Re: [Libguestfs] Hivex3: Saving values - always string
On Tue, Mar 04, 2014 at 02:38:01PM +0100, Martin Klíma wrote:
[..]
Hallo,
Hello. Just a note that the library is called "hivex". The "(3)"
printed after the name is a Unix convention that means it is in
section 3 of the manual, containing libraries:
https://en.wikipedia.org/wiki/Man_page#Manual_sections
I working on GUI interface for users to manipulate Windows Registry.
For that I choose to use really excellent library hivex3. Just now
I'm performing same test to see, if everything is saved correctly.
Most of things work really well, but there is problem with saving
some values and his types.
Description of problem:
For saving values is used function : node_set_values or node_set_value
This function take 3 arguments, node name, value type and value. It
seems that this function accept for value only strings (any other
type throw error). The problem lay when I want save values differed
then string. For example:
It's a little confusing. The value is indeed a string (in Python) but
in fact it's a binary object that is stored directly into the
registry. If you want to store a 32 bit integer (DWORD), you have to
encode that as a little-endian binary blob and put it in value.
Python has a module called 'struct' which you can use to do this
encoding (and decoding when you're pulling numbers out).
See the attached program which shows you how to use it.
value1 = { "key": "TEST_DWORD2(150)",
"t": 4, "value": "150" }
Result is saving value "150" not like DWORD but like STRING ->
0x313530, which is not valid DWORD value for Win Regedit.
This same is with saving binary values, binary or hex is handle like string.
Right, as this is setting the value field to a binary value 0x00303531,
that's assuming that Windows is able to read it at all since it has
the wrong length (3 bytes).
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines. Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v
Attachments:
- value.py (text/plain — 819 bytes)