GGFWPi

Read-only Raspberry Pi firmware and platform security auditor with SPI EEPROM acquisition, Secure Boot chain validation, OTP evidence, boot integrity baselines, policy gates, and portable .ggcap evidence packages.

Current release: 0.7.0-beta

Developed by GG Advanced IT Security UG — ggsec.de

Overview

GGFWPi is a Python-based security auditing tool for Raspberry Pi platforms. It combines firmware, boot-chain, operating-system, credential, network, and evidence-quality checks in one report.

The tool is designed for technical security assessments, platform hardening, firmware research, appliance validation, and repeatable evidence collection. It distinguishes between:

• confirmed security findings;
• policy failures;
• evidence coverage gaps;
• aggregate findings;
• informational observations;
• controls that are not required by the selected policy.

This distinction is also reflected in process exit codes, remediation counts, gate accounting, and summary accounting invariants.

Key capabilities

Firmware and boot security

• Read-only SPI EEPROM acquisition through flashrom and linux_spi.
• SPI chip identification and SHA-256 measurement.
• Raw SPI boot configuration extraction.
• Raw EEPROM configuration versus live firmware configuration comparison.
• SPI status-register write-protection assessment.
• Boot-chain resolution from config.txt and related boot files.
• Device-specific boot integrity baselines and drift detection.
• Raspberry Pi EEPROM update, debug, network-install, boot-order, and A/B capability observations.

Cryptographic Secure Boot validation

• Customer RSA-2048 public-key handling.
• boot.img and boot.sig SHA-256 and RSA PKCS#1 v1.5 verification.
• Signature timestamp and optional maximum-age policy.
• target-soc validation.
• EEPROM pubkey.bin parsing and consistency checks.
• EEPROM bootconf.txt and bootconf.sig validation.
• BCM2712 customer bootsys counter-signature validation.
• Customer public-key binding to OTP or external rpiboot -j provisioning metadata.
• Structured VALID, INVALID, and UNVERIFIED states.
• Embedded cryptographic known-answer self-tests.

GGFWPi validates the customer-controlled portion of the Secure Boot chain. Raspberry Pi vendor-root signatures are enforced by BootROM but are not independently replay-verified by GGFWPi.

OTP and provisioning evidence

• Model-aware OTP decoding.
• BCM2711 Secure Boot and JTAG-lock state decoding.
• Fail-closed BCM2712 evidence model for fields not available through the public runtime mapping.
• Optional external provisioning metadata collected with rpiboot -j.
• Structured unresolved-field reporting without inferring undocumented OTP rows.

Operating-system posture

• Weak and vendor-default credential detection.
• SSH configuration and authorized-key checks.
• Wildcard and potentially exposed network listeners.
• Firewall presence.
• APT repository transport and trust observations.
• Critical file permissions.
• Kernel mitigation and debug-interface checks.
• Suspicious process indicators.

Evidence and reporting

• Timestamped evidence directory.
• Standalone JSON report support.
• ZIP-based .ggcap evidence package.
• Evidence source, acquisition method, and trust-level metadata.
• Positive checks as well as findings.
• Deduplicated remediation groups.
• Complete gate accounting with explicit inclusion and exclusion reasons.
• Fail-closed summary-accounting invariants.

Tested environment

The current release has been hardware-tested on:

• Raspberry Pi 5;
• BCM2712;
• Kali Linux for Raspberry Pi;
• Python 3;
• Winbond W25Q16.V SPI EEPROM through /dev/spidev10.0.

The code contains platform-aware logic for other Raspberry Pi SoCs, with the most complete Secure Boot evidence paths currently implemented for BCM2711 and BCM2712.

Requirements

GGFWPi uses only the Python standard library for its core operation. RSA verification prefers the optional cryptography backend when installed and otherwise uses the embedded fail-closed verifier. Password verification can use one of the following backends:

• passlib — preferred;
• Python crypt, where available;
• system libcrypt through ctypes.

External tools used when available:

vcgencmd
rpi-eeprom-config
rpi-eeprom-update
rpi-eeprom-ab
flashrom

Root privileges are required for complete host inspection, /etc/shadow access, and SPI EEPROM acquisition.

Check the available CLI and dependencies:

python3 -m ggfw --help
# Compatibility entrypoint retained for existing automation:
python3 GGFWPi_v0.7.0-beta.py --help

Installation

Clone the repository:

git clone https://github.com/patapik/ggfwpi.git
cd ggfwpi

Install the package with both optional security backends:

python3 -m pip install '.[full]'

For a dependency-free checkout, python3 -m ggfw and the compatibility launcher continue to work with the standard-library fallback implementations.

Optional password-verification backend on Debian-based systems:

sudo apt update
sudo apt install python3-passlib

Install the Raspberry Pi EEPROM tools and flashrom through the packages appropriate for the target distribution. Verify their locations with:

command -v vcgencmd
command -v rpi-eeprom-config
command -v rpi-eeprom-update
command -v rpi-eeprom-ab
command -v flashrom

Quick start

1. Verify the cryptographic engine

This mode does not inspect the host or access SPI:

python3 GGFWPi_v0.7.0-beta.py --crypto-self-test
# Equivalent package entrypoint:
python3 -m ggfw --crypto-self-test

Expected result:

[*] Crypto self-test result: PASS
[*] Process exit code: 0

2. Run a standard audit

sudo python3 GGFWPi_v0.7.0-beta.py \
  --policy-profile default \
  --show-passed

3. Create a device-specific boot baseline

sudo mkdir -p /var/lib/ggfw

sudo python3 GGFWPi_v0.7.0-beta.py \
  --create-baseline /var/lib/ggfw/boot-baseline.json \
  --policy-profile default

Review and protect the baseline after creation. A baseline is a device-specific reference measurement, not an official vendor allowlist.

4. Compare against the baseline

sudo python3 GGFWPi_v0.7.0-beta.py \
  --baseline /var/lib/ggfw/boot-baseline.json \
  --policy-profile hardened \
  --show-passed \
  --fail-on HIGH

5. Audit a Secure Boot policy

sudo python3 GGFWPi_v0.7.0-beta.py \
  --baseline /var/lib/ggfw/boot-baseline.json \
  --policy-profile secure-boot-required \
  --show-otp \
  --secure-boot-evidence \
  --fail-on HIGH

For provisioned systems, provide external provisioning evidence and the expected customer public key:

sudo python3 GGFWPi_v0.7.0-beta.py \
  --baseline /var/lib/ggfw/boot-baseline.json \
  --policy-profile secure-boot-required \
  --otp-metadata /path/to/rpiboot-json-or-directory \
  --secure-boot-public-key /path/to/customer-public.pem \
  --max-boot-signature-age-days 365 \
  --show-otp \
  --secure-boot-evidence \
  --fail-on HIGH

Explicit external input paths are validated before acquisition begins. Missing, unreadable, ambiguous, or malformed input causes a controlled tool error.

Policy profiles

Gate semantics

Example CI gate:

sudo python3 GGFWPi_v0.7.0-beta.py \
  --policy-profile hardened \
  --fail-on HIGH

Severity-based gates evaluate leaf security and policy findings. By default:

• coverage gaps do not trigger a severity gate;
• aggregate findings never trigger process exit;
• every candidate finding is reported as either matched or excluded;
• excluded findings include explicit reasons.

Include leaf coverage gaps in a severity gate:

--fail-on HIGH --fail-on-coverage

Run a dedicated evidence-completeness gate:

--fail-on COVERAGE_GAP

Explicitly exclude finding attributes from gate evaluation:

--gate-exclude COVERAGE_GAP
--gate-exclude AGGREGATE

Exclusions affect process gating only. Findings remain visible in reports and evidence packages.

Exit codes

A security finding is not a tool failure. Exit code 2 indicates that the audit completed successfully and found conditions matching the configured gate.

Output

By default, GGFWPi creates:

ggfw-evidence/
├── ggfw-<timestamp>-<soc>/
│   ├── report.json
│   └── evidence/
└── ggfw-<timestamp>-<soc>.ggcap

The .ggcap file is a ZIP-based evidence container containing the report, manifest, collected artifacts, hashes, Secure Boot evidence, and supporting metadata.

Specify a package path:

--output /path/to/audit.ggcap

Write an additional standalone JSON report:

--json-output /path/to/report.json

Skip SPI acquisition when it is not available or not required:

--skip-spi

Run only OTP and Secure Boot evidence collection:

sudo python3 GGFWPi_v0.7.0-beta.py \
  --otp-only \
  --show-otp \
  --secure-boot-evidence

Extend the built-in weak/default password audit with a local UTF-8 wordlist:

sudo python3 -m ggfw --weak-password-file /secure/path/weak-passwords.txt

The file is bounded and read before the scan starts. Its contents and matched passwords are never written to reports; only candidate counts and the file's SHA-256 digest are recorded.

Read-only SPI design

GGFWPi does not write, erase, or modify SPI flash and does not enable or disable write protection. SPI interaction is limited to:

• programmer/chip probing;
• write-protection status queries;
• EEPROM reads.

Remediation instructions may describe external provisioning or recovery procedures, but the auditor itself remains read-only.

Evidence trust model

Most evidence collected from a running system is classified as in-band and normally receives MEDIUM trust because the examined operating system or firmware interface mediates the observation.

Higher-trust evidence can include:

• independent external SPI acquisition;
• offline file measurements;
• independently verified signed artifacts;
• externally acquired provisioning metadata with controlled provenance.

GGFWPi reports evidence limitations separately from confirmed security failures. Missing evidence is not automatically treated as a broken cryptographic signature.

Running the regression tests

Use the version-aware test runner:

python3 test_GGFWPi_latest.py

The first line identifies the selected module:

[*] GGFW regression target: GGFWPi_v0.7.0-beta.py

The suite covers:

• package and compatibility-launcher entrypoints;
• optional and built-in RSA backend behavior;
• strict DER rejection and fail-closed backend errors;
• bounded external weak-password dictionaries without credential disclosure;
• structured dual-use process heuristics;
• OTP decoders;
• Secure Boot positive and negative cryptographic fixtures;
• full BCM2711 and BCM2712 customer-chain scenarios;
• malformed and missing signature states;
• policy and gate behavior;
• summary and gate accounting invariants;
• .ggcap packaging;
• semantic selection of the current module.

Run the release-pinned suite:

python3 test_GGFWPi_v0.7.0.py

Important limitations

• A normal in-band SPI read is mediated by the running kernel and is not equivalent to an independent hardware-programmer acquisition.
• Public BCM2712 runtime OTP output does not expose every customer Secure Boot field. Use externally collected rpiboot -j metadata where conclusive provisioning evidence is required.
• Raspberry Pi vendor-root signatures are enforced by BootROM but are not independently replay-verified by GGFWPi.
• A device-specific baseline detects drift from the recorded state; it does not prove that the recorded state was originally trustworthy.
• A PASS for the embedded cryptographic self-test proves the known-answer implementation paths, not the provisioning state of the inspected device.

Repository layout

.
├── GGFWPi_v0.7.0-beta.py       # compatibility launcher
├── pyproject.toml
├── ggfw/
│   ├── models/                 # findings, evidence, reports
│   ├── parsers/                # config, cmdline, EEPROM image
│   ├── boot/                   # resolution and integrity
│   ├── hardware/               # platform, interrogation, OTP
│   ├── crypto/                 # RSA, signatures, validation, KAT
│   ├── engines/                # host and hardware policies
│   ├── spi/                    # read-only EEPROM acquisition
│   ├── reporting/              # console and policy gates
│   └── packaging/              # .ggcap evidence package
├── test_GGFWPi_latest.py
├── test_GGFWPi_v0.7.0.py
├── README.md
├── LICENSE
├── NOTICE
├── AUTHORS.md
├── SECURITY.md
├── CHANGELOG.md
└── .gitignore

Security reports

Do not publish suspected vulnerabilities in public GitHub issues. Follow the process in SECURITY.md.

Project status

GGFWPi is currently a beta security engineering and evidence-collection tool. Reports should be reviewed by a qualified analyst, particularly before destructive remediation, OTP provisioning, or irreversible Secure Boot configuration changes.

Author and project attribution

GGFWPi was developed by Maciej Gojny for GGSEC — GG Advanced IT Security UG.

Project website: https://ggsec.de

The original attribution is recorded in NOTICE and additional project information is available in AUTHORS.md.

License

GGFWPi is licensed under the Apache License, Version 2.0. Everyone may use, copy, modify, distribute, sublicense, and use the software commercially under the terms of that license.

Redistributions and derivative works must retain the applicable copyright, license, and attribution notices. Keep the LICENSE file and the attribution contained in NOTICE with redistributed copies, as required by Apache-2.0.

Copyright © 2026 GG Advanced IT Security UG.
Developed by Maciej Gojny for GGSEC.