[tor-commits] [tor/master] prop224: Add code that launches v3 HS desc fetches.
nickm at torproject.org
nickm at torproject.org
Thu Aug 24 19:13:51 UTC 2017
commit c754864cfda8cf1fffcf754c400be0c21b74b50d
Author: George Kadianakis <desnacked at riseup.net>
Date: Thu Jun 1 14:12:33 2017 +0300
prop224: Add code that launches v3 HS desc fetches.
Entry point is hs_client_refetch_v3_renddesc().
Will be used in subsequent commits.
Signed-off-by: David Goulet <dgoulet at torproject.org>
---
src/or/directory.c | 7 +++
src/or/hs_client.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
src/or/hs_client.h | 3 +
3 files changed, 169 insertions(+), 2 deletions(-)
diff --git a/src/or/directory.c b/src/or/directory.c
index e079a5941..7c96b43ca 100644
--- a/src/or/directory.c
+++ b/src/or/directory.c
@@ -1859,6 +1859,13 @@ directory_send_command(dir_connection_t *conn,
httpcommand = "GET";
tor_asprintf(&url, "/tor/rendezvous2/%s", resource);
break;
+ case DIR_PURPOSE_FETCH_HSDESC:
+ tor_assert(resource);
+ tor_assert(strlen(resource) <= ED25519_BASE64_LEN);
+ tor_assert(!payload);
+ httpcommand = "GET";
+ tor_asprintf(&url, "/tor/hs/3/%s", resource);
+ break;
case DIR_PURPOSE_UPLOAD_RENDDESC_V2:
tor_assert(!resource);
tor_assert(payload);
diff --git a/src/or/hs_client.c b/src/or/hs_client.c
index 37981c8b6..66068092f 100644
--- a/src/or/hs_client.c
+++ b/src/or/hs_client.c
@@ -2,7 +2,7 @@
/* See LICENSE for licensing information */
/**
- * \file hs_service.c
+ * \file hs_client.c
* \brief Implement next generation hidden service client functionality
**/
@@ -11,8 +11,12 @@
#include "hs_ident.h"
#include "connection_edge.h"
#include "rendclient.h"
-
+#include "hs_descriptor.h"
+#include "hs_cache.h"
+#include "config.h"
+#include "directory.h"
#include "hs_client.h"
+#include "router.h"
/** A prop224 v3 HS circuit successfully connected to the hidden
* service. Update the stream state at <b>hs_conn_ident</b> appropriately. */
@@ -25,6 +29,117 @@ hs_client_attempt_succeeded(const hs_ident_edge_conn_t *hs_conn_ident)
return;
}
+/* Given the pubkey of a hidden service in <b>onion_identity_pk</b>, fetch its
+ * descriptor by launching a dir connection to <b>hsdir</b>. Return 1 on
+ * success or -1 on error. */
+static int
+directory_launch_v3_desc_fetch(const ed25519_public_key_t *onion_identity_pk,
+ const routerstatus_t *hsdir)
+{
+ uint64_t current_time_period = hs_get_time_period_num(approx_time());
+ ed25519_public_key_t blinded_pubkey;
+ char base64_blinded_pubkey[ED25519_BASE64_LEN + 1];
+ hs_ident_dir_conn_t hs_conn_dir_ident;
+ int retval;
+
+ tor_assert(hsdir);
+ tor_assert(onion_identity_pk);
+
+ /* Get blinded pubkey */
+ hs_build_blinded_pubkey(onion_identity_pk, NULL, 0,
+ current_time_period, &blinded_pubkey);
+ /* ...and base64 it. */
+ retval = ed25519_public_to_base64(base64_blinded_pubkey, &blinded_pubkey);
+ if (BUG(retval < 0)) {
+ return -1;
+ }
+
+ /* Copy onion pk to a dir_ident so that we attach it to the dir conn */
+ ed25519_pubkey_copy(&hs_conn_dir_ident.identity_pk, onion_identity_pk);
+
+ /* Setup directory request */
+ directory_request_t *req =
+ directory_request_new(DIR_PURPOSE_FETCH_HSDESC);
+ directory_request_set_routerstatus(req, hsdir);
+ directory_request_set_indirection(req, DIRIND_ANONYMOUS);
+ directory_request_set_resource(req, base64_blinded_pubkey);
+ directory_request_upload_set_hs_ident(req, &hs_conn_dir_ident);
+ directory_initiate_request(req);
+ directory_request_free(req);
+
+ log_info(LD_REND, "Descriptor fetch request for service %s with blinded "
+ "key %s to directory %s",
+ safe_str_client(ed25519_fmt(onion_identity_pk)),
+ safe_str_client(base64_blinded_pubkey),
+ safe_str_client(routerstatus_describe(hsdir)));
+
+ /* Cleanup memory. */
+ memwipe(&blinded_pubkey, 0, sizeof(blinded_pubkey));
+ memwipe(base64_blinded_pubkey, 0, sizeof(base64_blinded_pubkey));
+ memwipe(&hs_conn_dir_ident, 0, sizeof(hs_conn_dir_ident));
+
+ return 1;
+}
+
+/** Return the HSDir we should use to fetch the descriptor of the hidden
+ * service with identity key <b>onion_identity_pk</b>. */
+static routerstatus_t *
+pick_hsdir_v3(const ed25519_public_key_t *onion_identity_pk)
+{
+ int retval;
+ char base64_blinded_pubkey[ED25519_BASE64_LEN + 1];
+ uint64_t current_time_period = hs_get_time_period_num(approx_time());
+ smartlist_t *responsible_hsdirs;
+ ed25519_public_key_t blinded_pubkey;
+ routerstatus_t *hsdir_rs = NULL;
+
+ tor_assert(onion_identity_pk);
+
+ responsible_hsdirs = smartlist_new();
+
+ /* Get blinded pubkey of hidden service */
+ hs_build_blinded_pubkey(onion_identity_pk, NULL, 0,
+ current_time_period, &blinded_pubkey);
+ /* ...and base64 it. */
+ retval = ed25519_public_to_base64(base64_blinded_pubkey, &blinded_pubkey);
+ if (BUG(retval < 0)) {
+ return NULL;
+ }
+
+ /* Get responsible hsdirs of service for this time period */
+ hs_get_responsible_hsdirs(&blinded_pubkey, current_time_period, 0, 1,
+ responsible_hsdirs);
+
+ log_debug(LD_REND, "Found %d responsible HSDirs and about to pick one.",
+ smartlist_len(responsible_hsdirs));
+
+ /* Pick an HSDir from the responsible ones. The ownership of
+ * responsible_hsdirs is given to this function so no need to free it. */
+ hsdir_rs = hs_pick_hsdir(responsible_hsdirs, base64_blinded_pubkey);
+
+ return hsdir_rs;
+}
+
+/** Fetch a v3 descriptor using the given <b>onion_identity_pk</b>.
+ *
+ * On success, 1 is returned. If no hidden service is left to ask, return 0.
+ * On error, -1 is returned. */
+static int
+fetch_v3_desc(const ed25519_public_key_t *onion_identity_pk)
+{
+ routerstatus_t *hsdir_rs =NULL;
+
+ tor_assert(onion_identity_pk);
+
+ hsdir_rs = pick_hsdir_v3(onion_identity_pk);
+ if (!hsdir_rs) {
+ log_info(LD_REND, "Couldn't pick a v3 hsdir.");
+ return 0;
+ }
+
+ return directory_launch_v3_desc_fetch(onion_identity_pk, hsdir_rs);
+}
+
/** A circuit just finished connecting to a hidden service that the stream
* <b>conn</b> has been waiting for. Let the HS subsystem know about this. */
void
@@ -85,3 +200,45 @@ hs_client_decode_descriptor(const char *desc_str,
return -1;
}
+/** Return true if there are any usable intro points in the v3 HS descriptor
+ * <b>desc</b>. */
+int
+hs_client_any_intro_points_usable(const hs_descriptor_t *desc)
+{
+ /* XXX stub waiting for more client-side work:
+ equivalent to v2 rend_client_any_intro_points_usable() */
+ tor_assert(desc);
+ return 1;
+}
+
+/** Launch a connection to a hidden service directory to fetch a hidden
+ * service descriptor using <b>identity_pk</b> to get the necessary keys.
+ *
+ * On success, 1 is returned. If no hidden service is left to ask, return 0.
+ * On error, -1 is returned. (retval is only used by unittests right now) */
+int
+hs_client_refetch_hsdesc(const ed25519_public_key_t *identity_pk)
+{
+ tor_assert(identity_pk);
+
+ /* Are we configured to fetch descriptors? */
+ if (!get_options()->FetchHidServDescriptors) {
+ log_warn(LD_REND, "We received an onion address for a hidden service "
+ "descriptor but we are configured to not fetch.");
+ return 0;
+ }
+
+ /* Check if fetching a desc for this HS is useful to us right now */
+ {
+ const hs_descriptor_t *cached_desc = NULL;
+ cached_desc = hs_cache_lookup_as_client(identity_pk);
+ if (cached_desc && hs_client_any_intro_points_usable(cached_desc)) {
+ log_warn(LD_GENERAL, "We would fetch a v3 hidden service descriptor "
+ "but we already have a useable descriprot.");
+ return 0;
+ }
+ }
+
+ return fetch_v3_desc(identity_pk);
+}
+
diff --git a/src/or/hs_client.h b/src/or/hs_client.h
index 348724ab3..0b446c00b 100644
--- a/src/or/hs_client.h
+++ b/src/or/hs_client.h
@@ -9,6 +9,7 @@
#ifndef TOR_HS_CLIENT_H
#define TOR_HS_CLIENT_H
+#include "crypto_ed25519.h"
#include "hs_descriptor.h"
void hs_client_note_connection_attempt_succeeded(
@@ -18,6 +19,8 @@ int hs_client_decode_descriptor(
const char *desc_str,
const ed25519_public_key_t *service_identity_pk,
hs_descriptor_t **desc);
+int hs_client_any_intro_points_usable(const hs_descriptor_t *desc);
+int hs_client_refetch_hsdesc(const ed25519_public_key_t *identity_pk);
#endif /* TOR_HS_CLIENT_H */
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