【C++】获取软件的数字签名

#include <wincrypt.h>
#pragma  comment(lib, "crypt32.lib")

//作用：获取软件的数字签名
//参数：
//		v_pwszFilePath  ---   程序的全路径
//		v_pwszSign      ---   用于返回数字签名的缓冲区,如果为NULL，
//					   	      那么将会需要的缓冲区大小
//      v_iBufSize      ---   v_pwszSign缓冲区的大小
//返回值：
//		-1		---  失败
//		0       ---  成功
//		其它值  ---  需要的缓冲区大小
//
//*****************************************************//

LONG GetSoftSign(WCHAR* v_pszFilePath,char * v_pszSign,int v_iBufSize)
{
	//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,
			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,
			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 (!(CertGetNameString(
			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);
	}

	return lRet;
}