public static PacketPayload.CursorWritingContext StartWriting(MemoryCursor cursor,
PacketVersion version,
PacketConnectionId destinationConnectionId,
PacketConnectionId sourceConnectionId,
PacketNumber largestAcknowledgedPacketNumber,
PacketNumber packetNumber)
{
var startOffset = cursor.AsOffset();
var firstByte = new PacketFirstByte()
.SetRtt()
.SetMaxPacketNumberLength();
firstByte.Write(cursor);
version.WriteBytes(cursor);
destinationConnectionId.WriteBytes(cursor);
sourceConnectionId.WriteBytes(cursor);
var context = PacketPayload.StartPacketWriting(cursor, startOffset);
var packetNumberBytes = firstByte.SlicePacketNumberBytes(cursor);
packetNumber
.EncodeByLargestAcknowledged(largestAcknowledgedPacketNumber)
.Fill(packetNumberBytes.Span);
return(context);
}
public static bool TryParseProtected(IAead aead, ICipher cipher, MemoryCursor cursor, PacketNumber largestAcknowledgedPacketNumber, out RttPacket result)
{
result = new RttPacket();
var startOffset = cursor.AsOffset();
var firstByte = PacketFirstByte.Parse(cursor.Peek(1).Span[0]);
if (!firstByte.IsHandshakeType())
{
return(false);
}
cursor.Move(1);
var version = PacketVersion.Parse(cursor);
var destinationConnectionId = PacketConnectionId.Parse(cursor);
var sourceConnectionId = PacketConnectionId.Parse(cursor);
var payload = PacketPayload.SliceLongProtectedPacketBytes(cursor, aead, cipher, startOffset, firstByte, largestAcknowledgedPacketNumber, out var packetNumber);
result = new RttPacket(version,
destinationConnectionId,
sourceConnectionId,
packetNumber,
payload);
return(true);
}
private ShortPacket(PacketConnectionId destinationConnectionId,
PacketNumber number,
MemoryBuffer payload)
{
DestinationConnectionId = destinationConnectionId;
Number = number;
Payload = payload;
}
private RetryPacket(PacketVersion version,
PacketConnectionId destinationConnectionId,
PacketConnectionId sourceConnectionId,
PacketToken retryToken,
PacketRetryIntegrityTag retryIntegrityTag)
{
Version = version;
DestinationConnectionId = destinationConnectionId;
SourceConnectionId = sourceConnectionId;
RetryToken = retryToken;
RetryIntegrityTag = retryIntegrityTag;
}
private HandshakePacket(PacketVersion version,
PacketConnectionId destinationConnectionId,
PacketConnectionId sourceConnectionId,
PacketNumber number,
MemoryBuffer payload)
{
Version = version;
DestinationConnectionId = destinationConnectionId;
SourceConnectionId = sourceConnectionId;
Number = number;
Payload = payload;
}
private InitialPacket(PacketVersion version,
PacketConnectionId destinationConnectionId,
PacketConnectionId sourceConnectionId,
PacketToken token,
PacketNumber number,
MemoryBuffer payload)
{
Version = version;
DestinationConnectionId = destinationConnectionId;
SourceConnectionId = sourceConnectionId;
Token = token;
Number = number;
Payload = payload;
}
public static PacketPayload.LongProtectedWritingContext StartProtectedWriting(IAead aead,
ICipher cipher,
MemoryCursor cursor,
PacketVersion version,
PacketConnectionId destinationConnectionId,
PacketConnectionId sourceConnectionId,
PacketNumber packetNumber,
PacketToken token)
{
var startPacketOffset = cursor.AsOffset();
var firstByte = new PacketFirstByte()
.SetInitial()
.SetMaxPacketNumberLength();
firstByte.Write(cursor);
version.WriteBytes(cursor);
destinationConnectionId.WriteBytes(cursor);
sourceConnectionId.WriteBytes(cursor);
token.WriteBytes(cursor);
return(PacketPayload.StartLongProtectedPacketWriting(cursor, aead, cipher, startPacketOffset, firstByte, packetNumber, null));
}
public static PacketPayload.ShortProtectedWritingContext StartProtectedWriting(IAead aead,
ICipher cipher,
MemoryCursor cursor,
PacketConnectionId destinationConnectionId,
PacketNumber packetNumber,
PacketNumber largestAcknowledgedPacketNumber)
{
var startOffset = cursor.AsOffset();
var firstByte = new PacketFirstByte().SetShort();
firstByte.Write(cursor);
destinationConnectionId.WriteValueBytes(cursor);
return(PacketPayload.StartShortProtectedPacketWriting(cursor, aead, cipher, startOffset, firstByte, packetNumber, largestAcknowledgedPacketNumber));
}
