= [wiki:Summit 2nd Summit] Day 2 =

09-Nov-2011, Mozilla SF.  [http://people.mozilla.com/~bwarner/tahoe/Summit2Day2.flv Video] (1.1GB flash .flv, 4 hours)

== Attendees ==
* Zack Weinberg
* Zooko
* David-Sarah
* Brian
* Shawn
* Mark Seaborn

== Ideas ==
  - Shawn: would be nice to have a more traditional username/password web frontend
    - I (warner)'m imagining an IService, listening for HTTP on a different port
      than the main WEBAPI port, with a public URL. You submit
      username+password, get a cookie, present a filename. The gateway
      translates that into a filecap.
    - maybe store one rootcap per username. use bcrypt/scrypt to defer
      exposure until user submits password.
    - adding ACLs: either put a table in the frontend (username->file
      list), or put ACL data in dirnode edge metadata and have frontend
      compare it against a username
    - sharing to public: tell frontend a filename/dirname and ask to make
      it public, it returns a tinyurl. Just like a tinyurl except it's a
      proxy instead of a redirect.
    - sharing to an individual: maybe have an encryption pubkey for each
      account, Alice tells frontend "share my ~/foo with user=Bob",
      frontend encrypts a note to itself with Kbob, later when Bob logs in,
      his password bcrypt-unlocks the decryption key Kbobpriv, decrypts the
      note, gets the dircap, adds to a table for Bob, lets him enumerate a
      list of inbound shared directories
  - zwol describing a Tor project, making Tor traffic look like other
    traffic: WoW, other web browsing. "Stegatorus"?
  - zwol thinking about censorship-resistance, content-centric networking

== Control Panel ==
    - Brian explained requirements for a tahoe web-control-panel:
      - examine/control Agent things like periodic backup jobs (local dir,
        dircap, schedule, status, progress), lease-renewal/repair jobs
        (dircap, schedule, status, progress)
      - not using browser ambient authority, accessed through NODEDIR (iff
        you can read/write to NODEDIR/private, you should be able to get to
        the Web Control Panel), 
      - not scoped to a particular filecap/dircap
      - yes scoped to "client authority" (i.e. an "Account", q.v. Accounting,
        for general uploads and maybe repair), or local-disk-authority
        (backup jobs), or server admin (for the server side of Accounting)
      - ok to have no-JS and yes-JS options, ok if the no-JS option is less
        pleasant
    - David-Sarah, Zack, Shawn designed a scheme
      - writes a "control.html" into NODEDIR/private/
      - "tahoe control" launches browser with {{{file://.../control.html}}}
      - yes-JS version:
        - it contains one big {{{<iframe src="http://WUI/control#SECRET">}}}
        - that page contains JS which pulls the secret out of the fragment,
          then does lots of XHR with the secret to present the control panel
      - no-JS version:
        - it contains a form with a big "Start" button and a secret in a
          hidden form-post argument
        - that returns a page with lots of forms, secrets in hidden
          post-args. All links are POSTs. "back" won't be pleasant (requires
          a 're-submit form?' confirmation each time).
      - benefits: keep secret out of address bar, out of Referrer header
    - other useful techniques:
      - to limit the lifetime of a powerful secret, 'tahoe control' can write
        a new secret into NODEDIR just before launching the browser, and the
        node can erase or change the secret just after accepting the
        resulting browser hit.
      - splitting the webapi into multiple origins is becoming more
        important: probably starting with one port for (control-panel,
        welcome, node-status, WUI-dirnodes, download-only WAPI), and a second
        one for (WUI-documents) that could be executable.
    - [attachment:day2-webcontrol.jpg whiteboard]

== Accounting Review ==
    - Brian presented his Accounting branch
      (https://github.com/warner/tahoe-lafs/tree/accounting) , only looking
      at the delta between the '466-ed25519' branch and the 'accounting'
      branch (it builds upon the #466 work)
    - deferred discussion of leasedb crawler and race conditions, that
      requires more serious design work. David-Sarah and Brian will huddle on
      it, probably online later
    - approach seemed good, code is still incomplete
    - needs: more tests, usable control panel, refinement of "account
      message" concept
    - need to carefully plan the merge with LAE's s3-backend: they overlap a
      lot. Removing leases from shares helps a bunch. s3-backend introduces
      async share-crawlers, accounting removes one big crawler but adds a new
      small one, which might need to be async-ified if that still seems like
      a good idea.
    - consensus was that #466 should definitely land first. But then whether
      accounting should land before s3-backend, or other way around, was
      unclear. accounting needs more development work before it's ready for
      landing, s3-backend might be closer. But some co-evolution and
      anticipatory refactoring should make things easier for everybody.
    - brief discussion about branches in Git vs Darcs, specifically for
      working on projects like this. Brian anticipates pain and suffering
      trying to test merges of s3-backend (managed in a darcs branch) with
      his accounting work (managed in git branches). David-Sarah suggested
      applying the git/darcs bridge on a branch too, brian skeptical.