[tor-commits] [tor/master] Refactor legacy code to support hs_ident along with rend_data.

[nickm at torproject.org]

commit 0b2018a4d078a6ea47678c296c634714ab7eee94
Author: George Kadianakis <desnacked at riseup.net>
Date:   Tue May 2 16:20:26 2017 +0300

    Refactor legacy code to support hs_ident along with rend_data.
    
    The legacy HS circuit code uses rend_data to match between circuits and
    streams. We refactor some of that code so that it understands hs_ident
    as well which is used for prop224.
---
 src/or/circuituse.c      | 40 +++++++++++++++++++++++++++++++++-------
 src/or/connection_edge.c |  8 +++++++-
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index 9f9d3ab..288b49e 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -42,6 +42,7 @@
 #include "control.h"
 #include "entrynodes.h"
 #include "hs_common.h"
+#include "hs_ident.h"
 #include "nodelist.h"
 #include "networkstatus.h"
 #include "policies.h"
@@ -55,6 +56,36 @@
 static void circuit_expire_old_circuits_clientside(void);
 static void circuit_increment_failure_count(void);
 
+/** Check whether the hidden service destination of the stream at
+ *  <b>edge_conn</b> is the same as the destination of the circuit at
+ *  <b>origin_circ</b>. */
+static int
+circuit_matches_with_rend_stream(const edge_connection_t *edge_conn,
+                                 const origin_circuit_t *origin_circ)
+{
+  /* Check if this is a v2 rendezvous circ/stream */
+  if ((edge_conn->rend_data && !origin_circ->rend_data) ||
+      (!edge_conn->rend_data && origin_circ->rend_data) ||
+      (edge_conn->rend_data && origin_circ->rend_data &&
+       rend_cmp_service_ids(rend_data_get_address(edge_conn->rend_data),
+                            rend_data_get_address(origin_circ->rend_data)))) {
+    /* this circ is not for this conn */
+    return 0;
+  }
+
+  /* Check if this is a v3 rendezvous circ/stream */
+  if ((edge_conn->hs_ident && !origin_circ->hs_ident) ||
+      (!edge_conn->hs_ident && origin_circ->hs_ident) ||
+      (edge_conn->hs_ident && origin_circ->hs_ident &&
+       !ed25519_pubkey_eq(&edge_conn->hs_ident->identity_pk,
+                          &origin_circ->hs_ident->identity_pk))) {
+    /* this circ is not for this conn */
+    return 0;
+  }
+
+  return 1;
+}
+
 /** Return 1 if <b>circ</b> could be returned by circuit_get_best().
  * Else return 0.
  */
@@ -169,14 +200,9 @@ circuit_is_acceptable(const origin_circuit_t *origin_circ,
       /* can't exit from this router */
       return 0;
     }
-  } else { /* not general */
+  } else { /* not general: this might be a rend circuit */
     const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
-    if ((edge_conn->rend_data && !origin_circ->rend_data) ||
-        (!edge_conn->rend_data && origin_circ->rend_data) ||
-        (edge_conn->rend_data && origin_circ->rend_data &&
-         rend_cmp_service_ids(rend_data_get_address(edge_conn->rend_data),
-                            rend_data_get_address(origin_circ->rend_data)))) {
-      /* this circ is not for this conn */
+    if (!circuit_matches_with_rend_stream(edge_conn, origin_circ)) {
       return 0;
     }
   }
diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c
index 8480a35..9c98c56 100644
--- a/src/or/connection_edge.c
+++ b/src/or/connection_edge.c
@@ -3566,8 +3566,14 @@ int
 connection_edge_is_rendezvous_stream(const edge_connection_t *conn)
 {
   tor_assert(conn);
-  if (conn->rend_data)
+
+  if (BUG(conn->rend_data && conn->hs_ident)) {
+    log_warn(LD_BUG, "Connection has both rend_data and hs_ident...");
+  }
+
+  if (conn->rend_data || conn->hs_ident) {
     return 1;
+  }
   return 0;
 }