Clients avoid choosing nodes that can't do ntor

If we know a node's version, and it can't do ntor, consider it not running.
If we have a node's descriptor, and it doesn't have a valid ntor key,
consider it not running.

Refactor these checks so they're consistent between authorities and clients.

1 files changed, 23 insertions, 2 deletions

diff --git a/src/or/nodelist.c b/src/or/nodelist.c
index a49bf03f61..a888ebefbd 100644
--- a/src/or/nodelist.c
+++ b/src/or/nodelist.c
@@ -1171,14 +1171,35 @@ node_get_pref_ipv6_dirport(const node_t *node, tor_addr_port_t *ap_out)
   }
 }
 
+/** Return true iff <b>md</b> has a curve25519 onion key.
+ * Use node_has_curve25519_onion_key() instead of calling this directly. */
+static int
+microdesc_has_curve25519_onion_key(const microdesc_t *md)
+{
+  if (!md) {
+    return 0;
+  }
+
+  if (!md->onion_curve25519_pkey) {
+    return 0;
+  }
+
+  if (tor_mem_is_zero((const char*)md->onion_curve25519_pkey->public_key,
+                      CURVE25519_PUBKEY_LEN)) {
+    return 0;
+  }
+
+  return 1;
+}
+
 /** Return true iff <b>node</b> has a curve25519 onion key. */
 int
 node_has_curve25519_onion_key(const node_t *node)
 {
   if (node->ri)
-    return node->ri->onion_curve25519_pkey != NULL;
+    return routerinfo_has_curve25519_onion_key(node->ri);
   else if (node->md)
-    return node->md->onion_curve25519_pkey != NULL;
+    return microdesc_has_curve25519_onion_key(node->md);
   else
     return 0;
 }