NAME¶
virt-win-reg - Export and merge Windows Registry entries from a Windows guest
SYNOPSIS¶
virt-win-reg domname 'HKLM\Path\To\Subkey'
virt-win-reg domname 'HKLM\Path\To\Subkey' name
virt-win-reg domname 'HKLM\Path\To\Subkey' @
virt-win-reg --merge domname [input.reg ...]
virt-win-reg [--options] disk.img ... # instead of domname
WARNING¶
You must
not use "virt-win-reg" with the
--merge option
on live virtual machines. If you do this, you
will get irreversible
disk corruption in the VM. "virt-win-reg" tries to stop you from
doing this, but doesn't catch all cases.
Modifying the Windows Registry is an inherently risky operation. The format is
deliberately obscure and undocumented, and Registry changes can leave the
system unbootable. Therefore when using the
--merge option, make sure
you have a reliable backup first.
DESCRIPTION¶
This program can export and merge Windows Registry entries from a Windows guest.
The first parameter is the libvirt guest name or the raw disk image of a Windows
guest.
If
--merge is
not specified, then the chosen registry key is
displayed/exported (recursively). For example:
$ virt-win-reg Windows7 'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft'
You can also display single values from within registry keys, for example:
$ cvkey='HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion'
$ virt-win-reg Windows7 $cvkey ProductName
Windows 7 Enterprise
With
--merge, you can merge a textual regedit file into the Windows
Registry:
$ virt-win-reg --merge Windows7 changes.reg
NOTE¶
This program is only meant for simple access to the registry. If you want to do
complicated things with the registry, we suggest you download the Registry
hive files from the guest using
libguestfs(3) or
guestfish(1)
and access them locally, eg. using
hivex(3),
hivexsh(1) or
hivexregedit(1).
OPTIONS¶
- --help
- Display brief help.
- --version
- Display version number and exit.
- --debug
- Enable debugging messages.
- -c URI
- --connect URI
- If using libvirt, connect to the given URI. If
omitted, then we connect to the default libvirt hypervisor.
If you specify guest block devices directly, then libvirt is not used at
all.
- --format raw
- Specify the format of disk images given on the command
line. If this is omitted then the format is autodetected from the content
of the disk image.
If disk images are requested from libvirt, then this program asks libvirt
for this information. In this case, the value of the format parameter is
ignored.
If working with untrusted raw-format guest disk images, you should ensure
the format is always specified.
- --merge
- In merge mode, this merges a textual regedit file into the
Windows Registry of the virtual machine. If this flag is not given
then virt-win-reg displays or exports Registry entries instead.
Note that --merge is unsafe to use on live virtual machines,
and will result in disk corruption. However exporting (without this flag)
is always safe.
- --encoding UTF-16LE|ASCII
- When merging (only), you may need to specify the encoding
for strings to be used in the hive file. This is explained in detail in
"ENCODING STRINGS" in Win::Hivex::Regedit(3).
The default is to use UTF-16LE, which should work with recent versions of
Windows.
- --unsafe-printable-strings
- When exporting (only), assume strings are UTF-16LE and
print them as strings instead of hex sequences. Remove the final zero
codepoint from strings if present.
This is unsafe and does not preserve the fidelity of strings in the original
Registry for various reasons:
- •
- Assumes the original encoding is UTF-16LE. ASCII strings
and strings in other encodings will be corrupted by this
transformation.
- •
- Assumes that everything which has type 1 or 2 is really a
string and that everything else is not a string, but the type field in
real Registries is not reliable.
- •
- Loses information about whether a zero codepoint followed
the string in the Registry or not.
This all happens because the Registry itself contains no information about how
strings are encoded (see "ENCODING STRINGS" in
Win::Hivex::Regedit(3)).
You should only use this option for quick hacking and debugging of the Registry
contents, and
never use it if the output is going to be passed into
another program or stored in another Registry.
SUPPORTED SYSTEMS¶
The program currently supports Windows NT-derived guests starting with Windows
XP through to at least Windows 7.
The following Registry keys are supported:
- "HKEY_LOCAL_MACHINE\SAM"
- "HKEY_LOCAL_MACHINE\SECURITY"
- "HKEY_LOCAL_MACHINE\SOFTWARE"
- "HKEY_LOCAL_MACHINE\SYSTEM"
- "HKEY_USERS\.DEFAULT"
- "HKEY_USERS\SID"
- where SID is a Windows User SID (eg.
"S-1-5-18").
- "HKEY_USERS\username"
- where username is a local user name (this is a
libguestfs extension).
You can use "HKLM" as a shorthand for "HKEY_LOCAL_MACHINE",
and "HKU" for "HKEY_USERS".
The literal keys "HKEY_USERS\$SID" and "HKEY_CURRENT_USER"
are not supported (there is no "current user").
ENCODING¶
"virt-win-reg" expects that regedit files have already been reencoded
in the local encoding. Usually on Linux hosts, this means UTF-8 with
Unix-style line endings. Since Windows regedit files are often in UTF-16LE
with Windows-style line endings, you may need to reencode the whole file
before or after processing.
To reencode a file from Windows format to Linux (before processing it with the
--merge option), you would do something like this:
iconv -f utf-16le -t utf-8 < win.reg | dos2unix > linux.reg
To go in the opposite direction, after exporting and before sending the file to
a Windows user, do something like this:
unix2dos linux.reg | iconv -f utf-8 -t utf-16le > win.reg
For more information about encoding, see
Win::Hivex::Regedit(3).
If you are unsure about the current encoding, use the
file(1) command.
Recent versions of Windows regedit.exe produce a UTF-16LE file with
Windows-style (CRLF) line endings, like this:
$ file software.reg
software.reg: Little-endian UTF-16 Unicode text, with very long lines,
with CRLF line terminators
This file would need conversion before you could
--merge it.
CurrentControlSet etc.¶
Registry keys like "CurrentControlSet" don't really exist in the
Windows Registry at the level of the hive file, and therefore you cannot
modify these.
"CurrentControlSet" is usually an alias for "ControlSet001".
In some circumstances it might refer to another control set. The way to find
out is to look at the "HKLM\SYSTEM\Select" key:
# virt-win-reg WindowsGuest 'HKLM\SYSTEM\Select'
[HKEY_LOCAL_MACHINE\SYSTEM\Select]
"Current"=dword:00000001
"Default"=dword:00000001
"Failed"=dword:00000000
"LastKnownGood"=dword:00000002
"Current" is the one which Windows will choose when it boots.
Similarly, other "Current..." keys in the path may need to be
replaced.
DELETING REGISTRY KEYS AND VALUES¶
To delete a whole registry key, use the syntax:
[-HKEY_LOCAL_MACHINE\Foo]
To delete a single value within a key, use the syntax:
[HKEY_LOCAL_MACHINE\Foo]
"Value"=-
WINDOWS TIPS¶
Note that some of these tips modify the guest disk image. The guest
must
be shut off, else you will get disk corruption.
RUNNING A BATCH SCRIPT WHEN A USER LOGS IN¶
Prepare a DOS batch script, VBScript or executable. Upload this using
guestfish(1). For this example the script is called
"test.bat" and it is uploaded into "C:\":
guestfish -i -d WindowsGuest upload test.bat /test.bat
Prepare a regedit file containing the registry change:
cat > test.reg <<'EOF'
[HKLM\Software\Microsoft\Windows\CurrentVersion\RunOnce]
"Test"="c:\\test.bat"
EOF
In this example we use the key "RunOnce" which means that the script
will run precisely once when the first user logs in. If you want it to run
every time a user logs in, replace "RunOnce" with "Run".
Now update the registry:
virt-win-reg --merge WindowsGuest test.reg
INSTALLING A SERVICE¶
This section assumes you are familiar with Windows services, and you either have
a program which handles the Windows Service Control Protocol directly or you
want to run any program using a service wrapper like SrvAny or the free
RHSrvAny.
First upload the program and optionally the service wrapper. In this case the
test program is called "test.exe" and we are using the RHSrvAny
wrapper:
guestfish -i -d WindowsGuest <<EOF
upload rhsrvany.exe /rhsrvany.exe
upload test.exe /test.exe
EOF
Prepare a regedit file containing the registry changes. In this example, the
first registry change is needed for the service itself or the service wrapper
(if used). The second registry change is only needed because I am using the
RHSrvAny service wrapper.
cat > service.reg <<'EOF'
[HKLM\SYSTEM\ControlSet001\services\RHSrvAny]
"Type"=dword:00000010
"Start"=dword:00000002
"ErrorControl"=dword:00000001
"ImagePath"="c:\\rhsrvany.exe"
"DisplayName"="RHSrvAny"
"ObjectName"="NetworkService"
[HKLM\SYSTEM\ControlSet001\services\RHSrvAny\Parameters]
"CommandLine"="c:\\test.exe"
"PWD"="c:\\Temp"
EOF
Notes:
- •
- For use of "ControlSet001" see the section above
in this manual page. You may need to adjust this according to the control
set that is in use by the guest.
- •
- "ObjectName" controls the privileges that the
service will have. An alternative is
"ObjectName"="LocalSystem" which would be the most
privileged account.
- •
- For the meaning of the magic numbers, see this Microsoft KB
article: <http://support.microsoft.com/kb/103000>.
Update the registry:
virt-win-reg --merge WindowsGuest service.reg
SHELL QUOTING¶
Be careful when passing parameters containing "\" (backslash) in the
shell. Usually you will have to use 'single quotes' or double backslashes (but
not both) to protect them from the shell.
Paths and value names are case-insensitive.
Libvirt guest names can contain arbitrary characters, some of which have meaning
to the shell such as "#" and space. You may need to quote or escape
these characters on the command line. See the shell manual page
sh(1)
for details.
SEE ALSO¶
hivex(3),
hivexsh(1),
hivexregedit(1),
guestfs(3),
guestfish(1),
virt-cat(1),
Sys::Guestfs(3),
Sys::Guestfs::Lib(3),
Win::Hivex(3),
Win::Hivex::Regedit(3),
Sys::Virt(3),
<
http://libguestfs.org/>.
BUGS¶
When reporting bugs, please enable debugging and capture the
complete
output:
export LIBGUESTFS_DEBUG=1
virt-win-reg --debug [... rest ...] > /tmp/virt-win-reg.log 2>&1
Attach /tmp/virt-win-reg.log to a new bug report at
<
https://bugzilla.redhat.com/>
AUTHOR¶
Richard W.M. Jones <
http://people.redhat.com/~rjones/>
COPYRIGHT¶
Copyright (C) 2010 Red Hat Inc.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
Street, Fifth Floor, Boston, MA 02110-1301 USA.