/*
This file is part of GNUnet.
Copyright (C)
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
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
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @file rps/gnunet-service-rps_sampler.c
* @brief sampler implementation
* @author Julius Bünger
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet-service-rps_sampler_elem.h"
#include
#include "rps-test_util.h"
#define LOG(kind, ...) GNUNET_log_from(kind,"rps-sampler_elem",__VA_ARGS__)
/***********************************************************************
* WARNING: This section needs to be reviewed regarding the use of
* functions providing (pseudo)randomness!
***********************************************************************/
/**
* Reinitialise a previously initialised sampler element.
*
* @param sampler_el The sampler element to (re-) initialise
*/
void
RPS_sampler_elem_reinit (struct RPS_SamplerElement *sampler_elem)
{
sampler_elem->is_empty = EMPTY;
// I guess I don't need to call GNUNET_CRYPTO_hmac_derive_key()...
GNUNET_CRYPTO_random_block(GNUNET_CRYPTO_QUALITY_STRONG,
&(sampler_elem->auth_key.key),
GNUNET_CRYPTO_HASH_LENGTH);
sampler_elem->last_client_request = GNUNET_TIME_UNIT_FOREVER_ABS;
sampler_elem->birth = GNUNET_TIME_absolute_get ();
sampler_elem->num_peers = 0;
sampler_elem->num_change = 0;
}
/**
* Create a sampler element and initialise it.
*
* In this implementation this means choosing an auth_key for later use in
* a hmac at random.
*
* @return a newly created RPS_SamplerElement which currently holds no id.
*/
struct RPS_SamplerElement *
RPS_sampler_elem_create (void)
{
struct RPS_SamplerElement *s;
s = GNUNET_new (struct RPS_SamplerElement);
RPS_sampler_elem_reinit (s);
return s;
}
/**
* Destroy a sampler element.
*
* @param sampler_elem the element to destroy
*/
void
RPS_sampler_elem_destroy (struct RPS_SamplerElement *sampler_elem)
{
GNUNET_free (sampler_elem);
}
/**
* Update a sampler element with a PeerID
*
* @param sampler_elem The sampler element to update
* @param new_ID The PeerID to update with
*/
void
RPS_sampler_elem_next (struct RPS_SamplerElement *sampler_elem,
const struct GNUNET_PeerIdentity *new_ID)
{
struct GNUNET_HashCode other_hash;
sampler_elem->num_peers++;
if (0 == GNUNET_memcmp (new_ID, &(sampler_elem->peer_id)))
{
LOG (GNUNET_ERROR_TYPE_DEBUG, "Have already PeerID %s\n",
GNUNET_i2s (&(sampler_elem->peer_id)));
}
else
{
GNUNET_CRYPTO_hmac(&sampler_elem->auth_key,
new_ID,
sizeof(struct GNUNET_PeerIdentity),
&other_hash);
if (EMPTY == sampler_elem->is_empty)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Got PeerID %s; Simply accepting (was empty previously).\n",
GNUNET_i2s(new_ID));
sampler_elem->peer_id = *new_ID;
sampler_elem->peer_id_hash = other_hash;
sampler_elem->num_change++;
}
else if (0 > GNUNET_CRYPTO_hash_cmp (&other_hash, &sampler_elem->peer_id_hash))
{
LOG (GNUNET_ERROR_TYPE_DEBUG, "Discarding old PeerID %s\n",
GNUNET_i2s (&sampler_elem->peer_id));
sampler_elem->peer_id = *new_ID;
sampler_elem->peer_id_hash = other_hash;
sampler_elem->num_change++;
}
else
{
LOG (GNUNET_ERROR_TYPE_DEBUG, "Keeping old PeerID %s\n",
GNUNET_i2s (&sampler_elem->peer_id));
}
}
sampler_elem->is_empty = NOT_EMPTY;
}
/**
* Set the min-wise independent function of the given sampler element.
*
* @param sampler_elem the sampler element
* @param auth_key the key to use
*/
void
RPS_sampler_elem_set (struct RPS_SamplerElement *sampler_elem,
struct GNUNET_CRYPTO_AuthKey auth_key)
{
sampler_elem->auth_key = auth_key;
}
/* end of gnunet-service-rps.c */