Migrate to IDF 5.5.3 candidate

Pin PlatformIO packages and toolchains, rebase protected SDK
overrides, and add WebSocket receive regression coverage. Document
isolated candidate validation, archive provenance, and remaining gates.

docs/security_hardening.md

@@ -2,6 +2,16 @@
 
 **Status: in progress.** Phase 8 is complete at the accepted 8D.22 scope. **9A crash/debug policy, 9B SSH admission/credential handling and 9C library cleanup/protocol policy** are implemented with host/build validation. At the user's request, hardware validation is deferred to **Phase 9 as a whole**, not an approval gate between implementation slices. **9D maintenance/lifecycle is in progress, with unresolved advisory and distribution/source/notice questions. Phase 9 is not complete or production-ready.** This document records policy and procedures, not unrun passes or production certification.
 
+## Current migration evidence — 2026-09-18
+
+Root `platformio.ini` now pins **PlatformIO espressif32 6.13.0 / framework-espidf 3.50503.0 (IDF 5.5.3)** and both Xtensa and RISC-V toolchains at **14.2.0+20251107**. These are exact version pins, not enforcement of archive hashes or a complete immutable build closure. The [candidate integration record](idf_candidate_integration.md) distinguishes the verified archive identities from the root configuration.
+
+Supplied parent evidence: a **fresh isolated application build PASS** in `.pio/idf-candidate-5.5.3/app-validated`, with **95,552 B linked RAM / 1,749,493 B flash**, versus historical **94,340 / 1,768,901 B**: **+1,212 B RAM / −19,408 B flash**. The default root `pio run` timed out after **200 seconds during installation, before compilation**; it is **not a normal root build PASS**. Final explicit-candidate Phase 9 validation with interop and web performance **PASS 24/24**; see [command and snapshot evidence](phase9_validation.md#current-candidate-execution--2026-09-18). Source equality covered **3,237 files**, pre/post SHA-256 **`3a1af78c15cfdd02da1055a8957b4086f9018862b7aa1c7c52fd2401a1a0a031`**.
+
+All **nine generated C sources plus one forced header** are validated as actual compilation inputs. The new WS correction makes five fixed-header `sizeof` comparisons signed; **982 behavioral cases / 10 mutation checks** cover generated WS receive behavior. The stale web-cookie IDF 5.5.0 fixture was corrected. [Rebase review](idf_553_rebase_review.md) retains old findings as history, not current blockers, and records all packaged Wi-Fi/PHY/coexistence/supplicant files matching the locked framework archive.
+
+The fix-bearing vendor Wi-Fi bundle is integrated in the validated candidate, **not radio-hardware vulnerability closure**. PMF/WPA3 is unchanged. Whole-phase target/radio/resource/recovery acceptance, complete dependency closure and release/source/legal gates remain pending; **Phase 9 is not complete or production-ready**. These are supplied parent results, not builds or hardware tests rerun by this documentation update.
+
 ## Scope and threat model
 
 Reduce network abuse, accidental diagnostic disclosure and unnecessary secret retention while preserving one UART1 broker writer, isolated observers and binary transparency. UART0 remains trusted physical administration/recovery; native USB remains network-independent UART1 access, not an admin console. Whole-device reboot interrupts every transport.
@@ -71,14 +81,14 @@ Hidden UART0 and shared remote-console prompts now reject overflow or unsupporte
 
 ### Reproducible source corrections
 
-`tools/security_overrides.py` verifies full original-file SHA-256 values and ESP-IDF 5.5.0, applies exact-once edits, and generates eight corrected C sources plus one header under the build directory (the original four 9C sources, three IDF advisory sources, and the additional wolfSSH `ssh.c`/`internal.h` ordering inputs). `cmake/security_overrides.cmake`, included after `project()`, replaces exactly the corresponding sources in existing IDF/component targets, retaining compilation properties. Installed SDK/managed sources and their notices remain unchanged. Missing, changed or ambiguous sources fail configuration; there is no unpatched fallback. Do not edit derived files or repin a hash merely to make an upgrade build.
+`tools/security_overrides.py` verifies full original-file SHA-256 values and ESP-IDF 5.5.3, applies exact-once edits, and generates nine corrected C sources plus one header under the build directory (the original four 9C sources, three IDF advisory sources, the additional wolfSSH `ssh.c`/`internal.h` ordering inputs, and the IDF 5.5.3 WS signed-receive correction). `cmake/security_overrides.cmake`, included after `project()`, replaces exactly the corresponding sources in existing IDF/component targets, retaining compilation properties. Installed SDK/managed sources and their notices remain unchanged. Missing, changed or ambiguous sources fail configuration; there is no unpatched fallback. Do not edit derived files or repin a hash merely to make an upgrade build.
 
 - **HTTPS:** delete TLS on post-handshake transport-allocation failure; fully destroy retained TLS configuration on failed HTTPD start; wipe the copied raw private key before free. Failed stop still retains live ownership.
 - **HTTPD parser:** allocate/copy/wipe/free scratch on resize, preserve the old pointer on allocation failure, wipe final scratch, and handle the null initial parser pointer without undefined subtraction. Pending/unread bytes retain their existing behavior.
 - **wolfSSH password parser:** bound both password lengths against the actual packet before application callbacks, reject malformed change-password fields without calling authentication, and wipe the bounded method-specific payload suffix before failure responses. Username/service/method prefixes remain intact. The current project callbacks are synchronous; library `WS_AUTH_PENDING` retains the payload for retry and is not claimed wiped.
 - **ESP-TLS server configuration:** enforce the static-lifetime TLS list below before handshake setup; client defaults and global cryptographic primitives remain unchanged. IDF dynamic TLS buffers are rejected because their cleanup bypasses the reviewed upstream record-buffer wipe.
 
-The new `src/ssh_memory.{c,h}` wolfSSL/wolfCrypt allocation hooks wipe the full owned usable allocation before release, including library import-failure and dynamic packet-buffer copies. They require the reviewed unpoisoned IDF 5.5.0 heap configuration; poisoning modes fail compilation rather than risking canary writes. No allocation header is added. Shrink retains capacity and wipes the tail; growth allocates/copies before wiping/freeing the old block, preserving it on allocation failure. PSRAM preference/internal fallback is unchanged. **Growth and HTTPD scratch resizing temporarily need both blocks; lower linked size is not evidence of safe runtime headroom.** Live inline buffers, in-place compaction tails, stack spills and every crypto intermediate are not comprehensively covered.
+The new `src/ssh_memory.{c,h}` wolfSSL/wolfCrypt allocation hooks wipe the full owned usable allocation before release, including library import-failure and dynamic packet-buffer copies. They require the reviewed unpoisoned IDF 5.5.3 heap configuration; poisoning modes fail compilation rather than risking canary writes. No allocation header is added. Shrink retains capacity and wipes the tail; growth allocates/copies before wiping/freeing the old block, preserving it on allocation failure. PSRAM preference/internal fallback is unchanged. **Growth and HTTPD scratch resizing temporarily need both blocks; lower linked size is not evidence of safe runtime headroom.** Live inline buffers, in-place compaction tails, stack spills and every crypto intermediate are not comprehensively covered.
 
 ### Explicit network protocol policy
 
@@ -107,7 +117,7 @@ The existing global five-verifications/60-second fixed window is unchanged: malf
 - [Security operations](security_operations.md) supplies source-checked provisioning, explicit-save, account/key/identity rotation, recovery, reconstruction and approved erase/decommissioning procedures. There is no implemented configuration backup/export or private-identity restore workflow. Commands and checklists are not device execution evidence; the user will validate Phase 9 as a whole.
 - [wolfSSL/wolfSSH review and implementation addendum](wolf_security_review.md): the **CVE-2025-12888** Xtensa mitigation now selects `CURVE25519_SMALL` and `ED25519_SMALL` consistently for wolfSSL and consumers. The PUBLIC forced-include resolved-settings guard rejects missing small implementations, X25519 blinding (incompatible with small in this pinned version), and unreviewed Curve448/Ed448 enablement. The existing generated wolfSSH override now bounds IGNORE/service strings, rejects zero-capacity string output and channel-window overflow, corrects ECC/Ed25519 key/signature labels, and enforces exact signature framing (ECC nested r/s bounds plus inner/outer consumption; Ed25519 outer consumption). These are PR892/881/880 subsets plus local framing corrections, not full backports; password wiping/async retention remain unchanged. PUBLIC `WOLFSSL_VALIDATE_ECC_IMPORT` and `WOLFSSL_ECDHX_SHARED_NOT_ZERO` now enable P-256 import validation and X25519 all-zero-result rejection, with effective production flags confirmed and fail-closed backend guards. See [key-validation evidence](ssh_key_validation_review.md) and [parser scope/limits](../tests/wolfssh_parser_contract/README.md). The restricted existing-profile correction for **CVE-2025-14942** is implemented as described below. The [finite remaining SSH review](ssh_parser_remaining_review.md) is complete: bounded exact CHANNEL_FAILURE recipient parsing (fatal policy retained), exact `ssh-userauth` service validation, and exact length/byte dispatch for all nine channel-request names are implemented. Unknown-request/trailing-payload behavior is preserved. PR899 client key skips are unchanged and blocked by current server role/ordering; PR918/919 forwarding is disabled. The inspected generic signature caller trace found no attacker-selected short-digest/OID path; generic APIs remain unpatched. These are profile-specific dispositions, not exhaustive parser/library safety; revisit on caller, feature, KEX or source changes. No exploit or whole-library clearance is demonstrated; added validation CPU/allocation cost and target interoperability remain unmeasured.
 - [Focused IDF review and implementation addendum](idf_security_review.md): pinned backports now implement DHCP option bounds (**CVE-2026-45160**), TLS 1.2 EMS failure return (**CVE-2026-50581**) and X.509 OID allocation-failure handling (**CVE-2026-34874**). Explicit nested-target validation places the mbedTLS edits on `mbedtls`/`mbedx509`, retaining source properties and exactly-one-source checks. WS negotiation **CVE-2026-45541** and ASN.1 named-data **CVE-2025-48965** remain unpatched with the review's qualified applicability, not blanket closure. The [finite IDF applicability completion](idf_security_review.md#finite-applicability-completion--2026-09-16) dispositions all six named findings: ECDH small-output, zero-length ECC PK parse, basicConstraints, server NewSessionTicket and stale ASN.1 length are not current paths/configurations for their documented reasons; optimized ECC reduction is active but its privileged-local/physical side-channel attacker model is excluded. No new current-path correction was established. That earlier review screened only the first advisory-index page. The subsequent [finite dependency coverage](dependency_advisory_coverage.md) accounts for all **22 IDF entries across three pages**, plus named managed-component and browser publication channels. The declared dated search is complete, not exhaustive advisory clearance; unpatched primitives, inaccessible full-release databases and fresh findings remain.
-- [Dependency license inventory](dependency_licenses.md) is a bounded engineering inventory, not legal or distribution clearance. All **eight generated C sources plus one header** carry prominent modification notices: the baseline **2026-09-15** notice plus **2026-09-16** ordering/provenance notices on wolfSSH outputs, with upstream notices retained, including both mbedTLS dual-license headers. That narrow finding is resolved. Radio-blob corresponding-source/exception questions, actual firmware/device/browser notice delivery, preferred-source packaging, wolfSSH package-license discrepancy and manual bitmap derivation, the distinct mockup Wi-Fi path and recipient license delivery remain open; [exact retained SVG provenance](icon_provenance.md) is resolved. Notice assembly does not prove recipient delivery. [Offline notice assembly](release_packaging.md) is implemented by [tools/release_notices.py](../tools/release_notices.py): 75 mandatory hash/size-pinned inputs, deterministic bounded outputs, fail-closed preflight and no overwrite/fetch/build/device access. Supplied agent evidence: **36 notice fixture tests PASS; two actual bundles verified deterministic, each 77 files / 4,433,930 bytes**. This includes retained SVGs and [exact icon provenance](icon_provenance.md), not corresponding-source delivery or legal clearance. These are agent measurements, not a parent rebuild or reassembly in this documentation turn.
+- [Dependency license inventory](dependency_licenses.md) is a bounded engineering inventory, not legal or distribution clearance. All **nine generated C sources plus one header** carry prominent modification notices: the baseline **2026-09-15** notice plus **2026-09-16** ordering/provenance notices on wolfSSH outputs, with upstream notices retained, including both mbedTLS dual-license headers. That narrow finding is resolved. Radio-blob corresponding-source/exception questions, actual firmware/device/browser notice delivery, preferred-source packaging, wolfSSH package-license discrepancy and manual bitmap derivation, the distinct mockup Wi-Fi path and recipient license delivery remain open; [exact retained SVG provenance](icon_provenance.md) is resolved. Notice assembly does not prove recipient delivery. [Offline notice assembly](release_packaging.md) is implemented by [tools/release_notices.py](../tools/release_notices.py): 75 mandatory hash/size-pinned inputs (nine IDF/toolchain notice entries semantically rebased for the candidate; the other 66 unchanged), deterministic bounded outputs, fail-closed preflight and no overwrite/fetch/build/device access. Supplied agent evidence: **36 notice fixture tests PASS; two actual bundles verified deterministic, each 77 files / 4,433,930 bytes**. This includes retained SVGs and [exact icon provenance](icon_provenance.md), not corresponding-source delivery or legal clearance. These are agent measurements, not a parent rebuild or reassembly in this documentation turn.
 - **Restricted ordering correction implemented, not a full upstream backport or sign-off.** The [ordering review](wolf_security_review.md#restricted-ordering-correction-and-remaining-gates) and [provenance/prerequisite disposition](../tools/wolfssh_order/README.md) document the audited PR793/819/840/855/921 subsets plus local gates. Existing X25519/P-256 KEX only; independent SELF/PEER state, exact expected replies and authentication-phase checks cover both roles. Queued NEWKEYS survives WANT_WRITE without duplication. **EXT_INFO is deliberately disabled; no `server-sig-algs` is sent**, and `extInfoSent` stays zero. CMake applies the generated ABI header BEFORE PUBLIC and via a PUBLIC forced include; joined `-include/path` flags fix PlatformIO sorting/deduplication for ordering and crypto guards. Review's misplaced EOF guard is corrected before channel mutation; verification found no scoped blocker. Target cleanup during rekey and no-EXT_INFO client compatibility remain pending.
 - No dependency versions were upgraded. Beyond the implemented backports above, proposed upgrades/backports remain candidates, not approved compatible versions. Re-audit coherent source/header changes, effective compile policy, exact-hash overrides and callback/parser contracts, then obtain host/build and whole-phase target evidence. 9A–9C passes below are historical scoped evidence, not closure of these newly recorded findings.
 
@@ -206,15 +216,15 @@ Retain these checks for the user's final whole-phase test session; do not stop i
 4. Repeatedly start/stop HTTPS and SSH and stress header parsing/authentication under the full transport mix. Capture internal/DMA/PSRAM free/minimum/largest-block and stack margins alongside serial/broker loss counters. Specifically measure old-plus-new allocation peaks and secure-free CPU cost; previous very low internal minima remain important.
 5. Verify exhausted web login returns early without stalled-body work, clears the used pre-login challenge, and recovers after the documented window. Check malformed requests below quota and correct credentials for normal behavior; do not infer fairness from a rate-limit pass.
 
-**Bounded host validation:** [tools/validate_phase9.py](../tools/validate_phase9.py) orchestrates **23 commands** by default, with no build or OpenSSH interop unless separately opted in. The stale console-boundary anchor was fixed by its owning agent; supplied follow-up agent result is **23/23 PASS**. Final supplied parent execution: `CCACHE_DISABLE=1 python3 -B tools/validate_phase9.py` **PASS 23/23**; `tests/phase9_validation/run.py` **PASS 10 tests**. No build or interop ran this turn. See [usage and execution boundaries](phase9_validation.md). No parent rebuild this turn; firmware source is unchanged. Historical build/interop results above are not fresh target or release evidence.
+**Bounded host validation:** 23 commands by default; build, OpenSSH interop and web performance are explicit options. Historical default 23/23 and 10 orchestrator fixtures passed on the earlier snapshot. Current supplied parent validation selects the isolated IDF 5.5.3 build/core/SDK, with `--interop --web-performance`: **PASS 24/24**. See [exact command, source equality and evidence limits](phase9_validation.md#current-candidate-execution--2026-09-18). This does not claim a successful default root build or whole-phase acceptance.
 
 ## Staged next work
 
-- **Implementation/maintenance gate:** the finite SSH and six-finding IDF reviews are complete for their stated profiles; do not re-list them as unimplemented. The [declared finite advisory search](dependency_advisory_coverage.md) is complete. Resolve the **unfixed PMF-capable SoftAP security blocker** through the [coherent vendor framework/ABI update plan](wifi_security_update_plan.md), retaining PMF/WPA3, exact override guards and fresh production-source/target tests. Residual direct-SDK AES-DMA applicability and publication-channel gaps remain; recheck the bounded snapshot before release. Optional ASN.1/ECDH/basicConstraints defense-in-depth backports are not implemented or required by a demonstrated current-path finding.
+- **Implementation/maintenance gate:** the finite SSH and six-finding IDF reviews are complete for their stated profiles; do not re-list them as unimplemented. The [declared finite advisory search](dependency_advisory_coverage.md) is complete. The fix-bearing vendor bundle is integrated in the validated IDF 5.5.3 candidate; complete the [remaining Wi-Fi target gates](wifi_security_update_plan.md), retaining PMF/WPA3 and exact override guards. Integration is not radio-hardware closure. Residual direct-SDK AES-DMA applicability and publication-channel gaps remain; recheck the bounded snapshot before release. Optional ASN.1/ECDH/basicConstraints defense-in-depth backports are not implemented or required by a demonstrated current-path finding.
 - **Release gate:** notice assembly is implemented; validate actual firmware/device/browser delivery, corresponding source and preferred asset sources, radio-blob legal basis, wolfSSH packaging clarification, remaining manual bitmap/mockup provenance, final runtime/bootloader attribution and any Installation Information. See [packaging gates](release_packaging.md#separate-work-before-distribution).
 - **Target/acceptance gate:** rehearse operations and the combined target checklist above, including panic/recovery, abuse/isolation, cleanup during rekey, intended-client compatibility without EXT_INFO, loaded KEX/rekey and heap/stack/CPU timing. Obtain explicit whole-phase acceptance; no scoped reviewer or host PASS can substitute.
 
-- **Continue 9D maintenance and lifecycle.** Execute the [remaining ordering gates and advisory work](wolf_security_review.md#restricted-ordering-correction-and-remaining-gates), implement and validate the coherent Wi-Fi correction identified by the completed finite dependency search, and revisit its explicit residual questions, and address the [release source/notice work](dependency_licenses.md#actionable-release-work-not-performed). Runbooks are documented, not rehearsed; remaining mitigations/reviews, distribution clearance and whole-phase acceptance remain outstanding.
+- **Continue 9D maintenance and lifecycle.** Execute the [remaining ordering gates and advisory work](wolf_security_review.md#restricted-ordering-correction-and-remaining-gates), target-validate the integrated coherent Wi-Fi correction identified by the completed finite dependency search, and revisit its explicit residual questions, and address the [release source/notice work](dependency_licenses.md#actionable-release-work-not-performed). Runbooks are documented, not rehearsed; remaining mitigations/reviews, distribution clearance and whole-phase acceptance remain outstanding.
 - **Retained evidence limits:** 9C completes a bounded cleanup/protocol review, not every-library-copy zeroization. Live inline residue, compaction tails, hardware/stack intermediates, global admission starvation and resource/interop measurements remain documented limitations or combined target gates. Any additional hardening must preserve owner lifetimes and bounded recovery.
 - **Phase 10: OTA trust.** Define independent image-signature verification, trust-anchor provisioning, rotation/revocation, rollback/downgrade and recovery policy without secure boot. Authenticated transport alone is not image-signing policy, and OTA signature checks cannot prevent physical firmware replacement.