public byte[] WriteData(byte[] sessionKey, byte fileNo, byte dataIn)
{
//byte fileNo = 0x01;
byte[] offset = new byte[] { 0x00, 0x00, 0x00 }; //offset of 0
byte[] length = new byte[] { 0x00, 0x00, 0x01 }; //length of 1
byte[] dataToWrite = new byte[] { dataIn };
byte[] dataForCRC32Header = new byte[] { (byte)DesfireCommand.CommandType.WriteData, fileNo, offset[2], offset[1], offset[0], length[2], length[1], length[0] };
byte[] dataForCRC32 = new byte[dataForCRC32Header.Length + dataToWrite.Length];
Array.Copy(dataForCRC32Header, dataForCRC32, dataForCRC32Header.Length);
Array.Copy(dataToWrite, 0, dataForCRC32, dataForCRC32Header.Length, dataToWrite.Length);
uint crc32 = Crc32.Compute(dataForCRC32);
string dataPlusCRC = Formatting.ByteArrayToHexString(dataToWrite) + Formatting.ByteArrayToHexString(BitConverter.GetBytes(crc32));
byte[] dataPlusCRCPadded = Formatting.HexStringToByteArray(dataPlusCRC);
Formatting.PadToMultipleOf(ref dataPlusCRCPadded, 16);
string initialIV = "00000000000000000000000000000000";
byte[] dataPlusCRCResultPaddedEncrypted = AESCrypto.AESEncrypt(
sessionKey,
Formatting.HexStringToByteArray(initialIV),
dataPlusCRCPadded);
byte[] extractIV = new byte[16];
Array.Copy(dataPlusCRCResultPaddedEncrypted, dataPlusCRCResultPaddedEncrypted.Length - 16, extractIV, 0, 16);
byte[] cmdToSendHeader = new byte[] { fileNo, offset[2], offset[1], offset[0], length[2], length[1], length[0] };
byte[] cmdToSend = new byte[cmdToSendHeader.Length + dataPlusCRCResultPaddedEncrypted.Length];
Array.Copy(cmdToSendHeader, cmdToSend, cmdToSendHeader.Length);
Array.Copy(dataPlusCRCResultPaddedEncrypted, 0, cmdToSend, cmdToSendHeader.Length, dataPlusCRCResultPaddedEncrypted.Length);
DesfireCommand desfireCommand = new DesfireCommand()
{
Command = (byte)DesfireCommand.CommandType.WriteData,
Data = cmdToSend
};
DesfireResponse desfireResFile = SendCommand(desfireCommand) as DesfireResponse;
if (!desfireResFile.Succeeded)
{
throw new DesFireException("Error:" + desfireResFile.SW);
}
byte[] cmac = AESCMAC.CMAC(
sessionKey,
extractIV,
new byte[] { desfireResFile.SW2 });
byte[] updatedIV = cmac;
byte[] data = ReadData(sessionKey, updatedIV, fileNo);
if (data[0] != dataToWrite[0])
{
throw new DesFireException("Data read not the same as data written");
}
return(data);
}
public byte[] ReadData(byte[] sessionKey, byte[] updatedIV, byte fileNo)
{
byte[] offset = new byte[] { 0x00, 0x00, 0x00 }; //offset of 0
byte[] length = new byte[] { 0x00, 0x00, 0x01 }; //length of 1
byte[] dataForCMAC = new byte[] { (byte)DesfireCommand.CommandType.ReadData, fileNo, offset[2], offset[1], offset[0], length[2], length[1], length[0] };
byte[] cmac = AESCMAC.CMAC(
sessionKey,
updatedIV,
dataForCMAC);
updatedIV = cmac;
byte[] cmdToSend = new byte[] { fileNo, offset[2], offset[1], offset[0], length[2], length[1], length[0] };
DesfireCommand desfireCommand = new DesfireCommand()
{
Command = (byte)DesfireCommand.CommandType.ReadData,
Data = cmdToSend
};
DesfireResponse desfireRes = SendCommand(desfireCommand) as DesfireResponse;
if (!desfireRes.Succeeded)
{
throw new DesFireException("Error:" + desfireRes.SW);
}
byte[] dataBytes = AESCrypto.AESDecrypt(
sessionKey,
updatedIV,
desfireRes.ResponseData);
byte[] extractIV = new byte[16];
Array.Copy(desfireRes.ResponseData, desfireRes.ResponseData.Length - 16, extractIV, 0, 16);
int lengthofData = 0x01;
byte[] data = new byte[lengthofData];
Array.Copy(dataBytes, data, data.Length);
byte[] crc = new byte[4];
Array.Copy(dataBytes, data.Length, crc, 0, crc.Length); //crc is 4 bytes long
byte[] dataPlusStatus = new byte[data.Length + 1];
Array.Copy(data, dataPlusStatus, data.Length);
Array.Copy(new byte[] { 0x00 }, 0, dataPlusStatus, data.Length, 1);
uint crc32 = Crc32.Compute(dataPlusStatus);
//compare crc32 to crc
if (BitConverter.ToUInt32(crc, 0) != crc32)
{
throw new DesFireException("CRC32 error");
}
return(data);
}
public static byte[] CMAC(byte[] key, byte[] iv, byte[] data)
{
// SubKey generation
// step 1, AES-128 with key K is applied to an all-zero input block.
byte[] L = AESCrypto.AESEncrypt(key, new byte[16], new byte[16]);
// step 2, K1 is derived through the following operation:
byte[] FirstSubkey = Rol(L); //If the most significant bit of L is equal to 0, K1 is the left-shift of L by 1 bit.
if ((L[0] & 0x80) == 0x80)
{
FirstSubkey[15] ^= 0x87; // Otherwise, K1 is the exclusive-OR of const_Rb and the left-shift of L by 1 bit.
}
// step 3, K2 is derived through the following operation:
byte[] SecondSubkey = Rol(FirstSubkey); // If the most significant bit of K1 is equal to 0, K2 is the left-shift of K1 by 1 bit.
if ((FirstSubkey[0] & 0x80) == 0x80)
{
SecondSubkey[15] ^= 0x87; // Otherwise, K2 is the exclusive-OR of const_Rb and the left-shift of K1 by 1 bit.
}
// MAC computing
if (((data.Length != 0) && (data.Length % 16 == 0)) == true)
{
// If the size of the input message block is equal to a positive multiple of the block size (namely, 128 bits),
// the last block shall be exclusive-OR'ed with K1 before processing
for (int j = 0; j < FirstSubkey.Length; j++)
{
data[data.Length - 16 + j] ^= FirstSubkey[j];
}
}
else
{
// Otherwise, the last block shall be padded with 10^i
byte[] padding = new byte[16 - data.Length % 16];
padding[0] = 0x80;
data = data.Concat <byte>(padding.AsEnumerable()).ToArray();
// and exclusive-OR'ed with K2
for (int j = 0; j < SecondSubkey.Length; j++)
{
data[data.Length - 16 + j] ^= SecondSubkey[j];
}
}
// The result of the previous process will be the input of the last encryption.
byte[] encResult = AESCrypto.AESEncrypt(key, iv, data);
byte[] HashValue = new byte[16];
Array.Copy(encResult, encResult.Length - HashValue.Length, HashValue, 0, HashValue.Length);
return(HashValue);
}
public byte[] AuthenticateAES()
{
string initialIV = "00000000000000000000000000000000";
string key = "00000000000000000000000000000000";
DesfireCommand desfireCommand = new DesfireCommand()
{
Command = (byte)DesfireCommand.CommandType.AuthenticateAES,
Data = new byte[] { 0x00 } //1 byte key number
};
DesfireResponse desfireRes1 = SendCommand(desfireCommand) as DesfireResponse;
if (!desfireRes1.SubsequentFrame) //additional frames expected
{
throw new DesFireException("Error:" + desfireRes1.SW);
}
byte[] rndBBytes = AESCrypto.AESDecrypt(
Formatting.HexStringToByteArray(key),
Formatting.HexStringToByteArray(initialIV),
desfireRes1.ResponseData);
byte[] rndBRotatedBytes = Formatting.RotateRight(rndBBytes);
string rndAGenerated = "2347C1557F80707ABDFF86BF9D965CA7";
string rndAPlusRndBRotated = rndAGenerated + Formatting.ByteArrayToHexString(rndBRotatedBytes);
string ivNew = Formatting.ByteArrayToHexString(desfireRes1.ResponseData);
byte[] rndAPlusRndBRotatedCipherBytes = AESCrypto.AESEncrypt(
Formatting.HexStringToByteArray(key),
Formatting.HexStringToByteArray(ivNew),
Formatting.HexStringToByteArray(rndAPlusRndBRotated));
desfireCommand = new DesfireCommand()
{
Command = (byte)DesfireCommand.CommandType.GetAdditionalFrame,
Data = rndAPlusRndBRotatedCipherBytes //32 byte enciphered RndA/RndB
};
byte[] extractIV = new byte[16];
Array.Copy(rndAPlusRndBRotatedCipherBytes, rndAPlusRndBRotatedCipherBytes.Length - 16, extractIV, 0, 16);
DesfireResponse desfireRes2 = SendCommand(desfireCommand) as DesfireResponse;
if (!desfireRes2.Succeeded)
{
throw new DesFireException("Error:" + desfireRes2.SW);
}
byte[] rndARotatedBytes = AESCrypto.AESDecrypt(
Formatting.HexStringToByteArray(key),
extractIV,
desfireRes2.ResponseData);
byte[] rndABytes = Formatting.RotateLeft(rndARotatedBytes);
if (rndAGenerated != Formatting.ByteArrayToHexString(rndABytes))
{
throw new DesFireException("rndA generated not same as rndA received");
}
string rndAString = Formatting.ByteArrayToHexString(rndABytes);
string rndBString = Formatting.ByteArrayToHexString(rndBBytes);
string sessionKey = rndAString.Substring(0, 8) + rndBString.Substring(0, 8) +
rndAString.Substring(24, 8) + rndBString.Substring(24, 8);
return(Formatting.HexStringToByteArray(sessionKey));
}