private byte[] GenerateCryptogram(CryptogramType cryptogramType)
{
var data = new List <byte>();
switch (cryptogramType)
{
case CryptogramType.Card:
data.AddRange(this.HostChallenge);
data.AddRange(this.SequenceCounter);
data.AddRange(this.CardChallenge);
break;
case CryptogramType.Host:
data.AddRange(this.SequenceCounter);
data.AddRange(this.CardChallenge);
data.AddRange(this.HostChallenge);
break;
}
data.Pad();
byte[] cryptogram = MAC.Algorithm1(data.ToArray(), this.EncryptionKey);
return(cryptogram);
}
/// <summary>
/// Process the GENERATE APPLICATION CRYPTOGRAM 1 of an EMV transaction.
/// </summary>
/// <param name="cryptogramType">Type of the cryptogram to be generated.</param>
/// <param name="unpredictableNumber">Unpredictable number.</param>
/// <returns>Last status word.</returns>
public UInt16 GenerateAc1(CryptogramType cryptogramType, byte[] unpredictableNumber)
{
BeforeGenerateAC1Event.Raise(this, new EmvEventArgs());
_tlvGenerateAC1UnpredictableNumber = new TlvData(0x9F37, (uint)unpredictableNumber.Length, unpredictableNumber);
_requestedAC1Type = cryptogramType;
byte referenceControlParameter;
switch (cryptogramType)
{
case CryptogramType.AAC:
referenceControlParameter = 0x00;
break;
case CryptogramType.ARQC:
referenceControlParameter = 0x80;
break;
case CryptogramType.TC:
referenceControlParameter = 0x40;
break;
default:
throw new Exception(String.Format("EMVApplication.generateAC1: bad Cryptogram Type [{0}]", cryptogramType));
}
// TODO: if CDA signature requested, set bit 5 to 1 (0x08)
// Build CDOL1 data
byte[] cdolDataValue;
if (Cdol1 != null)
{
// Use CDOL1 to build data
var tlvAll = new List <TlvData> {
TlvFci, TlvProcessingOptions, _tlvGenerateAC1UnpredictableNumber
};
tlvAll.AddRange(TlvRecords);
tlvAll.AddRange(TlvTerminalData);
tlvAll.Add(Tvr.Tlv);
cdolDataValue = Cdol1.BuildData(tlvAll);
}
else
{
cdolDataValue = new byte[0];
}
// Execute GENERATE AC
var cAPDU = new CommandAPDU(0x80, 0xAE, referenceControlParameter, 0x00, (UInt32)cdolDataValue.Length, cdolDataValue, 0); // Bad APDU !
var crp = new CommandResponsePair(cAPDU);
crp.Transmit(_cardChannel);
_lastStatusWord = crp.RApdu.StatusWord;
// If GET RESPONSE needed, do it
if (crp.RApdu.Sw1 == 0x61)
{
_tlvGenerateAC1Response = new TlvData();
crp = new CommandResponsePair(new GetResponseCommand(crp.RApdu.Sw2));
crp.Transmit(_cardChannel);
_lastStatusWord = crp.RApdu.StatusWord;
}
// Finally, store result
if (crp.RApdu.StatusWord == 0x9000)
{
_tlvGenerateAC1Response = new TlvData(crp.RApdu.Udr);
}
AfterGenerateAC1Event.Raise(this, new EmvEventArgs());
return(_lastStatusWord);
}
