[or-cvs] r6996: Add a comment about v0 fallback approach. Why did we dislike (in tor/trunk: . doc)

[nickm@xxxxxxxx]

Author: nickm
Date: 2006-08-09 02:41:29 -0400 (Wed, 09 Aug 2006)
New Revision: 6996

Modified:
   tor/trunk/
   tor/trunk/doc/tor-spec.txt
Log:
 r7056@Kushana:  nickm | 2006-08-08 23:40:53 -0700
 Add a comment about v0 fallback approach. Why did we dislike discriminating on X.509 certs again?



Property changes on: tor/trunk
___________________________________________________________________
Name: svk:merge
   - 1f724f9b-111a-0410-b636-93f1a77c1813:/local/or/tor/trunk:8207
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/eventdns:7014
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/mmap:7030
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/oo-connections:6950
   + 1f724f9b-111a-0410-b636-93f1a77c1813:/local/or/tor/trunk:8207
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/eventdns:7014
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/mmap:7030
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/oo-connections:6950
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/versions:7056

Modified: tor/trunk/doc/tor-spec.txt
===================================================================
--- tor/trunk/doc/tor-spec.txt	2006-08-09 00:58:27 UTC (rev 6995)
+++ tor/trunk/doc/tor-spec.txt	2006-08-09 06:41:29 UTC (rev 6996)
@@ -138,8 +138,8 @@
    additional fields to existing structures; implementations are constrained
    to ignore fields they do not expect.
 
-   Parties negotiate OR connection versions as described below in section
-   
+   Parties negotiate OR connection versions as described below in sections
+   4.1 and 4.2.
 
 2. Connections
 
@@ -305,14 +305,23 @@
    0 when the other side is recognized as a router running version
    0.1.2.??-alpha or earlier.
 
-   If a server finds that it wants to send a cell (for example because a
+   [If a server finds that it wants to send a cell (for example because a
    circuit wants to extend to that client, and the TLS connection
    is already established) yet no cell has arrived yet, we can't
    distinguish between a version 0 client and a slow network. We can't
    assume that the other side approves of version 0, so we can't just
    start using version 0. Perhaps the right answer is to then launch a
-   new TLS connection because you don't have a usable one after all?
+   new TLS connection because you don't have a usable one after all? -RD]
 
+   [That would seem to be thrashy.  Let's see if we can do better.  Remember,
+   normal v0 clients always send something after connecting, so if we have
+   had a connection for a while and gotten nothing over it, we could get away
+   with assuming it's bad.  Alternatively, we could identify V0 clients by
+   the OU=Tor field in the certificates: we don't check for it, and we never
+   documented it.  We might break other people's clients by sending them
+   hello cells, but only if those clients are nonconformant.  Am I right?
+   In any case, this seems way more reliable.  -NM]
+
 5. Circuit management
 
 5.1. CREATE and CREATED cells