工作中需要对网络传输的二进制配置文件进行md5运算生成校验码，以避免在网络传输中，文件的内容发生损坏和篡改。过程中大致是这样的：
1.服务端c++，请求端java；
2.请求端POST请求服务器上的某个文件，要求传输到请求端；
3.向服务端请求文件时，服务端需要对要传输的文件内容作md5加密，生成32字符校验码，将校验码作为http头信息字段传输到请求端；
4.请求端对传过来的文件也进行MD5加密，生成的校验码和服务器传来的做比较，相同即保证了数据的完整性和合法性，并对内容进行处理，否则，丢弃。
遇到的问题：需要保证请求端和服务器的md5算法一致，而往往C++和java的md5算法有多种，这里我们采用C++依照java的md5算法来实现，即用与java的MD5算法一致的C++算法来解决。
代码链接来源：http://blog.csdn.net/beyondhaven/article/details/8275110（谢谢BeyondHaven^_^）
MD5.h
1 #ifndef _DMSUTIL_H
2 #define _DMSUTIL_H
3 #ifdef __cplusplus
4 extern "C" {
5 #endif
6 /*————————————————————————.
7 | md5 encrypt function
8 .————————————————————————*/
9 void EncryptMD5(unsigned char *output, unsigned char *input);
10 void EncryptMD5str(char *output, unsigned char *input, int len);
11 /*————————————————————————.
12 | hash encrypt function
13 .————————————————————————*/
14 void EncryptHash(char *crypt, char *source);
15 /*————————————————————————.
16 | DES encrypt and decrypt function
17 .————————————————————————*/
18 void EncryptDes(unsigned char *source, unsigned char *encrypt);
19 void DecryptDes(unsigned char *encrypt, unsigned char *source);
20 #ifdef __cplusplus
21 }
22 #endif
23 #endif
MD5.cpp
1 #include <stdio.h>
2 #include <string.h>
3 #include "MD5Encrypt.h"
4 /*MD5 context*/
5 typedef struct MD5_CTX_S{
6 unsigned int state[4];
7 unsigned int count[2];
8 char buffer[64];
9 }MD5_CTX;
10
11 static unsigned char digest[16];
12 /*MD5 initialization*/
13 static void MD5Init(MD5_CTX *);
14 /*MD5 block update operation*/
15 static void MD5Update(MD5_CTX *, unsigned char *, unsigned int);
16 /*Ends an MD5 message-digest operation*/
17 static void MD5Final(unsigned char [16], MD5_CTX *);
18 /*MD5 padding*/
19 static void __md5_Pad (MD5_CTX *);
20 /*MD5 basic transformation*/
21 static void __md5_Transform (unsigned int [4], unsigned char [64]);
22 #ifdef i386
23 #define __md5_Encode memcpy
24 #define __md5_Decode memcpy
25 #else /* i386 */
26 /*
27 * __md5_Encodes input (u_int32_t) into output (unsigned char). Assumes len is
28 * a multiple of 4.
29 */
30 static void
31 __md5_Encode (unsigned char *output, unsigned int *input, unsigned int len)
32 {
33 unsigned int i, j;
34 for (i = 0, j = 0; j < len; i++, j += 4) {
35 output[j] = (unsigned char)(input[i] & 0xff);
36 output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
37 output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
38 output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
39 }
40 }
41 /*
42 * __md5_Decodes input (unsigned char) into output (u_int32_t). Assumes len is
43 * a multiple of 4.
44 */
45 static void
46 __md5_Decode (unsigned int *output, unsigned char *input, unsigned int len)
47 {
48 unsigned int i, j;
49 for (i = 0, j = 0; j < len; i++, j += 4)
50 output[i] = ((unsigned int)input[j]) | (((unsigned int)input[j+1]) << 8) |
51 (((unsigned int)input[j+2]) << 16) | (((unsigned int)input[j+3]) << 24);
52 }
53 #endif /* i386 */
54 /* F, G, H and I are basic MD5 functions. */
55 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
56 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
57 #define H(x, y, z) ((x) ^ (y) ^ (z))
58 #define I(x, y, z) ((y) ^ ((x) | (~z)))
59 /* ROTATE_LEFT rotates x left n bits. */
60 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
61 /*
62 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
63 * Rotation is separate from addition to prevent recomputation.
64 */
65 #define FF(a, b, c, d, x, s, ac) { 66 (a) += F ((b), (c), (d)) + (x) + (unsigned int)(ac); 67 (a) = ROTATE_LEFT ((a), (s)); 68 (a) += (b); 69 }
70 #define GG(a, b, c, d, x, s, ac) { 71 (a) += G ((b), (c), (d)) + (x) + (unsigned int)(ac); 72 (a) = ROTATE_LEFT ((a), (s)); 73 (a) += (b); 74 }
75 #define HH(a, b, c, d, x, s, ac) { 76 (a) += H ((b), (c), (d)) + (x) + (unsigned int)(ac); 77 (a) = ROTATE_LEFT ((a), (s)); 78 (a) += (b); 79 }
80 #define II(a, b, c, d, x, s, ac) { 81 (a) += I ((b), (c), (d)) + (x) + (unsigned int)(ac); 82 (a) = ROTATE_LEFT ((a), (s)); 83 (a) += (b); 84 }
85 /* MD5 initialization. Begins an MD5 operation, writing a new context. */
86 static void MD5Init (MD5_CTX *context)
87 {
88 context->count[0] = context->count[1] = 0;
89 /* Load magic initialization constants. */
90 context->state[0] = 0x67452301;
91 context->state[1] = 0xefcdab89;
92 context->state[2] = 0x98badcfe;
93 context->state[3] = 0x10325476;
94 }
95 /*
96 * MD5 block update operation. Continues an MD5 message-digest
97 * operation, processing another message block, and updating the
98 * context.
99 */
100 static void MD5Update ( MD5_CTX *context, unsigned char *input, unsigned int inputLen)
101 {
102 unsigned int i, index, partLen;
103 /* Compute number of bytes mod 64 */
104 index = (unsigned int)((context->count[0] >> 3) & 0x3F);
105 /* Update number of bits */
106 if ((context->count[0] += ((unsigned int)inputLen << 3))
107 < ((unsigned int)inputLen << 3))
108 context->count[1]++;
109 context->count[1] += ((unsigned int)inputLen >> 29);
110 partLen = 64 -index;
111 /* Transform as many times as possible. */
112 if (inputLen >= partLen) {
113 memcpy((void *)&context->buffer[index], (const void *)input,
114 partLen);
115 __md5_Transform (context->state, (unsigned char*)context->buffer);
116 for (i = partLen; i + 63 < inputLen; i += 64)
117 __md5_Transform (context->state, &input[i]);
118 index = 0;
119 }
120 else
121 i = 0;
122 /* Buffer remaining input */
123 memcpy ((void *)&context->buffer[index], (const void *)&input[i],
124 inputLen-i);
125 }
126 /*
127 * MD5 padding. Adds padding followed by original length.
128 */
129 static void __md5_Pad ( MD5_CTX *context)
130 {
131 unsigned char bits[8];
132 unsigned int index, padLen;
133 unsigned char PADDING[64];
134 memset(PADDING, 0, sizeof(PADDING));
135 PADDING[0] = 0x80;
136 /* Save number of bits */
137 __md5_Encode (bits, context->count, 8);
138 /* Pad out to 56 mod 64. */
139 index = (unsigned int)((context->count[0] >> 3) & 0x3f);
140 padLen = (index < 56) ? (56 - index) : (120 - index);
141 MD5Update (context, PADDING, padLen);
142 /* Append length (before padding) */
143 MD5Update (context, bits, 8);
144 }
145 /*
146 * MD5 finalization. Ends an MD5 message-digest operation, writing the
147 * the message digest and zeroizing the context.
148 */
149 static void MD5Final ( unsigned char digest[16], MD5_CTX *context)
150 {
151 /* Do padding. */
152 __md5_Pad (context);
153 /* Store state in digest */
154 __md5_Encode (digest, context->state, 16);
155 /* Zeroize sensitive information. */
156 memset ((void *)context, 0, sizeof (*context));
157 }
158 /* MD5 basic transformation. Transforms state based on block. */
159 static void
160 __md5_Transform (unsigned int state[4], unsigned char block[64])
161 {
162 unsigned int a, b, c, d, x[16];
163 a=state[0];
164 b=state[1];
165 c=state[2];
166 d=state[3];
167 __md5_Decode (x, block, 64);
168 /* Round 1 */
169 #define S11 7
170 #define S12 12
171 #define S13 17
172 #define S14 22
173 FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
174 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
175 FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
176 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
177 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
178 FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
179 FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
180 FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
181 FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
182 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
183 FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
184 FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
185 FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
186 FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
187 FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
188 FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
189 /* Round 2 */
190 #define S21 5
191 #define S22 9
192 #define S23 14
193 #define S24 20
194 GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
195 GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
196 GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
197 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
198 GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
199 GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
200 GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
201 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
202 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
203 GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
204 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
205 GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
206 GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
207 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
208 GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
209 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
210 /* Round 3 */
211 #define S31 4
212 #define S32 11
213 #define S33 16
214 #define S34 23
215 HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
216 HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
217 HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
218 HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
219 HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
220 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
221 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
222 HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
223 HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
224 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
225 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
226 HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
227 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
228 HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
229 HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
230 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
231 /* Round 4 */
232 #define S41 6
233 #define S42 10
234 #define S43 15
235 #define S44 21
236 II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
237 II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
238 II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
239 II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
240 II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
241 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
242 II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
243 II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
244 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
245 II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
246 II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
247 II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
248 II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
249 II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
250 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
251 II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
252 state[0] += a;
253 state[1] += b;
254 state[2] += c;
255 state[3] += d;
256 /* Zeroize sensitive information. */
257 memset ((void *)x, 0, sizeof (x));
258 }
259 void EncryptMD5(unsigned char *output, unsigned char *input)
260 {
261 MD5_CTX context;
262 MD5Init(&context);
263 MD5Update(&context, input, (unsigned int)strlen((char *)input));
264 MD5Final(output, &context);
265 return;
266 }
267 void EncryptMD5str(char *output, unsigned char *input, int len)
268 {
269 unsigned char strcrypt[16];
270 int i;
271 MD5_CTX context;
272 MD5Init(&context);
273 MD5Update(&context, input, len);
274 MD5Final(strcrypt, &context);
275 for (i=0; i < 16; i++)
276 sprintf(&output[i*2], "%02x", strcrypt[i]);
277 return;
278 }
测试用例
1 int main(int argc, char **argv)
2 {
3 int content_source_len = 0;
4 char* source_content = NULL;
5 FILE* fp = fopen(m_contentSource.c_str() , "rb");
6 if (fp != NULL)
7 {
8 fseek(fp, 0, SEEK_END);
9 content_source_len = ftell(fp);
10 fseek(fp, 0, SEEK_SET);
11 source_content = (char*) malloc(content_source_len * sizeof(char));
12 fread(source_content, content_source_len , sizeof(char), fp);
13 fclose(fp);
14 } //md5code_string是要发送的校验码
15 char md5code_string[50] = {0};
16 EncryptMD5str(md5code_string, (unsigned char *)source_content, content_source_len);
17 }
时间： 2024-10-12 05:19:06