Sigstore - Software Artifact Signing and Verification

Per Sigstore Cosign: sign + verify container images + OCI artifacts. Integrate with admission control + supply chain security.

• Sigstore evidence for SIGSTORE-3

• adoption + private deployment partial

Per Sigstore: keyless signing. Requirements include (a) Keyless Signing With Short-Lived Certificates via Fulcio + (b) OIDC identity-based signing + (c) Certificate Transparency Monitoring + (d) Reusable Workflow and Pipeline Hardening + (e) maintain Sigstore client integration.

• Sigstore evidence for SIGSTORE-1

• adoption + private deployment partial

Per Sigstore: private deployment + migration. Requirements include (a) Private Sigstore Deployment for Regulated Environments + (b) Long-Lived Key Migration and Sunset + (c) operate enterprise-internal Sigstore.

• Sigstore evidence for SIGSTORE-4

• adoption + private deployment partial

Support identity-based keyless signing using Fulcio certificates and Rekor transparency log by default

• Cosign deployment documentation
• OIDC identity provider integration
• ephemeral key procedures
• signing pipeline records

• no OIDC integration
• long-lived keys persisting
• no signing in CI/CD

Support signing with hardware tokens, KMS systems, or cosign-generated encrypted key pairs

• key generation procedures
• key storage documentation
• key rotation records
• signing pipeline integration

• weak key storage
• no rotation
• no HSM use

Store signatures and attestations in OCI-compliant registries alongside container images

• OCI registry configuration
• signature attachment procedures
• registry access controls
• retention policy

• signatures not stored alongside artifacts
• weak access controls
• no retention policy

Verify signed artifacts using timestamps and short-lived certificate validity windows

• verification policies
• admission controller configurations
• verification logs
• policy bundle records

• no admission controller
• weak verification policies
• missing logs

Issue short-lived certificates binding ephemeral keys to OpenID Connect identities

• Fulcio integration records
• ephemeral certificate logs
• lifetime policy documentation
• monitoring records

• overly long certificate lifetimes
• no Fulcio integration
• weak monitoring

Bind signer identity from OIDC provider to certificate for attributable signing without long-lived keys

• OIDC provider integration
• identity claim documentation
• binding verification records
• policy mapping

• weak identity mapping
• no policy enforcement on identity claims
• missing audit

Log all issued certificates to certificate transparency logs for auditability

• CT log monitoring records
• SCT verification procedures
• log inclusion proofs
• audit records

• no CT monitoring
• weak SCT verification
• missing inclusion proofs

Log all signing events in immutable transparency log providing auditable record of signature creation

• Rekor log entries
• inclusion proof records
• log monitoring procedures
• audit records

• no Rekor logging
• no inclusion proof verification
• weak monitoring

Store entries in append-only Merkle tree providing tamper-evident and verifiable record of signing events

• Merkle tree verification records
• consistency proof logs
• monitoring procedures
• audit reports

• no consistency proof checks
• weak monitoring
• no auditor role

Provide RESTful API for submission, validation, and querying of transparency log entries

• API integration documentation
• validation procedures
• API rate limiting records
• test results

• no API integration testing
• weak rate limiting
• missing validation

Verify signed timestamp in bundle ensuring it falls within certificate issuance time window

• timestamp authority integration
• timestamp verification records
• TSA configuration documentation
• audit logs

• no TSA integration
• weak verification
• no audit

Support in-toto attestation format for software supply chain metadata and provenance verification

• in-toto attestations
• SLSA framework alignment records
• provenance documents
• verification policies

• no provenance generation
• weak SLSA alignment
• missing verification

Enforce admission policies in container orchestrators to require valid Sigstore signatures before deployment

• policy bundles
• policy controller configurations
• enforcement logs
• policy versioning records

• no policy bundles
• weak controller deployment
• missing versioning

Per Sigstore: Rekor transparency log. Requirements include (a) record signing events to Rekor + (b) verify signatures + Rekor entries + (c) implement verification policy + (d) integrate with consumers.

• Sigstore evidence for SIGSTORE-2

• adoption + private deployment partial