44 lines
1.7 KiB
Markdown
44 lines
1.7 KiB
Markdown
# VEX Observations and Linksets
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This document describes how StellaOps stores and correlates VEX without rewriting upstream sources.
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## Observations (Append-Only Evidence)
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An observation is the immutable record of a VEX document *as received*.
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Recorded fields typically include:
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- **Provenance:** tenant, provider/issuer identity, retrieved/received timestamps (UTC), signature verification status, trust metadata, and content digest.
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- **Raw payload:** stored losslessly to support audit and offline verification.
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- **Derived indexes:** extracted identifiers and tuples used to correlate evidence (without replacing the raw payload).
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If upstream republishes a VEX document, the new version is stored as a new observation with a `supersedes` relationship.
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## Normalization (Projection Only)
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Normalization produces tuples used by downstream layers:
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- `(vulnerabilityId, productKey)` keys for correlation
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- VEX status and justification
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- Optional scope and validity windows
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Normalization is a projection; it does not delete, mutate, or merge upstream evidence.
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## Linksets (Correlation Without Precedence)
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Linksets group tuples that refer to the same conceptual product-vulnerability pair.
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Properties:
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- **Deterministic:** linkset identifiers are derived from canonical, sorted key material.
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- **Conflict-preserving:** disagreements remain visible (status, scope, justification, issuer identity).
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- **Provenance-linked:** every item in a linkset references its source observation digest and issuer metadata.
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Downstream consumers (Policy/Console/Exports) use linksets to explain what disagrees and why.
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## References
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- `docs/VEX_CONSENSUS_GUIDE.md`
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- `docs/modules/excititor/architecture.md`
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- `docs/modules/vex-lens/architecture.md`
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