safing-portmaster/windows_kext

Portmaster Windows kext

Implementation of Safing's Portmaster Windows kernel extension in Rust.

Documentation

• Driver -> entry point.
• WDK -> Windows Driver Kit interface.
• Packet Path -> Detiled documentation of what happens to a packet when it enters the kernel extension.
• Release -> Guide how to do a release build

Building

The Windows Portmaster Kernel Extension is currently only developed and tested for the amd64 (64-bit) architecture.

Prerequesites:

• Visual Studio 2022
  • Install C++ and Windows 11 SDK (22H2) components
  • Add link.exe and signtool in the PATH
• Rust
  • https://www.rust-lang.org/tools/install
• Cargo make(optional)
  • https://github.com/sagiegurari/cargo-make

Setup Test Signing:

In order to test the driver on your machine, you will have to test sign it (starting with Windows 10).

Create a new certificate for test signing:

:: Open a *x64 Free Build Environment* console as Administrator.

:: Run the MakeCert.exe tool to create a test certificate:
MakeCert -r -pe -ss PrivateCertStore -n "CN=DriverCertificate" DriverCertificate.cer

:: Install the test certificate with CertMgr.exe:
CertMgr /add DriverCertificate.cer /s /r localMachine root

Enable Test Signing on the dev machine:

:: Before you can load test-signed drivers, you must enable Windows test mode. To do this, run this command:
Bcdedit.exe -set TESTSIGNING ON
:: Then, restart Windows. For more information, see The TESTSIGNING Boot Configuration Option.

Build driver:

cd driver
cargo build

Build also works on linux

Link and sign: On a windows machine copy driver.lib form the project target directory (driver/target/x86_64-pc-windows-msvc/debug/driver.lib) in the same folder as link.bat. Run link.bat.

driver.sys should appear in the folder. Load and use the driver.

Test

• Install go
  • https://go.dev/dl/

cd kext_tester
go run .

make sure the hardcoded path in main.go is pointing to the correct .sys file