Files
mxaccess/rust
Joseph Doherty f14580e0db [M5] mxaccess-asb: F28 canonical-XML signing wired + registry-driven DH params
Adds `xml_canonical` module that emits XmlSerializer-compatible canonical
XML for the five primary `ConnectedRequest` shapes (AuthenticateMe,
Disconnect, KeepAlive, RegisterItemsRequest, UnregisterItemsRequest).
Six fixture-comparison tests verify byte-exact match against captured
.NET output, including the empty-MAC-IV variant that the live signing
flow uses (`authenticate-me-empty-mac-iv.xml`, 896 bytes; new
`emit_data_ns_byte_array` helper picks self-closing form for empty
byte[]).

Plumbing: `AsbAuthenticator::peek_next_message_number` exposes the
pre-allocated message number; `AsbClient::send_signed_envelope[_one_way]`
gain an `xml_for_signing: Option<&[u8]>` parameter. `connect`,
`disconnect`, `keep_alive`, `register_items`, `unregister_items` now
build a pre-signing `ConnectionValidator` (empty MAC + IV) + emit the
canonical XML + pass the bytes through to HMAC. Other ops (Read, Write,
Subscription) keep the legacy NBFX-bytes path until F28 expands to
cover their request shapes.

Live-bring-up wiring:
- `tools/Get-AsbPassphrase.ps1` now exports `MX_ASB_DH_PRIME`,
  `MX_ASB_DH_GENERATOR`, `MX_ASB_DH_HASH_ALGORITHM` (always — even when
  empty, so the example can distinguish "no env var" from "registry
  says empty"), and `MX_ASB_DH_KEY_SIZE`.
- `examples/asb-subscribe.rs` honours those env vars to override
  `CryptoParameters::defaults()`. Each AVEVA install picks its own DH
  group at provisioning time (768-bit prime is typical, vs the .NET
  reference's 1024-bit fallback that we previously hardcoded). Empty
  hashAlgorithm in the registry maps to `HashAlgorithm::Unrecognised`,
  matching `AsbSystemAuthenticator.CreateHmac:84-93` semantics where
  empty + forceHmac=true → HMAC-SHA1.
- `MxAsbClient.Probe --dump-signed-xml` flag (added in earlier commit)
  now traces the live HMAC inputs (`asb.sign.xml-utf8-len`,
  `asb.sign.xml-b64`, `asb.sign.hmac-b64`, etc.) so the Rust port can
  diff its canonical XML against .NET's byte-for-byte for any live
  scenario (env-driven via `Action<string>? sharedTrace`).

Wire-format alignment for `XmlSerializer` parity:
- `ItemIdentity::default()` and `absolute_by_name` now use
  `Some(String::new())` for null-able strings (matches .NET's
  `CreateAbsoluteItem` setting `ContextName = string.Empty` not null).
- `read_unicode_string` returns `Some(String::new())` for length-0
  rather than `None` — mirrors .NET's `AsbBinary.ReadUnicodeString:
  return string.Empty for byteLength == 0`. Wire format genuinely
  cannot distinguish null from empty (both encode as 4 bytes of zero);
  callers that need to preserve the distinction MUST track it in their
  domain types before encoding.

Live status (post-fix): Connect handshake completes end-to-end. The
canonical XML our emitter produces matches .NET's structure byte-for-
byte (verified by fixture comparison). DH prime/generator/hash now
match the live registry values. Despite all this, AuthenticateMe
still produces a generic dispatcher fault on the server — there's at
least one more subtle wire-byte or crypto mismatch that needs
isolation. F28 stays open with that note.

Workspace: 709 unit tests pass (was 702 + 7 new xml_canonical tests).
Clippy: clean (`-D warnings`).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-05 17:31:31 -04:00
..

mxaccess (Rust port)

Native Rust replacement for AVEVA / Wonderware MXAccess. See ../design/ for the architectural specification, ../src/ for the .NET reference (the executable spec), and ../CLAUDE.md for project-wide rules.

Status

M0 — Workspace skeleton. Stub types compile; nothing is implemented yet. See ../design/60-roadmap.md for the M0M6 milestone plan.

Layout

rust/
  Cargo.toml                 workspace root
  rust-toolchain.toml        1.85 stable
  crates/
    mxaccess-codec/          pure protocol codec, no I/O
    mxaccess-galaxy/         Galaxy SQL resolver (tiberius)
    mxaccess-rpc/            DCE/RPC + NTLMv2 + OXID + OBJREF
    mxaccess-callback/       INmxSvcCallback RPC server
    mxaccess-nmx/            INmxService2 client
    mxaccess-asb-nettcp/     net.tcp framing (MC-NMF + MC-NBFX/NBFS)
    mxaccess-asb/            IASBIDataV2 client
    mxaccess/                async session + Transport trait + public API
    mxaccess-compat/         LMXProxyServer-shaped facade

Build

cargo build --workspace
cargo test --workspace
cargo clippy --workspace -- -D warnings
cargo fmt --check

Live probes

. ..\tools\Setup-LiveProbeEnv.ps1
cargo test -p mxaccess --features live -- --ignored

The setup script fetches credentials from Infisical via wwtools/secrets/Get-Secret.ps1. Never inline plaintext credentials.

License

MIT — see ../LICENSE.