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/*
This file is part of GNUnet.
(C) 2001-2011 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 2, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
/**
* @author Nathan Evans
* @file nse/nse.h
*
* @brief Common type definitions for the network size estimation
* service and API.
*/
#ifndef NSE_H
#define NSE_H
#include "gnunet_common.h"
#define DEBUG_NSE GNUNET_YES
#define SIGNED_TIMESTAMP_SIZE sizeof(struct GNUNET_TIME_Absolute)
/** FIXME: define NSE message types here. */
struct GNUNET_Signed_Timestamp
{
char data[SIGNED_TIMESTAMP_SIZE];
};
/**
* Network size estimate sent from the service
* to clients. Contains the current size estimate
* (or 0 if none has been calculated) and the
* standard deviation of known estimates.
*
*/
struct GNUNET_NSE_ClientMessage
{
/**
* Type: GNUNET_MESSAGE_TYPE_NSE_UPDATE
*/
struct GNUNET_MessageHeader header;
/*
* The current estimated network size.
*/
double size_estimate;
/**
* The standard deviation (rounded down
* to the nearest integer) of size
* estimations.
*/
double std_deviation;
};
/**
* Network size estimate reply; sent when "this"
* peer's timer has run out before receiving a
* valid reply from another peer.
*
* FIXME: Is this the right way to do this?
* I think we need to include both the public
* key and the timestamp signed by the private
* key. This way a recipient
* can verify that the peer at least generated
* the public/private key pair, and that the
* timestamp matches what the current peer
* believes it should be. The receiving peer
* would then check whether the XOR of the peer
* identity and the timestamp is within a
* reasonable range of the current time
* (+/- N seconds). If a closer message which
* also verifies hasn't been received (or this
* message is a duplicate), the peer
* calculates the size estimate and forwards
* the request to all other peers.
*
* Hmm... Is it enought to *just* send the peer
* identity? Obviously this is smaller, but it
* doesn't allow us to verify that the
* public/private key pair were generated, right?
*/
struct GNUNET_NSE_ReplyMessage
{
/**
* Type: GNUNET_MESSAGE_TYPE_NSE_REPLY
*/
struct GNUNET_MessageHeader header;
/**
* The current timestamp value (which all
* peers should agree on) signed by the
* private key of the initiating peer.
*/
struct GNUNET_Signed_Timestamp timestamp;
/**
* Public key of the originator, signed timestamp
* is decrypted by this.
*/
struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pkey;
};
#endif
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