public LicenseResult(byte[] licenseData, Client client)
{
try
{
var rsaSigner = new RSASigner();
//We always should have the same format
using (var sourceStream = new MemoryStream(licenseData))
using (var reader = new BinaryReader(sourceStream))
{
long dataLength = reader.ReadInt64();
byte[] data = reader.ReadBytes((int)dataLength);
byte[] sign = reader.ReadBytes((int)(licenseData.Length - 8 - dataLength));
var signBuffer = RSASigner.GetSignBuffer(data, new[] { BitConverter.GetBytes(DateTime.UtcNow.Year), client.GetSerialNumber() });
bool valid = rsaSigner.Validate(signBuffer, sign);
if (!valid)
{
throw new LicenseValidationException("License sign is invalid (maybe clock shifting)");
}
LicenseData = client.Decrypt(data);
}
}
catch (Exception e)
{
throw new LicenseException("License corrupted", e);
}
}
public string ToOfflineData()
{
using (var memoryStream = new MemoryStream())
{
using (var writer = new BinaryWriter(memoryStream))
{
var header = (byte)((byte)Type << 7 | ClientId.Length);
writer.Write(header);
writer.Write(ClientId);
if (Type == RequestType.Activate)
{
//Write cert and license data
writer.Write((ushort)Certificate.Length);
writer.Write(Certificate);
if (LicenseKey.Length > 0)
{
writer.Write((ushort)LicenseKey.Length);
writer.Write(LicenseKey);
}
}
var data = memoryStream.ToArray();
var signBuffer = RSASigner.GetSignBuffer(data, new[] { HashSecret.GetSecret() });
writer.Write(SHA512.Create().ComputeHash(signBuffer));
return(DataEncoder.ToHexString(memoryStream.ToArray()));
}
}
}
public static LicenseRequest FromOfflineData(string data)
{
using (var memoryStream = new MemoryStream(DataEncoder.FromHexString(data)))
{
using (var reader = new BinaryReader(memoryStream))
{
var header = reader.ReadByte();
var type = (RequestType)(header >> 7);
var cidLength = header ^ (byte)type << 7;
var request = new LicenseRequest(type)
{
ClientId = reader.ReadBytes(cidLength)
};
if (type == RequestType.Activate)
{
request.Certificate = reader.ReadBytes(reader.ReadUInt16());
if (memoryStream.Position < memoryStream.Length - 66 /*UInt32+SHA512*/)
{
var licenseLength = reader.ReadUInt16();
if (licenseLength > 0)
{
request.LicenseKey = reader.ReadBytes(licenseLength);
}
}
else
{
request.LicenseKey = new byte[0];
}
}
var dataEnd = memoryStream.Position;
var sign = reader.ReadBytes(64);
//Verify sign
memoryStream.Position = 0;
var databuffer = reader.ReadBytes((int)dataEnd);
var signBuffer = RSASigner.GetSignBuffer(databuffer, new[] { HashSecret.GetSecret() });
var signToValidate = SHA512.Create().ComputeHash(signBuffer);
if (sign.Where((t, i) => t != signToValidate[i]).Any())
{
throw new LicenseValidationException("Signatures doesn't match");
}
return(request);
}
}
}