Add ExtendByEd25519ID consensus parameter/torrc option

I need to be able to turn on Ed25519 support in client generation
of  extend cells so I can test it, but leave it off-by-default until
enough clients support it for us to turn it on for a bunch at once.

This is part of #15056 / prop#220.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index e833fcba7c..bdbbacd3ec 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -1043,8 +1043,8 @@ circuit_send_next_onion_skin(origin_circuit_t *circ)
     ec.orport_ipv4.port = hop->extend_info->port;
     tor_addr_make_unspec(&ec.orport_ipv6.addr);
     memcpy(ec.node_id, hop->extend_info->identity_digest, DIGEST_LEN);
-    /* 15056 Either here or in the onion.c encoding code, we should make an
-     * option to decide whether we declare the ED identity (if we know one) */
+    /* Set the ED25519 identity too -- it will only get included
+     * in the extend2 cell if we're configured to use it, though. */
     memcpy(&ec.ed_pubkey, &hop->extend_info->ed_identity,
            sizeof(ed25519_public_key_t));