private void WriteDataToTag(Tag tag)
{
try
{
ndefHandler.SetKeys(AppSettings.Global.PubKey, AppSettings.Global.PrivKey);
ndefHandler.SetExtraSignDataFromTag(tag);
byte[] rawNdefMsg = ndefHandler.GenerateRawNdefMessage(writeData);
NdefMessage ndefMsg = new NdefMessage(rawNdefMsg);
bool?written = WriteNdef(tag, ndefMsg);
if (written == false)
{
written = FormatNdef(tag, ndefMsg);
}
if (written == true)
{
ShowToast("Written " + ndefMsg.ByteArrayLength + " bytes of NDEF data.");
Finish();
}
}
finally
{
ndefHandler.ClearKeys();
ndefHandler.ClearExtraSignData();
}
}
public static void SetExtraSignDataFromTag(this NdefHandler handler, Tag tag)
{
if (tag == null)
{
handler.ClearExtraSignData();
return;
}
byte[] uid = tag.GetId();
string[] techs = tag.GetTechList();
byte[] nuid = new byte[uid.Length + 1];
Buffer.BlockCopy(uid, 0, nuid, 0, uid.Length);
if (techs.Contains(Java.Lang.Class.FromType(typeof(MifareUltralight)).CanonicalName))
{
nuid[uid.Length] = 0xAA;
}
else if (techs.Contains(Java.Lang.Class.FromType(typeof(MifareClassic)).CanonicalName))
{
nuid[uid.Length] = 0xBB;
}
else
{
nuid = uid;
}
handler.SetExtraSignData(nuid);
}
private byte[] ProcessUpdate(byte[] apdu)
{
int address = ((apdu[2] & 0xFF) << 8) | (apdu[3] & 0xFF);
if (address < 0 || address >= 1024)
{
return(WRONG_PARAMETERS);
}
if (address != 0)
{
return(WRONG_PARAMETERS);
}
int length = apdu[4] & 0xFF;
if (apdu.Length < length + 5)
{
return(STATUS_FAILED);
}
if (dataToPublish == null || confirmed)
{
return(FILE_NOT_FOUND);
}
byte[] challenge = new byte[length];
Buffer.BlockCopy(apdu, 5, challenge, 0, length);
try
{
ndefHandler.SetKeys(AppSettings.Global.PubKey, AppSettings.Global.PrivKey);
ndefHandler.SetExtraSignData(challenge);
ndefHandler.KeepEmptyFields = true;
ndefData = ndefHandler.GenerateRawNdefMessage(dataToPublish);
return(STATUS_SUCCESS);
}
catch (Exception e)
{
ShowToast("Failed preparing HCE data: " + e.Message);
return(STATUS_FAILED);
}
finally
{
ndefHandler.ClearKeys();
ndefHandler.ClearExtraSignData();
}
}
private void ParseNdefIntent(Intent intent)
{
var rawMessages = intent.GetParcelableArrayExtra(NfcAdapter.ExtraNdefMessages);
if (rawMessages == null || rawMessages.Length != 1)
{
ShowToast("Can't handle this tag.");
BackToMain();
return;
}
NdefMessage msg = rawMessages[0] as NdefMessage;
Tag tag = intent.GetParcelableExtra(NfcAdapter.ExtraTag) as Tag;
ndefHandler.SetExtraSignDataFromTag(tag);
ndefHandler.SetKeys(AppSettings.Global.PubKey, AppSettings.Global.PrivKey);
try
{
tagData = ndefHandler.ParseNdefMessage(msg.ToByteArray());
if (ndefHandler.HasPubKey() && (tagData.ContainsKey(NdefHandler.SIG_VALID_KEY) || AppSettings.Global.KioskMode))
{
bool sigValid = Convert.ToBoolean(tagData.GetValueOrDefault(NdefHandler.SIG_VALID_KEY, bool.FalseString));
if (!sigValid)
{
ShowToast("Invalid Tag Signature!");
BackToMain();
return;
}
}
CheckForSettings();
UpdateTextView();
}
catch (NdefHandlerException e)
{
ShowToast(e.Message);
BackToMain();
}
finally
{
ndefHandler.ClearExtraSignData();
ndefHandler.ClearKeys();
}
}