Package org.drasyl.handler.remote.protocol

Class PublicHeader

java.lang.Object

org.drasyl.handler.remote.protocol.PublicHeader

@UnstableApi
public abstract class PublicHeader
extends Object

This class models the public header of a drasyl protocol message. The header is structured as follows:

• Flags: Several packet flags (bits 1-3: hop count, bit 4: set if message is armed, bits 5-8: unused).
• NetworkId: The 4 bytes network id value. Is a unique network-wide value. Used to filter messages from other networks.
• Nonce: The 24 bytes nonce value. Is used for encryption and as message id.
• Recipient: The 32 bytes recipient address. This value is optional. If not set it MUST be sent as 0.
• Sender: The 32 bytes sender address.
• ProofOfWork: The 4 bytes proof of work for the sender address.

The public header is only authenticated and protected from the 2th byte. The hop count is not protected. This allows us to update the hop count in-place during relaying.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	LENGTH

Constructor Summary

Constructors

Constructor	Description
PublicHeader()

Method Summary

Modifier and Type	Method	Description
byte[]	buildAuthTag(io.netty.buffer.ByteBufAllocator alloc)	Builds the authentication tag from this public header.
abstract boolean	getArmed()
abstract HopCount	getHopCount()
abstract int	getNetworkId()
abstract Nonce	getNonce()
abstract ProofOfWork	getProofOfWork()
abstract DrasylAddress	getRecipient()
abstract DrasylAddress	getSender()
static PublicHeader	of(io.netty.buffer.ByteBuf byteBuf)
static PublicHeader	of(HopCount hopCount, boolean isArmed, int networkId, Nonce nonce, DrasylAddress recipient, DrasylAddress sender, ProofOfWork proofOfWork)
static PublicHeader	of(RemoteMessage msg)
void	writeTo(io.netty.buffer.ByteBuf byteBuf)	Writes this header to the buffer byteBuf.
void	writeTo(io.netty.buffer.ByteBuf byteBuf, boolean withHopCount)	Writes this header to the buffer byteBuf.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

LENGTH

public static final int LENGTH

See Also:

• Constant Field Values

Constructor Details

PublicHeader

public PublicHeader()

Method Details

of

public static PublicHeader of(HopCount hopCount,
 boolean isArmed,
 int networkId,
 Nonce nonce,
 DrasylAddress recipient,
 DrasylAddress sender,
 ProofOfWork proofOfWork)

of

public static PublicHeader of(RemoteMessage msg)

of

public static PublicHeader of(io.netty.buffer.ByteBuf byteBuf)
                       throws InvalidMessageFormatException

Throws:

InvalidMessageFormatException

getHopCount

public abstract HopCount getHopCount()

getArmed

public abstract boolean getArmed()

getNetworkId

public abstract int getNetworkId()

getNonce

public abstract Nonce getNonce()

getRecipient

@Nullable
public abstract DrasylAddress getRecipient()

getSender

public abstract DrasylAddress getSender()

getProofOfWork

public abstract ProofOfWork getProofOfWork()

buildAuthTag

public byte[] buildAuthTag(io.netty.buffer.ByteBufAllocator alloc)

Builds the authentication tag from this public header.

Returns:

the authentication tag

writeTo

public void writeTo(io.netty.buffer.ByteBuf byteBuf,
 boolean withHopCount)

Writes this header to the buffer byteBuf.

Parameters:

byteBuf - writes this header to the given buffer

withHopCount - if the hop count should be included

writeTo

public void writeTo(io.netty.buffer.ByteBuf byteBuf)

Writes this header to the buffer byteBuf. Similar to #writeTo(ByteBuf, true).

Parameters:

byteBuf - writes this header to the given buffer