www.pudn.com > FileSecurity.rar > xEncrypt.cpp

// xEncrypt.cpp : 定义 DLL 应用程序的入口点。 
// 
 
#include "stdafx.h" 
#include "xEncrypt.h" 
 
#include  
#include  
#include  
#include  
    
#define BLOCK_SIZE            1000 
#define BUFFER_SIZE           1008 
 
 
 
#ifdef _MANAGED 
#pragma managed(push, off) 
#endif 
 
BOOL APIENTRY DllMain( HMODULE hModule, 
					  DWORD  ul_reason_for_call, 
					  LPVOID lpReserved 
					  ) 
{ 
	switch (ul_reason_for_call) 
	{ 
	case DLL_PROCESS_ATTACH: 
	case DLL_THREAD_ATTACH: 
	case DLL_THREAD_DETACH: 
	case DLL_PROCESS_DETACH: 
		break; 
	} 
	return TRUE; 
} 
 
#ifdef _MANAGED 
#pragma managed(pop) 
#endif 
 
 
// 加密文件 
XENCRYPT_API BOOL xEncrypt (LPTSTR lpszSource, 
							LPTSTR lpszDestination, 
							LPTSTR lpszPassword) 
{ 
	FILE *hSrcFile = NULL; 
	FILE *hDestFile = NULL; 
 
	HCRYPTPROV hProv = 0; 
	HCRYPTHASH hHash = 0; 
	HCRYPTKEY hKey = 0; 
	HCRYPTKEY hXchgKey = 0; 
 
	PBYTE pbBuffer = NULL; 
	PBYTE pbKeyBlob = NULL; 
 
	BOOL bEOF = 0;  
	BOOL bReturn = FALSE; 
 
	DWORD dwCount;  
	DWORD dwKeyBlobLen; 
 
	if ((hSrcFile = _wfopen (lpszSource, TEXT("rb"))) == NULL)  
	{ 
		goto exit; 
	} 
 
	if ((hDestFile = _wfopen (lpszDestination, TEXT("wb"))) == NULL)  
	{ 
		goto exit; 
	} 
 
	if (!CryptAcquireContext (&hProv, NULL, NULL, PROV_RSA_FULL, 0))  
	{ 
		DWORD ret = GetLastError(); 
		if (ret !=  NTE_BAD_KEYSET) 
		{ 
			goto exit; 
		} 
		else 
		{ 
			if (!CryptAcquireContext (&hProv, NULL, NULL, PROV_RSA_FULL, CRYPT_NEWKEYSET))  
			{ 
				goto exit; 
			} 
		} 
	} 
 
	if (lpszPassword == NULL)  
	{ 
		if (!CryptGenKey (hProv, CALG_RC2, CRYPT_EXPORTABLE, &hKey))  
		{ 
			goto exit; 
		} 
 
		if (!CryptGetUserKey (hProv, AT_KEYEXCHANGE, &hXchgKey))  
		{ 
			DWORD ret = GetLastError(); 
			if (ret != NTE_NO_KEY) 
			{ 
				goto exit; 
			} 
			if (!CryptGenKey(hProv,AT_KEYEXCHANGE,NULL,&hXchgKey)) 
			{ 
				goto exit; 
			} 
		} 
 
		if (!CryptExportKey (hKey, hXchgKey, SIMPLEBLOB, 0, NULL, &dwKeyBlobLen))  
		{ 
			goto exit; 
		} 
 
		if ((pbKeyBlob = (PBYTE)malloc(dwKeyBlobLen))==NULL)  
		{ 
			goto exit; 
		} 
 
		if (!CryptExportKey (hKey, hXchgKey, SIMPLEBLOB, 0, pbKeyBlob, &dwKeyBlobLen))  
		{ 
			goto exit; 
		} 
 
		fwrite (&dwKeyBlobLen, sizeof (DWORD), 1, hDestFile); 
 
		if (ferror (hDestFile))  
		{ 
			goto exit; 
		} 
 
		fwrite (pbKeyBlob, 1, dwKeyBlobLen, hDestFile); 
 
		if (ferror (hDestFile))  
		{ 
			goto exit; 
		} 
	}  
	else  
	{ 
		if (!CryptCreateHash (hProv, CALG_MD5, 0, 0, &hHash))  
		{ 
			goto exit; 
		} 
 
		if (!CryptHashData (hHash, (PBYTE)lpszPassword, wcslen (lpszPassword), 0))  
		{ 
			goto exit; 
		} 
 
		if (!CryptDeriveKey (hProv, CALG_RC2, hHash, 0, &hKey))  
		{ 
			goto exit; 
		} 
	} 
 
	if ((pbBuffer=(PBYTE)malloc(BUFFER_SIZE))==NULL)  
	{ 
		goto exit; 
	} 
 
	do  
	{ 
		dwCount = fread (pbBuffer, 1, BLOCK_SIZE, hSrcFile); 
 
		if (ferror (hSrcFile))  
		{ 
			goto exit; 
		} 
		bEOF = feof (hSrcFile); 
 
		if (!CryptEncrypt (hKey, 0, bEOF, 0, pbBuffer, &dwCount,  
			BUFFER_SIZE))  
		{ 
			goto exit; 
		} 
 
		fwrite (pbBuffer, 1, dwCount, hDestFile); 
		if (ferror (hDestFile))  
		{ 
			goto exit; 
		} 
 
	} while (!bEOF); 
 
	bReturn = TRUE; 
 
exit: 
	if (hSrcFile) fclose (hSrcFile); 
	if (hDestFile) fclose (hDestFile); 
 
	if (pbKeyBlob) free (pbKeyBlob); 
	if (pbBuffer) free (pbBuffer); 
 
	if (hKey) CryptDestroyKey (hKey); 
 
	if (hXchgKey) CryptDestroyKey (hXchgKey); 
 
	if (hHash) CryptDestroyHash (hHash); 
 
	if (hProv) CryptReleaseContext (hProv, 0); 
 
	return bReturn; 
} 
 
 
// 解密文件 
XENCRYPT_API BOOL xDecrypt (LPTSTR lpszSource, 
							LPTSTR lpszDestination, 
							LPTSTR lpszPassword) 
{ 
	FILE *hSrcFile = NULL;  
	FILE *hDestFile = NULL; 
 
	HCRYPTPROV hProv = 0; 
	HCRYPTHASH hHash = 0; 
	HCRYPTKEY hKey = 0; 
 
	PBYTE pbBuffer = NULL;  
	PBYTE pbKeyBlob = NULL; 
 
	BOOL bEOF = 0;  
	BOOL bReturn = FALSE; 
 
	DWORD dwCount;  
	DWORD dwKeyBlobLen; 
 
	if ((hSrcFile = _wfopen (lpszSource, TEXT("rb"))) == NULL)  
	{ 
		goto exit; 
	} 
 
	if ((hDestFile = _wfopen (lpszDestination, TEXT("wb"))) == NULL)  
	{ 
		goto exit; 
	} 
 
	if (!CryptAcquireContext (&hProv, NULL, NULL, PROV_RSA_FULL, 0))  
	{ 
		DWORD ret = GetLastError(); 
		if (ret !=  NTE_BAD_KEYSET) 
		{ 
			goto exit; 
		} 
		else 
		{ 
			if (!CryptAcquireContext (&hProv, NULL, NULL, PROV_RSA_FULL, CRYPT_NEWKEYSET))  
			{ 
				goto exit; 
			} 
		} 
	} 
 
 
	if (lpszPassword == NULL)  
	{ 
		fread (&dwKeyBlobLen, sizeof (DWORD), 1, hSrcFile); 
		if (ferror (hSrcFile) || feof (hSrcFile))  
		{ 
			goto exit; 
		} 
 
		if ((pbKeyBlob = (PBYTE)malloc (dwKeyBlobLen)) == NULL)  
		{ 
			goto exit; 
		} 
 
		fread (pbKeyBlob, 1, dwKeyBlobLen, hSrcFile); 
 
		if (ferror (hSrcFile) || feof (hSrcFile))  
		{ 
			goto exit; 
		} 
 
		if (!CryptImportKey (hProv, pbKeyBlob, dwKeyBlobLen, 0, 0, &hKey))  
		{ 
			goto exit; 
		} 
	}  
	else 
	{ 
		if (!CryptCreateHash (hProv, CALG_MD5, 0, 0, &hHash))  
		{ 
			goto exit; 
		} 
 
		if (!CryptHashData (hHash, (PBYTE)lpszPassword, wcslen (lpszPassword), 0))  
		{ 
			goto exit; 
		} 
 
		if (!CryptDeriveKey (hProv, CALG_RC2, hHash, 0, &hKey))  
		{ 
			goto exit; 
		} 
	} 
 
	if ((pbBuffer = (PBYTE)malloc (BUFFER_SIZE)) == NULL)  
	{ 
		goto exit; 
	} 
 
	do  
	{ 
		dwCount = fread (pbBuffer, 1, BLOCK_SIZE, hSrcFile); 
 
		if (ferror (hSrcFile))  
		{ 
			goto exit; 
		} 
 
		bEOF = feof (hSrcFile); 
 
		if (!CryptDecrypt (hKey, 0, bEOF, 0, pbBuffer, &dwCount))  
		{ 
			goto exit; 
		} 
 
		fwrite (pbBuffer, 1, dwCount, hDestFile); 
		if (ferror (hDestFile))  
		{ 
			goto exit; 
		} 
	} while (!bEOF); 
 
	bReturn = TRUE; 
exit: 
	if (hSrcFile) fclose (hSrcFile); 
	if (hDestFile) fclose (hDestFile); 
 
	if (pbKeyBlob) free (pbKeyBlob); 
	if (pbBuffer) free (pbBuffer); 
 
	if (hKey) CryptDestroyKey (hKey); 
 
	if (hHash) CryptDestroyHash (hHash); 
 
	if (hProv) CryptReleaseContext (hProv, 0); 
 
	return bReturn; 
 
}