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/*
This file is part of GNUnet
(C) 2010 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 gns/plugin_block_gns.c
* @brief blocks used for GNS records
* @author Martin Schanzenbach
*/
#include "platform.h"
#include "gnunet_block_plugin.h"
#include "gnunet_namestore_service.h"
#include "block_gns.h"
#include "gnunet_signatures.h"
/**
* Number of bits we set per entry in the bloomfilter.
* Do not change! -from fs
*/
#define BLOOMFILTER_K 16
/**
* Function called to validate a reply or a request. For
* request evaluation, simply pass "NULL" for the reply_block.
* Note that it is assumed that the reply has already been
* matched to the key (and signatures checked) as it would
* be done with the "get_key" function.
*
* @param cls closure
* @param type block type
* @param query original query (hash)
* @param bf pointer to bloom filter associated with query; possibly updated (!)
* @param bf_mutator mutation value for bf
* @param xquery extrended query data (can be NULL, depending on type)
* @param xquery_size number of bytes in xquery
* @param reply_block response to validate
* @param reply_block_size number of bytes in reply block
* @return characterization of result
*/
static enum GNUNET_BLOCK_EvaluationResult
block_plugin_gns_evaluate (void *cls, enum GNUNET_BLOCK_Type type,
const GNUNET_HashCode * query,
struct GNUNET_CONTAINER_BloomFilter **bf,
int32_t bf_mutator, const void *xquery,
size_t xquery_size, const void *reply_block,
size_t reply_block_size)
{
if (type != GNUNET_BLOCK_TYPE_GNS_NAMERECORD)
return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
if (reply_block_size == 0)
return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
char* name;
GNUNET_HashCode pkey_hash;
GNUNET_HashCode query_key;
GNUNET_HashCode name_hash;
GNUNET_HashCode mhash;
GNUNET_HashCode chash;
struct GNSNameRecordBlock *nrb;
struct GNSRecordBlock *rb;
uint32_t rd_count;
nrb = (struct GNSNameRecordBlock *)reply_block;
name = (char*)&nrb[1];
GNUNET_CRYPTO_hash(&nrb->public_key,
sizeof(nrb->public_key),
&pkey_hash);
GNUNET_CRYPTO_hash(name, strlen(name), &name_hash);
GNUNET_CRYPTO_hash_xor(&pkey_hash, &name_hash, &query_key);
/* Check query key against public key */
if (0 != GNUNET_CRYPTO_hash_cmp(query, &query_key))
return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
rd_count = ntohl(nrb->rd_count);
struct GNUNET_NAMESTORE_RecordData rd[rd_count];
int i = 0;
int record_match = 0;
uint32_t record_xquery = ntohl(*((uint32_t*)xquery));
rb = (struct GNSRecordBlock*)(&name[strlen(name) + 1]);
for (i=0; i<rd_count; i++)
{
rd[i].record_type = ntohl(rb->type);
rd[i].expiration =
GNUNET_TIME_absolute_ntoh(rb->expiration);
rd[i].data_size = ntohl(rb->data_length);
rd[i].flags = ntohl(rb->flags);
rd[i].data = (char*)&rb[1];
rb = (struct GNSRecordBlock *)((char*)&rb[1] + rd[i].data_size);
if (xquery_size == 0)
continue;
if (rd[i].record_type == record_xquery)
{
record_match++;
}
}
/*if (GNUNET_OK != GNUNET_NAMESTORE_verify_signature (&nrb->public_key,
name,
rd_count,
rd,
NULL))
{
GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Signature invalid\n");
return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
}*/
//No record matches query
if ((xquery_size > 0) && (record_match == 0))
return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Records match\n");
//FIXME do bf check before or after crypto??
if (NULL != bf)
{
GNUNET_CRYPTO_hash(reply_block, reply_block_size, &chash);
GNUNET_BLOCK_mingle_hash(&chash, bf_mutator, &mhash);
if (NULL != *bf)
{
GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Check BF\n");
if (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test(*bf, &mhash))
return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
}
else
{
*bf = GNUNET_CONTAINER_bloomfilter_init(NULL, 8, BLOOMFILTER_K);
}
GNUNET_CONTAINER_bloomfilter_add(*bf, &mhash);
}
GNUNET_log(GNUNET_ERROR_TYPE_INFO, "No dup\n");
return GNUNET_BLOCK_EVALUATION_OK_MORE;
}
/**
* Function called to obtain the key for a block.
*
* @param cls closure
* @param type block type
* @param block block to get the key for
* @param block_size number of bytes in block
* @param key set to the key (query) for the given block
* @return GNUNET_OK on success, GNUNET_SYSERR if type not supported
* (or if extracting a key from a block of this type does not work)
*/
static int
block_plugin_gns_get_key (void *cls, enum GNUNET_BLOCK_Type type,
const void *block, size_t block_size,
GNUNET_HashCode * key)
{
if (type != GNUNET_BLOCK_TYPE_GNS_NAMERECORD)
return GNUNET_SYSERR;
GNUNET_HashCode name_hash;
GNUNET_HashCode pkey_hash;
struct GNSNameRecordBlock *nrb = (struct GNSNameRecordBlock *)block;
GNUNET_CRYPTO_hash(&nrb[1], strlen((char*)&nrb[1]), &name_hash);
GNUNET_CRYPTO_hash(&nrb->public_key,
sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
&pkey_hash);
GNUNET_CRYPTO_hash_xor(&name_hash, &pkey_hash, key);
//FIXME calculate key from name and hash(pkey) here
return GNUNET_OK;
}
/**
* Entry point for the plugin.
*/
void *
libgnunet_plugin_block_gns_init (void *cls)
{
static enum GNUNET_BLOCK_Type types[] =
{
GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
GNUNET_BLOCK_TYPE_ANY /* end of list */
};
struct GNUNET_BLOCK_PluginFunctions *api;
api = GNUNET_malloc (sizeof (struct GNUNET_BLOCK_PluginFunctions));
api->evaluate = &block_plugin_gns_evaluate;
api->get_key = &block_plugin_gns_get_key;
api->types = types;
return api;
}
/**
* Exit point from the plugin.
*/
void *
libgnunet_plugin_block_gns_done (void *cls)
{
struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
GNUNET_free (api);
return NULL;
}
/* end of plugin_block_gns.c */
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