git.stella-ops.org/docs/features/checked/concelier/4-tier-backport-evidence-resolver.md

4-Tier Backport Evidence Resolver

Module

Concelier

Status

VERIFIED

Description

Multi-tier backport evidence resolution with tier precedence, distro mappings, cross-distro OVAL integration, and deterministic backport verdicts.

Implementation Details

• Modules: src/Concelier/__Libraries/StellaOps.Concelier.Merge/, src/Concelier/__Libraries/StellaOps.Concelier.BackportProof/
• Key Classes:
  • BackportEvidenceResolver (src/Concelier/__Libraries/StellaOps.Concelier.Merge/Backport/BackportEvidenceResolver.cs) - multi-tier evidence resolution with tier precedence logic
  • BackportStatusService (src/Concelier/__Libraries/StellaOps.Concelier.BackportProof/Services/BackportStatusService.cs) - backport status lookups with version comparison
  • FixIndexService (src/Concelier/__Libraries/StellaOps.Concelier.BackportProof/Services/FixIndexService.cs) - O(1) distro patch lookups via fix index
  • ProvenanceScopeService (src/Concelier/__Libraries/StellaOps.Concelier.Merge/Backport/ProvenanceScopeService.cs) - provenance scope tracking for backport-aware deduplication
• Persistence: ProvenanceScopeRepository (src/Concelier/__Libraries/StellaOps.Concelier.Persistence/Postgres/Repositories/ProvenanceScopeRepository.cs)
• Source: Feature matrix scan

E2E Test Plan

• Submit a CVE with known backport status across multiple distros and verify the BackportEvidenceResolver returns correct tier-based verdict
• Verify tier precedence: Tier 1 evidence (direct patch proof) overrides Tier 2/3/4 evidence
• Verify cross-distro resolution: same CVE produces correct backport verdicts for Alpine, Debian, and RedHat simultaneously
• Verify deterministic verdicts: identical inputs produce identical backport verdicts across repeated runs
• Verify FixIndexService returns O(1) lookup performance for known distro patch entries