Here’s a compact, first‑time‑friendly plan to add two high‑leverage features to your platform: an **image Smart‑Diff** (with signed, policy‑aware deltas) and **better binaries** (symbol/byte‑level SCA + provenance + SARIF).

# Smart‑Diff (images & containers) — what/why/how

**What it is:** Compute *deltas* between two images (or layers) and enrich them with context: which files, which packages, which configs flip behavior, and whether the change is actually *reachable at runtime*. Then sign the report so downstream tools can trust it.

**Why it matters:** Teams drown in “changed but harmless” noise. A diff that knows “is this reachable, config‑activated, and under the running user?” prioritizes real risk and shortens MTTR.

**How to ship it (Stella Ops‑style, on‑prem, .NET 10):**

* **Scope of diff**

  * Layer → file → package → symbol (map file changes to package + version; map package to symbols/exports when available).
  * Config/env lens: overlay `ENTRYPOINT/CMD`, env, feature flags, mounted secrets, user/UID.
* **Reachability gates (3‑bit severity gate)**

  * `Reachable?` (call graph / entrypoints / process tree)
  * `Config‑activated?` (feature flags, env, args)
  * `Running user?` (match file/dir ACLs, capabilities, container `User:`)
  * Compute a severity class from these bits (e.g., 0–7) and attach a short rationale.
* **Attestation**

  * Emit a **DSSE‑wrapped in‑toto attestation** with the Smart‑Diff as predicate.
  * Include: artifact digests (old/new), diff summary, gate bits, rule versions, and scanner build info.
  * Sign offline; verify with cosign/rekor when online is available.
* **Predicate (minimal JSON shape)**

```json
{
  "predicateType": "stellaops.dev/predicates/smart-diff@v1",
  "predicate": {
    "baseImage": {"name":"...", "digest":"sha256:..."},
    "targetImage": {"name":"...", "digest":"sha256:..."},
    "diff": {
      "filesAdded": [...],
      "filesRemoved": [...],
      "filesChanged": [{"path":"...", "hunks":[...]}],
      "packagesChanged": [{"name":"openssl","from":"1.1.1u","to":"3.0.14"}]
    },
    "context": {
      "entrypoint":["/app/start"],
      "env":{"FEATURE_X":"true"},
      "user":{"uid":1001,"caps":["NET_BIND_SERVICE"]}
    },
    "reachabilityGate": {"reachable":true,"configActivated":true,"runningUser":false,"class":6},
    "scanner": {"name":"StellaOps.Scanner","version":"...","ruleset":"reachability-2025.12"}
  }
}
```

* **Pipelines**

  * Scanner computes diff → predicate JSON → DSSE envelope → write `.intoto.jsonl`.
  * Optionally export a lightweight **human report** (markdown) and a **machine delta** (protobuf/JSON).

# Better binaries — symbol/byte SCA + provenance + SARIF

**What it is:** Go beyond package SBOMs. Identify *symbols, sections, and compiler fingerprints* in each produced binary; capture provenance (compiler, flags, LTO, link order, hashes); then emit:

1. an **in‑toto statement per binary**, and
2. a **SARIF 2.1.0** report for GitHub code scanning.

**Why it matters:** A lot of risk hides below package level (vendored code, static libs, LTO). Symbol/byte SCA catches it; provenance proves how the binary was built.

**How to ship it:**

* **Extractors (modular analyzers)**

  * ELF/PE/Mach‑O parsers (sections, imports/exports, build‑ids, rpaths).
  * Symbol tables (public + demangled), string tables, compiler notes (`.comment`), PDB/DWARF when present.
  * Fingerprints: rolling hashes per section/function; Bloom filters for quick symbol presence checks.
* **Provenance capture**

  * Compiler: name/version, target triple, LTO (on/off/mode).
  * Flags: `-O`, `-fstack-protector`, `-D_FORTIFY_SOURCE`, PIE/RELRO, CET/CFGuard.
  * Linker: version, libs, order, dead‑strip/LTO decisions.
* **In‑toto statement (per binary)**

```json
{
  "predicateType":"slsa.dev/provenance/v1",
  "subject":[{"name":"bin/app","digest":{"sha256":"..."}}],
  "predicate":{
    "builder":{"id":"stellaops://builder/ci"},
    "buildType":"stellaops.dev/build/native@v1",
    "metadata":{"buildInvocationID":"...","buildStartedOn":"...","buildFinishedOn":"..."},
    "materials":[{"uri":"git+ssh://...#<commit>","digest":{"sha1":"..."}}],
    "buildConfig":{
      "compiler":{"name":"clang","version":"18.1.3"},
      "flags":["-O2","-fstack-protector-strong","-fPIE"],
      "lto":"thin",
      "linker":{"name":"lld","version":"18.1.3"},
      "hardening":{"pie":true,"relro":"full","fortify":true}
    }
  }
}
```

* **SARIF 2.1.0 for GitHub code scanning**

  * One SARIF file per build (or per repo), tool name `StellaOps.BinarySCA`.
  * For each finding (e.g., vulnerable function signature or insecure linker flag), add:

    * `ruleId`, CWE/Vuln ID, severity, location (binary + symbol), `helpUri`.
  * Upload via Actions/API so issues appear in *Security → Code scanning alerts*.
* **CI wiring (on‑prem friendly)**

  * Build → run binary analyzers → write `binary.intoto.jsonl` + `sca.sarif.json`.
  * Sign the in‑toto statement (DSSE). If air‑gapped, store in your internal evidence bucket; sync to Rekor mirror later.
  * Optional: export a compact “binary SBOM” (function inventory + hashes).

# Minimal .NET 10 / CLI layout (suggested)

```
src/Scanner/StellaOps.Scanner.SmartDiff/
src/Scanner/StellaOps.Scanner.BinarySCA/
src/Predicates/StellaOps.Predicates/           # JSON schemas, versioned
src/Sign/StellaOps.Attestation/                # DSSE envelopes, cosign integration
src/Exports/StellaOps.Exports.Sarif/
src/Exports/StellaOps.Exports.InToto/
```

* **Contracts:** freeze JSON Schemas under `StellaOps.Predicates` and version them (e.g., `smart-diff@v1`, `binary-provenance@v1`).
* **Determinism:** lock analyzer rulesets + feeds with content hashes; record them in each predicate (`rulesetDigest`).

# Quick wins this week

* Implement the **3‑bit reachability gate** and surface it in your UI filter.
* Emit **DSSE‑wrapped in‑toto** for Smart‑Diff first (binary provenance next).
* Add a **basic SARIF exporter** that maps binary findings → GitHub alerts (even if only a couple rules to start: missing RELRO/PIE; insecure `__strcpy` occurrences).

If you want, I can draft:

* The JSON Schemas for `smart-diff@v1` and `binary-provenance@v1`.
* A tiny C# sample that wraps a predicate in DSSE and verifies with cosign.
* A SARIF emitter stub wired to your CI.
I will split this into two parts:

1. A compact list of Stella Ops advantages (how we win vs other scanners).
2. Concrete developer guidelines that make those advantages real in code.

---

## 1. Stella Ops advantages (what we are optimizing for)

When you build any feature, it should clearly reinforce at least one of these:

1. **Evidence-first, signed, replayable**
   Every non-trivial operation produces signed, DSSE-wrapped attestations and can be re-run later to obtain the same result byte-for-byte.

2. **Reachability-first triage (Smart-Diff + gates)**
   We never just say “this CVE exists”; we say: *it changed*, *it is or is not reachable*, *it is or is not activated by config*, and *which user actually executes it*.

3. **Binary-level SCA + provenance**
   We do not stop at packages. We inspect binaries (symbols, sections, toolchain fingerprints) and provide in-toto/SLSA provenance plus SARIF to development tools.

4. **Crypto-sovereign and offline-ready**
   All signing/verification can use local trust roots and local cryptographic profiles (FIPS / eIDAS / GOST / SM) with no hard dependency on public CAs or external clouds.

5. **Deterministic, replayable scans**
   A “scan” is a pure function of: artifact digests, feeds, rules, lattice policies, and configuration. Anything not captured there is a bug.

6. **Policy & lattice engine instead of ad-hoc rules**
   Risk and VEX decisions are the result of explicit lattice merge rules (“trust algebra”), not opaque if-else trees in the code.

7. **Proof-of-integrity graph**
   All artifacts (source → build → container → runtime) are connected in a cryptographic graph that can be traversed, audited, and exported.

8. **Quiet-by-design UX**
   The system is optimized to answer three questions fast:

   1. Can I ship this? 2) If not, what blocks me? 3) What is the minimal safe change?

Everything you build should clearly map to one or more of the above.

---

## 2. Developer guidelines by advantage

### 2.1 Evidence-first, signed, replayable

**Core rule:** Any non-trivial action must be traceable as a signed, re-playable evidence record.

**Implementation guidelines**

1. **Uniform attestation model**

   * Define and use a shared library, e.g. `StellaOps.Predicates`, with:

     * Versioned JSON Schemas (e.g. `smart-diff@v1`, `binary-provenance@v1`, `reachability-summary@v1`).
     * Strongly-typed C# DTOs that match the schemas.
   * Every module (Scanner, Sbomer, Concelier, Excititor/Vexer, Authority, Scheduler, Feedser) must:

     * Emit **DSSE-wrapped in-toto statements**.
     * Use the same hashing strategy (e.g., SHA-256 over canonical JSON, no whitespace variance).
     * Include tool name, version, ruleset/feeds digests and configuration id in each predicate.

2. **Link-not-merge**

   * Never rewrite or mutate third-party SBOM/VEX/attestations.
   * Instead:

     * Store original documents as immutable blobs addressed by hash.
     * Refer to them using digests and URIs (e.g. `sha256:…`) from your own predicates.
     * Emit **linking evidence**: “this SBOM (digest X) was used to compute decision Y”.

3. **Deterministic scan manifests**

   * Each scan must have a manifest object:

     ```json
     {
       "artifactDigest": "sha256:...",
       "scannerVersion": "1.2.3",
       "rulesetDigest": "sha256:...",
       "feedsDigests": { "nvd": "sha256:...", "vendorX": "sha256:..." },
       "latticePolicyDigest": "sha256:...",
       "configId": "prod-eu-1",
       "timestamp": "2025-12-09T13:37:00Z"
     }
     ```
   * Store it alongside results and include its digest in all predicates produced by that run.

4. **Signing & verification**

   * All attestation writing goes through a single abstraction, e.g.:

     ```csharp
     interface IAttestationSigner {
         Task<DSSEEnvelope> SignAsync<TPredicate>(TPredicate predicate, CancellationToken ct);
     }
     ```
   * Implementations may use:

     * Sigstore (Fulcio + Rekor) when online.
     * Local keys (HSM, TPM, file key) when offline.
   * Never do ad-hoc crypto directly in features; always go through the shared crypto layer (see 2.4).

---

### 2.2 Reachability-first triage and Smart-Diff

**Core rule:** You must never treat “found a CVE” as sufficient. You must track change + reachability + config + execution context.

#### Smart-Diff

1. **Diff levels**

   * Implement layered diffs:

     * Image / layer → file → package → symbol.
   * Map:

     * File changes → owning package, version.
     * Package changes → known vulnerabilities and exports.
   * Attach config context: entrypoint, env vars, feature flags, user/UID.

2. **Signed Smart-Diff predicate**

   * Use the minimal shape like (simplified):

     ```json
     {
       "predicateType": "stellaops.dev/predicates/smart-diff@v1",
       "predicate": {
         "baseImage": {...},
         "targetImage": {...},
         "diff": {...},
         "context": {...},
         "reachabilityGate": {...},
         "scanner": {...}
       }
     }
     ```
   * Always sign as DSSE and attach the scan manifest digest.

#### Reachability gate

Use the **3-bit gate** consistently:

* `reachable` (static/dynamic call graph says “yes”)
* `configActivated` (env/flags/args activate the code path)
* `runningUser` (the user/UID that can actually execute it)

Guidelines:

1. **Data model**

   ```csharp
   public sealed record ReachabilityGate(
       bool? Reachable,       // true / false / null for unknown
       bool? ConfigActivated,
       bool? RunningUser,
       int Class,             // 0..7 derived from the bits when all known
       string Rationale       // short explanation, human-readable
   );
   ```

2. **Unknowns must stay unknown**

   * Never silently treat `null` as `false` or `true`.
   * If any of the bits is `null`, compute `Class` only from known bits or set `Class = -1` to denote “incomplete”.
   * Feed all “unknown” cases into a dedicated “Unknowns ranking” path (separate heuristics and UX).

3. **Where reachability is computed**

   * Respect your standing rule: **lattice and reachability algorithms run in `Scanner.WebService`**, not in Concelier, Feedser, or Excitors/Vexer.
   * Other services only:

     * Persist / index results.
     * Prune / filter based on policy.
     * Present data — never recompute core reachability.

4. **Caching reachability**

   * Key caches by:

     * Artifact digest (image/layer/binary).
     * Ruleset/lattice digest.
     * Language/runtime version (for static analysis).
   * Pattern:

     * First time a call path is requested, compute and cache.
     * Subsequent accesses in the same scan use the in-memory cache.
     * For cross-scan reuse, store a compact summary keyed by (artifactDigest, rulesetDigest) in Scanner’s persistence node.
   * Never cache across incompatible rule or feed versions.

---

### 2.3 Binary-level SCA and provenance

**Core rule:** Treat each built binary as a first-class subject with its own SBOM, SCA, and provenance.

1. **Pluggable analyzers**

   * Create analyzers per binary format/language:

     * ELF, PE, Mach-O.
     * Language/toolchain detectors (GCC/Clang/MSVC/.NET/Go/Rust).
   * Common interface:

     ```csharp
     interface IBinaryAnalyzer {
         bool CanHandle(BinaryContext ctx);
         Task<BinaryAnalysisResult> AnalyzeAsync(BinaryContext ctx, CancellationToken ct);
     }
     ```

2. **Binary SBOM + SCA**

   * Output per-binary:

     * Function/symbol inventory (names, addresses).
     * Linked static libraries.
     * Detected third-party components (via fingerprints).
   * Map to known vulnerabilities via:

     * Symbol signatures.
     * Function-level or section-level hashes.
   * Emit:

     * CycloneDX/SPDX component entries for binaries.
     * A separate predicate `binary-sca@v1`.

3. **Provenance (in-toto/SLSA)**

   * Emit an in-toto statement per binary:

     * Subject = `bin/app` (digest).
     * Predicate = build metadata (compiler, flags, LTO, linker, hardening).
   * Always include:

     * Source material (git repo + commit).
     * Build environment (container image digest or runner OS).
     * Exact build command / script identifier.

4. **SARIF for GitHub / IDEs**

   * Provide an exporter:

     * Input: `BinaryAnalysisResult`.
     * Output: SARIF 2.1.0 with:

       * Findings: missing RELRO/PIE, unsafe functions, known vulns, weak flags.
       * Locations: binary path + symbol/function name.
   * Keep rule IDs stable and documented (e.g. `STB001_NO_RELRO`, `STB010_VULN_SYMBOL`).

---

### 2.4 Crypto-sovereign, offline-ready

**Core rule:** No feature may rely on a single global PKI or always-online trust path.

1. **Crypto abstraction**

   * Introduce a narrow interface:

     ```csharp
     interface ICryptoProfile {
         string Name { get; }
         IAttestationSigner AttestationSigner { get; }
         IVerifier DefaultVerifier { get; }
     }
     ```
   * Provide implementations:

     * `FipsCryptoProfile`
     * `EUeIDASCryptoProfile`
     * `GostCryptoProfile`
     * `SmCryptoProfile`
   * Selection via configuration, not code changes.

2. **Offline bundles**

   * Everything needed to verify a decision must be downloadable:

     * Scanner binaries.
     * Rules/feeds snapshot.
     * CA chains / trust roots.
     * Public keys for signers.
   * Implement a “bundle manifest” that ties these together and is itself signed.

3. **Rekor / ledger independence**

   * If Rekor is available:

     * Log attestations.
   * If not:

     * Log to Stella Ops Proof-Market Ledger or internal append-only store.
   * Features must not break when Rekor is absent.

---

### 2.5 Policy & lattice engine

**Core rule:** Risk decisions are lattice evaluations over facts; do not hide policy logic inside business code.

1. **Facts vs policy**

   * Facts are:

     * CVE presence, severity, exploit data.
     * Reachability gates.
     * Runtime events (was this function ever executed?).
     * Vendor VEX statements.
   * Policy is:

     * Lattice definitions and merge rules.
     * Trust preferences (vendor vs runtime vs scanner).
   * In code:

     * Facts are input DTOs stored in the evidence graph.
     * Policy is JSON/YAML configuration with versioned schemas.

2. **Single evaluation engine in Scanner.WebService**

   * Lattice evaluation must run only in `StellaOps.Scanner.WebService` (your standing rule).
   * Other services:

     * Request decisions from Scanner.
     * Pass only references (IDs/digests) to facts, not raw policy.

3. **Deterministic evaluation**

   * Lattice evaluation must:

     * Use only input facts + policy.
     * Never depend on current time, random, environment state.
   * Every decision object must include:

     * `policyDigest`
     * `inputFactsDigests[]`
     * `decisionReason` (short machine+human readable explanation)

---

### 2.6 Proof-of-integrity graph

**Core rule:** Everything is a node; all relationships are typed edges; nothing disappears.

1. **Graph model**

   * Nodes: source repo, commit, build job, SBOM, attestation, image, container runtime, host.
   * Edges: “built_from”, “scanned_with”, “deployed_as”, “executes_on”, “derived_from”.
   * Store in a graph store or graph-like relational schema:

     * IDs are content digests where possible.

2. **Append-only**

   * Never delete or overwrite nodes; mark as superseded if needed.
   * Evidence mutations (e.g. new scan) are new nodes/edges.

3. **APIs**

   * Provide traversal APIs:

     * “Given this CVE, which production pods are affected?”
     * “Given this pod, show full ancestry up to source commit.”
   * All UI queries must work via these APIs, not ad-hoc joins.

---

### 2.7 Quiet-by-design UX and observability

**Core rule:** Default to minimal, actionable noise; logs and telemetry must be compliant and air-gap friendly.

1. **Triage model**

   * Classify everything into:

     * “Blockers” (fail pipeline).
     * “Needs review” (warn but pass).
     * “Noise” (hidden unless requested).
   * The classification uses:

     * Lattice decisions.
     * Reachability gates.
     * Environment criticality (prod vs dev).

2. **Evidence-centric UX**

   * Each UI card or API answer must:

     * Reference the underlying attestations by ID/digest.
     * Provide a one-click path to “show raw evidence”.

3. **Logging & telemetry defaults**

   * Logging:

     * Structured JSON.
     * No secrets, no PII, no full source in logs.
     * Local file + log rotation is the default.
   * Telemetry:

     * OpenTelemetry-compatible exporters.
     * Pluggable sinks:

       * In-memory (dev).
       * Postgres.
       * External APM if configured.
   * For on-prem:

     * All telemetry must be optional.
     * The system must be fully operational with only local logs.

---

### 2.8 AI Codex / Zastava Companion

**Core rule:** AI is a consumer of the evidence graph, never a source of truth.

1. **Separation of roles**

   * Zastava:

     * Reads evidence, decisions, and context.
     * Produces explanations and remediation plans.
   * It must not:

     * Invent vulnerabilities or states not present in evidence.
     * Change decisions or policies.

2. **Interfaces**

   * Input:

     * IDs/digests of:

       * Attestations.
       * Lattice decisions.
       * Smart-Diff results.
   * Output:

     * Natural language summary.
     * Ordered remediation steps with references back to evidence IDs.

3. **Determinism around AI**

   * Core security behaviour must not depend on AI responses.
   * Pipelines should never “pass/fail based on AI text”.
   * AI is advice only; enforcement is always policy + lattice + evidence.

---

## 3. Cross-cutting rules for all Stella Ops developers

When you implement anything in Stella Ops, verify you comply with these:

1. **Determinism first**

   * If re-running with the same:

     * artifact digests,
     * feeds,
     * rules,
     * lattices,
     * config,
   * then results must be identical (except for timestamps and cryptographic randomness inside signatures).

2. **Offline-first**

   * No hard dependency on:

     * External CAs.
     * External DBs of vulnerabilities.
     * External ledgers.
   * All remote interactions must be:

     * Optional.
     * Pluggable.
     * Replaceable with local mirrors.

3. **Evidence over UI**

   * Never implement logic “only in the UI”.
   * The API and attestations must fully reflect what the UI shows.

4. **Contracts over convenience**

   * Schemas are contracts:

     * Version them.
     * Do not change existing fields’ meaning.
     * Add fields with defaults.
   * Deprecate explicitly, never silently break consumers.

5. **Golden fixtures**

   * For any new predicate or decision:

     * Create golden fixtures (input → output → attestations).
     * Use them in regression tests.
   * This is crucial for “deterministic replayable scans”.

6. **Respect service boundaries**

   * Scanner: facts + evaluation (lattices, reachability).
   * Sbomer: SBOM generation and normalization.
   * Concelier / Vexer: policy application, filtering, presentation; they “preserve prune source”.
   * Authority: signing keys, crypto profiles, trust roots.
   * Feedser: feeds ingestion; must never “decide”, only normalize.

If you want, next step I can do a very concrete checklist for adding a **new scanner feature** (e.g., “Smart-Diff for Python wheels”) with exact project structure (`src/Scanner/StellaOps.Scanner.*`), tests, and the minimal set of predicates and attestations that must be produced.