Merge remote-tracking branch 'public/feature20552'

4 files changed, 11 insertions, 1 deletions

diff --git a/changes/feature20552 b/changes/feature20552
new file mode 100644
index 0000000000..11954807a7
--- /dev/null
+++ b/changes/feature20552
@@ -0,0 +1,4 @@
+  o Minor features (ed25519 link handshake):
+    - Advertise support for the ed25519 link handshake using the
+      subprotocol-versions mechanism, so that clients can tell which
+      relays can identity themselves by Ed25519 ID.
diff --git a/src/or/or.h b/src/or/or.h
index a43e2a33cd..eb94f63d5e 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -2265,6 +2265,10 @@ typedef struct routerstatus_t {
    * accept EXTEND2 cells */
   unsigned int supports_extend2_cells:1;
 
+  /** True iff this router has a protocol list that allows it to negotiate
+   * ed25519 identity keys on a link handshake. */
+  unsigned int supports_ed25519_link_handshake:1;
+
   unsigned int has_bandwidth:1; /**< The vote/consensus had bw info */
   unsigned int has_exitsummary:1; /**< The vote/consensus had exit summaries */
   unsigned int bw_is_unmeasured:1; /**< This is a consensus entry, with
diff --git a/src/or/protover.c b/src/or/protover.c
index 6c2da165f7..5972e61be7 100644
--- a/src/or/protover.c
+++ b/src/or/protover.c
@@ -293,7 +293,7 @@ protover_get_supported_protocols(void)
     "HSIntro=3 "
     "HSRend=1-2 "
     "Link=1-4 "
-    "LinkAuth=1 "
+    "LinkAuth=1,3 "
     "Microdesc=1-2 "
     "Relay=1-2";
 }
diff --git a/src/or/routerparse.c b/src/or/routerparse.c
index b391e88f22..2cfd3fc58a 100644
--- a/src/or/routerparse.c
+++ b/src/or/routerparse.c
@@ -2682,6 +2682,8 @@ routerstatus_parse_entry_from_string(memarea_t *area,
     rs->protocols_known = 1;
     rs->supports_extend2_cells =
       protocol_list_supports_protocol(tok->args[0], PRT_RELAY, 2);
+    rs->supports_ed25519_link_handshake =
+      protocol_list_supports_protocol(tok->args[0], PRT_LINKAUTH, 3);
   }
   if ((tok = find_opt_by_keyword(tokens, K_V))) {
     tor_assert(tok->n_args == 1);