Whonix Windows Installer - Design Documentation
Work in progress.
Design / Features[edit]
- https://github.com/Whonix/Whonix-Installer
- https://github.com/Whonix/Whonix-Starter
- https://github.com/Whonix/Whonix-Starter-Binary
- https://gitlab.com/whonix/virtualbox-windows-installer-binary
WhonixStarter(.exe):
- new implementation of whonix.exe in lazarus (without NET framework)
- platform independent ( later linux/mac version possible )
- ui consists of two forms ( main & error )
- main form has two buttons for start/stop and manage Whonix VMs
- error form pops up if virtualbox is missing
WhonixStarterSetup.msi:
- installs windows version of WhonixStarter
- adds start menu entry
- adds desktop shortcut
- uninstall over Windows "Programs and Features" tool
WhonixSetup(.exe):
- ui consists of a main form with several pages guiding the user through the installation process
- platform independent ( later linux/mac version possible )
- installs VirtualBox and WhonixOVA
- executes WhonixStarterSetup.msi (Windows only)
- checks installed and only reinstall missing components
- does not uninstall or delete any component
Challenges:
- Whonix
.ova
is bigger than 2 GB. - Windows
.cab
files have a hardcoded 2 GB maximum file size.
Requirements:
- cross compile on Debian (source) for Windows (target)
- building does not require Windows
Build limitations:
- needs Debian bookworm or above because of minimal wixl and lazarus version
flow chart[edit]
(1) Whonix-Starter:
lazbuild
→WhonixStarter.lpr
→WhonixStarter.exe
wixl
→WhonixStarterSetup.wxs
→WhonixStarter.exe
,WhonixStarterSetup.wxs
→WhonixStarterSetup.msi
(2) Whonix-Installer:
lazbuild
→WhonixSetup.lpr
→WhonixSetup.exe
WhonixSetup.exe
+ append +Whonix.ova
→WhonixSetup-Xfce.exe
CI[edit]
Whonix-Starter:
- https://github.com/einsiedler90/Whonix-Starter/actions
- https://github.com/Whonix/Whonix-Starter/actions
Whonix-Installer:
- https://github.com/einsiedler90/Whonix-Installer/actions
- https://github.com/Whonix/Whonix-Installer/actions
code signing[edit]
Introduction[edit]
EV (extended validation) certificate required to avoid Microsoft SmartScreen Filter warning message.
- https://learn.microsoft.com/en-us/windows/win32/seccrypto/using-signtool-to-sign-a-file
- https://stackoverflow.com/questions/18287960/signing-windows-application-on-linux-based-distros
- https://packages.debian.org/bullseye/osslsigncode
- https://issuetracker.google.com/issues/130343741
- https://www.ssl.com/guide/supported-cloud-hsms-document-signing-ev-code-signing/
- https://github.com/mtrojnar/osslsigncode/issues/34
requirements[edit]
- EV code signing for Windows authenticode to avoid Microsoft SmartScreen Filter warning message.
- cross signing
- build scripts running on Debian Linux
- build result (program) running on Windows 64 bit
- avoid running proprietary closed source software on local build machine
- can be fully automated using build scripts
- avoid hardware token (compatibility, hassle)
- avoid proprietary closed source device drivers
- ideally avoid non-mainline Linux kernel drivers
- supports signing big files
providers[edit]
thalesgroup:
- asked. does not have Linux tools.
Certum:
- https://shop.certum.eu/open-source-code-signing.html
Certum Open Source developer certificate - EV extended validation?
- https://www.certum.ng/product/ev-code-signing-in-the-cloud/
- https://shop.certum.eu/ev-code-signing-in-the-cloud.html
- SimplySign cloud-based solution eliminates the need for a physical card and a reader
- https://www.files.certum.eu/software/SimplySignDesktop/Linux-Ubuntu/2.9.8-9.1.6.0/SimplySignDesktop-2.9.8-9.1.6.0-x86_64-prod-ubuntu.bin
- €379.00
sectigo:
- https://sectigostore.com/code-signing/sectigo-ev-code-signing-certificate
- cloud hsm supported?
- $410
certerassl:
- https://certerassl.com/certera-ev-code-signing-certificate
- use existing token
- no cloud hsm
- $309
ssl.com:
- https://www.ssl.com/ev/
- $239
- A) optional proprietary eSigner CodeSignTool
- $20.00 / month (= $240 / year) or $180.00 / year
- eSigner uses ssl.com's own Cloud HSM
- actual file needs to be present to be signed
- https://www.ssl.com/guide/esigner-pricing-for-code-signing/
- When using for example Google Cloud HSM then eSigner is optional.
- minimum price for eSigner:
- bug reports:
- B) optional Google Cloud HSM compatibility
- https://www.ssl.com/guide/supported-cloud-hsms-document-signing-ev-code-signing/
SSL.com’s fee for Google Cloud HSM attestation is $500.00 USD.
- https://www.ssl.com/guide/supported-cloud-hsms-document-signing-ev-code-signing/
Google Cloud HSM;
- https://github.com/GoogleCloudPlatform/kms-integrations/blob/master/kmsp11/docs/user_guide.md
- https://github.com/GoogleCloudPlatform/kms-integrations
- https://cloud.google.com/kms/docs/reference/pkcs11-tool
- ( https://cloud.google.com/kms/docs/reference/pkcs11-nginx
)
libkmsp11.so
Verification of Code Signing Process[edit]
Verification of VirtualBox[edit]
VirtualBox for Windows is signed using Microsoft Authenticode signatures ("signtool
").
VirtualBox's digital signature can be verified on the Linux platform using osslsigncode
. Example:
osslsigncode verify -in VirtualBox-*.exe
A script verify
has been added to the
virtualbox-windows-installer-binary
repository as a reminder and example how to verify the digital software signatures on the Linux platform.
Signing Whonix Windows Installer[edit]
This document is based on a case where an executable (hello.exe
) is signed using GitHub Actions (CI) and CodeSigner.
For more details on the test, please refer to this GitHub repository: https://github.com/adrelanos/codesigner-test
When a file (hello.exe
) is signed, creating hello_signed.exe
, the goal is to ensure that no additional modifications, beyond the signing process, have occurred. These could potentially include the insertion of malicious code.
Overview:
- Original file:
hello.exe
- Signed file:
hello_signed.exe
- Extracted signature file:
hello_signature.pem
- File with reattached signature:
hello_with_signature.exe
- File with reattached signature and reset PE header:
hello_with_signature_reset_PE.exe
- File with removed signature:
hello_without_signature.exe
- File with removed signature and reset PE header:
hello_without_signature_reset_PE.exe
pe-header-to-zero
To achieve this, the original file is compared with the signed file in various stages and through different methods. The key stages are as follows:
1. Extract the signature from the signed file using osslsigncode
:
osslsigncode extract-signature -in hello_signed.exe -out hello_signature.pem
2. The original file (hello.exe
) is then re-signed using this extracted signature to create a new file (hello_with_signature.exe
):
osslsigncode attach-signature -sigin hello_signature.pem -in hello.exe -out hello_with_signature.exe
At this point, one would expect hello_signed.exe
to be identical to hello_with_signature.exe
. However, it was discovered that the signing process (osslsigncode attach-signature
) modified the PE header of the file by adding a PE checksum, thus resulting in a difference between these two files.
To analyze and understand these differences, a set of tools were used, including diff
, vbindiff
, diffoscope
, and readpe
. These comparisons brought to light the change in the PE checksum.
3. In order to make a direct comparison, the PE checksum in hello_with_signature.exe
was reset to 0
, mirroring its original state in hello.exe
and hello_signed.exe
. This was achieved using a Python script named pe-header-to-zero
:
pe-header-to-zero hello_with_signature.exe hello_with_signature_reset_PE.exe
After running this script, the newly created file hello_with_signature_reset_PE.exe
was found to be an exact match to hello_signed.exe
.
4. The script pe-header-to-zero
was also used on hello_without_signature.exe
to create hello_without_signature_reset_PE.exe
:
pe-header-to-zero hello_without_signature.exe hello_without_signature_reset_PE.exe
It was found that hello_without_signature_reset_PE.exe
was an exact match to the original hello.exe
, further validating the process.
Following this thorough examination, it can be reasonably stated that the signing process did not introduce any unwanted or malicious modifications to the original executable file.
All operations were performed using the osslsigncode
tool.
To install and examine PE headers, the pev
tool was used:
sudo apt install pev
To view the PE checksum, the readpe
utility was used:
readpe hello_signed.exe
readpe hello_with_signature_reset_PE.exe
readpe hello_without_signature_reset_PE.exe
TODO[edit]
merge[edit]
Reminder: Always please merge first before developing further.
See Also[edit]
- previous, deprecated Whonix Windows Installer
- Dev/Windows_User_Interface (TODO: update)
- Verify the Whonix Windows Installer

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