接口定义：

// 加密数据
static BOOL xEncrypt(BYTE *pbSourceData, DWORD dwSourceDataLen, BYTE **pbDestData, DWORD *pdwDestDataLen, LPCTSTR lpszPassword);// 解密数据
static BOOL xDecrypt(BYTE *pbSourceData, DWORD dwSourceDataLen, BYTE **pbDestData, DWORD *pdwDestDataLen, LPCTSTR lpszPassword);// 加密文件
static BOOL xEncrypt(LPCTSTR lpszSource, LPCTSTR lpszDestination, LPCTSTR lpszPassword);// 解密文件
static BOOL xDecrypt(LPCTSTR lpszSource, LPCTSTR lpszDestination, LPCTSTR lpszPassword);

接口声明：

// 加密数据
BOOL xEncrypt(BYTE *pbSourceData, DWORD dwSourceDataLen, BYTE **pbDestData, DWORD *pdwDestDataLen, LPCTSTR lpszPassword)
{HCRYPTPROV hProv = 0;HCRYPTHASH hHash = 0;HCRYPTKEY hKey = 0, hXchgKey = 0;PBYTE pbBuffer = NULL, pbKeyBlob = NULL;BOOL bEOF = FALSE, bReturn = FALSE;DWORD dwCount = 0, dwKeyBlobLen = 0;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 (!CryptCreateHash(hProv, CALG_MD5, 0, 0, &hHash)){goto exit;}if (!CryptHashData(hHash, (PBYTE)lpszPassword, _tcslen(lpszPassword), 0)){goto exit;}if (!CryptDeriveKey(hProv, CALG_RC2, hHash, 0, &hKey)){goto exit;}if ((pbBuffer = (PBYTE)malloc(BUFFER_SIZE)) == NULL){goto exit;}memset(pbBuffer, 0, BUFFER_SIZE);memcpy(pbBuffer, pbSourceData, dwSourceDataLen);dwCount = dwSourceDataLen;bEOF = TRUE;if (!CryptEncrypt(hKey, 0, bEOF, 0, pbBuffer, &dwCount, BUFFER_SIZE)){goto exit;}*pbDestData = (PBYTE)malloc(dwCount);memcpy(*pbDestData, pbBuffer, dwCount);*pdwDestDataLen = dwCount;bReturn = TRUE;exit:if (pbKeyBlob) free(pbKeyBlob);if (hKey) CryptDestroyKey(hKey);if (pbBuffer) free(pbBuffer);if (hXchgKey) CryptDestroyKey(hXchgKey);if (hHash) CryptDestroyHash(hHash);if (hProv) CryptReleaseContext(hProv, 0);return bReturn;
}// 解密数据
BOOL xDecrypt(BYTE *pbSourceData, DWORD dwSourceDataLen, BYTE **pbDestData, DWORD *pdwDestDataLen, LPCTSTR lpszPassword)
{HCRYPTPROV hProv = 0;HCRYPTHASH hHash = 0;HCRYPTKEY hKey = 0;PBYTE pbBuffer = NULL, pbKeyBlob = NULL;BOOL bEOF = 0, bReturn = FALSE;DWORD dwCount = 0, dwKeyBlobLen = 0;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 (!CryptCreateHash(hProv, CALG_MD5, 0, 0, &hHash)){goto exit;}if (!CryptHashData(hHash, (PBYTE)lpszPassword, _tcslen(lpszPassword), 0)){goto exit;}if (!CryptDeriveKey(hProv, CALG_RC2, hHash, 0, &hKey)){goto exit;}if ((pbBuffer = (PBYTE)malloc(BUFFER_SIZE)) == NULL){goto exit;}memset(pbBuffer, 0, BUFFER_SIZE);memcpy(pbBuffer, pbSourceData, dwSourceDataLen);dwCount = dwSourceDataLen;bEOF = TRUE;if (!CryptDecrypt(hKey, 0, bEOF, 0, pbBuffer, &dwCount)){TRACE(_T("GetLastError()=%d"),GetLastError());goto exit;}*pbDestData = (PBYTE)malloc(dwCount);memcpy(*pbDestData, pbBuffer, dwCount);*pdwDestDataLen = dwCount;bReturn = TRUE;exit:if (pbKeyBlob) free(pbKeyBlob);if (hKey) CryptDestroyKey(hKey);if (pbBuffer) free(pbBuffer);if (hHash) CryptDestroyHash(hHash);if (hProv) CryptReleaseContext(hProv, 0);return bReturn;
}// 加密文件
BOOL xEncrypt(LPCTSTR lpszSource, LPCTSTR lpszDestination, LPCTSTR lpszPassword)
{FILE *hSrcFile = NULL, *hDestFile = NULL;HCRYPTPROV hProv = 0;HCRYPTHASH hHash = 0;HCRYPTKEY hKey = 0, hXchgKey = 0;PBYTE pbBuffer = NULL, pbKeyBlob = NULL;BOOL bEOF = FALSE, bReturn = FALSE;DWORD dwCount = 0, dwKeyBlobLen = 0;if (fopen_s(&hSrcFile, lpszSource, _T("rb")) != 0){goto exit;}if (fopen_s(&hDestFile, lpszDestination, _T("wb")) != 0){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, _tcslen(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
BOOL xDecrypt(LPCTSTR lpszSource, LPCTSTR lpszDestination, LPCTSTR lpszPassword)
{FILE *hSrcFile = NULL, *hDestFile = NULL;HCRYPTPROV hProv = 0;HCRYPTHASH hHash = 0;HCRYPTKEY hKey = 0;PBYTE pbBuffer = NULL, pbKeyBlob = NULL;BOOL bEOF = 0, bReturn = FALSE;DWORD dwCount = 0, dwKeyBlobLen = 0;if (fopen_s(&hSrcFile, lpszSource, _T("rb")) != 0){goto exit;}if (fopen_s(&hDestFile, lpszDestination, _T("wb")) != 0){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, _tcslen(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;
}