8.4 KiB
8.4 KiB
AI Attestations and Replay Semantics
Sprint: SPRINT_20251226_018_AI_attestations Task: AIATTEST-23
This guide documents the AI attestation schemas, authority classification, and deterministic replay semantics.
Overview
AI-generated artifacts in StellaOps are wrapped in cryptographic attestations that:
- Capture the exact inputs (prompts, context, model parameters)
- Prove the generation chain (model ID, weights digest, configuration)
- Enable deterministic replay for compliance verification
- Support divergence detection across environments
Attestation Types
AI Artifact Predicate
{
"_type": "https://stellaops.org/attestation/ai-artifact/v1",
"artifactId": "ai-artifact-20251226-001",
"artifactType": "explanation",
"authority": "ai-generated",
"generatedAt": "2025-12-26T10:30:00Z",
"model": {
"modelId": "llama3-8b-q4km",
"weightsDigest": "sha256:a1b2c3...",
"promptTemplateVersion": "v2.1.0"
},
"inputs": {
"systemPromptHash": "sha256:abc123...",
"userPromptHash": "sha256:def456...",
"contextHashes": ["sha256:111...", "sha256:222..."]
},
"parameters": {
"temperature": 0.0,
"seed": 42,
"maxTokens": 2048,
"topK": 1
},
"output": {
"contentHash": "sha256:789xyz...",
"tokenCount": 847
},
"replayManifest": {
"manifestId": "replay-20251226-001",
"manifestHash": "sha256:manifest..."
}
}
Artifact Types
| Type | Description | Authority |
|---|---|---|
explanation |
Vulnerability explanation for humans | ai-generated |
remediation |
Fix plan with upgrade paths | ai-generated |
vex_draft |
Draft VEX statement | ai-draft-requires-review |
policy_draft |
Draft policy rules | ai-draft-requires-review |
triage_suggestion |
Triage action suggestions | ai-suggestion |
Authority Classification
AI outputs are classified by their authority level:
ai-generated → Informational only, human review optional
ai-draft-requires-review → Draft requires explicit human approval
ai-suggestion → Suggestion, user decides action
ai-verified → AI output verified against ground truth
human-approved → AI output approved by human reviewer
Replay Manifest
The replay manifest captures everything needed to reproduce an AI generation:
{
"manifestVersion": "1.0",
"artifactId": "ai-artifact-20251226-001",
"artifactType": "explanation",
"model": {
"modelId": "llama3-8b-q4km",
"weightsDigest": "sha256:a1b2c3d4e5f6...",
"promptTemplateVersion": "v2.1.0"
},
"prompts": {
"systemPrompt": "You are a security analyst...",
"userPrompt": "Explain CVE-2024-1234 affecting lodash@4.17.20...",
"systemPromptHash": "sha256:abc123...",
"userPromptHash": "sha256:def456..."
},
"context": {
"contextPack": [...],
"contextHashes": ["sha256:111...", "sha256:222..."]
},
"parameters": {
"temperature": 0.0,
"seed": 42,
"maxTokens": 2048,
"topK": 1,
"topP": 1.0
},
"output": {
"content": "CVE-2024-1234 is a critical vulnerability...",
"contentHash": "sha256:789xyz...",
"tokenCount": 847
},
"metadata": {
"generatedAt": "2025-12-26T10:30:00Z",
"replayable": true,
"deterministicSettings": true
}
}
Deterministic Requirements
For an AI artifact to be replayable:
- Temperature must be 0: No randomness in token selection
- Seed must be fixed: Same seed across replays (default: 42)
- Model weights must match: Verified by weights digest
- Prompts must match: Verified by prompt hashes
- Context must match: All input hashes must verify
Configuration for Determinism
advisoryAi:
attestations:
requireDeterminism: true
defaultSeed: 42
inference:
local:
temperature: 0.0
seed: 42
topK: 1
topP: 1.0
Replay Workflow
Replay Execution
// Load replay manifest
var manifest = await LoadManifestAsync("replay-20251226-001.json");
// Create replayer with same model
var replayer = replayerFactory.Create(manifest.Model.ModelId);
// Execute replay
var result = await replayer.ReplayAsync(manifest, cancellationToken);
// Check if output is identical
if (result.Identical)
{
Console.WriteLine("Replay successful: output matches original");
}
else
{
Console.WriteLine($"Divergence detected: similarity = {result.SimilarityScore:P2}");
}
Divergence Detection
When replay produces different output:
{
"diverged": true,
"similarityScore": 0.97,
"originalHash": "sha256:789xyz...",
"replayedHash": "sha256:different...",
"details": [
{
"type": "content_divergence",
"description": "Content differs at position",
"position": 1842,
"originalSnippet": "...vulnerability allows...",
"replayedSnippet": "...vulnerability permits..."
}
]
}
Common Divergence Causes
| Cause | Detection | Resolution |
|---|---|---|
| Different model weights | Weights digest mismatch | Use exact model version |
| Non-zero temperature | Parameter check | Set temperature to 0 |
| Different seed | Parameter check | Use same seed |
| Prompt template change | Template version mismatch | Pin template version |
| Context ordering | Context hash mismatch | Sort context deterministically |
Attestation Signing
DSSE Envelope Format
AI attestations use DSSE (Dead Simple Signing Envelope):
{
"payloadType": "application/vnd.stellaops.ai-attestation+json",
"payload": "<base64-encoded-attestation>",
"signatures": [
{
"keyId": "stellaops-ai-signer-2025",
"sig": "<base64-signature>"
}
]
}
Signing Configuration
advisoryAi:
attestations:
sign: true
keyId: "stellaops-ai-signer-2025"
cryptoScheme: ed25519 # ed25519 | ecdsa-p256 | gost3410 | sm2
API Endpoints
Generate with Attestation
POST /api/v1/advisory/explain
Content-Type: application/json
{
"findingId": "finding-123",
"artifactDigest": "sha256:...",
"options": {
"generateAttestation": true,
"signAttestation": true
}
}
Response includes:
{
"explanation": "...",
"attestation": {
"predicateType": "https://stellaops.org/attestation/ai-artifact/v1",
"predicate": {...},
"signature": {...}
},
"replayManifestId": "replay-20251226-001"
}
Verify Attestation
POST /api/v1/attestation/verify
Content-Type: application/json
{
"attestation": {...},
"options": {
"verifySignature": true,
"verifyReplay": true
}
}
Replay Artifact
POST /api/v1/advisory/replay
Content-Type: application/json
{
"manifestId": "replay-20251226-001"
}
CLI Commands
# Generate explanation with attestation
stella advisory explain finding-123 --attest --sign
# Verify attestation
stella attest verify ai-artifact-20251226-001.dsse.json
# Replay from manifest
stella advisory replay --manifest replay-20251226-001.json
# Check divergence
stella advisory replay --manifest replay-20251226-001.json --detect-divergence
Storage and Retrieval
Attestation Storage
Attestations are stored in the Evidence Locker:
/evidence/ai-attestations/
├── 2025/12/26/
│ ├── ai-artifact-20251226-001.json
│ ├── ai-artifact-20251226-001.dsse.json
│ └── replay-20251226-001.json
Retrieval
GET /api/v1/attestation/ai-artifact-20251226-001
# Returns attestation + replay manifest
Audit Trail
AI operations are logged for compliance:
{
"timestamp": "2025-12-26T10:30:00Z",
"operation": "ai_generation",
"artifactId": "ai-artifact-20251226-001",
"artifactType": "explanation",
"modelId": "llama3-8b-q4km",
"authority": "ai-generated",
"user": "system",
"inputHashes": ["sha256:..."],
"outputHash": "sha256:...",
"signed": true,
"replayable": true
}
Integration with VEX
AI-drafted VEX statements require human approval:
graph LR
A[AI generates VEX draft] --> B[Authority: ai-draft-requires-review]
B --> C[Human reviews draft]
C --> D{Approve?}
D -->|Yes| E[Authority: human-approved]
D -->|No| F[Draft rejected]
E --> G[Publish VEX]