protected void SendMessage(
SSUHeader.MessageTypes message,
BufLen mackey,
BufLen cryptokey,
SendMessageGenerator gen)
{
SendMessage(Session.RemoteEP, message, mackey, cryptokey, gen, null);
}
protected void SendMessage(
IPEndPoint dest,
SSUHeader.MessageTypes message,
BufLen mackey,
BufLen cryptokey,
SendMessageGenerator gen)
{
SendMessage(dest, message, mackey, cryptokey, gen, null);
}
/**
* From PacketBuilder.java
* -----8<-----
* @param packet prepared packet with the first 32 bytes empty and a length
* whose size is mod 16.
* As of 0.9.7, length non-mod-16 is allowed; the
* last 1-15 bytes are included in the MAC calculation but are not encrypted.
* -----8<-----
*/
protected void SendMessage(
IPEndPoint dest,
SSUHeader.MessageTypes message,
BufLen mackey,
BufLen cryptokey,
SendMessageGenerator gen,
SendMessageGenerator genextrapadding)
{
var start = Session.Host.SendBuffers.Pop();
var writer = new BufRefLen(start);
var header = new SSUHeader(writer, message);
if (!gen(start, writer))
{
return;
}
// Do not cut to datalen & ~0xf as that might make data at the end unencrypted
var datapadding = BufUtils.Get16BytePadding(writer - start);
writer.Write(BufUtils.RandomBytes(datapadding));
var datalen = writer - start;
var encryptedbuf = new BufLen(start, 32, datalen - 32);
// TODO: Adding extra padding does not seem to work
if (genextrapadding != null)
{
if (!genextrapadding(start, writer))
{
return;
}
}
var packetlen = writer - start;
var data = new BufLen(start, 0, packetlen);
var hmac = new BufLen(data, 32);
SendMessageCipher.Init(true, cryptokey.ToParametersWithIV(header.IV));
SendMessageCipher.ProcessBytes(encryptedbuf);
I2PHMACMD5Digest.Generate(new BufLen[] {
hmac,
header.IV,
BufUtils.Flip16BL((ushort)((ushort)hmac.Length ^ I2PConstants.SSU_PROTOCOL_VERSION))
}, mackey, header.MAC);
#if LOG_MUCH_TRANSPORT
Logging.LogTransport(string.Format("SSUState SendMessage {0}: encrlen {1} bytes [0x{1:X}] (padding {2} bytes [0x{2:X}]), " +
"hmac {3} bytes [0x{3:X}], sendlen {4} bytes [0x{4:X}]",
Session.DebugId,
encryptedbuf.Length,
datapadding,
hmac.Length,
data.Length));
#endif
DataSent();
Send(dest, data);
}
