25 */
136   GG(d, a, b, c, x[14], 9, 0xc33707d6); /* 26 */
137   GG(c, d, a, b, x[ 3], 14, 0xf4d50d87); /* 27 */
138   GG(b, c, d, a, x[ 8], 20, 0x455a14ed); /* 28 */
139   GG(a, b, c, d, x[13], 5, 0xa9e3e905); /* 29 */
140   GG(d, a, b, c, x[ 2], 9, 0xfcefa3f8); /* 30 */
141   GG(c, d, a, b, x[ 7], 14, 0x676f02d9); /* 31 */
142   GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); /* 32 */
143 
144   /* Round 3 */
145   HH(a, b, c, d, x[ 5], 4, 0xfffa3942); /* 33 */
146   HH(d, a, b, c, x[ 8], 11, 0x8771f681); /* 34 */
147   HH(c, d, a, b, x[11], 16, 0x6d9d6122); /* 35 */
148   HH(b, c, d, a, x[14], 23, 0xfde5380c); /* 36 */
149   HH(a, b, c, d, x[ 1], 4, 0xa4beea44); /* 37 */
150   HH(d, a, b, c, x[ 4], 11, 0x4bdecfa9); /* 38 */
151   HH(c, d, a, b, x[ 7], 16, 0xf6bb4b60); /* 39 */
152   HH(b, c, d, a, x[10], 23, 0xbebfbc70); /* 40 */
153   HH(a, b, c, d, x[13], 4, 0x289b7ec6); /* 41 */
154   HH(d, a, b, c, x[ 0], 11, 0xeaa127fa); /* 42 */
155   HH(c, d, a, b, x[ 3], 16, 0xd4ef3085); /* 43 */
156   HH(b, c, d, a, x[ 6], 23,  0x4881d05); /* 44 */
157   HH(a, b, c, d, x[ 9], 4, 0xd9d4d039); /* 45 */
158   HH(d, a, b, c, x[12], 11, 0xe6db99e5); /* 46 */
159   HH(c, d, a, b, x[15], 16, 0x1fa27cf8); /* 47 */
160   HH(b, c, d, a, x[ 2], 23, 0xc4ac5665); /* 48 */
161 
162   /* Round 4 */
163   II(a, b, c, d, x[ 0], 6, 0xf4292244); /* 49 */
164   II(d, a, b, c, x[ 7], 10, 0x432aff97); /* 50 */
165   II(c, d, a, b, x[14], 15, 0xab9423a7); /* 51 */
166   II(b, c, d, a, x[ 5], 21, 0xfc93a039); /* 52 */
167   II(a, b, c, d, x[12], 6, 0x655b59c3); /* 53 */
168   II(d, a, b, c, x[ 3], 10, 0x8f0ccc92); /* 54 */
169   II(c, d, a, b, x[10], 15, 0xffeff47d); /* 55 */
170   II(b, c, d, a, x[ 1], 21, 0x85845dd1); /* 56 */
171   II(a, b, c, d, x[ 8], 6, 0x6fa87e4f); /* 57 */
172   II(d, a, b, c, x[15], 10, 0xfe2ce6e0); /* 58 */
173   II(c, d, a, b, x[ 6], 15, 0xa3014314); /* 59 */
174   II(b, c, d, a, x[13], 21, 0x4e0811a1); /* 60 */
175   II(a, b, c, d, x[ 4], 6, 0xf7537e82); /* 61 */
176   II(d, a, b, c, x[11], 10, 0xbd3af235); /* 62 */
177   II(c, d, a, b, x[ 2], 15, 0x2ad7d2bb); /* 63 */
178   II(b, c, d, a, x[ 9], 21, 0xeb86d391); /* 64 */
179   state[0] += a;
180   state[1] += b;
181   state[2] += c;
182   state[3] += d;
183 }
184 
185 
186 /******************************************************
187 *函数名称:Compute_data_md5
188 *输   入:data 校验数据首地址
189         len 校验数据长度
190         md5_str 字符串形式的MD5值
191 *输   出:无
192 *功   能:计算数据MD5值，并以字符串形式返回
193 *******************************************************/
194 int Compute_data_md5(unsigned char *data, unsigned int len,unsigned char *md5_str)
195 {
196     unsigned char md5_value[MD5_SIZE];
197     unsigned int i = 0;
198     
199     MD5_CTX md5;
200     
201     MD5Init(&md5);
202     MD5Update(&md5, data, len);
203     MD5Final(&md5, md5_value);
204     for(i = 0; i < MD5_SIZE; i++)
205     {
206         snprintf(md5_str + i*2, 2+1, "%02x", md5_value[i]);
207     }
208     md5_str[MD5_STR_LEN] = '\0'; // add end
209 }
210 
211 #if 0
212 int Compute_file_md5(const char *file_path, char *md5_str)
213 {
214   int i;
215   int fd;
216   int ret;
217   unsigned char data[READ_DATA_SIZE];
218   unsigned char md5_value[MD5_SIZE];
219   MD5_CTX md5;
220 
221   fd = open(file_path, O_RDONLY);
222   if (-1 == fd)
223   {
224     perror("open");
225     return -1;
226   }
227 
228   // init md5
229   MD5Init(&md5);
230 
231   while (1)
232   {
233     ret = read(fd, data, READ_DATA_SIZE);
234     if (-1 == ret)
235     {
236       perror("read");
237       return -1;
238     }
239 
240     MD5Update(&md5, data, ret);
241 
242     if (0 == ret || ret < READ_DATA_SIZE)
243     {
244       break;
245     }
246   }
247 
248   close(fd);
249 
250   MD5Final(&md5, md5_value);
251 
252   for(i = 0; i < MD5_SIZE; i++)
253   {
254     snprintf(md5_str + i*2, 2+1, "%02x", md5_value[i]);
255   }
256   md5_str[MD5_STR_LEN] = '\0'; // add end
257 
258   return 0;
259 }
260 #endif
View Code

 

posted @ 2016-07-05 14:04  emlslxl  阅读(1636)  评论(0)  编辑  收藏  举报