用CSP生成RSA密钥对

#include "stdafx.h"
#include <Windows.h>
#include <WinCrypt.h>

#define RSA_FROM_FILE		1

BOOL RSAGenKeys(PVOID &lpKeyPublic, PVOID &lpKeyPrivate, WORD KeyLength)
{
	BOOL IsOk;
	HCRYPTPROV CryptContext;

	IsOk = FALSE;
	lpKeyPublic = NULL;
	lpKeyPrivate = NULL;
	if (CryptAcquireContext(&CryptContext, NULL, MS_ENHANCED_PROV, PROV_RSA_FULL, CRYPT_NEWKEYSET) 
		|| CryptAcquireContext(&CryptContext, NULL, MS_ENHANCED_PROV, PROV_RSA_FULL, 0))
	{
		HCRYPTKEY KeyContext;
		
		if (CryptGenKey(CryptContext, AT_KEYEXCHANGE, MAKELONG(CRYPT_EXPORTABLE, KeyLength), &KeyContext))
		{
			DWORD cbKeyPrivate, cbKeyPublic;

			if (CryptExportKey(KeyContext, NULL, PUBLICKEYBLOB, 0, NULL, &cbKeyPublic)
				&& CryptExportKey(KeyContext, NULL, PRIVATEKEYBLOB, 0, NULL, &cbKeyPrivate))
			{
				lpKeyPublic = HeapAlloc(GetProcessHeap(), 0, cbKeyPublic);
				lpKeyPrivate = HeapAlloc(GetProcessHeap(), 0, cbKeyPrivate);
				if (CryptExportKey(KeyContext, NULL, PUBLICKEYBLOB, 0, PBYTE(lpKeyPublic), &cbKeyPublic)
					&& CryptExportKey(KeyContext, NULL, PRIVATEKEYBLOB, 0, PBYTE(lpKeyPrivate), &cbKeyPrivate))
				{
					IsOk = TRUE;
				}
				else
				{
					HeapFree(GetProcessHeap(), 0, lpKeyPublic);
					HeapFree(GetProcessHeap(), 0, lpKeyPrivate);
				}
			}
			CryptDestroyKey(KeyContext);
		}
		CryptReleaseContext(CryptContext, 0);
	}
	return IsOk;
}

#define CCRYPT_CONTAINER TEXT("CCryptProvider.ContainerX")

int _tmain(int argc, _TCHAR* argv[])
{
	PVOID lpKeyPublic, lpKeyPrivate;

#if RSA_FROM_FILE
	HCRYPTPROV CryptContext;

	lpKeyPublic = HeapAlloc(GetProcessHeap(), 0, 0x94);
	lpKeyPrivate = HeapAlloc(GetProcessHeap(), 0, 0x254);
	if (FILE *f = fopen("pub.key", "rb"))
	{
		fread(lpKeyPublic, 0x94, 1, f);
		fclose(f);
	}
	if (FILE *f = fopen("pri.key", "rb"))
	{
		fread(lpKeyPrivate, 0x254, 1, f);
		fclose(f);
	}
	if (CryptAcquireContext(&CryptContext, CCRYPT_CONTAINER, MS_ENHANCED_PROV, PROV_RSA_FULL, CRYPT_NEWKEYSET) 
		|| CryptAcquireContext(&CryptContext, CCRYPT_CONTAINER, MS_ENHANCED_PROV, PROV_RSA_FULL, 0))
	{
		HCRYPTKEY KeyPublic;
		HCRYPTKEY KeyPrivate;

		if (CryptImportKey(CryptContext, PBYTE(lpKeyPublic), HeapSize(GetProcessHeap(), 0, lpKeyPublic), NULL, 0, &KeyPublic))
		{
			if (CryptImportKey(CryptContext, PBYTE(lpKeyPrivate), HeapSize(GetProcessHeap(), 0, lpKeyPrivate), NULL, 0, &KeyPrivate))
			{
				BYTE buf1[128];
				DWORD dwbuf;

				memset(buf1, 0x90, sizeof(buf1));
				dwbuf = 64;
				if (CryptEncrypt(KeyPublic, NULL, TRUE, 0, buf1, &dwbuf, sizeof(buf1)))
				{
					if (CryptDecrypt(KeyPrivate, NULL, TRUE, 0, buf1, &dwbuf))
					{
						_tprintf(TEXT("encryption with RSA public keys.\n"));
					}
				}
				memset(buf1, 0x90, sizeof(buf1));
				dwbuf = 64;
				if (CryptEncrypt(KeyPrivate, NULL, TRUE, 0, buf1, &dwbuf, sizeof(buf1)))
				{
					if (CryptDecrypt(KeyPublic, NULL, TRUE, 0, buf1, &dwbuf))
					{
						_tprintf(TEXT("encryption with RSA private keys.\n"));
					}
				}
				CryptDestroyKey(KeyPrivate);
			}
			CryptDestroyKey(KeyPublic);
		}
		CryptReleaseContext(CryptContext, 0);
	}
	HeapFree(GetProcessHeap(), 0, lpKeyPublic);
	HeapFree(GetProcessHeap(), 0, lpKeyPrivate);
#else
	if (RSAGenKeys(lpKeyPublic, lpKeyPrivate, 1024))
	{
		if (FILE *f = fopen("pub.key", "wb"))
		{
			fwrite(lpKeyPublic, HeapSize(GetProcessHeap(), 0, lpKeyPublic), 1, f);
			fclose(f);
		}
		if (FILE *f = fopen("pri.key", "wb"))
		{
			fwrite(lpKeyPrivate, HeapSize(GetProcessHeap(), 0, lpKeyPrivate), 1, f);
			fclose(f);
		}
		HeapFree(GetProcessHeap(), 0, lpKeyPublic);
		HeapFree(GetProcessHeap(), 0, lpKeyPrivate);
	}
#endif
	_gettchar();
	return 0;
}