在Win2000/XP的AdvApi32.dll中实现了基本的Hash和RSA算法，但微软没有给出函数和数据的定义。
下面演示MD5算法的调用。
#include <windows.h>
/* Data structure for MD5 (Message-Digest) computation */
typedef struct {
ULONG i[2]; /* number of _bits_ handled mod 2^64 */
ULONG buf[4]; /* scratch buffer */
unsigned char in[64]; /* input buffer */
unsigned char digest[16]; /* actual digest after MD5Final call */
} MD5_CTX;
#define MD5DIGESTLEN 16
#define PROTO_LIST(list) list
/*
* MTS: Each of these assumes MD5_CTX is locked against simultaneous use.
*/
typedef void (WINAPI* PMD5Init) PROTO_LIST ((MD5_CTX *));
typedef void (WINAPI* PMD5Update) PROTO_LIST ((MD5_CTX *, const unsigned char *, unsigned int));
typedef void (WINAPI* PMD5Final )PROTO_LIST ((MD5_CTX *));
PMD5Init MD5Init = NULL;
PMD5Update MD5Update = NULL;
PMD5Final MD5Final = NULL;
const char *Hex2ASC(const BYTE *Hex, int Len)
{
static char ASC[4096 * 2];
int i;
for (i = 0; i < Len; i++)
{
ASC[i * 2] = "0123456789ABCDEF"[Hex[i] >> 4];
ASC[i * 2 + 1] = "0123456789ABCDEF"[Hex[i] & 0x0F];
}
ASC[i * 2] = '\0';
return ASC;
}
int main()
{
MD5_CTX ctx;
unsigned char buf[4] = "1233";
HINSTANCE hDLL;
if ( (hDLL = LoadLibrary("advapi32.dll")) > 0 )
{
MD5Init = (PMD5Init)GetProcAddress(hDLL,"MD5Init");
MD5Update = (PMD5Update)GetProcAddress(hDLL,"MD5Update");
MD5Final = (PMD5Final)GetProcAddress(hDLL,"MD5Final");
MD5Init(&ctx);
MD5Update(&ctx,buf,4);
MD5Final(&ctx);
printf(Hex2ASC(ctx.digest,16));
}
return 0;
}
是不是很简单呢。另外AdvApi32.Dll中还有其他的一些算法如RSA，
DSA，SHA等，
以上代码在WinXP SP1/vc6.0 下调试通过