public async Task GenerateQrCode(string contactName)
{
IUserModel user = _storageService.GetUser();
string publicKey = RsaKeyTools.ExtractPublicKey(user.KeyPair);
Tuple <string, string> pkElements = RsaKeyTools.DecomposePublicKey(publicKey);
string contents = ComposeQrData(user.Id, contactName, pkElements.Item1, pkElements.Item2);
IBarcodeWriter writer = QrTools.GetQrWriter();
var matrix = writer.Encode(contents);
var wb = writer.Write(matrix);
await PictureLibraryTools.SaveWriteableBitmap(wb, string.Format(QrCodeFileName, contactName));
}
public bool ParseQrCode(string qrData, out QrContact contact)
{
contact = null;
string[] elements = DecomposeQrData(qrData);
if (elements?.Length != QrElements.Count)
{
return(false);
}
int userId;
if (!Int32.TryParse(elements[QrElements.IdIndex], NumberStyles.None, CultureInfo.InvariantCulture, out userId))
{
return(false);
}
if (userId == _storageService.GetUser().Id)
{
return(false);
}
string name = elements[QrElements.NameIndex];
string modulus = elements[QrElements.ModulusIndex];
string exponent = elements[QrElements.ExponentIndex];
string publicKey;
if (!RsaKeyTools.ComposePublicKey(modulus, exponent, out publicKey))
{
return(false);
}
contact = new QrContact()
{
Name = name, PublicKey = publicKey, UserId = userId
};
return(true);
}
public string ExtractPublicKey(string keyPair)
{
return(RsaKeyTools.ExtractPublicKey(keyPair));
}