[tahoe-dev] [tahoe-lafs] #1164: use XSalsa20+AES-128 encryption

[tahoe-lafs]

#1164: use XSalsa20+AES-128 encryption
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 Reporter:  zooko   |           Owner:  somebody 
     Type:  defect  |          Status:  new      
 Priority:  major   |       Milestone:  undecided
Component:  code    |         Version:  1.8β     
 Keywords:          |   Launchpad Bug:           
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 In order to protect against weaknesses in AES (such as timing or side-
 channel attacks, or cryptanalysis, possibly far in the future and applied
 against old ciphertexts), want to use a combined encryption of AES-128 and
 XSalsa20. Yu Xue (Student) and Jack Lloyd (Mentor) are working on
 implementing that mode for GSoC 2010:

 http://tahoe-lafs.org/trac/pycryptopp/ticket/46

 This ticket is to integrate that encryption mode into Tahoe-LAFS. The
 steps are to define new capability versions, such as by inserting an
 {{{X}}} into the cap type designator:

 http://tahoe-lafs.org/pipermail/tahoe-dev/2010-August/004878.html
 http://tahoe-lafs.org/pipermail/tahoe-dev/2010-August/004879.html

 And to make it so that caps of that new type get encrypted/decrypted with
 XSalsa20+AES-128 instead of with AES-256. For the first release of Tahoe-
 LAFS which includes that functionality, it will still by default create
 new caps using the old encryption of only AES-256. It is important that
 people feel free to upgrade to new versions of Tahoe-LAFS without having
 to take any steps to ensure backward-compatibility, and that means that
 the new version of Tahoe-LAFS ''must not'', by default, produce caps that
 older versions of Tahoe-LAFS (such as v1.8.0) can't read.

 [http://tahoe-lafs.org/pipermail/tahoe-dev/2010-August/004936.html This
 tahoe-dev letter] lists all the places where the current source code
 (which is Tahoe-LAFS v1.8.0c1) uses encryption:
  * [source:src/allmydata/dirnode.py at 4539#L174]
  * [source:src/allmydata/dirnode.py at 4539#L293]
  * [source:src/allmydata/immutable/filenode.py at 4661#L166]
  * [source:src/allmydata/immutable/upload.py at 4655#L619]
  * [source:src/allmydata/immutable/upload.py at 4655#L728]
  * [source:src/allmydata/mutable/filenode.py at 4329#L131]
  * [source:src/allmydata/mutable/filenode.py at 4329#L136]
  * [source:src/allmydata/mutable/publish.py at 4329#L400]
  * [source:src/allmydata/mutable/retrieve.py at 4329#L518]
  * [source:src/allmydata/util/fileutil.py at 4609#L118]

-- 
Ticket URL: <http://tahoe-lafs.org/trac/tahoe-lafs/ticket/1164>
tahoe-lafs <http://tahoe-lafs.org>
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