/**
* Constant for how many bits the initial string regex should have.
*/
-#define INITIAL_BITS 10
+#define INITIAL_BITS 8
/**
* Get all edges leaving state 's'.
*
* @param s state.
- * @param edges all edges leaving 's'.
+ * @param edges all edges leaving 's', expected to be allocated and have enough
+ * space for s->transitions_count elements.
*
* @return number of edges.
*/
struct GNUNET_REGEX_Automaton *new;
b = ctx->stack_tail;
+ GNUNET_assert (NULL != b);
GNUNET_CONTAINER_DLL_remove (ctx->stack_head, ctx->stack_tail, b);
a = ctx->stack_tail;
+ GNUNET_assert (NULL != a);
GNUNET_CONTAINER_DLL_remove (ctx->stack_head, ctx->stack_tail, a);
state_add_transition (ctx, a->end, 0, b->start);
struct GNUNET_REGEX_State *end;
b = ctx->stack_tail;
+ GNUNET_assert (NULL != b);
GNUNET_CONTAINER_DLL_remove (ctx->stack_head, ctx->stack_tail, b);
a = ctx->stack_tail;
+ GNUNET_assert (NULL != a);
GNUNET_CONTAINER_DLL_remove (ctx->stack_head, ctx->stack_tail, a);
start = nfa_state_create (ctx, 0);
return 0;
result = 1;
- strp = string;
sset = nfa_closure_create (a, a->start, 0);
for (strp = string; NULL != strp && *strp; strp++)
/**
* Get the first key for the given 'input_string'. This hashes the first x bits
- * of the 'input_strings'.
+ * of the 'input_string'.
*
* @param input_string string.
* @param string_len length of the 'input_string'.
* @return number of bits of 'input_string' that have been consumed
* to construct the key
*/
-unsigned int
-GNUNET_REGEX_get_first_key (const char *input_string, unsigned int string_len,
- struct GNUNET_HashCode *key)
+size_t
+GNUNET_REGEX_get_first_key (const char *input_string, size_t string_len,
+ struct GNUNET_HashCode * key)
{
unsigned int size;
/**
* Check if the given 'proof' matches the given 'key'.
*
- * @param proof partial regex
- * @param key hash
+ * @param proof partial regex of a state.
+ * @param key hash of a state.
*
- * @return GNUNET_OK if the proof is valid for the given key
+ * @return GNUNET_OK if the proof is valid for the given key.
*/
int
GNUNET_REGEX_check_proof (const char *proof, const struct GNUNET_HashCode *key)
{
- return GNUNET_OK;
+ struct GNUNET_HashCode key_check;
+
+ GNUNET_CRYPTO_hash (proof, strlen (proof), &key_check);
+ return (0 ==
+ GNUNET_CRYPTO_hash_cmp (key, &key_check)) ? GNUNET_OK : GNUNET_NO;
+}
+
+/**
+ * Recursive helper function for iterate_initial_edges. Will call iterator
+ * function for each initial state.
+ *
+ * @param max_len maximum length of the path in the graph.
+ * @param cur_len current length of the path already traversed.
+ * @param consumed_string string consumed by traversing the graph till this state.
+ * @param next_state next state in the graph that is reachable with 'label' transition.
+ * @param label label of the transition to the next state.
+ * @param iterator iterator function called for each edge.
+ * @param iterator_cls closure for the iterator function.
+ */
+static void
+iterate_initial_edge (const unsigned int max_len, unsigned int cur_len,
+ char *consumed_string,
+ struct GNUNET_REGEX_State *next_state, const char label,
+ GNUNET_REGEX_KeyIterator iterator, void *iterator_cls)
+{
+ char *temp;
+ struct GNUNET_REGEX_Transition *t;
+ struct GNUNET_REGEX_Edge edge;
+ struct GNUNET_HashCode hash;
+ size_t constr_len;
+
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "max_len: %u, cur_len: %u, consumed_string: %s\n", max_len,
+ cur_len, consumed_string);
+
+ if (max_len == cur_len)
+ {
+ constr_len = strlen (consumed_string);
+ GNUNET_CRYPTO_hash (consumed_string, constr_len - 1, &hash);
+ GNUNET_asprintf (&temp, "%c", label);
+ edge.label = temp;
+ edge.destination = next_state->hash;
+ consumed_string[constr_len - 1] = '\0';
+ iterator (iterator_cls, &hash, consumed_string, 0, 1, &edge);
+ GNUNET_free (temp);
+
+ return;
+ }
+ else if (cur_len <= max_len)
+ {
+ cur_len++;
+ for (t = next_state->transitions_head; NULL != t; t = t->next)
+ {
+ if (NULL != consumed_string)
+ GNUNET_asprintf (&temp, "%s%c", consumed_string, t->label);
+ else
+ GNUNET_asprintf (&temp, "%c", t->label);
+
+ iterate_initial_edge (max_len, cur_len, temp, t->to_state, t->label,
+ iterator, iterator_cls);
+ GNUNET_free (temp);
+ }
+ }
+}
+
+/**
+ * Iterate over all initial edges that aren't actually part of the automaton.
+ * This is needed to find the initial states returned by
+ * GNUNET_REGEX_get_first_key.
+ *
+ * @param a the automaton for which the initial states should be computed.
+ * @param initial_len length of the initial state string.
+ * @param iterator iterator function called for each edge.
+ * @param iterator_cls closure for the iterator function.
+ */
+void
+iterate_initial_edges (struct GNUNET_REGEX_Automaton *a,
+ const unsigned int initial_len,
+ GNUNET_REGEX_KeyIterator iterator, void *iterator_cls)
+{
+ iterate_initial_edge (initial_len + 1, 0, NULL, a->start, 0, iterator,
+ iterator_cls);
}
for (s = a->states_head; NULL != s; s = s->next)
s->marked = GNUNET_NO;
+ iterate_initial_edges (a, INITIAL_BITS, iterator, iterator_cls);
iterate_edge (a->start, iterator, iterator_cls);
}
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