[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
[tor-bugs] #24182 [Core Tor/Tor]: Pad INTRODUCE cells to hide the number of link specifiers
#24182: Pad INTRODUCE cells to hide the number of link specifiers
---------------------------+-----------------------------------------------
Reporter: teor | Owner: (none)
Type: defect | Status: new
Priority: Medium | Milestone: Tor: 0.3.3.x-final
Component: Core | Version:
Tor/Tor |
Severity: Normal | Keywords: prop224, tor-hs, defence-in-depth
Actual Points: | Parent ID: #23493
Points: 0.5 | Reviewer:
Sponsor: |
---------------------------+-----------------------------------------------
Before #23577, there are two sizes of introduce cell data:
* legacy id and IPv4 (24 bytes)
* legacy id and IPv4 and ed25519 id (56 bytes)
After #23577: there are another two sizes:
* legacy id and IPv4 and IPv6 (40 bytes)
* legacy id and IPv4 and ed25519 id and IPv6 (72 bytes)
And if we ever remove IPv4 addresses, or add another link specifier, we
create even more sizes.
This is ok at the moment, because we pad all cells to
HS_CELL_INTRODUCE1_MIN_SIZE (246 bytes), and no cells are larger than this
size. But we should make sure we are padding larger cells to the maximum
cell length, to avoid splitting the rendezvous point anonymity set with
future link specifiers.
--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24182>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online
_______________________________________________
tor-bugs mailing list
tor-bugs@xxxxxxxxxxxxxxxxxxxx
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs