net.i2p.router.transport.ntcp
Class EstablishState

java.lang.Object
  net.i2p.router.transport.ntcp.EstablishState

 class EstablishState
extends Object

Handle the 4-phase establishment, which is as follows:

 Alice                   contacts                      Bob
 =========================================================

 Message 1 (Session Request):
  X+(H(X) xor Bob.identHash)----------------------------->

 Message 2 (Session Created):
  <----------------------------------------Y+E(H(X+Y)+tsB, sk, Y[239:255])

 Message 3 (Session Confirm A):
  E(sz+Alice.identity+tsA+padding+S(X+Y+Bob.identHash+tsA+tsB), sk, hX_xor_Bob.identHash[16:31])--->

 Message 4 (Session Confirm B):
  <----------------------E(S(X+Y+Alice.identHash+tsA+tsB)+padding, sk, prev)

  Key:

    X, Y: 256 byte DH keys
    H(): 32 byte SHA256 Hash
    E(data, session key, IV): AES256 Encrypt
    S(): 40 byte DSA Signature
    tsA, tsB: timestamps (4 bytes, seconds since epoch)
    sk: 32 byte Session key
    sz: 2 byte size of Alice identity to follow

 

Alternately, when Bob receives a connection, it could be a check connection (perhaps prompted by Bob asking for someone to verify his listener). check connections are formatted per isCheckInfo() NOTE: Check info is unused.

Constructor Summary

EstablishState(RouterContext ctx, NTCPTransport transport, NTCPConnection con)

Method Summary

boolean	confirmWritten() we have written all of the data required to confirm the connection establishment
String	getError()
Exception	getException()
byte[]	getExtraBytes() if complete, this will contain any bytes received as part of the handshake that were after the actual handshake.
boolean	getFailedBySkew()
boolean	isComplete()
boolean	isCorrupt() did the handshake fail for some reason?
void	prepareOutbound() We are Alice.
void	receive(ByteBuffer src) parse the contents of the buffer as part of the handshake.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

EstablishState

public EstablishState(RouterContext ctx,
                      NTCPTransport transport,
                      NTCPConnection con)

Method Detail

receive

public void receive(ByteBuffer src)

parse the contents of the buffer as part of the handshake. if the handshake is completed and there is more data remaining, the data are copieed out so that the next read will be the (still encrypted) remaining data (available from getExtraBytes) All data must be copied out of the buffer as Reader.processRead() will return it to the pool.

confirmWritten

public boolean confirmWritten()

we have written all of the data required to confirm the connection establishment

getFailedBySkew

public boolean getFailedBySkew()

isCorrupt

public boolean isCorrupt()

did the handshake fail for some reason?

isComplete

public boolean isComplete()

Returns:

is the handshake complete and valid?

prepareOutbound

public void prepareOutbound()

We are Alice. We are establishing an outbound connection, so prepare ourselves by queueing up the write of the first part of the handshake This method sends message #1 to Bob.

getExtraBytes

public byte[] getExtraBytes()

if complete, this will contain any bytes received as part of the handshake that were after the actual handshake. This may return null.

getError

public String getError()

getException

public Exception getException()

toString

public String toString()

Overrides:

toString in class Object