Avalonia apps pack every resource (compiled XAML, image/SVG assets, ...)
behind a single !AvaloniaResources manifest blob, which until now fell
through to the generic resource node and could not be browsed. Parse the
blob's index and expose each packed file as its own entry, mirroring how
.resources files are unpacked, so individual files can be viewed and
saved. The reader is bounds-checked against crafted offsets/sizes in the
same defensive spirit as the recent .rsrc parsing guards.
Assisted-by: Claude:claude-opus-4-8:Claude Code
ReadWin32Resources walked the PE resource directory tree with raw native pointer
arithmetic over attacker-controlled offsets, counts and sizes, with no bounds
checks, no recursion-depth limit and no cycle detection. The root section pointer
came from GetSectionData, whose length was read and then discarded, leaving every
dereference unbounded.
A crafted assembly could therefore turn merely opening it (the Save as project
feature reads these resources unconditionally) into an uncatchable process kill or
an out-of-bounds native read: a subdirectory entry pointing back at itself recursed
until the stack overflowed; an inflated entry count walked off the section end; and
a data entry whose Size was up to 4 GB made Buffer.MemoryCopy read far past the
section, faulting on an unmapped page or copying adjacent process memory into the
byte[] later written to app.ico/app.manifest on disk. None of this is containable,
since a StackOverflowException cannot be caught and the repo has no corrupted-state
exception handling. This is the sibling of the bundle signature fix in a154a7bbb.
Carry the section length alongside the root pointer and bounds-check every offset,
entry count, name-string length and data Size against it, cap recursion depth and
track visited directory offsets to break cycles. A hostile or truncated file now
yields a bounded, partial tree instead of a crash; well-formed resources parse
exactly as before. The parser no longer needs the whole PEReader, only a delegate
that resolves a data RVA to a bounded pointer, which is the seam the new tests drive
over a pinned buffer.
Assisted-by: Claude:claude-opus-4-8:Claude Code
On FIPS-mode systems the platform crypto provider refuses to create
SHA-1 instances (OpenSSL: error:03000098 invalid digest), so merely
displaying a strong-named assembly's identity failed. The public-key
token is a non-secret identity hash whose algorithm is fixed by
ECMA-335, so the two token sites now use dotnet/runtime's managed
Sha1ForNonSecretPurposes, vendored with its license header intact and
shielded from the repo formatter via generated_code in .editorconfig
so future upstream syncs diff cleanly. IncrementalHash was considered
and rejected: like SHA1.Create(), it resolves the digest through the
host crypto policy, and Roslyn's equivalent token code also relies on
the platform SHA-1, so it offers no precedent for FIPS safety.
Assisted-by: Claude:claude-fable-5:Claude Code
Compilation uses the .NET builds of the Roslyn toolsets (tasks/netcore*,
bincore csc.dll/vbc.dll launched through the dotnet host). ilasm/ildasm
options use the '-' prefix, which all platforms accept. The dotnet-hosted
compilers have no implicit references or SDK path: net40 compiles pass
mscorlib explicitly, and vbc gets -sdkpath, _MYTYPE=Empty and
-vbruntime:Microsoft.VisualBasic.Core.dll (the facade in the ref packs is
not followed for runtime helpers). The TestRunner gets a self-contained
build for the host platform.
Configurations depending on Windows-only tools or runtimes (legacy
csc/vbc, Roslyn 1.x/2.x, mcs, Force32Bit, executing net40 binaries) are
filtered from the matrix off-Windows via Tester.SupportedOnCurrentPlatform
or gated with [Platform("Win")]. PdbGen comparisons normalize document
name separators, and Correctness/Async uses Console.IsInputRedirected
instead of the Windows-only Console.CapsLock.
Assisted-by: Claude:claude-fable-5:Claude Code
Siegfried Pammer
Christoph Wille
Peter Crabtree
dotnet format
Daniel Grunwald
Kirill Osenkov