PKI Compliance Gate (CertGuard Engine)

PKI Compliance Gate (CertGuard Engine) is a Policy-as-Code engine for X.509 certificates, CA/Browser Forum Baseline Requirements, and API TLS posture checks.

One YAML policy profile is the source of truth for evaluation, CI gating, and generated CP/CPS Section 7 documentation.

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Quick Start

Option 1: GitHub Action in CI/CD

Pin an immutable release tag (there is no moving v1 tag). v0.2.0 is the current source version; use the most recent published tag.

Upgrading from 0.1.x is a breaking change. Expiry and EC key policy are now enforced by default, and the report no longer carries a score field. See CHANGELOG.md.

steps:
  - uses: actions/checkout@v4
  - name: Run PKI Compliance Gate
    uses: thulisa-n/pki-compliance-gate@v0.2.0
    with:
      cert: 'tests/certificates/valid_cert.pem'

Option 2: Install from PyPI

python3 -m pip install "pki-compliance-gate==0.2.0"
pki-gate --cert path/to/server.crt
pki-gate --version

Option 3: Run from a clone

python3 -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"

# Evaluate a certificate
pki-gate --cert tests/certificates/valid_cert.pem

# Export CP/CPS Section 7 documentation from the policy YAML
pki-gate --mode export-cps-doc --policy policies/cabf_policy.yaml --summary-output CPS_SECTION_7.md

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What this repo enforces

The default profile (policies/cabf_policy.yaml) enforces:

• Validity: maximum 200 days; certificate must be inside its notBefore/notAfter window.
• Key material: RSA >= 2048; ECDSA >= 256 bits on P-256/P-384/P-521 only; RSA and EC are the only permitted algorithms.
• Signature: no SHA-1 or MD5.
• Identity: SAN required; internal suffixes blocked (.local, .internal, .intranet).
• Optional overlays (off by default): DCV attestation, RFC 5280 extension and path profile, HSM/FIPS issuance attestation, crypto-transition targets, OPA/Rego gate, zlint and openssl asn1parse.
• API TLS posture (--mode apisec --endpoint example.com): live TLS version, weak-cipher, expiry and certificate checks.

Coverage matrix

Every control the engine can emit. A control the active profile does not enable is reported as not_applicable -- defined but not assessed -- and is never counted as a pass.

Control	Rule ID	Category	Severity	Standard reference
certificate_expiry_window	OPS-RENEWAL-WINDOW	VALIDITY	low	Operational renewal policy
certificate_not_expired	RFC-5280-4.1.2.5	VALIDITY	critical	RFC 5280 4.1.2.5 / CA/B Forum BR 6.3.2
certificate_not_yet_valid	RFC-5280-4.1.2.5	VALIDITY	high	RFC 5280 4.1.2.5
crypto_transition_rsa_target	CRYPTO-AGILITY-RSA	CRYPTO-TRANSITION	medium	Crypto transition readiness profile
crypto_transition_signature_hash	CRYPTO-AGILITY-HASH	CRYPTO-TRANSITION	high	Crypto transition readiness profile
crypto_transition_validity_target	CRYPTO-AGILITY-VALIDITY	CRYPTO-TRANSITION	high	Crypto transition readiness profile
dcv_method	CAB-BR-3.2.2.4	DCV	high	CA/B Forum BR 3.2.2.4
dcv_recency	CAB-BR-4.2.1	DCV	high	CA/B Forum BR 4.2.1
ec_curve_allowed	CAB-BR-6.1.5	CRYPTOGRAPHY	critical	CA/B Forum BR 6.1.5
ec_key_size	CAB-BR-6.1.5	CRYPTOGRAPHY	critical	CA/B Forum BR 6.1.5
internal_domain_check	CAB-BR-7.1.4.2.1	POLICY	high	CA/B Forum BR 7.1.4.2.1
issuance_fips_level	FIPS-140-CONTROL	ISSUANCE	medium	FIPS 140-2/140-3
issuance_hsm_attestation	PKCS11-HSM-ATTESTATION	ISSUANCE	high	PKCS#11 / FIPS operations
key_algorithm_allowed	CAB-BR-6.1.5	CRYPTOGRAPHY	critical	CA/B Forum BR 6.1.5
rfc5280_authority_key_identifier	RFC-5280-4.2.1.1	RFC5280	medium	RFC 5280 4.2.1.1
rfc5280_critical_extension_profile	RFC-5280-4.2	RFC5280	high	RFC 5280 4.2
rfc5280_end_entity_ca	RFC-5280-4.2.1.9	RFC5280	high	RFC 5280 4.2.1.9
rfc5280_key_usage_profile	RFC-5280-4.2.1.3	RFC5280	high	RFC 5280 4.2.1.3
rfc5280_path_aki_ski_match	RFC-5280-4.2.1.1	RFC5280	medium	RFC 5280 4.2.1.1
rfc5280_path_issuer_subject_match	RFC-5280-6	RFC5280	high	RFC 5280 6.1
rfc5280_subject_key_identifier	RFC-5280-4.2.1.2	RFC5280	medium	RFC 5280 4.2.1.2
rsa_key_size	CAB-BR-6.1.5	CRYPTOGRAPHY	critical	CA/B Forum BR 6.1.5
san_extension	RFC-5280-4.2.1.6	IDENTITY	high	CA/B Forum BR 7.1.4.2.1
signature_algorithm	CAB-BR-7.1.3	CRYPTOGRAPHY	critical	CA/B Forum BR 7.1.3
validity_days	CAB-BR-6.3.2	VALIDITY	high	CA/B Forum BR 6.3.2

Not covered yet

Stated plainly so the matrix above is not mistaken for full BR conformance. None of the following are implemented: revocation checking (CRL/OCSP), OCSP must-staple, Certificate Transparency / SCT embedding, chain building and full path validation, extendedKeyUsage profiles, CN-in-SAN consistency, wildcard placement rules, reserved or internal IP addresses in SANs (only DNS suffixes are checked), and serial-number entropy.

Evidence and integrity

Each run writes a compliance report, per-control evidence, and an evidence_manifest.json that records a SHA-256 digest of every evidence file, the engine version, and the digest of the policy bytes that produced the verdict.

Digests detect accidental change and single-file tampering. They are not signatures -- a party able to rewrite the whole bundle can recompute them. Tamper-evident custody comes from the cosign keyless signature produced in this repository's CI on push to main (GitHub native attestations are published only on public repositories). The .seal file is a digest, not a seal; the name is retained for pipeline compatibility.

Exit codes

• 0: no failing checks (and lint not failed)
• 1: only low-severity check failures
• 2: medium/high failures, lint failure, or CLI usage/input errors
• 3: at least one critical check failure

--fail-on-waived counts waived findings as failures, for audit runs where an approved exception must still block.

Reports carry no percentage score

A single percentage was removed in report schema 2.0. It counted controls the policy had never enabled, so an almost-empty profile read 100%, and a certificate failing a critical control could still present as ~95%. Reports now carry findings bucketed by severity and a coverage block stating how much was actually assessed:

Compliant: NO
Risk Level: HIGH
Findings: critical=2
Coverage: 10 of 25 controls evaluated (8 pass, 2 fail, 0 waived, 15 not applicable)

How it flows

flowchart LR
    A[PEM Certificate / Domain] --> B[X509 and TLS Parser]
    B --> C[Policy Validator Engine]
    C --> D[Compliance Report]
    C --> E[CP/CPS Docs Exporter]
    C --> F[Audit Evidence]
    D --> G[CI Exit Code 0..3]

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Execution modes

Mode	Example	What the code does
evaluate	pki-gate --cert server.crt	Full policy evaluation of a certificate file.
export-cps-doc	pki-gate --mode export-cps-doc	Renders the YAML policy as CP/CPS Section 7 Markdown.
apisec	pki-gate --mode apisec --endpoint example.com	Scans a live endpoint for TLS posture.
triage	pki-gate --mode triage --report-input report.json	Turns report findings into severity-ranked next actions.
assure	pki-gate --mode assure --report-input report.json	Independently recomputes whether the report's compliant flag matches checks and lint.
watch	pki-gate --mode watch	Diffs the loaded policy against policies/standards_baseline.yaml.
heal	pki-gate --mode heal --healed-cert new_cert.pem	Writes a remediation plan; re-evaluates only if --healed-cert is provided.
summary	pki-gate --mode summary --report-input report.json	Writes a reviewer Markdown summary.
trend	pki-gate --mode trend --report-input report.json	Writes a trend snapshot JSON.
signals	pki-gate --mode signals	Reads curated external signals JSON and writes recommendations.

Repository structure

src/certguard/          Core agents, CLI, bundled policy, and engine
src/certguard/policy_exporter.py  CP/CPS exporter
src/main.py             Backward-compatible repository entrypoint
policies/               Policy YAML profiles and Rego rules
tests/                  Automated test suite
action.yml              Composite GitHub Action
.github/workflows/      CI workflows

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Distribution status

The GitHub Action, wheel, and sdist are published from the v0.2.0 tag. Install the CLI with pip install pki-compliance-gate==0.2.0. Later GitHub releases reuse .github/workflows/publish.yml with PyPI trusted publishing (OIDC, no API token in the repository).

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License

Licensed under the MIT License.