/// <summary>
/// Creates a new <seealso cref="BluetoothUnlockPacket"/> object from the given payload.
/// </summary>
/// <param name="payload">The API frame payload. It must start with the frame type corresponding
/// to a Bluetooth Unlock packet (<c>0x2C</c>). The byte array must be in <see cref="OperatingMode.API"/>
/// mode.</param>
/// <returns>Parsed Bluetooth Unlock packet.</returns>
/// <exception cref="ArgumentException">If <c>payload[0] != APIFrameType.BLE_UNLOCK.GetValue()</c>
/// or if <c>payload.Length <![CDATA[<]]> <see cref="MIN_API_PAYLOAD_LENGTH"/></c>.</exception>
/// <exception cref="ArgumentNullException">If <c><paramref name="payload"/> == null</c>.</exception>
public static BluetoothUnlockPacket CreatePacket(byte[] payload)
{
if (payload == null)
{
throw new ArgumentNullException("Bluetooth Unlock packet payload cannot be null.");
}
// 1 (Frame type) + 1 (Step) + 32 (Hash length)
if (payload.Length < MIN_API_PAYLOAD_LENGTH)
{
throw new ArgumentException("Incomplete Bluetooth Unlock packet.");
}
if ((payload[0] & 0xFF) != APIFrameType.BLE_UNLOCK.GetValue())
{
throw new ArgumentException("Payload is not a Bluetooth Unlock packet.");
}
// payload[0] is the frame type.
int index = 1;
// SRP phase.
SrpPhase phase = SrpPhase.UNKNOWN.Get(payload[index]);
index = index + 1;
// Data.
byte[] data = null;
if (index < payload.Length)
{
data = new byte[payload.Length - index];
Array.Copy(payload, index, data, 0, data.Length);
}
return(new BluetoothUnlockPacket(phase, data));
}
/// <summary>
/// Class constructor. Instantiates a <see cref="BluetoothUnlockPacket"/> with the given parameters.
/// </summary>
/// <param name="phase">The SRP phase.</param>
/// <param name="data">The data.</param>
/// <exception cref="ArgumentException">If <paramref name="phase"/> is <see cref="SrpPhase.UNKNOWN"/>.</exception>
/// <exception cref="ArgumentNullException">If <paramref name="data"/> is <c>null</c>.</exception>
/// <seealso cref="Models.SrpPhase"/>
public BluetoothUnlockPacket(SrpPhase phase, byte[] data) : base(APIFrameType.BLE_UNLOCK)
{
if (phase == SrpPhase.UNKNOWN)
{
throw new ArgumentException("SRP phase cannot be unknown.");
}
SrpPhase = phase;
Data = data ?? throw new ArgumentNullException("Data cannot be null.");
logger = LogManager.GetLogger <BluetoothUnlockPacket>();
}
/// <summary>
/// Gets the <see cref="SrpPhase"/> associated with the specified ID <paramref name="value"/>.
/// </summary>
/// <param name="source"></param>
/// <param name="value">ID value to retrieve <see cref="SrpPhase"/>.</param>
/// <returns>The <see cref="SrpPhase"/> for the specified ID <paramref name="value"/>,
/// <see cref="SrpPhase.UNKNOWN"/> if it does not exist.</returns>
public static SrpPhase Get(this SrpPhase source, byte value)
{
var values = Enum.GetValues(typeof(SrpPhase)).OfType <SrpPhase>();
if (values.Cast <byte>().Contains(value))
{
return((SrpPhase)value);
}
return(SrpPhase.UNKNOWN);
}
/// <summary>
/// Returns the <see cref="SrpPhase"/> in string format.
/// </summary>
/// <param name="source"></param>
/// <returns>The <see cref="SrpPhase"/> in string format.</returns>
public static string ToDisplayString(this SrpPhase source)
{
return(string.Format("({0}) {1}", HexUtils.ByteArrayToHexString(ByteUtils.IntToByteArray((byte)source)), GetName(source)));
}
/// <summary>
/// Gets the SRP phase name.
/// </summary>
/// <param name="source"></param>
/// <returns>The SRP phase name.</returns>
public static string GetName(this SrpPhase source)
{
return(lookupTable.ContainsKey(source) ? lookupTable[source] : source.ToString());
}
/// <summary>
/// Gets the SRP phase value.
/// </summary>
/// <param name="source"></param>
/// <returns>The SRP phase value.</returns>
public static byte GetValue(this SrpPhase source)
{
return((byte)source);
}
/// <summary>
/// Starts the bluetooth authentication with the XBee device.
/// </summary>
/// <exception cref="BluetoothAuthenticationException">If there is any error performing the
/// bluetooth authentication.</exception>
/// <exception cref="InterfaceNotOpenException">If the connection interface is not open.</exception>
/// <exception cref="XBeeException">If there is any error in the communication process.</exception>
public void Authenticate()
{
// Check connection.
if (!device.IsOpen)
{
throw new InterfaceNotOpenException();
}
device.PacketReceived += ReceiveBLEPacket;
try
{
User user = new User(API_USERNAME, password);
// Phase 1.
byte[] clientEphemeral = user.StartAuthentication();
expectedPhase = SrpPhase.PHASE_2;
unlockResponse = null;
device.SendPacketAsync(new BluetoothUnlockPacket(SrpPhase.PHASE_1, clientEphemeral));
lock (unlockLock)
{
Monitor.Wait(unlockLock, TIMEOUT_AUTH);
}
CheckResponsePacket();
// Phase 2.
int index = 0;
byte[] salt = new byte[LENGTH_SALT];
Array.Copy(unlockResponse.Data, index, salt, 0, salt.Length);
index += LENGTH_SALT;
byte[] serverEphemeral = new byte[LENGTH_EPHEMERAL];
Array.Copy(unlockResponse.Data, index, serverEphemeral, 0, serverEphemeral.Length);
// Phase 3.
byte[] clientSessionProof = user.ProcessChallenge(salt, serverEphemeral);
expectedPhase = SrpPhase.PHASE_4;
unlockResponse = null;
device.SendPacketAsync(new BluetoothUnlockPacket(SrpPhase.PHASE_3, clientSessionProof));
lock (unlockLock)
{
Monitor.Wait(unlockLock, TIMEOUT_AUTH);
}
CheckResponsePacket();
// Phase 4.
index = 0;
byte[] serverSessionProof = new byte[LENGTH_SESSION_PROOF];
Array.Copy(unlockResponse.Data, index, serverSessionProof, 0, serverSessionProof.Length);
index += LENGTH_SESSION_PROOF;
TxNonce = new byte[LENGTH_NONCE];
Array.Copy(unlockResponse.Data, index, TxNonce, 0, TxNonce.Length);
index += LENGTH_NONCE;
RxNonce = new byte[LENGTH_NONCE];
Array.Copy(unlockResponse.Data, index, RxNonce, 0, RxNonce.Length);
user.VerifySession(serverSessionProof);
if (!user.authenticated)
{
throw new BluetoothAuthenticationException(string.Format(ERROR_AUTH_EXTENDED, ERROR_BAD_PROOF));
}
// Save the sesion key.
Key = user.SessionKey;
}
catch (IOException e)
{
throw new XBeeException(ERROR_WRITING, e);
}
finally
{
device.PacketReceived -= ReceiveBLEPacket;
}
}
