1 files changed, 257 insertions, 0 deletions

diff --git a/src/revocation/plugin_block_revocation.c b/src/revocation/plugin_block_revocation.c
new file mode 100644
index 000000000..eb0766b81
--- /dev/null
+++ b/src/revocation/plugin_block_revocation.c
@@ -0,0 +1,257 @@
+/*
+     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 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., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
+*/
+
+/**
+ * @file block/plugin_block_revocation.c
+ * @brief revocation for a block plugin
+ * @author Christian Grothoff
+ */
+
+#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
+
+/**
+ * Number of bits we set per entry in the bloomfilter.
+ * Do not change!
+ */
+#define BLOOMFILTER_K 16
+
+
+/**
+ * How big is the BF we use for DHT blocks?
+ */
+#define REVOCATION_BF_SIZE 8
+
+
+/**
+ * Context used inside the plugin.
+ */
+struct InternalContext
+{
+
+  unsigned int matching_bits;
+
+};
+
+
+/**
+ * Create a new block group.
+ *
+ * @param ctx block context in which the block group is created
+ * @param type type of the block for which we are creating the group
+ * @param nonce random value used to seed the group creation
+ * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
+ * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
+ * @param va variable arguments specific to @a type
+ * @return block group handle, NULL if block groups are not supported
+ *         by this @a type of block (this is not an error)
+ */
+static struct GNUNET_BLOCK_Group *
+block_plugin_revocation_create_group (void *cls,
+                                      enum GNUNET_BLOCK_Type type,
+                                      uint32_t nonce,
+                                      const void *raw_data,
+                                      size_t raw_data_size,
+                                      va_list va)
+{
+  unsigned int bf_size;
+  const char *guard;
+
+  guard = va_arg (va, const char *);
+  if (0 == strcmp (guard,
+                   "seen-set-size"))
+    bf_size = GNUNET_BLOCK_GROUP_compute_bloomfilter_size (va_arg (va, unsigned int),
+                                                           BLOOMFILTER_K);
+  else if (0 == strcmp (guard,
+                        "filter-size"))
+    bf_size = va_arg (va, unsigned int);
+  else
+  {
+    GNUNET_break (0);
+    bf_size = REVOCATION_BF_SIZE;
+  }
+  GNUNET_break (NULL == va_arg (va, const char *));
+  return GNUNET_BLOCK_GROUP_bf_create (cls,
+                                       bf_size,
+                                       BLOOMFILTER_K,
+                                       type,
+                                       nonce,
+                                       raw_data,
+                                       raw_data_size);
+}
+
+
+/**
+ * Function called to validate a reply or a request.  For
+ * request evaluation, simply pass "NULL" for the reply_block.
+ *
+ * @param cls our `struct InternalContext`
+ * @param ctx context
+ * @param type block type
+ * @param group block group to use
+ * @param eo control flags
+ * @param query original query (hash)
+ * @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_revocation_evaluate (void *cls,
+                                  struct GNUNET_BLOCK_Context *ctx,
+                                  enum GNUNET_BLOCK_Type type,
+                                  struct GNUNET_BLOCK_Group *group,
+                                  enum GNUNET_BLOCK_EvaluationOptions eo,
+                                  const struct GNUNET_HashCode *query,
+                                  const void *xquery,
+                                  size_t xquery_size,
+                                  const void *reply_block,
+                                  size_t reply_block_size)
+{
+  struct InternalContext *ic = cls;
+  struct GNUNET_HashCode chash;
+  const struct RevokeMessage *rm = reply_block;
+
+  if (NULL == reply_block)
+    return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
+  if (reply_block_size != sizeof (*rm))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
+  }
+  if (GNUNET_YES !=
+      GNUNET_REVOCATION_check_pow (&rm->public_key,
+                                   rm->proof_of_work,
+                                   ic->matching_bits))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
+  }
+  if (GNUNET_OK !=
+      GNUNET_CRYPTO_ecdsa_verify (GNUNET_SIGNATURE_PURPOSE_REVOCATION,
+                                  &rm->purpose,
+                                  &rm->signature,
+                                  &rm->public_key))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
+  }
+  GNUNET_CRYPTO_hash (&rm->public_key,
+                      sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey),
+                      &chash);
+  if (GNUNET_YES ==
+      GNUNET_BLOCK_GROUP_bf_test_and_set (group,
+                                          &chash))
+    return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
+  return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
+}
+
+
+/**
+ * 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_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;
+
+  if (block_size != sizeof (*rm))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  GNUNET_CRYPTO_hash (&rm->public_key,
+                      sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey),
+                      key);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Entry point for the plugin.
+ *
+ * @param cls the configuration to use
+ */
+void *
+libgnunet_plugin_block_revocation_init (void *cls)
+{
+  static 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;
+
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_number (cfg,
+                                             "REVOCATION",
+                                             "WORKBITS",
+                                             &matching_bits))
+    return NULL;
+
+  api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
+  api->evaluate = &block_plugin_revocation_evaluate;
+  api->get_key = &block_plugin_revocation_get_key;
+  api->create_group = &block_plugin_revocation_create_group;
+  api->types = types;
+  ic = GNUNET_new (struct InternalContext);
+  ic->matching_bits = (unsigned int) matching_bits;
+  api->cls = ic;
+  return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ */
+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 */