plugin_block_revocation.c

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/*
     This file is part of GNUnet
     Copyright (C) 2017 GNUnet e.V.
 
     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 <http://www.gnu.org/licenses/>.
 
     SPDX-License-Identifier: AGPL3.0-or-later
 */
 
#include "platform.h"
#include "gnunet_signatures.h"
#include "gnunet_block_plugin.h"
#include "gnunet_block_group_lib.h"
#include "revocation.h"
#include "gnunet_revocation_service.h"
 
#define DEBUG_REVOCATION GNUNET_EXTRA_LOGGING
 
struct InternalContext
{
  unsigned int matching_bits;
  struct GNUNET_TIME_Relative epoch_duration;
};
 
 
static enum GNUNET_GenericReturnValue
block_plugin_revocation_check_query (void *cls,
                                     enum GNUNET_BLOCK_Type type,
                                     const struct GNUNET_HashCode *query,
                                     const void *xquery,
                                     size_t xquery_size)
{
  (void) cls;
  (void) query;
  (void) xquery;
  if (GNUNET_BLOCK_TYPE_REVOCATION != type)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  if (0 != xquery_size)
    return GNUNET_NO;
  return GNUNET_OK;
}
 
 
static enum GNUNET_GenericReturnValue
block_plugin_revocation_check_block (void *cls,
                                     enum GNUNET_BLOCK_Type type,
                                     const void *block,
                                     size_t block_size)
{
  struct InternalContext *ic = cls;
  const struct RevokeMessage *rm = block;
  const struct GNUNET_REVOCATION_PowP *pow
    = (const struct GNUNET_REVOCATION_PowP *) &rm[1];
  struct GNUNET_IDENTITY_PublicKey pk;
  size_t pklen;
  size_t left;
 
  if (GNUNET_BLOCK_TYPE_REVOCATION != type)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  if (block_size < sizeof(*rm) + sizeof(*pow))
  {
    GNUNET_break_op (0);
    return GNUNET_NO;
  }
  if (block_size != sizeof(*rm) + ntohl (rm->pow_size))
  {
    GNUNET_break_op (0);
    return GNUNET_NO;
  }
  left = block_size - sizeof (*rm) - sizeof (*pow);
  if (GNUNET_SYSERR ==
      GNUNET_IDENTITY_read_public_key_from_buffer (&pow[1],
                                                   left,
                                                   &pk,
                                                   &pklen))
  {
    GNUNET_break_op (0);
    return GNUNET_NO;
  }
  if (0 == pklen)
  {
    GNUNET_break_op (0);
    return GNUNET_NO;
  }
  if (GNUNET_YES !=
      GNUNET_REVOCATION_check_pow (pow,
                                   ic->matching_bits,
                                   ic->epoch_duration))
  {
    GNUNET_break_op (0);
    return GNUNET_NO;
  }
  return GNUNET_OK;
}
 
 
static enum GNUNET_BLOCK_ReplyEvaluationResult
block_plugin_revocation_check_reply (
  void *cls,
  enum GNUNET_BLOCK_Type type,
  struct GNUNET_BLOCK_Group *group,
  const struct GNUNET_HashCode *query,
  const void *xquery,
  size_t xquery_size,
  const void *reply_block,
  size_t reply_block_size)
{
  (void) cls;
  (void) group;
  (void) query;
  (void) xquery;
  (void) xquery_size;
  (void) reply_block;
  (void) reply_block_size;
  if (GNUNET_BLOCK_TYPE_REVOCATION != type)
  {
    GNUNET_break (0);
    return GNUNET_BLOCK_REPLY_TYPE_NOT_SUPPORTED;
  }
  return GNUNET_BLOCK_REPLY_OK_LAST;
}
 
 
static enum GNUNET_GenericReturnValue
block_plugin_revocation_get_key (void *cls,
                                 enum GNUNET_BLOCK_Type type,
                                 const void *block,
                                 size_t block_size,
                                 struct GNUNET_HashCode *key)
{
  const struct RevokeMessage *rm = block;
  const struct GNUNET_REVOCATION_PowP *pow
    = (const struct GNUNET_REVOCATION_PowP *) &rm[1];
  struct GNUNET_IDENTITY_PublicKey pk;
  size_t pklen;
  size_t left;
 
  if (GNUNET_BLOCK_TYPE_REVOCATION != type)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  if (block_size < sizeof(*rm) + sizeof(*pow))
  {
    GNUNET_break_op (0);
    return GNUNET_NO;
  }
  if (block_size != sizeof(*rm) + ntohl (rm->pow_size))
  {
    GNUNET_break_op (0);
    return GNUNET_NO;
  }
  left = block_size - sizeof (*rm) - sizeof (*pow);
  if (GNUNET_SYSERR == GNUNET_IDENTITY_read_public_key_from_buffer (&pow[1],
                                                                    left,
                                                                    &pk,
                                                                    &pklen))
  {
    GNUNET_break_op (0);
    return GNUNET_NO;
  }
  if (0 == pklen)
  {
    GNUNET_break_op (0);
    return GNUNET_NO;
  }
  GNUNET_CRYPTO_hash (&pow[1],
                      pklen,
                      key);
  return GNUNET_OK;
}
 
 
void *
libgnunet_plugin_block_revocation_init (void *cls)
{
  static const enum GNUNET_BLOCK_Type types[] = {
    GNUNET_BLOCK_TYPE_REVOCATION,
    GNUNET_BLOCK_TYPE_ANY       /* end of list */
  };
  const struct GNUNET_CONFIGURATION_Handle *cfg = cls;
  struct GNUNET_BLOCK_PluginFunctions *api;
  struct InternalContext *ic;
  unsigned long long matching_bits;
  struct GNUNET_TIME_Relative epoch_duration;
 
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_number (cfg,
                                             "REVOCATION",
                                             "WORKBITS",
                                             &matching_bits))
    return NULL;
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_time (cfg,
                                           "REVOCATION",
                                           "EPOCH_DURATION",
                                           &epoch_duration))
    return NULL;
 
  api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
  api->get_key = &block_plugin_revocation_get_key;
  api->check_query = &block_plugin_revocation_check_query;
  api->check_block = &block_plugin_revocation_check_block;
  api->check_reply = &block_plugin_revocation_check_reply;
  api->create_group = NULL;
  api->types = types;
  ic = GNUNET_new (struct InternalContext);
  ic->matching_bits = (unsigned int) matching_bits;
  ic->epoch_duration = epoch_duration;
  api->cls = ic;
  return api;
}
 
 
void *
libgnunet_plugin_block_revocation_done (void *cls)
{
  struct GNUNET_BLOCK_PluginFunctions *api = cls;
  struct InternalContext *ic = api->cls;
 
  GNUNET_free (ic);
  GNUNET_free (api);
  return NULL;
}
 
 
/* end of plugin_block_revocation.c */