Skip to content

GitLab

  • Projects
  • Groups
  • Snippets
  • Help
    • Loading...
  • Help
    • Help
    • Support
    • Community forum
    • Submit feedback
    • Contribute to GitLab
  • Sign in
Trac
Trac
  • Project overview
    • Project overview
    • Details
    • Activity
  • Issues 246
    • Issues 246
    • List
    • Boards
    • Labels
    • Service Desk
    • Milestones
  • Operations
    • Operations
    • Metrics
    • Incidents
  • Analytics
    • Analytics
    • Value Stream
  • Wiki
    • Wiki
  • Members
    • Members
  • Collapse sidebar
  • Activity
  • Create a new issue
  • Issue Boards

GitLab is used only for code review, issue tracking and project management. Canonical locations for source code are still https://gitweb.torproject.org/ https://git.torproject.org/ and git-rw.torproject.org.

  • Legacy
  • TracTrac
  • Issues
  • #24182

Closed (moved)
Open
Opened Nov 08, 2017 by teor@teor

Pad INTRODUCE cells to hide the number of link specifiers

Before #23577 (moved), 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 (moved): 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.

To upload designs, you'll need to enable LFS and have admin enable hashed storage. More information
Assignee
Assign to
Tor: unspecified
Milestone
Tor: unspecified
Assign milestone
Time tracking
None
Due date
None
Reference: legacy/trac#24182