fix(intunewin): align Detection.xml with IntuneWinAppUtil.exe reference format

Four structural defects in the generated Detection.xml caused Intune's upload
wizard to silently fail metadata parsing (empty form, OK button greyed):

1. Missing ToolVersion="1.8.6.0" XML attribute on ApplicationInfo — the wizard
   uses this to validate the package was produced by a compatible tool.
2. Spurious xmlns="http://schemas.microsoft.com/IntuneWin" namespace — changes
   element identity for Intune's XML parser (reference emits no namespace).
3. <?xml version="1.0" ?> declaration header — reference uses OmitXmlDeclaration=true.
4. Extra <MacAlgorithm> child element inside EncryptionInfo — not present in
   the reference FileEncryptionInfo model (svrooij/ContentPrep verified).

Fix: switched from toprettyxml() to tostring(xml_declaration=False)+indent(),
added ToolVersion attribute, removed xmlns and MacAlgorithm.
Tests updated to assert the corrected reference format; all 114 pass.

Root cause verified against svrooij/ContentPrep Packager.cs + ApplicationInfo.cs
(open-source C# reference implementation of IntuneWinAppUtil.exe).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

imptune/generators/intunewin_builder.py

@@ -11,6 +11,12 @@ Encrypted blob layout (from svrooij.io reverse-engineering):
 
 IMPORTANT: IV is 16 bytes, NOT 32. STACK.md has a documentation error on this point.
 
+Detection.xml format matches the reference IntuneWinAppUtil.exe output exactly:
+    - ToolVersion is an XML *attribute* on <ApplicationInfo> (not a child element)
+    - No xmlns namespace declaration (reference uses [XmlRoot("ApplicationInfo")] with no namespace)
+    - No <?xml ...?> declaration header (reference uses OmitXmlDeclaration=true)
+    - No <MacAlgorithm> element (not present in reference FileEncryptionInfo model)
+
 Outer ZIP structure:
     IntuneWinPackage/
     ├── Contents/
@@ -24,13 +30,18 @@ import hmac
 import io
 import os
 import zipfile
-import xml.dom.minidom
-from xml.etree.ElementTree import Element, SubElement, tostring
+from xml.etree.ElementTree import Element, SubElement, indent, tostring
 
 from Crypto.Cipher import AES
 from Crypto.Util.Padding import pad
 
 
+# Version string that matches the reference IntuneWinAppUtil.exe tool.
+# Intune's upload wizard validates or uses this field to confirm the package
+# was produced by a compatible tool version.
+_TOOL_VERSION = "1.8.6.0"
+
+
 def build_intunewin(source_dir: str, setup_file: str, output_path: str) -> None:
     """Build a .intunewin file from source_dir, with setup_file as entry point.
 
@@ -76,9 +87,14 @@ def build_intunewin(source_dir: str, setup_file: str, output_path: str) -> None:
     file_digest = hashlib.sha256(plaintext).digest()
 
     # --- Step 7: Build Detection.xml ---
+    # Format MUST match IntuneWinAppUtil.exe reference output exactly:
+    #   - ToolVersion is an XML attribute on ApplicationInfo (not a child element)
+    #   - No xmlns namespace (reference omits it)
+    #   - No <?xml?> declaration header
+    #   - No MacAlgorithm element (not in reference FileEncryptionInfo model)
     app_info = Element(
         "ApplicationInfo",
-        attrib={"xmlns": "http://schemas.microsoft.com/IntuneWin"},
+        attrib={"ToolVersion": _TOOL_VERSION},
     )
     SubElement(app_info, "Name").text = setup_file
     SubElement(app_info, "UnencryptedContentSize").text = str(len(plaintext))
@@ -90,14 +106,14 @@ def build_intunewin(source_dir: str, setup_file: str, output_path: str) -> None:
     SubElement(enc_info, "MacKey").text = base64.b64encode(mac_key).decode()
     SubElement(enc_info, "InitializationVector").text = base64.b64encode(iv).decode()
     SubElement(enc_info, "Mac").text = base64.b64encode(mac_digest).decode()
-    SubElement(enc_info, "MacAlgorithm").text = "SHA256"
     SubElement(enc_info, "ProfileIdentifier").text = "ProfileVersion1"
     SubElement(enc_info, "FileDigest").text = base64.b64encode(file_digest).decode()
     SubElement(enc_info, "FileDigestAlgorithm").text = "SHA256"
 
-    detection_xml = xml.dom.minidom.parseString(
-        tostring(app_info, encoding="unicode")
-    ).toprettyxml(indent="  ")
+    # indent() adds pretty-print whitespace in-place (Python 3.9+).
+    # tostring with xml_declaration=False omits the <?xml?> header.
+    indent(app_info, space="  ")
+    detection_xml = tostring(app_info, encoding="unicode", xml_declaration=False)
 
     # --- Step 8: Build outer ZIP (STORED — no extra compression on encrypted content) ---
     with zipfile.ZipFile(output_path, "w", compression=zipfile.ZIP_STORED) as outer:

tests/test_intunewin.py

@@ -2,7 +2,13 @@
 Byte-level validation tests for the .intunewin file format.
 
 These tests serve as the format specification: if they pass, the byte layout is correct.
-The only remaining validation is a real Intune upload (manual, Phase 5 gate).
+The only remaining validation is a real Intune upload (manual, Phase 10 gate).
+
+Detection.xml format follows the IntuneWinAppUtil.exe reference exactly:
+  - ToolVersion is an XML *attribute* on <ApplicationInfo> (not a child element)
+  - No xmlns namespace (reference uses [XmlRoot("ApplicationInfo")] with no Namespace param)
+  - No <?xml?> declaration header (reference uses OmitXmlDeclaration=true)
+  - No MacAlgorithm element (not present in reference FileEncryptionInfo model)
 """
 import base64
 import hashlib
@@ -16,10 +22,7 @@ import pytest
 from Crypto.Cipher import AES
 from Crypto.Util.Padding import unpad
 
-from imptune.generators.intunewin_builder import build_intunewin
-
-
-NAMESPACE = "http://schemas.microsoft.com/IntuneWin"
+from imptune.generators.intunewin_builder import _TOOL_VERSION, build_intunewin
 
 
 @pytest.fixture
@@ -59,30 +62,22 @@ def package_contents(built_package):
 
 
 def _get_xml_text(tree, tag):
-    """Get text of a direct child element (with namespace)."""
-    elem = tree.find(f"{{{NAMESPACE}}}{tag}")
-    if elem is None:
-        # Try without namespace as fallback
-        elem = tree.find(tag)
+    """Get text of a direct child element (no namespace — reference omits xmlns)."""
+    elem = tree.find(tag)
     return elem.text if elem is not None else None
 
 
 def _get_encryption_info(tree):
-    """Get EncryptionInfo sub-element."""
-    enc = tree.find(f"{{{NAMESPACE}}}EncryptionInfo")
-    if enc is None:
-        enc = tree.find("EncryptionInfo")
-    return enc
+    """Get EncryptionInfo sub-element (no namespace — reference omits xmlns)."""
+    return tree.find("EncryptionInfo")
 
 
 def _get_enc_text(tree, tag):
-    """Get text of a child of EncryptionInfo."""
+    """Get text of a child of EncryptionInfo (no namespace)."""
     enc = _get_encryption_info(tree)
     if enc is None:
         return None
-    elem = enc.find(f"{{{NAMESPACE}}}{tag}")
-    if elem is None:
-        elem = enc.find(tag)
+    elem = enc.find(tag)
     return elem.text if elem is not None else None
 
 
@@ -108,32 +103,48 @@ class TestOuterZipStructure:
 
 class TestDetectionXml:
     def test_detection_xml_valid(self, package_contents):
-        """Detection.xml is valid XML with ApplicationInfo root element in the correct namespace."""
+        """Detection.xml is valid XML with ApplicationInfo root element and ToolVersion attribute.
+
+        Reference format: <ApplicationInfo ToolVersion="1.8.6.0"> with NO xmlns namespace.
+        Presence of xmlns would change element identity for Intune's XML parser, causing
+        silent metadata-parse failure in the upload wizard.
+        """
         tree = package_contents["tree"]
-        assert tree.tag == f"{{{NAMESPACE}}}ApplicationInfo", (
-            f"Root element must be ApplicationInfo with namespace {NAMESPACE}, got {tree.tag}"
+        assert tree.tag == "ApplicationInfo", (
+            f"Root element must be plain 'ApplicationInfo' (no xmlns namespace), got {tree.tag!r}"
+        )
+        assert tree.get("ToolVersion") == _TOOL_VERSION, (
+            f"ApplicationInfo must have ToolVersion attribute = {_TOOL_VERSION!r}, "
+            f"got {tree.get('ToolVersion')!r}"
         )
 
     def test_detection_xml_fields(self, package_contents):
-        """Detection.xml contains all required elements including all 8 EncryptionInfo sub-elements."""
+        """Detection.xml contains all required elements matching the reference FileEncryptionInfo model.
+
+        The reference model has 7 EncryptionInfo sub-elements (MacAlgorithm is NOT present).
+        """
         tree = package_contents["tree"]
         # Direct children
         for field in ("Name", "UnencryptedContentSize", "FileName", "SetupFile"):
             assert _get_xml_text(tree, field) is not None, f"Missing field: {field}"
 
-        # EncryptionInfo sub-elements (all 8 required)
+        # EncryptionInfo sub-elements — 7 required (MacAlgorithm absent per reference schema)
         for field in (
             "EncryptionKey",
             "MacKey",
             "InitializationVector",
             "Mac",
-            "MacAlgorithm",
             "ProfileIdentifier",
             "FileDigest",
             "FileDigestAlgorithm",
         ):
             assert _get_enc_text(tree, field) is not None, f"Missing EncryptionInfo/{field}"
 
+        # MacAlgorithm must NOT be present (not in reference FileEncryptionInfo model)
+        assert _get_enc_text(tree, "MacAlgorithm") is None, (
+            "EncryptionInfo/MacAlgorithm must NOT be present — not in reference schema"
+        )
+
     def test_setup_file_in_detection_xml(self, package_contents):
         """SetupFile element matches the setup_file argument passed to build_intunewin."""
         tree = package_contents["tree"]