VC++下使用md5函数

使用windows的动态链接库advapi32.dll.

此动态链接库提供以下md5函数：

MD5Init(&ctx);
MD5Update(&ctx, buf, len);
MD5Final(&ctx);

具体使用如下

新建文件 common.h

1. #include <windows.h>

2. /* Data structure for MD5 (Message-Digest) computation */

3. typedef struct {

4. ULONG i[2]; /* number of _bits_ handled mod 2^64 */

5. ULONG buf[4]; /* scratch buffer */

6. unsigned char in[64]; /* input buffer */

7. unsigned char digest[16]; /* actual digest after MD5Final call */

8. } MD5_CTX;

9.  
10.  

11. #define MD5DIGESTLEN 16

12.  

13. #define PROTO_LIST(list) list

14.  
15.  

16. /*

17. * MTS: Each of these assumes MD5_CTX is locked against simultaneous use.

18. */

19. typedef void (WINAPI* PMD5Init) PROTO_LIST ((MD5_CTX *));

20. typedef void (WINAPI* PMD5Update) PROTO_LIST ((MD5_CTX *, const unsigned char *, unsigned int));

21. typedef void (WINAPI* PMD5Final )PROTO_LIST ((MD5_CTX *));

22.  

23. //end globle define

24.  
25.  
26.  
27.  
28.  

29. class Ccommon

30. {

31. public:

32. Ccommon();

33. virtual ~Ccommon();

34. const char * md5(const char * str);

35. const char * Hex2ASC(const BYTE *Hex, int Len);

36. PMD5Init MD5Init;

37. PMD5Update MD5Update;

38. PMD5Final MD5Final;

39.  

40. };

新建文件 common.cpp

1. #include "stdafx.h"

2. #include "common.h"

3.  

4. //

5. // Construction/Destruction

6. //

7.  

8. Ccommon::Ccommon()

9. {

10.  

11. }

12.  

13. Ccommon::~Ccommon()

14. {

15.  

16. }

17.  

18. const char * Ccommon::Hex2ASC(const BYTE *Hex, int Len)

19. {

20. static char ASC[4096 * 2];

21. int i;

22.  

23. for (i = 0; i < Len; i++)

24. {

25. ASC[i * 2] = "0123456789abcdef"[Hex[i] >> 4];

26. ASC[i * 2 + 1] = "0123456789abcdef"[Hex[i] & 0x0F];

27. }

28. ASC[i * 2] = 0;

29. return ASC;

30. }

31.  
32.  

33. const char * Ccommon::md5(const char * str)

34. {

35. MD5_CTX ctx;

36. const unsigned char * buf = reinterpret_cast<const unsigned char *>(str);

37. int len = strlen(str);

38. HINSTANCE hDLL;

39. if ( (hDLL = LoadLibraryA("advapi32.dll")) > 0 )

40. {

41.  

42. MD5Init = (PMD5Init)GetProcAddress(hDLL,"MD5Init");

43. MD5Update = (PMD5Update)GetProcAddress(hDLL,"MD5Update");

44. MD5Final = (PMD5Final)GetProcAddress(hDLL,"MD5Final");

45.  

46. MD5Init(&ctx);

47. MD5Update(&ctx, buf, len);

48. MD5Final(&ctx);

49. }

50. return Hex2ASC(ctx.digest, 16);

51. }

调用方法

1. //引入头文件

2. #include "common.h"

3. //声明类

4. Ccommon md5Class;

5. name=md5Class.md5(name);

6.  

注意事项

MD5加密后的大小写是由 Hex2ASC函数里

1. ASC[i * 2] = "0123456789abcdef"[Hex[i] >> 4];

2. ASC[i * 2 + 1] = "0123456789abcdef"[Hex[i] & 0x0F];

这两句代码控制的 这里我改为了小写 默认应该是大写 看大家需求而定

如果需要大写改为：

1. ASC[i * 2] = "0123456789ABCDEF"[Hex[i] >> 4];

2. ASC[i * 2 + 1] = "0123456789ABCDEF"[Hex[i] & 0x0F];

3.