[tor-commits] [tor/master] prop224: Fix hidserv request code to work for both v2 and v3.
nickm at torproject.org
nickm at torproject.org
Thu Aug 24 19:13:51 UTC 2017
commit 15c9b7e891dea655476dc77a07cef8824402fb00
Author: George Kadianakis <desnacked at riseup.net>
Date: Thu Jun 1 13:56:43 2017 +0300
prop224: Fix hidserv request code to work for both v2 and v3.
See documentation of `last_hid_serv_requests_` for how it works. strmaps are
cool!
Signed-off-by: David Goulet <dgoulet at torproject.org>
---
src/or/hs_common.c | 121 ++++++++++++++++++++++++++++++----------------------
src/or/hs_common.h | 11 ++++-
src/or/rendclient.c | 8 ++--
3 files changed, 82 insertions(+), 58 deletions(-)
diff --git a/src/or/hs_common.c b/src/or/hs_common.c
index 48d5f78bb..dbd384833 100644
--- a/src/or/hs_common.c
+++ b/src/or/hs_common.c
@@ -1325,8 +1325,8 @@ hs_get_responsible_hsdirs(const ed25519_public_key_t *blinded_pk,
/** Return the period for which a hidden service directory cannot be queried
* for the same descriptor ID again, taking TestingTorNetwork into account. */
-static time_t
-hsdir_requery_period(const or_options_t *options)
+time_t
+hs_hsdir_requery_period(const or_options_t *options)
{
tor_assert(options);
@@ -1337,17 +1337,25 @@ hsdir_requery_period(const or_options_t *options)
}
}
-/** Contains the last request times to hidden service directories for
- * certain queries; each key is a string consisting of the
- * concatenation of a base32-encoded HS directory identity digest and
- * base32-encoded HS descriptor ID; each value is a pointer to a time_t
- * holding the time of the last request for that descriptor ID to that
- * HS directory. */
+/** Tracks requests for fetching hidden service descriptors. It's used by
+ * hidden service clients, to avoid querying HSDirs that have already failed
+ * giving back a descriptor. The same data structure is used to track both v2
+ * and v3 HS descriptor requests.
+ *
+ * The string map is a key/value store that contains the last request times to
+ * hidden service directories for certain queries. Specifically:
+ *
+ * key = base32(hsdir_identity) + base32(hs_identity)
+ * value = time_t of last request for that hs_identity to that HSDir
+ *
+ * where 'hsdir_identity' is the identity digest of the HSDir node, and
+ * 'hs_identity' is the descriptor ID of the HS in the v2 case, or the ed25519
+ * identity public key of the HS in the v3 case. */
static strmap_t *last_hid_serv_requests_ = NULL;
/** Returns last_hid_serv_requests_, initializing it to a new strmap if
* necessary. */
-static strmap_t *
+STATIC strmap_t *
get_last_hid_serv_requests(void)
{
if (!last_hid_serv_requests_)
@@ -1355,30 +1363,26 @@ get_last_hid_serv_requests(void)
return last_hid_serv_requests_;
}
-#define LAST_HID_SERV_REQUEST_KEY_LEN (REND_DESC_ID_V2_LEN_BASE32 + \
- REND_DESC_ID_V2_LEN_BASE32)
-
/** Look up the last request time to hidden service directory <b>hs_dir</b>
- * for descriptor ID <b>desc_id_base32</b>. If <b>set</b> is non-zero,
- * assign the current time <b>now</b> and return that. Otherwise, return the
- * most recent request time, or 0 if no such request has been sent before.
- */
-static time_t
-lookup_last_hid_serv_request(routerstatus_t *hs_dir,
- const char *desc_id_base32,
- time_t now, int set)
+ * for descriptor request key <b>req_key_str</b> which is the descriptor ID
+ * for a v2 service or the blinded key for v3. If <b>set</b> is non-zero,
+ * assign the current time <b>now</b> and return that. Otherwise, return the
+ * most recent request time, or 0 if no such request has been sent before. */
+time_t
+hs_lookup_last_hid_serv_request(routerstatus_t *hs_dir,
+ const char *req_key_str,
+ time_t now, int set)
{
char hsdir_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
- char hsdir_desc_comb_id[LAST_HID_SERV_REQUEST_KEY_LEN + 1];
+ char *hsdir_desc_comb_id = NULL;
time_t *last_request_ptr;
strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
+
+ /* Create the key */
base32_encode(hsdir_id_base32, sizeof(hsdir_id_base32),
hs_dir->identity_digest, DIGEST_LEN);
- tor_snprintf(hsdir_desc_comb_id, sizeof(hsdir_desc_comb_id), "%s%s",
- hsdir_id_base32,
- desc_id_base32);
- /* XXX++?? tor_assert(strlen(hsdir_desc_comb_id) ==
- LAST_HID_SERV_REQUEST_KEY_LEN); */
+ tor_asprintf(&hsdir_desc_comb_id, "%s%s", hsdir_id_base32, req_key_str);
+
if (set) {
time_t *oldptr;
last_request_ptr = tor_malloc_zero(sizeof(time_t));
@@ -1386,20 +1390,23 @@ lookup_last_hid_serv_request(routerstatus_t *hs_dir,
oldptr = strmap_set(last_hid_serv_requests, hsdir_desc_comb_id,
last_request_ptr);
tor_free(oldptr);
- } else
- last_request_ptr = strmap_get_lc(last_hid_serv_requests,
- hsdir_desc_comb_id);
+ } else {
+ last_request_ptr = strmap_get(last_hid_serv_requests,
+ hsdir_desc_comb_id);
+ }
+
+ tor_free(hsdir_desc_comb_id);
return (last_request_ptr) ? *last_request_ptr : 0;
}
/** Clean the history of request times to hidden service directories, so that
* it does not contain requests older than REND_HID_SERV_DIR_REQUERY_PERIOD
* seconds any more. */
-static void
-directory_clean_last_hid_serv_requests(time_t now)
+void
+hs_clean_last_hid_serv_requests(time_t now)
{
strmap_iter_t *iter;
- time_t cutoff = now - hsdir_requery_period(get_options());
+ time_t cutoff = now - hs_hsdir_requery_period(get_options());
strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
for (iter = strmap_iter_init(last_hid_serv_requests);
!strmap_iter_done(iter); ) {
@@ -1417,33 +1424,43 @@ directory_clean_last_hid_serv_requests(time_t now)
}
}
-/** Remove all requests related to the descriptor ID <b>desc_id</b> from the
- * history of times of requests to hidden service directories.
- * <b>desc_id</b> is an unencoded descriptor ID of size DIGEST_LEN.
+/** Remove all requests related to the descriptor request key string
+ * <b>req_key_str</b> from the history of times of requests to hidden service
+ * directories.
*
* This is called from rend_client_note_connection_attempt_ended(), which
* must be idempotent, so any future changes to this function must leave it
* idempotent too. */
void
-purge_hid_serv_from_last_hid_serv_requests(const char *desc_id)
+hs_purge_hid_serv_from_last_hid_serv_requests(const char *req_key_str)
{
strmap_iter_t *iter;
strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
- char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
- /* Key is stored with the base32 encoded desc_id. */
- base32_encode(desc_id_base32, sizeof(desc_id_base32), desc_id,
- DIGEST_LEN);
for (iter = strmap_iter_init(last_hid_serv_requests);
!strmap_iter_done(iter); ) {
const char *key;
void *val;
strmap_iter_get(iter, &key, &val);
- /* XXX++?? tor_assert(strlen(key) == LAST_HID_SERV_REQUEST_KEY_LEN); */
- if (tor_memeq(key + LAST_HID_SERV_REQUEST_KEY_LEN -
- REND_DESC_ID_V2_LEN_BASE32,
- desc_id_base32,
- REND_DESC_ID_V2_LEN_BASE32)) {
+
+ /* XXX: The use of REND_DESC_ID_V2_LEN_BASE32 is very wrong in terms of
+ * semantic, see #23305. */
+
+ /* Length check on the strings we are about to compare. The "key" contains
+ * both the base32 HSDir identity digest and the requested key at the
+ * directory. The "req_key_str" can either be a base32 descriptor ID or a
+ * base64 blinded key which should be the second part of "key". BUG on
+ * this check because both strings are internally controlled so this
+ * should never happen. */
+ if (BUG((strlen(req_key_str) + REND_DESC_ID_V2_LEN_BASE32) <
+ strlen(key))) {
+ iter = strmap_iter_next(last_hid_serv_requests, iter);
+ continue;
+ }
+
+ /* Check if the tracked request matches our request key */
+ if (tor_memeq(key + REND_DESC_ID_V2_LEN_BASE32, req_key_str,
+ strlen(req_key_str))) {
iter = strmap_iter_next_rmv(last_hid_serv_requests, iter);
tor_free(val);
} else {
@@ -1457,9 +1474,9 @@ purge_hid_serv_from_last_hid_serv_requests(const char *desc_id)
* accessed all of the HSDir relays responsible for the descriptor
* recently. */
void
-rend_client_purge_last_hid_serv_requests(void)
+hs_purge_last_hid_serv_requests(void)
{
- /* Don't create the table if it doesn't exist yet (and it may very
+ /* Don't create the table if it doesn't exist yet (and it may very
* well not exist if the user hasn't accessed any HSes)... */
strmap_t *old_last_hid_serv_requests = last_hid_serv_requests_;
/* ... and let get_last_hid_serv_requests re-create it for us if
@@ -1496,15 +1513,15 @@ pick_hsdir(const char *desc_id, const char *desc_id_base32)
hid_serv_get_responsible_directories(responsible_dirs, desc_id);
/* Clean request history first. */
- directory_clean_last_hid_serv_requests(now);
+ hs_clean_last_hid_serv_requests(now);
/* Only select those hidden service directories to which we did not send a
* request recently and for which we have a router descriptor here. */
SMARTLIST_FOREACH_BEGIN(responsible_dirs, routerstatus_t *, dir) {
- time_t last = lookup_last_hid_serv_request(dir, desc_id_base32,
- 0, 0);
+ time_t last = hs_lookup_last_hid_serv_request(dir, desc_id_base32,
+ 0, 0);
const node_t *node = node_get_by_id(dir->identity_digest);
- if (last + hsdir_requery_period(options) >= now ||
+ if (last + hs_hsdir_requery_period(options) >= now ||
!node || !node_has_descriptor(node)) {
SMARTLIST_DEL_CURRENT(responsible_dirs, dir);
continue;
@@ -1536,7 +1553,7 @@ pick_hsdir(const char *desc_id, const char *desc_id_base32)
} else {
/* Remember that we are requesting a descriptor from this hidden service
* directory now. */
- lookup_last_hid_serv_request(hs_dir, desc_id_base32, now, 1);
+ hs_lookup_last_hid_serv_request(hs_dir, desc_id_base32, now, 1);
}
return hs_dir;
diff --git a/src/or/hs_common.h b/src/or/hs_common.h
index aa810c0db..4692a3a01 100644
--- a/src/or/hs_common.h
+++ b/src/or/hs_common.h
@@ -187,8 +187,6 @@ const char *rend_data_get_desc_id(const rend_data_t *rend_data,
const uint8_t *rend_data_get_pk_digest(const rend_data_t *rend_data,
size_t *len_out);
-void rend_client_purge_last_hid_serv_requests(void);
-void purge_hid_serv_from_last_hid_serv_requests(const char *desc_id);
routerstatus_t *pick_hsdir(const char *desc_id, const char *desc_id_base32);
void hs_get_subcredential(const ed25519_public_key_t *identity_pk,
@@ -224,6 +222,14 @@ void hs_get_responsible_hsdirs(const ed25519_public_key_t *blinded_pk,
uint64_t time_period_num, int is_next_period,
int is_client, smartlist_t *responsible_dirs);
+time_t hs_hsdir_requery_period(const or_options_t *options);
+time_t hs_lookup_last_hid_serv_request(routerstatus_t *hs_dir,
+ const char *desc_id_base32,
+ time_t now, int set);
+void hs_clean_last_hid_serv_requests(time_t now);
+void hs_purge_hid_serv_from_last_hid_serv_requests(const char *desc_id);
+void hs_purge_last_hid_serv_requests(void);
+
int hs_set_conn_addr_port(const smartlist_t *ports, edge_connection_t *conn);
void hs_inc_rdv_stream_counter(origin_circuit_t *circ);
@@ -242,6 +248,7 @@ STATIC void get_disaster_srv(uint64_t time_period_num, uint8_t *srv_out);
#ifdef TOR_UNIT_TESTS
+STATIC strmap_t *get_last_hid_serv_requests(void);
STATIC uint64_t get_time_period_length(void);
STATIC uint8_t *get_first_cached_disaster_srv(void);
diff --git a/src/or/rendclient.c b/src/or/rendclient.c
index 28e02a65e..a621d27f9 100644
--- a/src/or/rendclient.c
+++ b/src/or/rendclient.c
@@ -42,7 +42,7 @@ rend_client_purge_state(void)
rend_cache_purge();
rend_cache_failure_purge();
rend_client_cancel_descriptor_fetches();
- rend_client_purge_last_hid_serv_requests();
+ hs_purge_last_hid_serv_requests();
}
/** Called when we've established a circuit to an introduction point:
@@ -636,7 +636,7 @@ fetch_v2_desc_by_addr(rend_data_t *rend_query, smartlist_t *hsdirs)
sizeof(descriptor_id)) != 0) {
/* Not equal from what we currently have so purge the last hid serv
* request cache and update the descriptor ID with the new value. */
- purge_hid_serv_from_last_hid_serv_requests(
+ hs_purge_hid_serv_from_last_hid_serv_requests(
rend_data->descriptor_id[chosen_replica]);
memcpy(rend_data->descriptor_id[chosen_replica], descriptor_id,
sizeof(rend_data->descriptor_id[chosen_replica]));
@@ -1036,14 +1036,14 @@ rend_client_note_connection_attempt_ended(const rend_data_t *rend_data)
for (replica = 0; replica < ARRAY_LENGTH(rend_data_v2->descriptor_id);
replica++) {
const char *desc_id = rend_data_v2->descriptor_id[replica];
- purge_hid_serv_from_last_hid_serv_requests(desc_id);
+ hs_purge_hid_serv_from_last_hid_serv_requests(desc_id);
}
log_info(LD_REND, "Connection attempt for %s has ended; "
"cleaning up temporary state.",
safe_str_client(onion_address));
} else {
/* We only have an ID for a fetch. Probably used by HSFETCH. */
- purge_hid_serv_from_last_hid_serv_requests(rend_data_v2->desc_id_fetch);
+ hs_purge_hid_serv_from_last_hid_serv_requests(rend_data_v2->desc_id_fetch);
}
}
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