# Inline DSSE Provenance

> **Status:** Draft – aligns with the November 2025 advisory “store DSSE attestation refs inline on every SBOM/VEX event node.”  
> **Owners:** Authority Guild · Feedser Guild · Platform Guild · Docs Guild.

This document defines how Stella Ops records provenance for SBOM, VEX, scan, and derived events: every event node in the Mongo event graph includes DSSE + Rekor references and verification metadata so audits and replay become first-class queries.

---

## 1. Event patch (Mongo schema)

```jsonc
{
  "_id": "evt_...",
  "kind": "SBOM|VEX|SCAN|INGEST|DERIVED",
  "subject": {
    "purl": "pkg:nuget/example@1.2.3",
    "digest": { "sha256": "..." },
    "version": "1.2.3"
  },
  "provenance": {
    "dsse": {
      "envelopeDigest": "sha256:...",
      "payloadType": "application/vnd.in-toto+json",
      "key": {
        "keyId": "cosign:SHA256-PKIX:ABC...",
        "issuer": "fulcio",
        "algo": "ECDSA"
      },
      "rekor": {
        "logIndex": 1234567,
        "uuid": "b3f0...",
        "integratedTime": 1731081600,
        "mirrorSeq": 987654   // optional
      },
      "chain": [
        { "type": "build", "id": "att:build#...", "digest": "sha256:..." },
        { "type": "sbom",  "id": "att:sbom#...",  "digest": "sha256:..." }
      ]
    }
  },
  "trust": {
    "verified": true,
    "verifier": "Authority@stella",
    "witnesses": 1,
    "policyScore": 0.92
  },
  "ts": "2025-11-11T12:00:00Z"
}
```

### Key fields

| Field | Description |
|-------|-------------|
| `provenance.dsse.envelopeDigest` | SHA-256 of the DSSE envelope (not payload). |
| `provenance.dsse.payloadType` | Usually `application/vnd.in-toto+json`. |
| `provenance.dsse.key` | Key fingerprint / issuer / algorithm. |
| `provenance.dsse.rekor` | Rekor transparency log metadata (index, UUID, integrated time). |
| `provenance.dsse.chain` | Optional chain of dependent attestations (build → sbom → scan). |
| `trust.*` | Result of local verification (DSSE signature, Rekor proof, policy). |

---

## 2. Write path (ingest flow)

1. **Obtain provenance metadata** for each attested artifact (build, SBOM, VEX, scan). The CI script (`scripts/publish_attestation_with_provenance.sh`) captures `envelopeDigest`, Rekor `logIndex`/`uuid`, and key info.
2. **Authority/Feedser** verify the DSSE + Rekor proof (local cosign/rekor libs or the Signer service) and set `trust.verified = true`, `trust.verifier = "Authority@stella"`, `trust.witnesses = 1`.
3. **Attach** the provenance block before appending the event to Mongo, using `StellaOps.Provenance.Mongo` helpers.
4. **Backfill** historical events by resolving known subjects → attestation digests and running an update script.

### 2.1 Supplying metadata from Concelier statements

Concelier ingestion jobs can now inline provenance when they create advisory statements. Add an `AdvisoryProvenance` entry with `kind = "dsse"` (or `dsse-metadata` / `attestation-dsse`) and set `value` to the same JSON emitted by the CI snippet. `AdvisoryEventLog` and `AdvisoryMergeService` automatically parse that entry, hydrate `AdvisoryStatementInput.Provenance/Trust`, and persist the metadata alongside the statement.

```json
{
  "source": "attestor",
  "kind": "dsse",
  "value": "{ \"dsse\": { \"envelopeDigest\": \"sha256:…\", \"payloadType\": \"application/vnd.in-toto+json\" }, \"trust\": { \"verified\": true, \"verifier\": \"Authority@stella\" } }",
  "recordedAt": "2025-11-10T00:00:00Z"
}
```

Providing the metadata during ingestion keeps new statements self-contained and reduces the surface that the `/events/statements/{statementId}/provenance` endpoint needs to backfill later.

Reference helper: `src/__Libraries/StellaOps.Provenance.Mongo/ProvenanceMongoExtensions.cs`.

---

### 2.2 Advisory AI structured chunk schema (GHSA/Cisco parity)

Advisory AI consumes the canonical `Advisory` aggregate and emits structured chunks that mirror GHSA GraphQL and Cisco PSIRT provenance anchors. The response contract is:

```jsonc
{
  "advisoryKey": "CVE-2025-0001",
  "fingerprint": "<sha256 of canonical advisory>",
  "total": 3,
  "truncated": false,
  "entries": [
    {
      "type": "workaround",                // sorted by (type, observationPath, documentId)
      "chunkId": "c0ffee12",              // sha256(advisory.observationId + observationPath)[:16]
      "content": { /* structured field */ },
      "provenance": {
        "documentId": "tenant-a:chunk:newest", // Mongo _id of backing observation
        "observationPath": "/references/0",    // JSON Pointer into the observation
        "source": "nvd",
        "kind": "workaround",
        "value": "tenant-a:chunk:newest",
        "recordedAt": "2025-01-07T00:00:00Z",
        "fieldMask": ["/references/0"]
      }
    }
  ]
}
```

Determinism requirements:

- Order entries by `(type, observationPath, documentId)` to keep cache keys stable across nodes.
- Always include the advisory `fingerprint` in cache keys and responses.
- Preserve observation-level provenance by emitting both `documentId` and `observationPath` under `provenance`.

These anchors let Attestor/Console deep-link evidence and allow offline mirrors to prove origin without merging transforms.

---

## 3. CI/CD snippet

See `scripts/publish_attestation_with_provenance.sh`:

```bash
rekor-cli upload --rekor_server "$REKOR_URL" \
  --artifact "$ATTEST_PATH" --type dsse --format json > rekor-upload.json
LOG_INDEX=$(jq '.LogIndex' rekor-upload.json)
UUID=$(jq -r '.UUID' rekor-upload.json)
ENVELOPE_SHA256=$(sha256sum "$ATTEST_PATH" | awk '{print $1}')
cat > provenance-meta.json <<EOF
{
  "subject": { "imageRef": "$IMAGE_REF", "digest": { "sha256": "$IMAGE_DIGEST" } },
  "dsse": {
    "envelopeDigest": "sha256:$ENVELOPE_SHA256",
    "payloadType": "application/vnd.in-toto+json",
    "key": { "keyId": "$KEY_ID", "issuer": "$KEY_ISSUER", "algo": "$KEY_ALGO" },
    "rekor": { "logIndex": $LOG_INDEX, "uuid": "$UUID", "integratedTime": $(jq '.IntegratedTime' rekor-upload.json) }
  }
}
EOF
```

Feedser ingests this JSON and maps it to `DsseProvenance` + `TrustInfo`.

---

## 4. Mongo indexes

Create indexes to keep provenance queries fast (`mongosh`):

```javascript
db.events.createIndex(
  { "subject.digest.sha256": 1, "kind": 1, "provenance.dsse.rekor.logIndex": 1 },
  { name: "events_by_subject_kind_provenance" }
);

db.events.createIndex(
  { "kind": 1, "trust.verified": 1, "provenance.dsse.rekor.logIndex": 1 },
  { name: "events_unproven_by_kind" }
);

db.events.createIndex(
  { "provenance.dsse.rekor.logIndex": 1 },
  { name: "events_by_rekor_logindex" }
);

db.events.createIndex(
  { "provenance.dsse.envelopeDigest": 1 },
  { name: "events_by_envelope_digest", sparse: true }
);

db.events.createIndex(
  { "ts": -1, "kind": 1, "trust.verified": 1 },
  { name: "events_by_ts_kind_verified" }
);
```

Deployment options:
- **Ops script:** `mongosh stellaops_db < ops/mongo/indices/events_provenance_indices.js`
- **C# helper:** `MongoIndexes.EnsureEventIndexesAsync(database, ct)`

This section was updated as part of `PROV-INDEX-401-030` (completed 2025-11-27).

---

## 5. Query recipes

* **All proven VEX for an image digest:**

```javascript
db.events.find({
  kind: "VEX",
  "subject.digest.sha256": "<digest>",
  "provenance.dsse.rekor.logIndex": { $exists: true },
  "trust.verified": true
})
```

* **Compliance gap (unverified data used for decisions):**

```javascript
db.events.aggregate([
  { $match: { kind: { $in: ["VEX","SBOM","SCAN"] } } },
  { $match: {
      $or: [
        { "trust.verified": { $ne: true } },
        { "provenance.dsse.rekor.logIndex": { $exists: false } }
      ]
    }
  },
  { $group: { _id: "$kind", count: { $sum: 1 } } }
])
```

* **Replay slice:** filter for events where `provenance.dsse.chain` covers build → sbom → scan and export referenced attestation digests.

---

## 6. Policy gates

Examples:

```yaml
rules:
  - id: GATE-PROVEN-VEX
    when:
      all:
        - kind: "VEX"
        - trust.verified: true
        - key.keyId in VendorAllowlist
        - rekor.integratedTime <= releaseFreeze
    then:
      decision: ALLOW

  - id: BLOCK-UNPROVEN
    when:
      any:
        - trust.verified != true
        - provenance.dsse.rekor.logIndex missing
    then:
      decision: FAIL
      reason: "Unproven evidence influences decision; require Rekor-backed attestation."
```

---

## 7. UI nudges

* **Provenance chip** on findings/events: `Verified • Rekor#1234567 • KeyID:cosign:...` (click → inclusion proof & DSSE preview).
* Facet filter: `Provenance = Verified / Missing / Key-Policy-Mismatch`.

---

## 8. Implementation tasks

| Task ID | Scope |
|---------|-------|
| `PROV-INLINE-401-028` | Extend Authority/Feedser write-paths to attach `provenance.dsse` + `trust` blocks using `StellaOps.Provenance.Mongo`. |
| `PROV-BACKFILL-401-029` | Backfill historical events with DSSE/Rekor refs based on existing attestation digests. |
| `PROV-INDEX-401-030` | Create Mongo indexes and expose helper queries for audits. |

Keep this document updated when new attestation types or mirror/witness policies land.

---

## 9. Feedser API for provenance updates

Feedser exposes a lightweight endpoint for attaching provenance after an event is recorded:

```
POST /events/statements/{statementId}/provenance
Headers: X-Stella-Tenant, Authorization (if Authority is enabled)
Body: { "dsse": { ... }, "trust": { ... } }
```

The body matches the JSON emitted by `publish_attestation_with_provenance.sh`. Feedser validates the payload, ensures `trust.verified = true`, and then calls `AttachStatementProvenanceAsync` so the DSSE metadata lands inline on the target statement. Clients receive HTTP 202 on success, 400 on malformed input, and 404 if the statement id is unknown.

---

## 10. Backfill service

`EventProvenanceBackfillService` (`src/StellaOps.Events.Mongo/EventProvenanceBackfillService.cs`) orchestrates backfilling historical events with DSSE provenance metadata.

### 10.1 Components

| Class | Purpose |
|-------|---------|
| `IAttestationResolver` | Interface for resolving attestation metadata by subject digest. |
| `EventProvenanceBackfillService` | Queries unproven events, resolves attestations, updates events. |
| `StubAttestationResolver` | Test/development stub implementation. |

### 10.2 Usage

```csharp
var resolver = new MyAttestationResolver(rekorClient, attestationRepo);
var backfillService = new EventProvenanceBackfillService(mongoDatabase, resolver);

// Count unproven events
var count = await backfillService.CountUnprovenEventsAsync(
    new[] { "SBOM", "VEX", "SCAN" });

// Backfill with progress reporting
var progress = new Progress<BackfillResult>(r =>
    Console.WriteLine($"{r.EventId}: {r.Status}"));

var summary = await backfillService.BackfillAllAsync(
    kinds: new[] { "SBOM", "VEX", "SCAN" },
    limit: 1000,
    progress: progress);

Console.WriteLine($"Processed: {summary.TotalProcessed}");
Console.WriteLine($"Success: {summary.SuccessCount}");
Console.WriteLine($"Not found: {summary.NotFoundCount}");
Console.WriteLine($"Errors: {summary.ErrorCount}");
```

### 10.3 Implementing IAttestationResolver

Implementations should query the attestation store (Rekor, CAS, or local Mongo) by subject digest:

```csharp
public class RekorAttestationResolver : IAttestationResolver
{
    private readonly IRekorClient _rekor;
    private readonly IAttestationRepository _attestations;

    public async Task<AttestationResolution?> ResolveAsync(
        string subjectDigestSha256,
        string eventKind,
        CancellationToken cancellationToken)
    {
        // Look up attestation by subject digest
        var record = await _attestations.GetAsync(subjectDigestSha256, eventKind, cancellationToken);
        if (record is null) return null;

        // Fetch Rekor proof if available
        var proof = await _rekor.GetProofAsync(record.RekorUuid, RekorBackend.Sigstore, cancellationToken);

        return new AttestationResolution
        {
            Dsse = new DsseProvenance { /* ... */ },
            Trust = new TrustInfo { Verified = true, Verifier = "Authority@stella" },
            AttestationId = record.Id
        };
    }
}
```

### 10.4 Reference files

- `src/StellaOps.Events.Mongo/IAttestationResolver.cs`
- `src/StellaOps.Events.Mongo/EventProvenanceBackfillService.cs`
- `src/StellaOps.Events.Mongo/StubAttestationResolver.cs`

This section was added as part of `PROV-BACKFILL-401-029` (completed 2025-11-27).