Merge branch 'bug26627_033' into bug26627_033_merged_master

1 files changed, 14 insertions, 6 deletions

diff --git a/src/feature/hs/hs_circuit.c b/src/feature/hs/hs_circuit.c
index cd312e98be..541b165dd5 100644
--- a/src/feature/hs/hs_circuit.c
+++ b/src/feature/hs/hs_circuit.c
@@ -566,10 +566,14 @@ retry_service_rendezvous_point(const origin_circuit_t *circ)
   return;
 }
 
-/* Add all possible link specifiers in node to lspecs.
- * legacy ID is mandatory thus MUST be present in node. If the primary address
- * is not IPv4, log a BUG() warning, and return an empty smartlist.
- * Includes ed25519 id and IPv6 link specifiers if present in the node. */
+/* Add all possible link specifiers in node to lspecs:
+ *  - legacy ID is mandatory thus MUST be present in node;
+ *  - include ed25519 link specifier if present in the node, and the node
+ *    supports ed25519 link authentication, even if its link versions are not
+ *    compatible with us;
+ *  - include IPv4 link specifier, if the primary address is not IPv4, log a
+ *    BUG() warning, and return an empty smartlist;
+ *  - include IPv6 link specifier if present in the node. */
 static void
 get_lspecs_from_node(const node_t *node, smartlist_t *lspecs)
 {
@@ -607,8 +611,12 @@ get_lspecs_from_node(const node_t *node, smartlist_t *lspecs)
   link_specifier_set_ls_len(ls, link_specifier_getlen_un_legacy_id(ls));
   smartlist_add(lspecs, ls);
 
-  /* ed25519 ID is only included if the node has it. */
-  if (!ed25519_public_key_is_zero(&node->ed25519_id)) {
+  /* ed25519 ID is only included if the node has it, and the node declares a
+     protocol version that supports ed25519 link authentication, even if that
+     link version is not compatible with us. (We are sending the ed25519 key
+     to another tor, which may support different link versions.) */
+  if (!ed25519_public_key_is_zero(&node->ed25519_id) &&
+      node_supports_ed25519_link_authentication(node, 0)) {
     ls = link_specifier_new();
     link_specifier_set_ls_type(ls, LS_ED25519_ID);
     memcpy(link_specifier_getarray_un_ed25519_id(ls), &node->ed25519_id,