[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
[tor-commits] [torspec/master] Correct our description of circID MSB logic
commit 3540da456b70c46d7601101b73c57439c455ff73
Author: Nick Mathewson <nickm@xxxxxxxxxxxxxx>
Date: Tue Sep 19 09:35:22 2017 -0400
Correct our description of circID MSB logic
In protocol <= 3 we allowed OPs to set the circID msb however they
wanted. We don't do that any more in >= 4.
Closes ticket 22882.
---
tor-spec.txt | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/tor-spec.txt b/tor-spec.txt
index f7bd546..4d572ec 100644
--- a/tor-spec.txt
+++ b/tor-spec.txt
@@ -792,18 +792,19 @@ see tor-design.pdf.
To prevent CircID collisions, when one node sends a CREATE cell to
another, it chooses from only one half of the possible values based
- on the ORs' public identity keys. In link protocol version 3 or
- lower, if the sending node has a lower key, it chooses a CircID with
- an MSB of 0; otherwise, it chooses a CircID with an MSB of 1. (Public
- keys are compared numerically by modulus.)
+ on the ORs' public identity keys.
+
+ In link protocol version 3 or lower, if the sending node has a lower
+ key, it chooses a CircID with an MSB of 0; otherwise, it chooses a
+ CircID with an MSB of 1. (Public keys are compared numerically by
+ modulus.) With protocol version 3 or lower, a client with no public key
+ MAY choose any CircID it wishes, since clients never need to process a
+ CREATE cell.
In link protocol version 4 or higher, whichever node initiated the
connection sets its MSB to 1, and whichever node didn't initiate the
connection sets its MSB to 0.
- (An OP with no public key MAY choose any CircID it wishes, since an OP
- never needs to process a CREATE cell.)
-
The CircID value 0 is specifically reserved for cells that do not
belong to any circuit: CircID 0 must not be used for circuits. No
other CircID value, including 0x8000 or 0x80000000, is reserved.
_______________________________________________
tor-commits mailing list
tor-commits@xxxxxxxxxxxxxxxxxxxx
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-commits