P24 GetBalance

P24GetBalance.cs

void Main() {
	GetBalance("card number").Dump();
}

Decimal GetBalance(String card) {
	var requestData = GetBalanceRequestData(card);
	
	var request = HttpWebRequest.CreateHttp("https://api.privatbank.ua/p24api/balance");
	request.Method = "POST";
	using (var stream = request.GetRequestStream())
	using (var writer = new StreamWriter(stream)) {
		writer.Write(requestData);
	}
	
	var response = request.GetResponse();
	String responseData;
	using (var stream = response.GetResponseStream())
	using (var reader = new StreamReader(stream)) {
		responseData = reader.ReadToEnd();
	}
	var doc = XDocument.Parse(responseData);
	var balanceString = doc
		.Element("response")
		.Element("data")
		.Element("info")
		.Element("cardbalance")
		.Element("av_balance")
		.Value;
	return Decimal.Parse(balanceString, CultureInfo.InvariantCulture);
}

String GetBalanceRequestData(String card) {
	var data = new XElement("data",
		new XElement("oper", "cmt"),
		new XElement("wait", "0"),
		new XElement("test", "0"),
		new XElement("payment",
			new XAttribute("id", ""),
			new XElement("prop",
				new XAttribute("name", "cardnum"),
				new XAttribute("value", card)
			),
			new XElement("prop",
				new XAttribute("name", "country"),
				new XAttribute("value", "UA")
			)
		)
	);
	var signature = GetSignature(data);
	var dataString = data.ToString(SaveOptions.DisableFormatting);
	
	var request = new XElement("request",
		new XAttribute("version", "1.0"),
		new XElement("merchant",
			new XElement("id", Util.GetPassword("p24 id")),
			new XElement("signature", signature)
		),
		data
	);
	
	var doc = new XDocument(new XDeclaration("1.0", "UTF-8", "no"), request);
	
	return doc.ToString(SaveOptions.DisableFormatting);
}

String GetSignature(XElement data) {
	var dataString = data.ToString(SaveOptions.DisableFormatting);
	dataString = dataString.Substring("<data>".Length, dataString.Length - "<data>".Length - "</data>".Length);
	dataString += Util.GetPassword("p24 secret");
	
	var md5 = new MD5Cng();
	var hash = md5.ComputeHash(Encoding.UTF8.GetBytes(dataString));
	
	var sha1 = new SHA1Cng();
	dataString = String.Concat(hash.Select(b => b.ToString("x2")));
	hash = sha1.ComputeHash(Encoding.UTF8.GetBytes(dataString));
	return String.Concat(hash.Select(b => b.ToString("x2")));
}