Base64編碼

編碼：

std::string CCryptoEnvelop::Base64EncryptStr(byte* pPlaintext, int nLen)
{
	std::string outstr;
	if (NULL == pPlaintext || nLen < 1)
		return outstr;

	Base64Encoder encoder;
	encoder.Put(pPlaintext, nLen);
	encoder.MessageEnd();

	word64 size = encoder.MaxRetrievable();
	if(size)
	{
		outstr.resize(size);		
		encoder.Get((byte*)outstr.data(), size);
	}

	return outstr;
}

//路徑能夠是png,word,excel格式的文件
CString COnePictureOneTable::GetBase64ToPath(const CString& strPath )
{
	FILE*pFile = NULL;
	fopen_s(&pFile, CComVar(strPath).ToString().c_str(), "rb");
	if (pFile == NULL)
		return _T("");
	fseek(pFile, 0x0L, SEEK_END);
	long size = ftell(pFile);//文件大小單位爲字節（B），1MB = 1024KB，1KB = 1024B
	byte *buf = new byte[size];
	fseek(pFile, 0x0L, SEEK_SET);
	fread(buf, sizeof(byte), size, pFile);
	fclose(pFile);

	CString strBase64 = CCryptoEnvelop::Base64EncryptStr(buf, size).c_str();
	delete[] buf;
	buf = NULL;
	return strBase64;
}

解碼：

std::string CCryptoEnvelop::Base64EncryptStr(std::string plaintext)
{
	std::string outstr;

	Base64Encoder encoder;
	encoder.Put((byte*)plaintext.c_str(), plaintext.length());
	encoder.MessageEnd();

	word64 size = encoder.MaxRetrievable();
	if(size)
	{
		outstr.resize(size);		
		encoder.Get((byte*)outstr.data(), outstr.size());
	}

	return outstr;
}