[tahoe-dev] [tahoe-lafs] #280: get_hash method in webapi for extension caching logic.

[tahoe-lafs]

#280: get_hash method in webapi for extension caching logic.
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     Reporter:  nejucomo   |        Type:  enhancement             
       Status:  new        |    Priority:  minor                   
    Milestone:  undecided  |   Component:  code-frontend-web       
      Version:  0.7.0      |    Keywords:  webapi caching extension
Launchpad_bug:             |  
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Comment(by zooko):

 There is currently no hash of the plaintext stored.  See
 http://allmydata.org/~zooko/lafs.pdf diagram 1 for what is stored for an
 immutable file currently.  We used to have one, but we took it out because
 it was visible to anyone (it was stored on storage servers unencrypted),
 and this enables anyone to mount guess-and-check attacks (per
 http://hacktahoe.org/drew_perttula.html ). #453 (safely add plaintext_hash
 to immutable UEB) is a ticket to add plaintext hashes back but store them
 encrypted under the read-cap.

 If we had #453, we could easily give out the hash-of-plaintext or else the
 root-of-merkle-tree-of-plaintext to serve this API.  But wait a minute,
 what's the use case of this proposed API again?  How come the user can't
 just use the verify cap instead of this hash-of-the-plaintext?

-- 
Ticket URL: <http://allmydata.org/trac/tahoe/ticket/280#comment:8>
tahoe-lafs <http://allmydata.org>
secure decentralized file storage grid