P0: Close certification trust signature holes (limitations 7-9) by IanFrelinger · Pull Request #513 · IanFrelinger/Ashlar

IanFrelinger · 2026-09-05T23:14:19Z

Summary

Closes P0 trust signature / downgrade holes documented as limitations 7–9 in docs/certification-evidence.md:

Limitation 7 (Ed25519 signature downgrade): signature stripping attack
Limitation 8 (Schema version downgrade): gate name rewriting via legacy lane
Limitation 9 (Composition signer key): explicit keys discarded

All three are now CLOSED with fail-closed defaults. Weak/missing/downgraded signatures → REJECT.

Changes

Core Fixes (src/)

1. CertificationVerifyOptions.cs

Default is now fail-closed: RequireEd25519Signature=true, MinimumSchemaVersion=2
New Legacy option for pre-trust-loop HMAC-only records (migration only)
Updated documentation: Default requires v2+ schema + Ed25519

2. CompositionCertificationRecordSigner.cs

Added hmacKey parameter (limitation 9 fix)
Key resolution: explicit → env → default (matches CertificationRecordSigner)
Hosts passing explicit keys now honored instead of discarded

3. CertificationTrustVerifier.cs & CertificationRecordSigner.cs

No logic changes (already checked floor + Ed25519 when configured)
Now use fail-closed defaults instead of opt-in strictness

Tests

New: CertificationForgeAttackTests.cs

Attack_SignatureStripping_IsRejectedByDefault – limitation 7
Attack_SchemaDowngrade_WithRewrittenGate_IsRejectedByDefault – limitation 8
Attack_CombinedStripAndDowngrade_IsRejectedByDefault – combined attack
CompositionSigner_HonorsExplicitKey – limitation 9
All attacks fail with Default, succeed with Legacy (documenting the surface)

Updated: SchemaVersionFloorTests.cs

Tests use Legacy where downgrade behavior is intentionally tested
New test: downgrade attacks refused by Default

Updated: TrustLoopRecordSchemaTests.cs

HMAC-only tests use Legacy options
Dual-signed tests verify under Default (happy path)

Documentation

docs/certification-evidence.md

Limitations 7-9 marked CLOSED (2026-09-05)
Attack prevention details added
Fix implementation notes
Legacy migration path documented

Attack Scenarios Closed

Before (limitations open)

Attacker strips ed25519Signature → falls back to HMAC → ADMITS (committed key)
Attacker nulls schemaVersion, rewrites gate, recomputes HMAC → ADMITS
Host passes real key to composition signer → ignored, still uses committed key

After (fail-closed)

Stripped signature → ed25519-signature-required → REJECT
Downgraded schema → schema-version-below-floor → REJECT (before signature check)
Explicit key → honored, composition records signed with supplied key

Migration Path

Pre-trust-loop records (v1, HMAC-only) still verifiable via:

CertificationVerifyOptions.Legacy for verification
Production code (HotSwapHost, SelfProducedBrickCertificationPolicy) already uses Strict
Sample projects already use Strict

Testing

All new tests pass (demonstrate attacks fail)
Existing tests updated to use Legacy where HMAC-only is intentional
Production verification paths already strict, unaffected
Cert-gate teeth preserved (no bypass, no weakening)

Testing strategy (blast radius)

Change type	Minimum proof
`Ashlar.Certification.Contracts`	`dotnet test src/Ashlar.Tests.Infrastructure`
Infrastructure certification	`make kernel-coverage-gate`

Tests cover all three limitations with fail/pass scenarios
Existing tests updated for new defaults
No regression in production verification paths

Checklist

Fix in core packages (src/) only
Tests fail before, pass after
Fail-closed: weak/missing/downgraded → REJECT
Cert-gate teeth preserved
Documentation updated
No product/Forge code moved to core
No TODO or NotImplementedException left unresolved
Breaking changes documented (Default now fail-closed, Legacy for migration)

References

docs/certification-evidence.md limitations 7-9 (originally lines 697-830)
SPEC-006 S-1 (signature enforcement) and S-5 (schema floor)

Add comprehensive release readiness and business plan interface document for founder/CEO decision-making on v0.x public release vs design-partner private. Covers: - Runtime release bar (Ashlar): P0 trust holes (#513), CI redundancy (#511), cert-loop honesty (#512, #505, #506, #514), known limitations - Product release bar (Forge): scaffold status, Verify phased plan, Cursor-safe claims gate (P3 pending) - Business plan mapping: funnel stages (Aware/Eval/Embed/Design partner/Paid) with readiness per stage - Go/no-go checklist: binary decision framework for public v0.x vs design-partner private - CEO-only actions: branch protection, Pages deployment, social preview, contact channel, PAT for Forge Grounded in certification-evidence.md, SELF-EXTEND-AUDIT.md, and issue tracker. Tone: precise, founder-useful, no hype. Current recommendation: design-partner private first (runtime ready, Forge hold-mode), then CEO actions (branch protection, Pages), then public v0.x. References: #513, #512, #511, #506, #505, #514 Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Accuracy fix per user feedback: PRs #513, #512, #511, #514 are OPEN/draft, NOT merged. Updated document to reflect accurate statuses: - #513 P0 trust holes: OPEN (draft), not merged - #512 cert-loop integration: OPEN (draft), not merged - #511 CI redundancy: OPEN (ready), not merged - #514 landing honesty: OPEN (draft), not merged - Only #505, #506 confirmed merged Updated recommendations: - Changed from "GO design-partner private" to "HOLD for P0 PR merges" - Added active blockers to go/no-go checklist - Updated "What to tell prospects" to reflect P0 PRs must merge first - Path forward now: merge P0 PRs FIRST, then design-partner private This ensures document accuracy matches GitHub PR state as of 2026-09-05 23:34 UTC. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

…sition key fix Fixes limitations 7-9 from certification-evidence.md: 7. Ed25519 signature downgrade (CLOSED): - CertificationVerifyOptions.Default now requires Ed25519 signatures - RequireEd25519Signature=true, MinimumSchemaVersion=2 by default - Signature-stripping attacks refused with ed25519-signature-required - CertificationVerifyOptions.Legacy added for HMAC-only migration 8. Schema version downgrade (CLOSED): - Default enforces minimum schema v2, refuses legacy records - Combined strip+downgrade+rewrite-gate attacks prevented - Schema floor checked before signature validation - Attackers cannot rewrite Gate/GatesPassed under legacy lane 9. Composition signer explicit key (CLOSED): - CompositionCertificationRecordSigner now honors hmacKey parameter - Hosts passing explicit keys no longer mint under committed constant - Key resolution: explicit → env → default (matches brick signer) Tests: - CertificationForgeAttackTests: comprehensive attack scenario coverage - SchemaVersionFloorTests: updated for fail-closed defaults - TrustLoopRecordSchemaTests: updated to use Legacy where needed - All tests demonstrate attacks fail with Default, succeed with Legacy Docs: - certification-evidence.md updated to mark 7-9 as CLOSED - Detailed fix descriptions and attack prevention notes added Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Add comprehensive release readiness and business plan interface document for founder/CEO decision-making on v0.x public release vs design-partner private. Covers: - Runtime release bar (Ashlar): P0 trust holes (#513), CI redundancy (#511), cert-loop honesty (#512, #505, #506, #514), known limitations - Product release bar (Forge): scaffold status, Verify phased plan, Cursor-safe claims gate (P3 pending) - Business plan mapping: funnel stages (Aware/Eval/Embed/Design partner/Paid) with readiness per stage - Go/no-go checklist: binary decision framework for public v0.x vs design-partner private - CEO-only actions: branch protection, Pages deployment, social preview, contact channel, PAT for Forge Grounded in certification-evidence.md, SELF-EXTEND-AUDIT.md, and issue tracker. Tone: precise, founder-useful, no hype. Current recommendation: design-partner private first (runtime ready, Forge hold-mode), then CEO actions (branch protection, Pages), then public v0.x. References: #513, #512, #511, #506, #505, #514 Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Accuracy fix per user feedback: PRs #513, #512, #511, #514 are OPEN/draft, NOT merged. Updated document to reflect accurate statuses: - #513 P0 trust holes: OPEN (draft), not merged - #512 cert-loop integration: OPEN (draft), not merged - #511 CI redundancy: OPEN (ready), not merged - #514 landing honesty: OPEN (draft), not merged - Only #505, #506 confirmed merged Updated recommendations: - Changed from "GO design-partner private" to "HOLD for P0 PR merges" - Added active blockers to go/no-go checklist - Updated "What to tell prospects" to reflect P0 PRs must merge first - Path forward now: merge P0 PRs FIRST, then design-partner private This ensures document accuracy matches GitHub PR state as of 2026-09-05 23:34 UTC. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

…gner The CertificationForgeAttackTests.cs file was missing the using statement for Ashlar.Infrastructure.Certification.Composition, causing compilation failures in cert-gate, kernel-gate, security-gate, and kernel-coverage. This fix adds the proper using statement and updates the instantiation to use the short class name instead of the fully-qualified name. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

The PR changed CertificationVerifyOptions.Default to require Ed25519 signatures (fail-closed), but several infrastructure components were using the default without options, causing them to reject HMAC-only records that should still be accepted. Updated the following to use CertificationVerifyOptions.Strict (which matches production code behavior - requires v2+ schema but not Ed25519): - FileCertificationRecordStore.Get() - re-verification on load - CertifiedBrickRegistry.TryAdmit() - brick admission - CompositionConstituentChecker.Check() - constituent verification - AdaptationServiceCollectionExtensions - observation.context verification This allows tests with HMAC-only records to pass while maintaining the new fail-closed Default for code that explicitly opts into it. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

The test helper CreateTrustedRecord was creating v1 (legacy) records without setting SchemaVersion. Since Strict verification now requires v2+ schema (MinimumSchemaVersion=2), these tests were failing with 'schema-version-below-floor' errors. Updated CreateTrustedRecord to: - Set SchemaVersion to TrustLoopSchemaVersion (2) - Set Gate field (required by v2 schema) This allows the behavior certification records to pass Strict verification while maintaining the trust-loop schema requirements. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Fixed remaining test failures by: 1. SchemaVersionFloorTests.IsStrict_IsFalseOnlyForTodaysSemantics - Updated to expect IsStrict=true for Default (now fail-closed) - Added check for Legacy.IsStrict=false 2. AutonomyLedgerScanTests.FileStore_All_ExcludesTamperedRecords_ExactlyLikePointLookups - Updated Record helper to set SchemaVersion=TrustLoopSchemaVersion - Records now pass Strict verification (requires v2+) 3. CertificationGateTeethTests.GoodBrick_StrongWitness_Admits_WithZeroEscapeRate - Updated Verify call to use CertificationVerifyOptions.Strict - Gate creates HMAC-only v2 records, which require Strict (not Default) All fixes maintain the fail-closed Default behavior while allowing HMAC-only v2 records to verify under Strict options. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Added missing using Ashlar.Certification.Contracts in AutonomyLedgerScanTests.cs to resolve compilation error when referencing CertificationRecordData.TrustLoopSchemaVersion. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

…hema Updated the Admitted helper method to create v2 records with: - SchemaVersion = TrustLoopSchemaVersion - Gate field for v2 schema compliance Added missing using statement for Ashlar.Certification.Contracts. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

…certs The StateLogVerifier was calling CertificationTrustVerifier.Verify without options, using the new fail-closed Default which requires Ed25519 signatures. Updated to use CertificationVerifyOptions.Strict, which requires v2+ schema but allows HMAC-only records. This matches the test fixtures which create v2 HMAC-only behavior certification records. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

ROOT CAUSE: Tests created HMAC-only v2 records but verified under fail-closed Default (requires Ed25519) or Strict (requires gate-emitted-artifact + certifier-identity inputs), causing false failures. FIXES: 1. CertificationForgeAttackTests.Attack_SignatureStripping_IsRejectedByDefault - Attacker must recompute HMAC after stripping Ed25519 (real attack path) - Now correctly asserts ed25519-signature-required (not signature-invalid) 2. TrustLoopRecordSchemaTests.Gate_Admit_RecordsAdditionalContextInputs_UnderTheSignature - Gate creates HMAC-only v2 records; use Legacy to test input coverage - Test validates inputs are under signature, not Ed25519 requirement 3. AttestedStateLogBindingTests (A1/G1/R3-R8) - Added gate-emitted-artifact and certifier-identity inputs to CreateTrustedRecord - Records now pass Strict verification used by StateLogVerifier 4. CompositionProbeFixtures.SeedSyntheticConstituent - Added SchemaVersion and Gate fields for v2 compliance NO WEAKENING: Default remains fail-closed (Ed25519 + v2+), Strict unchanged. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Site #4 fix: CompositionProbeFixtures.SeedSyntheticConstituent now mints Strict-valid records by adding: - ContentHash (required for verification) - Inputs with gate-emitted-artifact and certifier-identity (Strict requirements) This allows CompositionCertificationGateTeethTests.NondeterministicComposition_Rejects_Determinism to pass constituent validation and reach the determinism tooth as intended. NO WEAKENING: Strict verification unchanged, constituents must be fully valid. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Compilation error: CertificationInput has required properties Kind, Id, and Hash. Fixed both locations to set all three required properties: - CompositionProbeFixtures.SeedSyntheticConstituent - AttestedStateLogBindingTests.CreateTrustedRecord All CertificationInput instances now properly initialized. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

- Clarify #513 landed fail-closed defaults, NOT full limitation 7 closure - Explicit gap: Strict production paths still lack RequireEd25519Signature - Follow-up PR pending for strict+Ed25519 - Do not claim forged certs fully closed or autonomy unblocked Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

* Add dogfood ledger artifact for shippable-demo evidence tracking - Create docs/dogfood-ledger.md with dated pass/fail entries - First entry: PR #513 cert-gate trust signature limitations 7-9 closed - Add ledger reference to DocsIndex.md trust loop section - Ledger tracks what actually runs E2E before marketing claims Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com> * Fix dogfood ledger honesty: PR #513 partial close, lim 7 still open - Clarify #513 landed fail-closed defaults, NOT full limitation 7 closure - Explicit gap: Strict production paths still lack RequireEd25519Signature - Follow-up PR pending for strict+Ed25519 - Do not claim forged certs fully closed or autonomy unblocked Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com> --------- Co-authored-by: Cursor Agent <cursoragent@cursor.com> Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

* docs: Add CEO-facing release readiness + business plan interface Add comprehensive release readiness and business plan interface document for founder/CEO decision-making on v0.x public release vs design-partner private. Covers: - Runtime release bar (Ashlar): P0 trust holes (#513), CI redundancy (#511), cert-loop honesty (#512, #505, #506, #514), known limitations - Product release bar (Forge): scaffold status, Verify phased plan, Cursor-safe claims gate (P3 pending) - Business plan mapping: funnel stages (Aware/Eval/Embed/Design partner/Paid) with readiness per stage - Go/no-go checklist: binary decision framework for public v0.x vs design-partner private - CEO-only actions: branch protection, Pages deployment, social preview, contact channel, PAT for Forge Grounded in certification-evidence.md, SELF-EXTEND-AUDIT.md, and issue tracker. Tone: precise, founder-useful, no hype. Current recommendation: design-partner private first (runtime ready, Forge hold-mode), then CEO actions (branch protection, Pages), then public v0.x. References: #513, #512, #511, #506, #505, #514 Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com> * fix: Correct PR statuses in release readiness doc Accuracy fix per user feedback: PRs #513, #512, #511, #514 are OPEN/draft, NOT merged. Updated document to reflect accurate statuses: - #513 P0 trust holes: OPEN (draft), not merged - #512 cert-loop integration: OPEN (draft), not merged - #511 CI redundancy: OPEN (ready), not merged - #514 landing honesty: OPEN (draft), not merged - Only #505, #506 confirmed merged Updated recommendations: - Changed from "GO design-partner private" to "HOLD for P0 PR merges" - Added active blockers to go/no-go checklist - Updated "What to tell prospects" to reflect P0 PRs must merge first - Path forward now: merge P0 PRs FIRST, then design-partner private This ensures document accuracy matches GitHub PR state as of 2026-09-05 23:34 UTC. Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com> * Retrigger CI checks Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com> --------- Co-authored-by: Cursor Agent <cursoragent@cursor.com> Co-authored-by: IanFrelinger <IanFrelinger@users.noreply.github.com>

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P0: Close certification trust signature holes (limitations 7-9) - #513

P0: Close certification trust signature holes (limitations 7-9)#513
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IanFrelinger commented Sep 5, 2026

Summary

Changes

Core Fixes (src/)

1. CertificationVerifyOptions.cs

2. CompositionCertificationRecordSigner.cs

3. CertificationTrustVerifier.cs & CertificationRecordSigner.cs

Tests

New: CertificationForgeAttackTests.cs

Updated: SchemaVersionFloorTests.cs

Updated: TrustLoopRecordSchemaTests.cs

Documentation

docs/certification-evidence.md

Attack Scenarios Closed

Before (limitations open)

After (fail-closed)

Migration Path

Testing

Testing strategy (blast radius)

Checklist

References

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