When we establish any new connection, reset the delays on all the other
Reconnectors. This will trigger a new batch of connection attempts. The idea
is to detect when we (the client) have been offline for a while, and to
connect to all servers when we get back online. By accelerating the timers
inside the Reconnectors, we try to avoid spending a long time in a
partially-connected state (which increases the chances of causing problems
with mutable files, by not updating all the shares that we ought to).
not status instances. Fix this. The symptom was that following a link like
'up-123' that referred to an old operation (no longer in memory) while an
upload was active would get an ugly traceback instead of a "no such resource"
message.
when the confwiz configures a node (i.e. typically once on mac, once per
install on windows) in addition to writing the root_dir.cap retrieved from
the native_client backend into a config file, it additionally writes a hash
thereof into the 'convergence' config file.
this causes uploads from this node to use a consistent 'convergence' hashing
value matching any other nodes with the same configured root_dir, i.e. for
the most part other systems installed and configured on the same account.
This removes the guess-partial-information attack vector, and reduces
the amount of overhead that we consume with each file. It also introduces
a forwards-compability break: older versions of the code (before the
previous download-time "make hashes optional" patch) will be unable
to read files uploaded by this version, as they will complain about the
missing hashes. This patch is experimental, and is being pushed into
trunk to obtain test coverage. We may undo it before releasing 1.0.
Now upload or encode methods take a required argument named "convergence" which can be either None, indicating no convergent encryption at all, or a string, which is the "added secret" to be mixed in to the content hash key. If you want traditional convergent encryption behavior, set the added secret to be the empty string.
This patch also renames "content hash key" to "convergent encryption" in a argument names and variable names. (A different and larger renaming is needed in order to clarify that Tahoe supports immutable files which are not encrypted content-hash-key a.k.a. convergent encryption.)
This patch also changes a few unit tests to use non-convergent encryption, because it doesn't matter for what they are testing and non-convergent encryption is slightly faster.
This removes the guess-partial-information attack vector, and reduces
the amount of overhead that we consume with each file. It also introduces
a forwards-compability break: older versions of the code (before the
previous download-time "make hashes optional" patch) will be unable
to read files uploaded by this version, as they will complain about the
missing hashes. This patch is experimental, and is being pushed into
trunk to obtain test coverage. We may undo it before releasing 1.0.
Removing the plaintext hashes can help with the guess-partial-information
attack. This does not affect compatibility, but if and when we actually
remove any hashes from the share, that will introduce a
forwards-compatibility break: tahoe-0.9 will not be able to read such files.
