Harden package metadata normalization

DEVELOPER_GUIDE.md

@@ -160,6 +160,15 @@ part name on each pack run; the normalizer rewrites that part to
 matching content-type and relationship references, and gives ZIP entries stable
 timestamps. This is the package reproducibility boundary for `.nupkg` and
 `.snupkg` archives (#2756).
+Before rewriting, the normalizer rejects packages with more than 4096 ZIP
+entries, any entry above 128 MiB uncompressed, total uncompressed content above
+512 MiB, or XML reference text above 16 MiB so crafted packages cannot force
+unbounded normalization work (#2892).
+It also rejects unsafe ZIP entry names before creating the destination archive:
+absolute paths, Windows drive roots, backslash separators, empty path segments,
+parent-directory segments, empty normalized names, and destination names that
+collide after path normalization are not preserved into normalized packages
+(#2894).
 
 When you intentionally update a dependency (or add a new direct `PackageReference`), regenerate the lock files locally and commit the diff in the same change:
 
@@ -2048,6 +2057,14 @@ release の `dotnet publish`（RID ごと）と `dotnet pack`（NuGet パッケ
 `package/services/metadata/core-properties/core-properties.psmdcp` に書き換え、
 対応する content-type / relationship 参照も更新し、ZIP entry timestamp を固定します。
 これが `.nupkg` / `.snupkg` archive の package 再現性境界です (#2756)。
+書き換え前に、normalizer は 4096 を超える ZIP entry、128 MiB を超える
+uncompressed entry、512 MiB を超える合計 uncompressed content、または
+16 MiB を超える XML 参照テキストを持つ package を拒否し、細工された
+package が無制限の normalize 作業を強制できないようにします (#2892)。
+また destination archive を作る前に unsafe な ZIP entry 名も拒否します。
+absolute path、Windows drive root、backslash separator、空の path segment、
+parent-directory segment、空に正規化される名前、path 正規化後に衝突する
+destination 名は、normalized package に保持されません (#2894)。
 
 依存を意図的に更新する（あるいは直接 `PackageReference` を追加する）場合は、ローカルで lock ファイルを再生成し、同じ変更でコミットしてください:
 

changelog.d/unreleased/2892.security.md

@@ -0,0 +1,18 @@
+---
+category: security
+issues:
+  - 2892
+affected:
+  - tools/CodeIndex.PackageNormalize/CodeIndex.PackageNormalize.csproj
+  - tools/CodeIndex.PackageNormalize/PackageNormalizeCli.cs
+  - tests/CodeIndex.Tests/ReleaseWorkflowTests.cs
+  - DEVELOPER_GUIDE.md
+---
+
+## English
+
+- **Package normalization now caps ZIP resource usage (#2892)** — `CodeIndex.PackageNormalize` now rejects packages that exceed documented ZIP entry-count, per-entry, total-uncompressed, or XML-text limits before rewriting release artifacts.
+
+## 日本語
+
+- **Package normalize が ZIP resource 使用量を上限で制限するようになりました (#2892)** — `CodeIndex.PackageNormalize` は release artifact を書き換える前に、文書化された ZIP entry 数、entry 単位、合計 uncompressed size、XML text の上限を超える package を拒否します。

changelog.d/unreleased/2894.security.md

@@ -0,0 +1,17 @@
+---
+category: security
+issues:
+  - 2894
+affected:
+  - tools/CodeIndex.PackageNormalize/PackageNormalizeCli.cs
+  - tests/CodeIndex.Tests/ReleaseWorkflowTests.cs
+  - DEVELOPER_GUIDE.md
+---
+
+## English
+
+- **Package normalization now rejects unsafe ZIP entry names (#2894)** — `CodeIndex.PackageNormalize` validates source and destination ZIP entry names before rewriting, preventing absolute paths, parent traversal, backslash separators, empty path segments, and normalized duplicate destination names from being preserved.
+
+## 日本語
+
+- **Package normalize が unsafe な ZIP entry 名を拒否するようになりました (#2894)** — `CodeIndex.PackageNormalize` は書き換え前に source / destination の ZIP entry 名を検証し、absolute path、parent traversal、backslash separator、空の path segment、正規化後に重複する destination 名が保持されないようにします。

tests/CodeIndex.Tests/ReleaseWorkflowTests.cs

@@ -146,6 +146,172 @@ public void PackageNormalizer_RewritesRandomCorePropertiesPartDeterministically(
         }
     }
 
+    [Fact]
+    public void PackageNormalizer_RejectsPackageThatExceedsEntryCountLimit()
+    {
+        var projectRoot = TestProjectHelper.CreateTempProject(nameof(PackageNormalizer_RejectsPackageThatExceedsEntryCountLimit));
+        try
+        {
+            var packagePath = Path.Combine(projectRoot, "too-many-entries.nupkg");
+            CreatePackageWithEntries(
+                packagePath,
+                ("package/services/metadata/core-properties/random.psmdcp", ""),
+                ("payload.txt", "ok"));
+
+            var limits = PackageNormalizeLimits.Default with { MaxEntryCount = 1 };
+
+            var exception = Assert.Throws<InvalidOperationException>(() => PackageCorePropertiesNormalizer.NormalizePackage(packagePath, limits));
+            Assert.Contains("2 ZIP entries", exception.Message);
+            Assert.Contains("limit of 1", exception.Message);
+            Assert.False(File.Exists(packagePath + ".normalize-tmp"));
+        }
+        finally
+        {
+            TestProjectHelper.DeleteDirectory(projectRoot);
+        }
+    }
+
+    [Fact]
+    public void PackageNormalizer_RejectsEntryThatExceedsPerEntryLimit()
+    {
+        var projectRoot = TestProjectHelper.CreateTempProject(nameof(PackageNormalizer_RejectsEntryThatExceedsPerEntryLimit));
+        try
+        {
+            var packagePath = Path.Combine(projectRoot, "large-entry.nupkg");
+            CreatePackageWithEntries(
+                packagePath,
+                ("package/services/metadata/core-properties/random.psmdcp", ""),
+                ("payload.bin", "123456"));
+
+            var limits = PackageNormalizeLimits.Default with
+            {
+                MaxEntryUncompressedBytes = 5,
+                MaxTotalUncompressedBytes = 100,
+            };
+
+            var exception = Assert.Throws<InvalidOperationException>(() => PackageCorePropertiesNormalizer.NormalizePackage(packagePath, limits));
+            Assert.Contains("payload.bin", exception.Message);
+            Assert.Contains("per-entry limit of 5 bytes", exception.Message);
+            Assert.False(File.Exists(packagePath + ".normalize-tmp"));
+        }
+        finally
+        {
+            TestProjectHelper.DeleteDirectory(projectRoot);
+        }
+    }
+
+    [Fact]
+    public void PackageNormalizer_RejectsPackageThatExceedsTotalUncompressedLimit()
+    {
+        var projectRoot = TestProjectHelper.CreateTempProject(nameof(PackageNormalizer_RejectsPackageThatExceedsTotalUncompressedLimit));
+        try
+        {
+            var packagePath = Path.Combine(projectRoot, "large-total.nupkg");
+            CreatePackageWithEntries(
+                packagePath,
+                ("package/services/metadata/core-properties/random.psmdcp", ""),
+                ("a.txt", "1234"),
+                ("b.txt", "5678"));
+
+            var limits = PackageNormalizeLimits.Default with
+            {
+                MaxEntryUncompressedBytes = 10,
+                MaxTotalUncompressedBytes = 6,
+            };
+
+            var exception = Assert.Throws<InvalidOperationException>(() => PackageCorePropertiesNormalizer.NormalizePackage(packagePath, limits));
+            Assert.Contains("b.txt", exception.Message);
+            Assert.Contains("uncompressed size exceed the limit of 6 bytes", exception.Message);
+            Assert.False(File.Exists(packagePath + ".normalize-tmp"));
+        }
+        finally
+        {
+            TestProjectHelper.DeleteDirectory(projectRoot);
+        }
+    }
+
+    [Fact]
+    public void PackageNormalizer_RejectsXmlEntryThatExceedsTextLimit()
+    {
+        var projectRoot = TestProjectHelper.CreateTempProject(nameof(PackageNormalizer_RejectsXmlEntryThatExceedsTextLimit));
+        try
+        {
+            var packagePath = Path.Combine(projectRoot, "large-xml.nupkg");
+            CreatePackageWithEntries(
+                packagePath,
+                ("package/services/metadata/core-properties/random.psmdcp", ""),
+                ("[Content_Types].xml", "123456"));
+
+            var limits = PackageNormalizeLimits.Default with
+            {
+                MaxEntryUncompressedBytes = 100,
+                MaxTotalUncompressedBytes = 100,
+                MaxXmlTextChars = 5,
+            };
+
+            var exception = Assert.Throws<InvalidOperationException>(() => PackageCorePropertiesNormalizer.NormalizePackage(packagePath, limits));
+            Assert.Contains("[Content_Types].xml", exception.Message);
+            Assert.Contains("text limit of 5 characters", exception.Message);
+        }
+        finally
+        {
+            TestProjectHelper.DeleteDirectory(projectRoot);
+        }
+    }
+
+    [Theory]
+    [InlineData("/payload.txt", "must be a relative path")]
+    [InlineData("C:/payload.txt", "must be a relative path")]
+    [InlineData("./C:/payload.txt", "must be a relative path")]
+    [InlineData("../payload.txt", "must not contain parent-directory segments")]
+    [InlineData("folder\\payload.txt", "must use '/' separators")]
+    [InlineData("folder//payload.txt", "must not contain empty path segments")]
+    public void PackageNormalizer_RejectsUnsafeZipEntryNames(string unsafeEntryName, string expectedMessage)
+    {
+        var projectRoot = TestProjectHelper.CreateTempProject(nameof(PackageNormalizer_RejectsUnsafeZipEntryNames));
+        try
+        {
+            var packagePath = Path.Combine(projectRoot, "unsafe-name.nupkg");
+            CreatePackageWithEntries(
+                packagePath,
+                ("package/services/metadata/core-properties/random.psmdcp", ""),
+                (unsafeEntryName, "payload"));
+
+            var exception = Assert.Throws<InvalidOperationException>(() => PackageCorePropertiesNormalizer.NormalizePackage(packagePath));
+            Assert.Contains(unsafeEntryName, exception.Message);
+            Assert.Contains(expectedMessage, exception.Message);
+            Assert.False(File.Exists(packagePath + ".normalize-tmp"));
+        }
+        finally
+        {
+            TestProjectHelper.DeleteDirectory(projectRoot);
+        }
+    }
+
+    [Fact]
+    public void PackageNormalizer_RejectsDestinationNamesThatNormalizeToDuplicates()
+    {
+        var projectRoot = TestProjectHelper.CreateTempProject(nameof(PackageNormalizer_RejectsDestinationNamesThatNormalizeToDuplicates));
+        try
+        {
+            var packagePath = Path.Combine(projectRoot, "duplicate-normalized-name.nupkg");
+            CreatePackageWithEntries(
+                packagePath,
+                ("package/services/metadata/core-properties/random.psmdcp", ""),
+                ("docs/readme.txt", "one"),
+                ("docs/./readme.txt", "two"));
+
+            var exception = Assert.Throws<InvalidOperationException>(() => PackageCorePropertiesNormalizer.NormalizePackage(packagePath));
+            Assert.Contains("docs/./readme.txt", exception.Message);
+            Assert.Contains("duplicate destination name docs/readme.txt", exception.Message);
+            Assert.False(File.Exists(packagePath + ".normalize-tmp"));
+        }
+        finally
+        {
+            TestProjectHelper.DeleteDirectory(projectRoot);
+        }
+    }
+
     [Fact]
     public void ReleaseWorkflow_PublishesOfficialContainerImage()
     {
@@ -212,6 +378,13 @@ private static void CreateMinimalNuGetPackage(string packagePath, string corePro
             """);
     }
 
+    private static void CreatePackageWithEntries(string packagePath, params (string EntryName, string Content)[] entries)
+    {
+        using var archive = ZipFile.Open(packagePath, ZipArchiveMode.Create);
+        foreach (var entry in entries)
+            WriteZipEntry(archive, entry.EntryName, entry.Content);
+    }
+
     private static void WriteZipEntry(ZipArchive archive, string entryName, string content)
     {
         var entry = archive.CreateEntry(entryName);

tools/CodeIndex.PackageNormalize/CodeIndex.PackageNormalize.csproj

@@ -8,4 +8,8 @@
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <InternalsVisibleTo Include="CodeIndex.Tests" />
+  </ItemGroup>
+
 </Project>