mxaccess/rust/crates/mxaccess-asb/tests/fixtures/signed-xml/README.md

Signed-request XML fixtures

Canonical XmlSerializer output for every ConnectedRequest shape that the .NET reference HMACs in AsbSystemAuthenticator.Sign (src/MxAsbClient/AsbSystemAuthenticator.cs:79). The Rust port's canonical-XML emitter (F28) must produce these exact UTF-8 bytes for the HMAC to match the server's recomputation.

Capture procedure

dotnet run --project src\MxAsbClient.Probe -c Release -- --dump-signed-xml > capture.txt

The probe's --dump-signed-xml flag (added 2026-05-05) builds each shape with deterministic field values and prints the output of AsbSerialization.ToXml(...) (src/MxAsbClient/AsbSerialization.cs:12).

Pinned values

All shapes use the same ConnectionValidator:

• ConnectionId = 8cba964a-74c1-ef74-f6aa-761b3540191b
• MessageNumber = 42
• MessageAuthenticationCode = AAECAwQFBgcICQoLDA0ODw== (base64 of bytes 0..15)
• SignatureInitializationVector = EBESExQVFhcYGRobHB0eHw== (base64 of bytes 16..31)

AuthenticateMe and Disconnect use AuthenticationData with:

• Data = "deterministic-ciphertext-bytes" (base64-encoded)
• InitializationVector = "0123456789abcdef" (base64-encoded)

RegisterItemsRequest uses one ItemIdentity with Type = Name (0), ReferenceType = Absolute (1), Name = "TestChildObject.TestInt", ContextName = "".

UnregisterItemsRequest uses one ItemIdentity with Type = Id (1), ReferenceType = Absolute (1), Name = null, ContextName = null, Id = 0xCAFEBABEDEADBEEF (14627333968688430831), IdSpecified = true.

Observed serialiser behaviour

These rules were inferred from the captured output and from the .NET source for XmlSerializer:

1. Element name = class name, NOT [MessageContract.WrapperName]. XmlSerializer does not honour WCF's MessageContract attributes.

2. Top-element xmlns ordering (after <?xml ... ?>): xmlns:xsi, then xmlns:xsd, then default xmlns. The AsbSerialization.ToXml post-process (AsbSerialization.cs:36-47) reparses with XDocument.Load and reorders to put xsi before xsd — XmlSerializer's native order is the opposite.

3. Field order = C# declaration order (with inherited fields first), NOT [MessageBodyMember.Order].

4. [XmlType(Namespace = ...)] on a field's type triggers an xmlns="..." redeclaration on EACH child element of that type's instance, NOT on the wrapper element itself. e.g. inside <ConnectionValidator>, every direct child gets xmlns="http://asb.contracts.data/20111111".

5. byte[] fields serialise as base64 text content. Guid as canonical lowercase D-format (8cba964a-74c1-...). ulong as decimal. bool as "true" / "false".

6. Null reference-type fields with [XmlElement(IsNullable = true)] produce <Name xsi:nil="true" xmlns="..." />. Empty string fields produce a self-closing <ContextName xmlns="..." />.

7. *Specified pattern: a public bool field named XxxSpecified = true causes XmlSerializer to emit the corresponding <Xxx> element. IdSpecified = false (default) → <Id> omitted. IdSpecified = true → <Id> emitted with the int value. The *Specified field itself is [XmlIgnore] and never emitted.

8. Self-closing elements use /> (space before />).

9. Indentation: 2 spaces, \r\n line endings, no trailing newline after the closing tag.

10. XML declaration: <?xml version="1.0" encoding="utf-16"?> — note utf-16 even though AsbSystemAuthenticator.Sign HMACs Encoding.UTF8.GetBytes(...) of this string. The declaration is a static .NET StringWriter default; the actual byte encoding fed to HMAC is UTF-8.

Files

• authenticate-me.xml — AuthenticateMe
• disconnect.xml — Disconnect
• keep-alive.xml — KeepAlive
• register-items.xml — RegisterItemsRequest
• unregister-items.xml — UnregisterItemsRequest

Each file is the verbatim UTF-8 representation of request.ToXml(), with literal \r\n line endings preserved. Treat as binary (don't let your editor reformat).