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/*
This file is part of GNUnet.
(C) 2009, 2010, 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 3, 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.
*/
/**
* @file core/gnunet-service-core_kx.h
* @brief code for managing the key exchange (SET_KEY, PING, PONG) with other peers
* @author Christian Grothoff
*/
#ifndef GNUNET_SERVICE_CORE_KX_H
#define GNUNET_SERVICE_CORE_KX_H
#include "gnunet_util_lib.h"
/**
* Information about the status of a key exchange with another peer.
*/
struct GSC_KeyExchangeInfo
{
/**
* SetKeyMessage to transmit, NULL if we are not currently trying
* to send one.
*/
struct SetKeyMessage *skm;
/**
* Non-NULL if we are currently looking up HELLOs for this peer.
* for this peer.
*/
struct GNUNET_PEERINFO_IteratorContext *pitr;
/**
* Public key of the neighbour, NULL if we don't have it yet.
*/
struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *public_key;
/**
* We received a PING message before we got the "public_key"
* (or the SET_KEY). We keep it here until we have a key
* to decrypt it. NULL if no PING is pending.
*/
struct PingMessage *pending_ping;
/**
* We received a PONG message before we got the "public_key"
* (or the SET_KEY). We keep it here until we have a key
* to decrypt it. NULL if no PONG is pending.
*/
struct PongMessage *pending_pong;
/**
* Key we use to encrypt our messages for the other peer
* (initialized by us when we do the handshake).
*/
struct GNUNET_CRYPTO_AesSessionKey encrypt_key;
/**
* Key we use to decrypt messages from the other peer
* (given to us by the other peer during the handshake).
*/
struct GNUNET_CRYPTO_AesSessionKey decrypt_key;
/**
* At what time did we generate our encryption key?
*/
struct GNUNET_TIME_Absolute encrypt_key_created;
/**
* At what time did the other peer generate the decryption key?
*/
struct GNUNET_TIME_Absolute decrypt_key_created;
/**
* At what frequency are we currently re-trying SET_KEY messages?
*/
struct GNUNET_TIME_Relative set_key_retry_frequency;
/**
* ID of task used for re-trying SET_KEY and PING message.
*/
GNUNET_SCHEDULER_TaskIdentifier retry_set_key_task;
/**
* ID of task used for sending keep-alive pings.
*/
GNUNET_SCHEDULER_TaskIdentifier keep_alive_task;
/**
* What was our PING challenge number (for this peer)?
*/
uint32_t ping_challenge;
/**
* What is our connection status?
*/
enum PeerStateMachine status;
};
/**
* We received a SET_KEY message. Validate and update
* our key material and status.
*
* @param kx key exchange status for the corresponding peer
* @param msg the set key message we received
* @param ats performance data
* @param ats_count number of entries in ats (excluding 0-termination)
*/
void
GSC_KX_handle_set_key (struct GSC_KeyExchangeInfo *n,
const struct GNUNET_MessageHandler *msg,
const struct GNUNET_TRANSPORT_ATS_Information *ats,
uint32_t ats_count);
/**
* We received a PING message. Validate and transmit
* a PONG message.
*
* @param kx key exchange status for the corresponding peer
* @param msg the encrypted PING message itself
* @param ats performance data
* @param ats_count number of entries in ats (excluding 0-termination)
*/
void
GSC_KX_handle_ping (struct GSC_KeyExchangeInfo *kx,
const struct GNUNET_MessageHeader *msg,
const struct GNUNET_TRANSPORT_ATS_Information *ats,
uint32_t ats_count);
/**
* We received a PONG message. Validate and update our status.
*
* @param kx key exchange status for the corresponding peer
* @param msg the encrypted PONG message itself
* @param ats performance data
* @param ats_count number of entries in ats (excluding 0-termination)
*/
void
GSC_KX_handle_pong (struct GSC_KeyExchangeInfo *kx,
const struct GNUNET_MessageHeader *msg,
const struct GNUNET_TRANSPORT_ATS_Information *ats,
uint32_t ats_count);
/**
* Encrypt and transmit a message with the given payload.
*
* @param kx key exchange context
* @param payload payload of the message
* @param payload_size number of bytes in 'payload'
*/
void
GSC_KX_encrypt_and_transmit (struct GSC_KeyExchangeInfo *kx,
const void *payload,
size_t payload_size);
/**
* We received an encrypted message. Decrypt, validate and
* pass on to the appropriate clients.
*
* @param kx key exchange information context
* @param msg encrypted message
* @param ats performance data
* @param ats_count number of entries in ats (excluding 0-termination)
*/
void
GSC_KX_handle_encrypted_message (struct GSC_KeyExchangeInfo *kx,
const struct GNUNET_MessageHeader *msg,
const struct GNUNET_TRANSPORT_ATS_Information *ats,
uint32_t ats_count);
/**
* Start the key exchange with the given peer.
*
* @param pid identity of the peer to do a key exchange with
* @return key exchange information context
*/
struct GSC_KeyExchangeInfo *
GSC_KX_start (const struct GNUNET_PeerIdentity *pid);
/**
* Stop key exchange with the given peer. Clean up key material.
*
* @param kx key exchange to stop
*/
void
GSC_KX_stop (struct GSC_KeyExchangeInfo *kx);
/**
* Initialize KX subsystem.
*
* @return GNUNET_OK on success, GNUNET_SYSERR on failure
*/
int
GSC_KX_init (void);
/**
* Shutdown KX subsystem.
*/
void
GSC_KX_done (void);
#endif
/* end of gnunet-service-core_kx.h */
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