[2020]C++验证文件数字签名(无内存泄露版本)

傻逼百度 一堆复制粘贴的帖子 这些帖子无一例外都有内存泄露.
给个没内存泄露的自己的修改版:
```cpp

LONG CdigitalSig::GetSoftSign(PCWSTR v_pszFilePath, char* v_pszSign, int v_iBufSize)
{
	VMProtectBeginVirtualization("GetSoftSign");
	//首先判断参数是否正确
	if (v_pszFilePath == NULL) return -1;

HCERTSTORE		  hStore = NULL;
	HCRYPTMSG		  hMsg = NULL;
	PCCERT_CONTEXT    pCertContext = NULL;
	BOOL			  bResult;
	DWORD dwEncoding, dwContentType, dwFormatType;
	PCMSG_SIGNER_INFO pSignerInfo = NULL;
	PCMSG_SIGNER_INFO pCounterSignerInfo = NULL;
	DWORD			  dwSignerInfo;
	CERT_INFO		  CertInfo;
	SYSTEMTIME        st;
	LONG              lRet;
	DWORD             dwDataSize = 0;

char   chTemp[MAX_PATH] = { 0 };

do
	{
		
		//从签名文件中获取存储句柄
		bResult = CryptQueryObject(
			CERT_QUERY_OBJECT_FILE,										//指示要查询的对象的类型
			v_pszFilePath,
			CERT_QUERY_CONTENT_FLAG_PKCS7_SIGNED_EMBED,
			CERT_QUERY_FORMAT_FLAG_BINARY,
			0,
			&dwEncoding,
			&dwContentType,
			&dwFormatType,
			&hStore,
			&hMsg,
			NULL
			);

if (!bResult)
		{
			lRet = -1;
			break;
		}
		//获取签名信息所需的缓冲区大小
		bResult = CryptMsgGetParam(
			hMsg,
			CMSG_SIGNER_INFO_PARAM,
			0,
			NULL,
			&dwSignerInfo
			);
		if (!bResult)
		{
			lRet = -1;
			break;
		}

//分配缓冲区
		pSignerInfo = (PCMSG_SIGNER_INFO)LocalAlloc(LPTR, dwSignerInfo);
		if (pSignerInfo == NULL)
		{
			lRet = -1;
			break;
		}

//获取签名信息
		bResult = CryptMsgGetParam(
			hMsg,
			CMSG_SIGNER_INFO_PARAM,
			0,
			pSignerInfo,
			&dwSignerInfo
			);
		if (!bResult)
		{
			lRet = -1;
			break;
		}

CertInfo.Issuer = pSignerInfo->Issuer;
		CertInfo.SerialNumber = pSignerInfo->SerialNumber;

pCertContext = CertFindCertificateInStore(
			hStore,
			CRYPT_ASN_ENCODING,
			0,
			CERT_FIND_SUBJECT_CERT,
			(PVOID)&CertInfo,
			NULL
			);
		if (pCertContext == NULL)
		{
			lRet = -1;
			break;
		}

//获取数字键名
		//没有给定缓冲区，那么说明只要获取下需要的长度
		if (v_pszSign == NULL)
		{
			dwDataSize = CertGetNameString(
				pCertContext,
				CERT_NAME_SIMPLE_DISPLAY_TYPE,
				0,
				NULL,
				NULL,
				0
				);
			if (dwDataSize != 0)
			{
				lRet = dwDataSize;
			}
			else
			{
				lRet = -1;
			}

break;
		}

if (!(CertGetNameStringA(
			pCertContext,
			CERT_NAME_SIMPLE_DISPLAY_TYPE,
			0,
			NULL,
			v_pszSign,
			v_iBufSize
			)
			)
			)
		{

lRet = -1;
			break;
		}
		lRet = 0;

} while (FALSE);

if (pSignerInfo != NULL)
	{
		LocalFree((HLOCAL)pSignerInfo);
	}
	if (hStore != NULL)
		CertCloseStore(hStore, 0);
	if (hMsg != NULL)
		CryptMsgClose(hMsg);
	if (pCertContext != NULL)
		CertFreeCertificateContext(pCertContext);
	return lRet;
	VMProtectEnd();
}
```

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