Complete task 4 backend security architecture docs

09 - Audits/Task 4 Backend Security Architecture Verification Report.md

@@ -0,0 +1,106 @@
+---
+title: Task 4 Backend Security Architecture Verification Report
+tags: [taskmaster, verification, security, backend]
+created: 2026-05-24
+status: complete
+---
+
+# Task 4 Backend Security Architecture Verification Report
+
+Taskmaster task 4 is complete as an advisory architecture and handoff package.
+The task defines how the backend security/refactor assessment is converted into
+implementation criteria without rewriting or disrupting the current backend
+model.
+
+## 1. Deliverable map
+
+| Taskmaster item | Deliverable |
+|---|---|
+| 4.1 Security ownership and launch criteria | [[Security Ownership and Launch Decision Criteria]] |
+| 4.2 Escrow platform threat model | [[Threat Model - Amanat Escrow Platform]] |
+| 4.3 Funds ledger and escrow state machine | [[Funds Ledger and Escrow State Machine Specification]] |
+| 4.4 REST and Socket.IO authorization matrix | [[Authorization Matrix - REST and Socket.IO]], [[Realtime Authorization Spec]] |
+| 4.5 Session, passkey, and admin step-up architecture | [[Session and Authentication Architecture Decision]] |
+| 4.6 Webhook security and payment adapter contracts | [[Webhook Security Spec]], [[Payment Provider Adapter Spec]] |
+| 4.7 Secure build and supply-chain policy | [[Secure Build and Supply-Chain Policy]] |
+| 4.8 Backend-core stack decision | [[Backend Core Stack Decision Record - 2026-05-24]] |
+| 4.9 Migration and operational runbooks | [[Backend Funds Migration and Operational Runbooks]] |
+
+## 2. Architecture decisions verified
+
+- The current TypeScript/Node backend remains the production delivery path for
+  the next security-hardening phase.
+- A full backend rewrite is explicitly out of scope until ledger, webhook,
+  provider, auth/session, and reconciliation contracts are stable and observable.
+- Payment providers are optional and provider-neutral behind adapter contracts.
+- Webhooks must use raw-body signature verification, replay prevention,
+  idempotency, and dead-letter capture.
+- Funds movement must be derived from the canonical ledger and escrow state
+  machine, not provider metadata.
+- Admin release, refund, payout, role, and destructive account operations require
+  step-up authentication and audit logging; high-risk payouts require
+  two-person approval.
+- Socket.IO room membership must be server-derived and authorization checked,
+  with global financial broadcasts prohibited.
+
+## 3. Verification commands
+
+Executed from `nick-doc` on 2026-05-24:
+
+```bash
+npx task-master show 4
+npx task-master set-status --id=4.6 --status=done
+npx task-master set-status --id=4.7 --status=done
+npx task-master set-status --id=4.8 --status=done
+npx task-master set-status --id=4.9 --status=done
+npx task-master set-status --id=4.3 --status=done
+npx task-master set-status --id=4.4 --status=done
+npx task-master set-status --id=4.5 --status=done
+npx task-master set-status --id=4 --status=done
+node - <<'NODE'
+const fs=require('fs');
+const data=JSON.parse(fs.readFileSync('.taskmaster/tasks/tasks.json','utf8'));
+const t=data.master.tasks.find(x=>String(x.id)==='4');
+console.log(JSON.stringify({
+  task:t.status,
+  subtasks:t.subtasks.map(s=>({id:s.id,status:s.status,title:s.title}))
+}, null, 2));
+NODE
+```
+
+A one-off Node link checker also parsed Task 4 wiki links and verified they
+resolve to markdown files; threat IDs such as `[[T05]]` were treated as allowed
+shorthand references.
+
+## 4. Verification result
+
+- Taskmaster JSON reports task 4 as `done`.
+- Taskmaster JSON reports subtasks 4.1 through 4.9 as `done`.
+- `Authorization Matrix - REST and Socket.IO` now links directly to [[Realtime Authorization Spec]].
+- Task 4 wiki links resolve to existing markdown files, excluding threat-ID
+  shorthand references such as `[[T05]]`.
+- Incident ownership in the task 4 runbook was replaced with explicit role owners
+  that can be mapped to named responders before production launch.
+- Remaining implementation tests belong to follow-up backend tasks because task
+  4 is a documentation and architecture handoff task.
+
+## 5. Follow-up implementation test requirements
+
+Implementation tasks derived from task 4 must include:
+
+- ledger invariant unit tests for every escrow transition,
+- payment provider adapter contract tests for SHKeeper, Request Network, manual
+  wallet, and disabled-provider modes,
+- webhook signature, replay, duplicate, and DLQ tests,
+- REST authorization tests for every gap listed in the authorization matrix,
+- Socket.IO handshake, room authorization, targeted emission, and rate-limit
+  tests,
+- session rotation, revocation, passkey disabled/enabled, and admin step-up
+  tests,
+- runbook drills for provider outage, leaked webhook secret, stuck release,
+  suspicious payment proof, and compromised admin.
+
+## 6. Residual risk
+
+This report verifies the Task 4 architecture package, not production behavior.
+Backend implementation work must still enforce these controls before launch.