[PATCH] Add ability to save/load an md5 checkpoint file

Werner Koch wk at gnupg.org
Thu Dec 1 13:28:44 CET 2011


On Wed, 30 Nov 2011 22:59, ben.guthro at virtualcomputer.com said:
> For large encryption streams - it can be convenient to write a checkpoint file, 
> to be able to be able to resume later.

I can image that is is usable.  However, your code does not fit into the
Libgcrypt architecture: It is only for an old and for most purposes
broken algorithm, it uses direct write to a file and it is not
architecture neutral.  Further we would need copyright assignments to
the FSF.

A better way of doing this is to have a general way of serializing and
exporting/importing the state of a hash algorithm.  Given that the state
is an internal property of Libgcrypt, we can't export it because that
would mean to keep that serialized state compatible to all future
versions; this is a too high burden for maintenance.  What we can do is
to return the state a long with a version number and allow restoring it
only if the version number matches - that should be okay for this
purpose.

It is a bit of work, though.


Salam-Shalom,

   Werner


-- 
Die Gedanken sind frei.  Ausnahmen regelt ein Bundesgesetz.




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