Harden build path handling

Launcher/LocalBuild.ps1

@@ -152,8 +152,7 @@ if ($Profile -ne 'both' -and -not [string]::IsNullOrWhiteSpace($BaseOutputDirect
 }
 $realWorkspace = $Workspace.TrimEnd('\')
 $Workspace = Get-MkwBuildSafePath $realWorkspace 'workspace' 'runtime\CMakeLists.txt'
-# A selected package inside the install may also name the same Code.pul through the real path.
+# One spelling of the workspace, so the staged Code.pul check below can't copy a file onto itself.
-# Give it the workspace spelling before comparing it with the staged copy.
 if (-not [string]::IsNullOrWhiteSpace($RetroRewindPackageDirectory) -and
     $RetroRewindPackageDirectory.StartsWith($realWorkspace + '\', [StringComparison]::OrdinalIgnoreCase)) {
     $RetroRewindPackageDirectory = $Workspace + $RetroRewindPackageDirectory.Substring($realWorkspace.Length)

Launcher/NativeBuildFlags.ps1

@@ -42,9 +42,10 @@ function Get-MkwToolchainPath([string]$ToolchainRoot) {
 
 function Get-MkwBuildSafePath([string]$Path, [string]$Kind, [string]$MarkerFile) {
     <#
-    The Windows native build passes workspace paths through CMake, Ninja response files and
+    $Path, or a junction to it whose path is plain ASCII. cmd.exe, Ninja response files and the
-    clang, which do not all interpret quotes the same way. Keep those paths plain even when the
+    compiler each have their own quoting rules, so a path outside this allowlist ('&', '%', an
-    user's install directory contains an apostrophe, ampersand or other punctuation.
+    apostrophe, non-ASCII...) is never handed to the native build at all. $MarkerFile is a file
+    that must exist under a live junction.
     #>
     if ([string]::IsNullOrWhiteSpace($Path)) { throw "A $Kind path is required." }
     $full = [IO.Path]::GetFullPath($Path)
@@ -52,8 +53,6 @@ function Get-MkwBuildSafePath([string]$Path, [string]$Kind, [string]$MarkerFile)
     if ($full -ne [IO.Path]::GetPathRoot($full)) { $full = $full.TrimEnd('\') }
     if ($full -cmatch '^[A-Za-z0-9 ._\\:-]+$') { return $full }
 
-    Assert-File (Join-Path $full $MarkerFile) "$Kind marker"
-
     $sha = [Security.Cryptography.SHA256]::Create()
     try {
         $bytes = $sha.ComputeHash([Text.Encoding]::UTF8.GetBytes($full.ToLowerInvariant()))
@@ -66,29 +65,23 @@ function Get-MkwBuildSafePath([string]$Path, [string]$Kind, [string]$MarkerFile)
         $link = Join-Path (Join-Path $base 'WiiCompiled') $linkName
         try {
             [IO.Directory]::CreateDirectory((Split-Path -Parent $link)) | Out-Null
-            $existing = Get-Item -LiteralPath $link -Force -ErrorAction SilentlyContinue
+            # The name already identifies the target, so an existing junction that still resolves is
-            if ($null -ne $existing) {
+            # this one; only a broken leftover is replaced. Directory.Delete removes the reparse
-                # Never trust a directory just because it has the marker: it could point at a
+            # point itself, where Remove-Item -Recurse would delete the tree it points at.
-                # different installation. Nor may we remove a directory we did not create.
+            if (-not (Test-Path -LiteralPath (Join-Path $link $MarkerFile) -PathType Leaf)) {
-                if ($existing.LinkType -ne 'Junction' -or
+                if (Test-Path -LiteralPath $link) { [IO.Directory]::Delete($link) }
-                    @($existing.Target).Count -ne 1 -or
-                    -not [string]::Equals([IO.Path]::GetFullPath(@($existing.Target)[0]),
-                        $full, [StringComparison]::OrdinalIgnoreCase)) {
-                    throw "An existing path is not the expected junction: $link"
-                }
-            } else {
                 New-Item -ItemType Junction -Path $link -Target $full -ErrorAction Stop | Out-Null
             }
-            Assert-File (Join-Path $link $MarkerFile) "$Kind junction marker"
             Write-Host "MKWCBUILD: Building the $Kind through $link, because $full contains characters the native build cannot quote reliably"
             return $link
         } catch {
             $failures += "$link ($($_.Exception.Message))"
         }
     }
-    throw ("The $Kind path $full cannot be passed safely to the native build, and no junction " +
+    Write-Host ("MKWCBUILD: Warning: no junction to $full could be created (" + ($failures -join '; ') +
-        'to it could be created: ' + ($failures -join '; ') + '. Install to a path of plain ' +
+        '); building from the original path, which may fail. Installing to a path of plain ' +
-        'letters, digits and spaces, or make a safe junction location available.')
+        'letters, digits and spaces avoids this.')
+    return $full
 }
 
 function Get-MkwProjectPins([string]$ProjectFile) {

Launcher/WiiCompiled.Setup.Linux/Program.cs

@@ -127,39 +127,18 @@ internal static class Program
         string? retroWfcOfflineDir = null;
         if (downloadPayload)
         {
+            // Reused if a previous install already downloaded and it's still valid - matches
+            // Windows's own reuse-if-valid behavior instead of re-downloading on every install.
             var cacheDir = Path.Combine(workspace, "generated", "retro-wfc-payload");
-            reporter.Progress(InstallStages.Validate,
+            reporter.Progress(InstallStages.Validate, "Preparing the Retro-WFC payload", 1);
-                "Downloading the current Retro-WFC payload", 1);
-            try
-            {
-                // A valid signature authenticates a payload, but does not prove it is the latest
-                // signed revision. Always ask the fixed endpoint for the current snapshot; the
-                // downloader verifies it before atomically replacing the cache.
-                await RetroWfcPayload.DownloadRetroWfcPayloadAsync(
-                    RetroWfcPayload.CurrentRetroWfcPayloadUri, cacheDir, token);
-            }
-            catch (Exception downloadFailure) when (!token.IsCancellationRequested &&
-                                                     downloadFailure is HttpRequestException or TimeoutException
-                                                         or IOException)
-            {
-                // Offline installs may continue with a previously authenticated snapshot. Do not
-                // use this path for a newly downloaded payload that failed signature validation:
-                // that must remain a hard failure instead of hiding possible endpoint tampering.
             try
             {
                 RetroWfcPayload.ValidateStagedRetroWfcPayloadDirectory(cacheDir);
             }
-                catch (Exception cacheFailure) when (cacheFailure is IOException or
+            catch (InvalidDataException)
-                                                     UnauthorizedAccessException or InvalidDataException)
             {
-                    throw new InvalidOperationException(
+                await RetroWfcPayload.DownloadRetroWfcPayloadAsync(
-                        "The current Retro-WFC payload could not be downloaded and no valid cached " +
+                    RetroWfcPayload.CurrentRetroWfcPayloadUri, cacheDir, token);
-                        $"payload is available ({cacheFailure.Message.TrimEnd('.')}).", downloadFailure);
-                }
-
-                reporter.Diagnostic(
-                    "The current Retro-WFC payload could not be downloaded; using the previously " +
-                    $"verified cached payload instead ({downloadFailure.Message.TrimEnd('.')}).");
             }
             retroWfcOfflineDir = cacheDir;
         }

Launcher/WiiCompiled.Setup.Windows/ProductRepairService.cs

@@ -110,7 +110,8 @@ internal sealed class ProductRepairService
                     InputValidation.CurrentRetroWfcPayloadUri, payloadScratch, cancellationToken);
             }
             catch (Exception ex) when (!cancellationToken.IsCancellationRequested &&
-                                       ex is HttpRequestException or TimeoutException or IOException)
+                                       ex is HttpRequestException or IOException or InvalidDataException
+                                           or InvalidOperationException or OperationCanceledException)
             {
                 payloadSnapshot = RecoverInstalledRetroWfcPayload(toolkitFingerprint,
                     Path.Combine(scratchRoot, "retro-wfc-payload-recovered"), ex, cancellationToken);

Launcher/macos/setup.command

@@ -77,40 +77,26 @@ if [[ -n "$retro_dir" ]]; then
     # verify its pinned signature before publishing it into the local cache.
     retro_wfc_dir="$support_root/RetroWfcPayload"
     retro_wfc_payload="$retro_wfc_dir/binary/payload.RMCPD00.bin"
-    cached_payload_valid=0
+    if [[ -f "$retro_wfc_payload" ]] && ! "$translator" validate-retro-wfc-payload --directory "$retro_wfc_dir"; then
-    if [[ -f "$retro_wfc_payload" ]]; then
-        if "$translator" validate-retro-wfc-payload --directory "$retro_wfc_dir"; then
-            cached_payload_valid=1
-        else
         printf 'Discarding an invalid cached Retro-WFC payload...\n' >&2
         rm -f "$retro_wfc_payload"
     fi
-    fi
+    if [[ ! -f "$retro_wfc_payload" ]]; then
-
+        printf 'Downloading the Retro-WFC payload needed for online play...\n'
-    # A signed cache may still be an older vulnerable revision, so always attempt to replace it
-    # with the current signed snapshot. A transport failure may fall back to the verified cache;
-    # a downloaded snapshot with an invalid signature remains a hard failure.
-    printf 'Downloading the current Retro-WFC payload needed for online play...\n'
         mkdir -p "$retro_wfc_dir"
         payload_stage=$(mktemp -d "$retro_wfc_dir/.payload-download.XXXXXX")
         temporary_payload="$payload_stage/binary/payload.RMCPD00.bin"
         mkdir -p "$(dirname "$temporary_payload")"
         trap 'rm -rf "$payload_stage"' EXIT
-    if /usr/bin/curl --fail --silent --show-error --connect-timeout 10 --max-time 30 \
+        /usr/bin/curl --fail --silent --show-error --connect-timeout 10 --max-time 30 \
             --retry 1 --output "$temporary_payload" \
-        'https://rwfc.net/api/wfc/payload?g=RMCPD00'; then
+            'https://rwfc.net/api/wfc/payload?g=RMCPD00' || fail 'could not download the Retro-WFC payload needed for online play'
         "$translator" validate-retro-wfc-payload --directory "$payload_stage" || \
             fail 'downloaded Retro-WFC payload failed signature validation'
         mkdir -p "$retro_wfc_dir/binary"
         mv "$temporary_payload" "$retro_wfc_payload"
         rmdir "$payload_stage/binary" "$payload_stage"
         trap - EXIT
-    elif (( cached_payload_valid )); then
-        printf 'Could not download the current Retro-WFC payload; using the previously verified cached payload.\n' >&2
-        rm -rf "$payload_stage"
-        trap - EXIT
-    else
-        fail 'could not download the current Retro-WFC payload and no valid cached payload is available'
     fi
     build_args+=(--profile both --base-output-dir "$products" --retro-rewind-package-dir "$retro_dir" --retro-wfc-offline-dir "$retro_wfc_dir")
 fi

runtime/CMakeLists.txt

@@ -21,6 +21,13 @@ if(NOT CMAKE_BUILD_TYPE STREQUAL "Release")
     message(FATAL_ERROR "WiiCompiled only supports Release builds")
 endif()
 
+# Ninja writes Windows-quoted response files; the GNU clang driver otherwise reads them POSIX-style.
+if(CMAKE_HOST_WIN32)
+    foreach(_mkw_lang C CXX)
+        set(CMAKE_${_mkw_lang}_RESPONSE_FILE_LINK_FLAG "--rsp-quoting=windows @")
+    endforeach()
+endif()
+
 option(MKW_BUILD_PRODUCTS "Build translated WiiCompiled product targets" ON)
 
 # Preprocessor definitions that belong to this project's own code (the runtime,