Here’s a compact, practical blueprint for a **binary‑fingerprint store + trust‑scoring engine** that lets you quickly tell whether a system binary is patched, backported, or risky—even fully offline.

# Why this matters (plain English)

Package versions lie (backports!). Instead of trusting names like `libssl 1.1.1k`, we trust **what’s inside**: build IDs, section hashes, compiler metadata, and signed provenance. With that, we can answer: *Is this exact binary known‑good, known‑bad, or unknown—on this distro, on this date, with these patches?*

---

# Core concept

* **Binary Fingerprint** = tuple of:

  * **Build‑ID** (ELF/PE), if present.
  * **Section‑level hashes** (e.g., `.text`, `.rodata`, selected function ranges).
  * **Compiler/Linker metadata** (vendor/version, LTO flags, PIE/RELRO, sanitizer bits).
  * **Symbol graph sketch** (optional, min‑hash of exported symbol names + sizes).
  * **Feature toggles** (FIPS mode, CET/CFI present, Fortify level, RELRO type, SSP).
* **Provenance Chain** (who built it): Upstream → Distro vendor (with patchset) → Local rebuild.
* **Trust Score**: combines provenance weight + cryptographic attestations + “golden set” matches + observed patch deltas.

---

# Minimal architecture (fits Stella Ops style)

1. **Ingesters**

   * `ingester.distro`: walks repo mirrors or local systems, extracts ELF/PE, computes fingerprints, captures package→file mapping, vendor patch metadata (changelog, source SRPM diffs).
   * `ingester.upstream`: indexes upstream releases, commit tags, and official build artifacts.
   * `ingester.local`: indexes CI outputs (your own builds), in‑toto/DSSE attestations if available.

2. **Fingerprint Store (offline‑ready)**

   * **Primary DB**: PostgreSQL (authoritative).
   * **Accelerator**: Valkey (ephemeral) for fast lookup by Build‑ID and section hash prefixes.
   * **Bundle Export**: signed, chunked SQLite/Parquet packs for air‑gapped sites.

3. **Trust Engine**

   * Scores (0–100) per binary instance using:

     * Provenance weight (Upstream signed > Distro signed > Local unsigned).
     * Attestation presence/quality (in‑toto/DSSE, reproducible build stamp).
     * Patch alignment vs **Golden Set** (reference fingerprints for “fixed” and “vulnerable” builds).
     * Hardening baseline (RELRO/PIE/SSP/CET/CFI).
     * Divergence penalty (unexpected section deltas vs vendor‑declared patch).
   * Emits **Verdict**: `Patched`, `Likely Patched (Backport)`, `Unpatched`, `Unknown`, with rationale.

4. **Query APIs**

   * `/lookup/by-buildid/{id}`
   * `/lookup/by-hash/{algo}/{prefix}`
   * `/classify` (batch): accepts an SBOM file list or live filesystem scan.
   * `/explain/{fingerprint}`: returns diff vs Golden Set and the proof trail.

---

# Data model (tables you can lift into Postgres)

* `artifact`
  `(artifact_id PK, file_sha256, size, mime, elf_machine, pe_machine, ts, signers[])`
* `fingerprint`
  `(fp_id PK, artifact_id, build_id, text_hash, rodata_hash, sym_sketch, compiler_vendor, compiler_ver, lto, pie, relro, ssp, cfi, cet, flags jsonb)`
* `provenance`
  `(prov_id PK, fp_id, origin ENUM('upstream','distro','local'), vendor, distro, release, package, version, source_commit, patchset jsonb, attestation_hash, attestation_quality_score)`
* `golden_set`
  `(golden_id PK, package, cve, status ENUM('fixed','vulnerable'), fp_ref, method ENUM('vendor-advisory','diff-sig','function-patch'), notes)`
* `trust_score`
  `(fp_id, score int, verdict, reasons jsonb, computed_at)`

Indexes: `(build_id)`, `(text_hash)`, `(rodata_hash)`, `(package, version)`, GIN on `patchset`, `reasons`.

---

# How detection works (fast path)

1. **Exact match**
   Build‑ID hit → join `golden_set` → return verdict + reason.
2. **Near match (backport mode)**
   No Build‑ID match → compare `.text`/`.rodata` and function‑range hashes against “fixed” Golden Set:

   * If patched function ranges match, mark **Likely Patched (Backport)**.
   * If vulnerable function ranges match, mark **Unpatched**.
3. **Heuristic fallback**
   Symbol sketch + compiler metadata + hardening flags narrow candidate set; compute targeted function hashes only (don’t hash the whole file).

---

# Building the “Golden Set”

* Sources:

  * Vendor advisories (per‑CVE “fixed in” builds).
  * Upstream tags containing the fix commit.
  * Distro SRPM diffs for backports (extract exact hunk regions; compute function‑range hashes pre/post).
* Store **both**:

  * “Fixed” fingerprints (post‑patch).
  * “Vulnerable” fingerprints (pre‑patch).
* Annotate evidence method:

  * `vendor-advisory` (strong), `diff-sig` (strong if clean hunk), `function-patch` (targeted).

---

# Trust scoring (example)

* Base by provenance:

  * Upstream + signed + reproducible: **+40**
  * Distro signed with changelog & SRPM diff: **+30**
  * Local unsigned: **+10**
* Attestations:

  * Valid DSSE + in‑toto chain: **+20**
  * Reproducible build proof: **+10**
* Golden Set alignment:

  * Matches “fixed”: **+20**
  * Matches “vulnerable”: **−40**
  * Partial (patched functions match, rest differs): **+10**
* Hardening:

  * PIE/RELRO/SSP/CET/CFI each **+2** (cap +10)
* Divergence penalties:

  * Unexplained text‑section drift **−10**
  * Suspicious toolchain fingerprint **−5**

Verdict bands: `≥80 Patched`, `65–79 Likely Patched (Backport)`, `35–64 Unknown`, `<35 Unpatched`.

---

# CLI outline (Stella Ops‑style)

```bash
# Index a filesystem or package repo
stella-fp index /usr/bin /lib --out fp.db --bundle out.bundle.parquet

# Score a host (offline)
stella-fp classify --fp-store fp.db --golden golden.db --out verdicts.json

# Explain a result
stella-fp explain --fp <fp_id> --golden golden.db

# Maintain Golden Set
stella-fp golden add --package openssl --cve CVE-2023-XXXX --status fixed --from-srpm path.src.rpm
stella-fp golden add --package openssl --cve CVE-2023-XXXX --status vulnerable --from-upstream v1.1.1k
```

---

# Implementation notes (ELF/PE)

* **ELF**: read Build‑ID from `.note.gnu.build-id`; hash `.text` and selected function ranges (use DWARF/eh_frame or symbol table when present; otherwise lightweight linear‑sweep with sanity checks). Record RELRO/PIE from program headers.
* **PE**: use Debug Directory (GUID/age) and Section Table; capture CFG/ASLR/NX/GS flags.
* **Function‑range hashing**: normalize NOPs/padding, zero relocation slots, mask address‑relative operands (keeps hashes stable across vendor rebuilds).
* **Performance**: cache per‑section hash; only compute function hashes when near‑match needs confirmation.

---

# How this plugs into your world

* **Sbomer/Vexer**: attach trust scores & verdicts to components in CycloneDX/SPDX; emit VEX statements like “Fixed by backport: evidence=diff‑sig, source=Astra/RedHat SRPM.”
* **Feedser**: when CVE feed says “vulnerable by version,” override with binary proof from Golden Set.
* **Policy Engine**: gate deployments on `verdict ∈ {Patched, Likely Patched}` OR `score ≥ 65`.

---

# Next steps you can action today

1. Create schemas above in Postgres; scaffold a small `stella-fp` Go/.NET tool to compute fingerprints for `/bin`, `/lib*` on one reference host (e.g., Debian + Alpine).
2. Hand‑curate a **pilot Golden Set** for 3 noisy CVEs (OpenSSL, glibc, curl). Store both pre/post patch fingerprints and 2–3 backported vendor builds each.
3. Wire a `classify` step into your CI/CD and surface the **verdict + rationale** in your VEX output.

If you want, I can drop in starter code (C#/.NET 10) for the fingerprint extractor and the Postgres schema migration, plus a tiny “function‑range hasher” that masks relocations and normalizes padding.