[tor-commits] [torspec/master] Clarify all-zeroes relay fingerprint behavior

[nickm at torproject.org]

commit 1f0d38a7632b1861039d040089b245eba24e3318
Author: Taylor Yu <catalyst at torproject.org>
Date:   Fri Jul 20 16:56:29 2018 -0500

    Clarify all-zeroes relay fingerprint behavior
    
    The all-zeroes special case for EXTEND/EXTEND2 cells is for relay
    fingerprints/public keys, not cell crypto digests.
    
    Closes ticket 26893.
---
 tor-spec.txt | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/tor-spec.txt b/tor-spec.txt
index b88befe..02bb9ae 100644
--- a/tor-spec.txt
+++ b/tor-spec.txt
@@ -1264,11 +1264,12 @@ see tor-design.pdf.
    cell to the next onion router, with the enclosed HLEN, HTYPE, and HDATA
    as its payload.
 
-   As special cases, if the extend cell includes a digest of
-   all zeroes, or asks to extend back to the relay that sent the extend
-   cell, the circuit will fail and be torn down. The initiating onion
-   router chooses some circID not yet used on the connection between the
-   two onion routers.  (But see section 5.1.1 above, concerning choosing
+   As special cases, if the EXTEND/EXTEND2 cell includes a legacy
+   identity, identity fingerprint, or Ed25519 identity of all zeroes, or
+   asks to extend back to the relay that sent the extend cell, the
+   circuit will fail and be torn down. The initiating onion router
+   chooses some circID not yet used on the connection between the two
+   onion routers.  (But see section 5.1.1 above, concerning choosing
    circIDs.)
 
    When an onion router receives a CREATE/CREATE2 cell, if it already has a