private Message GetPendingMessage()
{
DtlsReassembler next = (DtlsReassembler)mCurrentInboundFlight[mNextReceiveSeq];
if (next != null)
{
byte[] body = next.GetBodyIfComplete();
if (body != null)
{
mPreviousInboundFlight = null;
return(UpdateHandshakeMessagesDigest(new Message(mNextReceiveSeq++, next.MsgType, body)));
}
}
return(null);
}
private bool ProcessRecord(int windowSize, int epoch, byte[] buf, int off, int len)
{
bool checkPreviousFlight = false;
while (len >= MessageHeaderLength)
{
int fragment_length = TlsUtilities.ReadUint24(buf, off + 9);
int message_length = fragment_length + MessageHeaderLength;
if (len < message_length)
{
// NOTE: Truncated message - ignore it
break;
}
int length = TlsUtilities.ReadUint24(buf, off + 1);
int fragment_offset = TlsUtilities.ReadUint24(buf, off + 6);
if (fragment_offset + fragment_length > length)
{
// NOTE: Malformed fragment - ignore it and the rest of the record
break;
}
/*
* NOTE: This very simple epoch check will only work until we want to support
* renegotiation (and we're not likely to do that anyway).
*/
byte msg_type = TlsUtilities.ReadUint8(buf, off + 0);
int expectedEpoch = msg_type == HandshakeType.finished ? 1 : 0;
if (epoch != expectedEpoch)
{
break;
}
int message_seq = TlsUtilities.ReadUint16(buf, off + 4);
if (message_seq >= (mNextReceiveSeq + windowSize))
{
// NOTE: Too far ahead - ignore
}
else if (message_seq >= mNextReceiveSeq)
{
DtlsReassembler reassembler = (DtlsReassembler)mCurrentInboundFlight[message_seq];
if (reassembler == null)
{
reassembler = new DtlsReassembler(msg_type, length);
mCurrentInboundFlight[message_seq] = reassembler;
}
reassembler.ContributeFragment(msg_type, length, buf, off + MessageHeaderLength, fragment_offset,
fragment_length);
}
else if (mPreviousInboundFlight != null)
{
/*
* NOTE: If we receive the previous flight of incoming messages in full again,
* retransmit our last flight
*/
DtlsReassembler reassembler = (DtlsReassembler)mPreviousInboundFlight[message_seq];
if (reassembler != null)
{
reassembler.ContributeFragment(msg_type, length, buf, off + MessageHeaderLength, fragment_offset,
fragment_length);
checkPreviousFlight = true;
}
}
off += message_length;
len -= message_length;
}
bool result = checkPreviousFlight && CheckAll(mPreviousInboundFlight);
if (result)
{
ResendOutboundFlight();
ResetAll(mPreviousInboundFlight);
}
return(result);
}
