commit acc7c4ee9578e37a66dff6a09c86bee5777f782d
Author: David Goulet <dgou...@torproject.org>
Date: Wed Mar 8 17:31:36 2017 -0500
prop224: Establish rendezvous circuit for service
Signed-off-by: David Goulet <dgou...@torproject.org>
---
src/or/hs_cell.c | 5 +-
src/or/hs_circuit.c | 274 +++++++++++++++++++++++++++++++++++++++++++++++----
src/or/hs_common.c | 16 +++
src/or/hs_common.h | 16 +++
src/or/rendservice.c | 36 +------
src/or/rendservice.h | 1 -
6 files changed, 292 insertions(+), 56 deletions(-)
diff --git a/src/or/hs_cell.c b/src/or/hs_cell.c
index aff6ee04e..18d15fe0a 100644
--- a/src/or/hs_cell.c
+++ b/src/or/hs_cell.c
@@ -363,7 +363,6 @@ hs_cell_parse_introduce2(hs_cell_introduce2_data_t *data,
uint8_t *decrypted = NULL;
size_t encrypted_section_len;
const uint8_t *encrypted_section;
- curve25519_public_key_t client_pk;
trn_cell_introduce1_t *cell = NULL;
trn_cell_introduce_encrypted_t *enc_cell = NULL;
hs_ntor_intro_cell_keys_t *intro_keys = NULL;
@@ -404,7 +403,8 @@ hs_cell_parse_introduce2(hs_cell_introduce2_data_t *data,
/* Build the key material out of the key material found in the cell. */
intro_keys = get_introduce2_key_material(data->auth_pk, data->enc_kp,
data->subcredential,
- encrypted_section, &client_pk);
+ encrypted_section,
+ &data->client_pk);
if (intro_keys == NULL) {
log_info(LD_REND, "Invalid INTRODUCE2 encrypted data. Unable to "
"compute key material on circuit %u for service %s",
@@ -490,7 +490,6 @@ hs_cell_parse_introduce2(hs_cell_introduce2_data_t *data,
log_info(LD_REND, "Valid INTRODUCE2 cell. Launching rendezvous circuit.");
done:
- memwipe(&client_pk, 0, sizeof(client_pk));
if (intro_keys) {
memwipe(intro_keys, 0, sizeof(hs_ntor_intro_cell_keys_t));
tor_free(intro_keys);
diff --git a/src/or/hs_circuit.c b/src/or/hs_circuit.c
index a11699227..7184e1e18 100644
--- a/src/or/hs_circuit.c
+++ b/src/or/hs_circuit.c
@@ -11,6 +11,7 @@
#include "circuitlist.h"
#include "circuituse.h"
#include "config.h"
+#include "policies.h"
#include "relay.h"
#include "rephist.h"
#include "router.h"
@@ -22,6 +23,7 @@
#include "hs_service.h"
/* Trunnel. */
+#include "ed25519_cert.h"
#include "hs/cell_common.h"
#include "hs/cell_establish_intro.h"
@@ -240,6 +242,46 @@ count_opened_desc_intro_point_circuits(const hs_service_t
*service,
return count;
}
+/* From a given service, rendezvous cookie and handshake infor, create a
+ * rendezvous point circuit identifier. This can't fail. */
+static hs_ident_circuit_t *
+create_rp_circuit_identifier(const hs_service_t *service,
+ const uint8_t *rendezvous_cookie,
+ const curve25519_public_key_t *server_pk,
+ const hs_ntor_rend_cell_keys_t *keys)
+{
+ hs_ident_circuit_t *ident;
+ uint8_t handshake_info[CURVE25519_PUBKEY_LEN + DIGEST256_LEN];
+
+ tor_assert(service);
+ tor_assert(rendezvous_cookie);
+ tor_assert(server_pk);
+ tor_assert(keys);
+
+ ident = hs_ident_circuit_new(&service->keys.identity_pk,
+ HS_IDENT_CIRCUIT_RENDEZVOUS);
+ /* Copy the RENDEZVOUS_COOKIE which is the unique identifier. */
+ memcpy(ident->rendezvous_cookie, rendezvous_cookie,
+ sizeof(ident->rendezvous_cookie));
+ /* Build the HANDSHAKE_INFO which looks like this:
+ * SERVER_PK [32 bytes]
+ * AUTH_INPUT_MAC [32 bytes]
+ */
+ memcpy(handshake_info, server_pk->public_key, CURVE25519_PUBKEY_LEN);
+ memcpy(handshake_info + CURVE25519_PUBKEY_LEN, keys->rend_cell_auth_mac,
+ DIGEST256_LEN);
+ tor_assert(sizeof(ident->rendezvous_handshake_info) ==
+ sizeof(handshake_info));
+ memcpy(ident->rendezvous_handshake_info, handshake_info,
+ sizeof(ident->rendezvous_handshake_info));
+ /* Finally copy the NTOR_KEY_SEED for e2e encryption on the circuit. */
+ tor_assert(sizeof(ident->rendezvous_ntor_key_seed) ==
+ sizeof(keys->ntor_key_seed));
+ memcpy(ident->rendezvous_ntor_key_seed, keys->ntor_key_seed,
+ sizeof(ident->rendezvous_ntor_key_seed));
+ return ident;
+}
+
/* From a given service and service intro point, create an introduction point
* circuit identifier. This can't fail. */
static hs_ident_circuit_t *
@@ -308,22 +350,225 @@ send_establish_intro(const hs_service_t *service,
memwipe(payload, 0, sizeof(payload));
}
-/* ========== */
-/* Public API */
-/* ========== */
+/* From a list of link specifier, an onion key and if we are requesting a
+ * direct connection (ex: single onion service), return a newly allocated
+ * extend_info_t object. This function checks the firewall policies and if we
+ * are allowed to extend to the chosen address.
+ *
+ * if either IPv4 or legacy ID is missing, error.
+ * if not direct_conn, IPv4 is prefered.
+ * if direct_conn, IPv6 is prefered if we have one available.
+ * if firewall does not allow the chosen address, error.
+ *
+ * Return NULL if we can fulfill the conditions. */
+static extend_info_t *
+get_rp_extend_info(const smartlist_t *link_specifiers,
+ const curve25519_public_key_t *onion_key, int direct_conn)
+{
+ int have_v4 = 0, have_v6 = 0, have_legacy_id = 0, have_ed25519_id = 0;
+ char legacy_id[DIGEST_LEN] = {0};
+ uint16_t port_v4 = 0, port_v6 = 0, port = 0;
+ tor_addr_t addr_v4, addr_v6, *addr = NULL;
+ ed25519_public_key_t ed25519_pk;
+ extend_info_t *info = NULL;
+
+ tor_assert(link_specifiers);
+ tor_assert(onion_key);
-int
-hs_circ_launch_rendezvous_point(const hs_service_t *service,
- const curve25519_public_key_t *onion_key,
- const uint8_t *rendezvous_cookie)
+ SMARTLIST_FOREACH_BEGIN(link_specifiers, const link_specifier_t *, ls) {
+ switch (link_specifier_get_ls_type(ls)) {
+ case LS_IPV4:
+ /* Skip if we already seen a v4. */
+ if (have_v4) continue;
+ tor_addr_from_ipv4h(&addr_v4,
+ link_specifier_get_un_ipv4_addr(ls));
+ port_v4 = link_specifier_get_un_ipv4_port(ls);
+ have_v4 = 1;
+ break;
+ case LS_IPV6:
+ /* Skip if we already seen a v6. */
+ if (have_v6) continue;
+ tor_addr_from_ipv6_bytes(&addr_v6,
+ (const char *) link_specifier_getconstarray_un_ipv6_addr(ls));
+ port_v6 = link_specifier_get_un_ipv6_port(ls);
+ have_v6 = 1;
+ break;
+ case LS_LEGACY_ID:
+ /* Make sure we do have enough bytes for the legacy ID. */
+ if (link_specifier_getlen_un_legacy_id(ls) < sizeof(legacy_id)) {
+ break;
+ }
+ memcpy(legacy_id, link_specifier_getconstarray_un_legacy_id(ls),
+ sizeof(legacy_id));
+ have_legacy_id = 1;
+ break;
+ case LS_ED25519_ID:
+ memcpy(ed25519_pk.pubkey,
+ link_specifier_getconstarray_un_ed25519_id(ls),
+ ED25519_PUBKEY_LEN);
+ have_ed25519_id = 1;
+ break;
+ default:
+ /* Ignore unknown. */
+ break;
+ }
+ } SMARTLIST_FOREACH_END(ls);
+
+ /* IPv4, legacy ID and ed25519 are mandatory. */
+ if (!have_v4 || !have_legacy_id || !have_ed25519_id) {
+ goto done;
+ }
+ /* By default, we pick IPv4 but this might change to v6 if certain
+ * conditions are met. */
+ addr = &addr_v4; port = port_v4;
+
+ /* If we are NOT in a direct connection, we'll use our Guard and a 3-hop
+ * circuit so we can't extend in IPv6. And at this point, we do have an IPv4
+ * address available so go to validation. */
+ if (!direct_conn) {
+ goto validate;
+ }
+
+ /* From this point on, we have a request for a direct connection to the
+ * rendezvous point so make sure we can actually connect through our
+ * firewall. We'll prefer IPv6. */
+
+ /* IPv6 test. */
+ if (have_v6 &&
+ fascist_firewall_allows_address_addr(&addr_v6, port_v6,
+ FIREWALL_OR_CONNECTION, 1, 1)) {
+ /* Direct connection and we can reach it in IPv6 so go for it. */
+ addr = &addr_v6; port = port_v6;
+ goto validate;
+ }
+ /* IPv4 test and we are sure we have a v4 because of the check above. */
+ if (fascist_firewall_allows_address_addr(&addr_v4, port_v4,
+ FIREWALL_OR_CONNECTION, 0, 0)) {
+ /* Direct connection and we can reach it in IPv4 so go for it. */
+ addr = &addr_v4; port = port_v4;
+ goto validate;
+ }
+
+ validate:
+ /* We'll validate now that the address we've picked isn't a private one. If
+ * it is, are we allowing to extend to private address? */
+ if (!extend_info_addr_is_allowed(addr)) {
+ log_warn(LD_REND, "Rendezvous point address is private and it is not "
+ "allowed to extend to it: %s:%u",
+ fmt_addr(&addr_v4), port_v4);
+ goto done;
+ }
+
+ /* We do have everything for which we think we can connect successfully. */
+ info = extend_info_new(NULL, legacy_id, &ed25519_pk, NULL, onion_key,
+ addr, port);
+ done:
+ return info;
+}
+
+/* For a given service, the ntor onion key and a rendezvous cookie, launch a
+ * circuit to the rendezvous point specified by the link specifiers. On
+ * success, a circuit identifier is attached to the circuit with the needed
+ * data. This function will try to open a circuit for a maximum value of
+ * MAX_REND_FAILURES then it will give up. */
+static void
+launch_rendezvous_point_circuit(const hs_service_t *service,
+ const hs_service_intro_point_t *ip,
+ const hs_cell_introduce2_data_t *data)
{
+ int circ_needs_uptime;
+ time_t now = time(NULL);
+ extend_info_t *info = NULL;
+ origin_circuit_t *circ;
+
tor_assert(service);
- tor_assert(onion_key);
- tor_assert(rendezvous_cookie);
- /* XXX: Implement rendezvous launch support. */
- return 0;
+ tor_assert(ip);
+ tor_assert(data);
+
+ circ_needs_uptime = hs_service_requires_uptime_circ(service->config.ports);
+ /* Help predict this next time */
+ rep_hist_note_used_internal(now, circ_needs_uptime, 1);
+
+ /* Get the extend info data structure for the chosen rendezvous point
+ * specified by the given link specifiers. */
+ info = get_rp_extend_info(data->link_specifiers, &data->onion_pk,
+ service->config.is_single_onion);
+ if (info == NULL) {
+ /* We are done here, we can't extend to the rendezvous point. */
+ goto end;
+ }
+
+ for (int i = 0; i < MAX_REND_FAILURES; i++) {
+ int circ_flags = CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_IS_INTERNAL;
+ if (circ_needs_uptime) {
+ circ_flags |= CIRCLAUNCH_NEED_UPTIME;
+ }
+ /* Firewall and policies are checked when getting the extend info. */
+ if (service->config.is_single_onion) {
+ circ_flags |= CIRCLAUNCH_ONEHOP_TUNNEL;
+ }
+
+ circ = circuit_launch_by_extend_info(CIRCUIT_PURPOSE_S_CONNECT_REND, info,
+ circ_flags);
+ if (circ != NULL) {
+ /* Stop retrying, we have a circuit! */
+ break;
+ }
+ }
+ if (circ == NULL) {
+ log_warn(LD_REND, "Giving up on launching rendezvous circuit to %s "
+ "for service %s",
+ safe_str_client(extend_info_describe(info)),
+ safe_str_client(service->onion_address));
+ goto end;
+ }
+ log_info(LD_REND, "Rendezvous circuit launched to %s with cookie %s "
+ "for service %s",
+ safe_str_client(extend_info_describe(info)),
+ safe_str_client(hex_str((const char *) data->rendezvous_cookie,
+ REND_COOKIE_LEN)),
+ safe_str_client(service->onion_address));
+ tor_assert(circ->build_state);
+ /* Rendezvous circuit have a specific timeout for the time spent on trying
+ * to connect to the rendezvous point. */
+ circ->build_state->expiry_time = now + MAX_REND_TIMEOUT;
+
+ /* Create circuit identifier and key material. */
+ {
+ hs_ntor_rend_cell_keys_t keys;
+ curve25519_keypair_t ephemeral_kp;
+ /* No need for extra strong, this is only for this circuit life time. This
+ * key will be used for the RENDEZVOUS1 cell that will be sent on the
+ * circuit once opened. */
+ curve25519_keypair_generate(&ephemeral_kp, 0);
+ if (hs_ntor_service_get_rendezvous1_keys(&ip->auth_key_kp.pubkey,
+ &ip->enc_key_kp,
+ &ephemeral_kp, &data->client_pk,
+ &keys) < 0) {
+ /* This should not really happened but just in case, don't make tor
+ * freak out, close the circuit and move on. */
+ log_info(LD_REND, "Unable to get RENDEZVOUS1 key material for "
+ "service %s",
+ safe_str_client(service->onion_address));
+ circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
+ goto end;
+ }
+ circ->hs_ident = create_rp_circuit_identifier(service,
+ data->rendezvous_cookie,
+ &ephemeral_kp.pubkey, &keys);
+ memwipe(&ephemeral_kp, 0, sizeof(ephemeral_kp));
+ memwipe(&keys, 0, sizeof(keys));
+ tor_assert(circ->hs_ident);
+ }
+
+ end:
+ extend_info_free(info);
}
+/* ========== */
+/* Public API */
+/* ========== */
+
/* For a given service and a service intro point, launch a circuit to the
* extend info ei. If the service is a single onion, a one-hop circuit will be
* requested. Return 0 if the circuit was successfully launched and tagged
@@ -517,12 +762,7 @@ hs_circ_handle_introduce2(const hs_service_t *service,
ip->introduce2_count++;
/* Launch rendezvous circuit with the onion key and rend cookie. */
- ret = hs_circ_launch_rendezvous_point(service, &data.onion_pk,
- data.rendezvous_cookie);
- if (ret < 0) {
- goto done;
- }
-
+ launch_rendezvous_point_circuit(service, ip, &data);
/* Success. */
ret = 0;
diff --git a/src/or/hs_common.c b/src/or/hs_common.c
index 102e4689f..571f4c517 100644
--- a/src/or/hs_common.c
+++ b/src/or/hs_common.c
@@ -19,6 +19,7 @@
#include "hs_common.h"
#include "hs_service.h"
#include "rendcommon.h"
+#include "rendservice.h"
/* Ed25519 Basepoint value. Taken from section 5 of
* https://tools.ietf.org/html/draft-josefsson-eddsa-ed25519-03 */
@@ -724,7 +725,22 @@ hs_overlap_mode_is_active(const networkstatus_t
*consensus, time_t now)
if (valid_after_tm.tm_hour > 0 && valid_after_tm.tm_hour < 12) {
return 1;
}
+ return 0;
+}
+
+/* Return 1 if any virtual port in ports needs a circuit with good uptime.
+ * Else return 0. */
+int
+hs_service_requires_uptime_circ(const smartlist_t *ports)
+{
+ tor_assert(ports);
+ SMARTLIST_FOREACH_BEGIN(ports, rend_service_port_config_t *, p) {
+ if (smartlist_contains_int_as_string(get_options()->LongLivedPorts,
+ p->virtual_port)) {
+ return 1;
+ }
+ } SMARTLIST_FOREACH_END(p);
return 0;
}
diff --git a/src/or/hs_common.h b/src/or/hs_common.h
index 6abcd9831..f9e3f297a 100644
--- a/src/or/hs_common.h
+++ b/src/or/hs_common.h
@@ -107,6 +107,21 @@ typedef enum {
HS_AUTH_KEY_TYPE_ED25519 = 2,
} hs_auth_key_type_t;
+/* Represents the mapping from a virtual port of a rendezvous service to a
+ * real port on some IP. */
+typedef struct rend_service_port_config_t {
+ /* The incoming HS virtual port we're mapping */
+ uint16_t virtual_port;
+ /* Is this an AF_UNIX port? */
+ unsigned int is_unix_addr:1;
+ /* The outgoing TCP port to use, if !is_unix_addr */
+ uint16_t real_port;
+ /* The outgoing IPv4 or IPv6 address to use, if !is_unix_addr */
+ tor_addr_t real_addr;
+ /* The socket path to connect to, if is_unix_addr */
+ char unix_addr[FLEXIBLE_ARRAY_MEMBER];
+} rend_service_port_config_t;
+
void hs_init(void);
void hs_free_all(void);
@@ -128,6 +143,7 @@ void hs_build_blinded_keypair(const ed25519_keypair_t *kp,
const uint8_t *secret, size_t secret_len,
uint64_t time_period_num,
ed25519_keypair_t *kp_out);
+int hs_service_requires_uptime_circ(const smartlist_t *ports);
void rend_data_free(rend_data_t *data);
rend_data_t *rend_data_dup(const rend_data_t *data);
diff --git a/src/or/rendservice.c b/src/or/rendservice.c
index 8239803fb..7353a4f99 100644
--- a/src/or/rendservice.c
+++ b/src/or/rendservice.c
@@ -83,22 +83,6 @@ static smartlist_t* rend_get_service_list_mutable(
smartlist_t* substitute_service_list);
static int rend_max_intro_circs_per_period(unsigned int n_intro_points_wanted);
-/** Represents the mapping from a virtual port of a rendezvous service to
- * a real port on some IP.
- */
-struct rend_service_port_config_s {
- /* The incoming HS virtual port we're mapping */
- uint16_t virtual_port;
- /* Is this an AF_UNIX port? */
- unsigned int is_unix_addr:1;
- /* The outgoing TCP port to use, if !is_unix_addr */
- uint16_t real_port;
- /* The outgoing IPv4 or IPv6 address to use, if !is_unix_addr */
- tor_addr_t real_addr;
- /* The socket path to connect to, if is_unix_addr */
- char unix_addr[FLEXIBLE_ARRAY_MEMBER];
-};
-
/* Hidden service directory file names:
* new file names should be added to rend_service_add_filenames_to_list()
* for sandboxing purposes. */
@@ -1694,24 +1678,6 @@ rend_service_get_by_service_id(const char *id)
return NULL;
}
-/** Return 1 if any virtual port in <b>service</b> wants a circuit
- * to have good uptime. Else return 0.
- */
-static int
-rend_service_requires_uptime(rend_service_t *service)
-{
- int i;
- rend_service_port_config_t *p;
-
- for (i=0; i < smartlist_len(service->ports); ++i) {
- p = smartlist_get(service->ports, i);
- if (smartlist_contains_int_as_string(get_options()->LongLivedPorts,
- p->virtual_port))
- return 1;
- }
- return 0;
-}
-
/** Check client authorization of a given <b>descriptor_cookie</b> of
* length <b>cookie_len</b> for <b>service</b>. Return 1 for success
* and 0 for failure. */
@@ -2029,7 +1995,7 @@ rend_service_receive_introduction(origin_circuit_t
*circuit,
goto err;
}
- circ_needs_uptime = rend_service_requires_uptime(service);
+ circ_needs_uptime = hs_service_requires_uptime_circ(service->ports);
/* help predict this next time */
rep_hist_note_used_internal(now, circ_needs_uptime, 1);
diff --git a/src/or/rendservice.h b/src/or/rendservice.h
index 78f4b92c2..a6d6ec6a4 100644
--- a/src/or/rendservice.h
+++ b/src/or/rendservice.h
@@ -16,7 +16,6 @@
#include "hs_service.h"
typedef struct rend_intro_cell_s rend_intro_cell_t;
-typedef struct rend_service_port_config_s rend_service_port_config_t;
#ifdef RENDSERVICE_PRIVATE
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