Merge remote-tracking branch 'teor/bug20472-029-v2' into maint-0.2.9 (733b2452) · Commits · jarl / tor

changes/bug20472

0 → 100644

+4 −0

Original line number	Diff line number	Diff line
		o Minor bugfixes (circuits):
		- Remove a BUG warning in circuit_pick_extend_handshake. Instead, assume
		all nodes support EXTEND2. Use ntor whenever a key is available.
		Bugfix on commit 10aa913 from 19163 in 0.2.9.3-alpha. Fixes bug 20472.

src/or/circuitbuild.c

+23 −42

Original line number	Diff line number	Diff line
		@@ -814,7 +814,8 @@ circuit_timeout_want_to_count_circ(origin_circuit_t *circ)
		/** Decide whether to use a TAP or ntor handshake for connecting to <b>ei</b>
		* directly, and set <b>cell_type_out</b> and <b>handshake_type_out</b>
		* accordingly.
		* Note that TAP handshakes are only used for direct connections:
		* Note that TAP handshakes in CREATE cells are only used for direct
		* connections:
		* - from Tor2web to intro points not in the client's consensus, and
		* - from Single Onions to rend points not in the service's consensus.
		* This is checked in onion_populate_cpath. */
		@@ -823,58 +824,43 @@ circuit_pick_create_handshake(uint8_t *cell_type_out,
		uint16_t *handshake_type_out,
		const extend_info_t *ei)
		{
		/* XXXX030 Remove support for deciding to use TAP. */
		/* torspec says: In general, clients SHOULD use CREATE whenever they are
		* using the TAP handshake, and CREATE2 otherwise. */
		if (extend_info_supports_ntor(ei)) {
		*cell_type_out = CELL_CREATE2;
		*handshake_type_out = ONION_HANDSHAKE_TYPE_NTOR;
		return;
		}

		} else {
		/* XXXX030 Remove support for deciding to use TAP and EXTEND. */
		*cell_type_out = CELL_CREATE;
		*handshake_type_out = ONION_HANDSHAKE_TYPE_TAP;
		}
		}

		/** Decide whether to use a TAP or ntor handshake for connecting to <b>ei</b>
		* directly, and set *<b>handshake_type_out</b> accordingly. Decide whether,
		* in extending through <b>node</b> to do so, we should use an EXTEND2 or an
		* EXTEND cell to do so, and set *<b>cell_type_out</b> and
		* *<b>create_cell_type_out</b> accordingly.
		* Note that TAP handshakes are only used for extend handshakes:
		/** Decide whether to use a TAP or ntor handshake for extending to <b>ei</b>
		* and set *<b>handshake_type_out</b> accordingly. Decide whether we should
		* use an EXTEND2 or an EXTEND cell to do so, and set *<b>cell_type_out</b>
		* and *<b>create_cell_type_out</b> accordingly.
		* Note that TAP handshakes in EXTEND cells are only used:
		* - from clients to intro points, and
		* - from hidden services to rend points.
		* This is checked in onion_populate_cpath. */
		* This is checked in onion_populate_cpath.
		*/
		static void
		circuit_pick_extend_handshake(uint8_t *cell_type_out,
		uint8_t *create_cell_type_out,
		uint16_t *handshake_type_out,
		const node_t *node_prev,
		const extend_info_t *ei)
		{
		uint8_t t;
		circuit_pick_create_handshake(&t, handshake_type_out, ei);

		/* XXXX030 Remove support for deciding to use TAP. */

		/* It is an error to extend if there is no previous node. */
		if (BUG(node_prev == NULL)) {
		*cell_type_out = RELAY_COMMAND_EXTEND;
		*create_cell_type_out = CELL_CREATE;
		return;
		}

		/* It is an error for a node with a known version to be so old it does not
		* support ntor. */
		tor_assert_nonfatal(routerstatus_version_supports_ntor(node_prev->rs, 1));

		/* Assume relays without tor versions or routerstatuses support ntor.
		* The authorities enforce ntor support, and assuming and failing is better
		* than allowing a malicious node to perform a protocol downgrade to TAP. */
		if (*handshake_type_out != ONION_HANDSHAKE_TYPE_TAP &&
		(node_has_curve25519_onion_key(node_prev) \|\|
		(routerstatus_version_supports_ntor(node_prev->rs, 1)))) {
		/* torspec says: Clients SHOULD use the EXTEND format whenever sending a TAP
		* handshake... In other cases, clients SHOULD use EXTEND2. */
		if (*handshake_type_out != ONION_HANDSHAKE_TYPE_TAP) {
		*cell_type_out = RELAY_COMMAND_EXTEND2;
		*create_cell_type_out = CELL_CREATE2;
		} else {
		/* XXXX030 Remove support for deciding to use TAP and EXTEND. */
		*cell_type_out = RELAY_COMMAND_EXTEND;
		*create_cell_type_out = CELL_CREATE;
		}
		@@ -1030,15 +1016,10 @@ circuit_send_next_onion_skin(origin_circuit_t *circ)
		return - END_CIRC_REASON_INTERNAL;
		}

		{
		const node_t *prev_node;
		prev_node = node_get_by_id(hop->prev->extend_info->identity_digest);
		circuit_pick_extend_handshake(&ec.cell_type,
		&ec.create_cell.cell_type,
		&ec.create_cell.handshake_type,
		prev_node,
		hop->extend_info);
		}

		tor_addr_copy(&ec.orport_ipv4.addr, &hop->extend_info->addr);
		ec.orport_ipv4.port = hop->extend_info->port;

src/or/networkstatus.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -2360,10 +2360,10 @@ client_would_use_router(const routerstatus_t *rs, time_t now,
		/* We'd drop it immediately for being too old. */
		return 0;
		}
		if (!routerstatus_version_supports_ntor(rs, 1)) {
		/* We'd ignore it because it doesn't support ntor.
		if (!routerstatus_version_supports_extend2_cells(rs, 1)) {
		/* We'd ignore it because it doesn't support EXTEND2 cells.
		* If we don't know the version, download the descriptor so we can
		* check if it supports ntor. */
		* check if it supports EXTEND2 cells and ntor. */
		return 0;
		}
		return 1;

src/or/routerlist.c

+8 −6

Original line number	Diff line number	Diff line
		@@ -2344,9 +2344,10 @@ router_add_running_nodes_to_smartlist(smartlist_t *sl, int allow_invalid,
		continue;
		if (node_is_unreliable(node, need_uptime, need_capacity, need_guard))
		continue;
		/* Don't choose nodes if we are certain they can't do ntor */
		if (node->rs && !routerstatus_version_supports_ntor(node->rs, 1))
		/* Don't choose nodes if we are certain they can't do EXTEND2 cells */
		if (node->rs && !routerstatus_version_supports_extend2_cells(node->rs, 1))
		continue;
		/* Don't choose nodes if we are certain they can't do ntor. */
		if ((node->ri \|\| node->md) && !node_has_curve25519_onion_key(node))
		continue;
		/* Choose a node with an OR address that matches the firewall rules */
		@@ -5609,12 +5610,13 @@ routerinfo_has_curve25519_onion_key(const routerinfo_t *ri)
		return 1;
		}

		/* Is rs running a tor version known to support ntor?
		/* Is rs running a tor version known to support EXTEND2 cells?
		* If allow_unknown_versions is true, return true if we can't tell
		* (from a versions line or a protocols line) whether it supports ntor.
		* (from a versions line or a protocols line) whether it supports extend2
		* cells.
		* Otherwise, return false if the version is unknown. */
		int
		routerstatus_version_supports_ntor(const routerstatus_t *rs,
		routerstatus_version_supports_extend2_cells(const routerstatus_t *rs,
		int allow_unknown_versions)
		{
		if (!rs) {

src/or/routerlist.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -207,7 +207,7 @@ int routerinfo_incompatible_with_extrainfo(const crypto_pk_t *ri,
		signed_descriptor_t *sd,
		const char **msg);
		int routerinfo_has_curve25519_onion_key(const routerinfo_t *ri);
		int routerstatus_version_supports_ntor(const routerstatus_t *rs,
		int routerstatus_version_supports_extend2_cells(const routerstatus_t *rs,
		int allow_unknown_versions);

		void routerlist_assert_ok(const routerlist_t *rl);