dotnet · simonrozsival · Aug 19, 2026 · Aug 20, 2026 · Aug 20, 2026 · Aug 20, 2026
@@ -5,10 +5,10 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.IO.Compression;
 
 using Xamarin.Android.AssemblyStore;
 using Xamarin.Android.Tools;
-using Xamarin.Tools.Zip;
 
 namespace Xamarin.Android.Tools.DecompressAssemblies
 {
@@ -79,15 +79,15 @@ static bool ExtractIndividualEntries (ZipArchive apk, string filePath, string as
 		{
 			bool retVal = true;
 			int assemblyCount = 0;
-			foreach (ZipEntry entry in apk) {
+			foreach (var entry in apk.Entries) {
 				if (!TryGetAssemblyOutputPath (entry.FullName, assembliesPath, nativeLibrariesPath, out string assemblyName)) {
 					continue;
 				}
 
 				assemblyCount++;
 
 				using (var stream = new MemoryStream ()) {
-					entry.Extract (stream);
+					Utils.Extract (entry, stream);
 					stream.Seek (0, SeekOrigin.Begin);
 					string outputFile = GetSafeOutputFile (outputDirectory, assemblyName);
 					using var payload = new MemoryStream ();
@@ -166,15 +166,15 @@ static string GetAndroidAbi (AndroidTargetArch arch)
 
 		static bool HasAssemblyStore (ZipArchive apk, string assembliesPath, string nativeLibrariesPath)
 		{
-			if (apk.ContainsEntry ($"{assembliesPath}assemblies.blob")) {
+			if (Utils.ContainsEntry (apk, $"{assembliesPath}assemblies.blob", caseSensitive: true)) {
 				return true;
 			}
 
 			foreach (AndroidTargetArch arch in targetArchitectures) {
 				string abi = GetAndroidAbi (arch);
 				if (
-					apk.ContainsEntry ($"{nativeLibrariesPath}{abi}/libassembly-store.so") ||
-					apk.ContainsEntry ($"{nativeLibrariesPath}{abi}/libassemblies.{abi}.blob.so")
+					Utils.ContainsEntry (apk, $"{nativeLibrariesPath}{abi}/libassembly-store.so", caseSensitive: true) ||
+					Utils.ContainsEntry (apk, $"{nativeLibrariesPath}{abi}/libassemblies.{abi}.blob.so", caseSensitive: true)
 				) {
 					return true;
 				}
@@ -185,7 +185,7 @@ static bool HasAssemblyStore (ZipArchive apk, string assembliesPath, string nati
 
 		static bool ExtractFromArchive (string filePath, string assembliesPath, string nativeLibrariesPath, string outputDirectory)
 		{
-			using (ZipArchive apk = ZipArchive.Open (filePath, FileMode.Open)) {
+			using (ZipArchive apk = Utils.OpenZip (filePath)) {
 				if (HasAssemblyStore (apk, assembliesPath, nativeLibrariesPath)) {
 					return ExtractAssemblyStores (filePath, outputDirectory);
 				}

@@ -12,7 +12,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Xamarin.LibZipSharp" Version="$(LibZipSharpVersion)" />
     <PackageReference Include="System.IO.Hashing" Version="$(SystemIOHashingPackageVersion)" />
     <PackageReference Include="ELFSharp" Version="$(ELFSharpVersion)" />
     <PackageReference Include="K4os.Compression.LZ4" Version="$(LZ4PackageVersion)" />

@@ -1,9 +1,9 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.IO.Compression;
 
 using Xamarin.Android.Tools;
-using Xamarin.Tools.Zip;
 
 namespace Xamarin.Android.AssemblyStore;
 
@@ -127,7 +127,7 @@ public static (IList<AssemblyStoreExplorer>? explorers, string? errorMessage) Op
 	static (IList<AssemblyStoreExplorer>? explorers, string? errorMessage) OpenArchive (FileInfo fi, IList<string> paths)
 	{
 		string? errorMessage;
-		using (var zip = ZipArchive.Open (fi.FullName, FileMode.Open)) {
+		using (var zip = Utils.OpenZip (fi.FullName)) {
 			(IList<AssemblyStoreExplorer>? explorers, string? loadError, bool pathsFound) = TryLoad (fi, zip, paths);
 			if (pathsFound) {
 				return (explorers, loadError);
@@ -172,13 +172,15 @@ static bool IsV1Store (FileInfo info)
 		var ret = new List<AssemblyStoreExplorer> ();
 
 		foreach (string path in paths) {
-			if (!zip.ContainsEntry (path)) {
+			if (!Utils.ContainsEntry (zip, path, caseSensitive: true)) {
 				continue;
 			}
 
-			ZipEntry entry = zip.ReadEntry (path);
+			var entry = Utils.ReadEntry (zip, path, caseSensitive: true);
+			if (entry == null)
+				continue;
 			var stream = new MemoryStream ();
-			entry.Extract (stream);
+			Utils.Extract (entry, stream);
 			ret.Add (new AssemblyStoreExplorer (stream, $"{fi.FullName}!{path}"));
 		}
 

@@ -1,10 +1,11 @@
 using System;
 using System.IO;
 using System.Buffers;
+using System.IO.Compression;
+using System.Linq;
 
 using ELFSharp.ELF;
 using ELFSharp.ELF.Sections;
-using Xamarin.Tools.Zip;
 
 namespace Xamarin.Android.AssemblyStore;
 
@@ -224,7 +225,7 @@ public static (FileFormat format, FileInfo? info) DetectFileFormat (string path)
 
 	static FileFormat DetectAndroidArchive (FileInfo info, FileFormat defaultFormat)
 	{
-		using var zip = ZipArchive.Open (info.FullName, FileMode.Open);
+		using var zip = OpenZip (info.FullName);
 
 		if (HasAllEntries (zip, aabZipEntries)) {
 			return FileFormat.Aab;
@@ -244,11 +245,38 @@ static FileFormat DetectAndroidArchive (FileInfo info, FileFormat defaultFormat)
 	static bool HasAllEntries (ZipArchive zip, string[] entries)
 	{
 		foreach (string entry in entries) {
-			if (!zip.ContainsEntry (entry, caseSensitive: true)) {
+			if (!ContainsEntry (zip, entry, caseSensitive: true)) {
 				return false;
 			}
 		}
 
 		return true;
 	}
+
+	public static ZipArchive OpenZip (string path)
+	{
+		return ZipFile.OpenRead (path);
+	}
+
+	public static ZipArchive OpenZip (Stream stream, bool leaveOpen = false)
+	{
+		return new ZipArchive (stream, ZipArchiveMode.Read, leaveOpen);
+	}
+
+	public static bool ContainsEntry (ZipArchive archive, string entryName, bool caseSensitive = false)
+	{
+		return ReadEntry (archive, entryName, caseSensitive) != null;
+	}
+
+	public static ZipArchiveEntry? ReadEntry (ZipArchive archive, string entryName, bool caseSensitive = false)
+	{
+		var comparison = caseSensitive ? StringComparison.Ordinal : StringComparison.OrdinalIgnoreCase;
+		return archive.Entries.FirstOrDefault (entry => string.Equals (entry.FullName, entryName, comparison));
+	}
+
+	public static void Extract (ZipArchiveEntry entry, Stream destination)
+	{
+		using var stream = entry.Open ();
+		stream.CopyTo (destination);
+	}
 }
@@ -1,8 +1,8 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-
-using Xamarin.Tools.Zip;
+using System.IO.Compression;
+using Xamarin.Android.AssemblyStore;
 
 namespace Xamarin.Android.AssemblyStore.V1
 {
@@ -215,20 +215,20 @@ void ReadStoreSetFromArchive (string baseName, string archivePath, string extens
 			}
 
 			basePathInArchive = $"{basePathInArchive}/{baseName}.";
-			using (ZipArchive archive = ZipArchive.Open (archivePath, FileMode.Open)) {
+			using (ZipArchive archive = Utils.OpenZip (archivePath)) {
 				ReadStoreSetFromArchive (archive, basePathInArchive);
 			}
 		}
 
 		void ReadStoreSetFromArchive (ZipArchive archive, string basePathInArchive)
 		{
-			foreach (ZipEntry entry in archive) {
+			foreach (var entry in archive.Entries) {
 				if (!entry.FullName.StartsWith (basePathInArchive, StringComparison.Ordinal)) {
 					continue;
 				}
 
 				using (var stream = new MemoryStream ()) {
-					entry.Extract (stream);
+					Utils.Extract (entry, stream);
 
 					if (entry.FullName.EndsWith (".blob", StringComparison.Ordinal)) {
 						AddStore (new AssemblyStoreReader (stream, GetStoreArch (entry.FullName), keepStoreInMemory));

@@ -82,7 +82,6 @@ Search `.csproj` files for `<PackageReference>` elements. Current third-party Nu
 |---------|------------|-------------|
 | ELFSharp | KonradKuczynski/ELFSharp | https://elfsharp.it/ (MIT + LLVM) |
 | K4os.Compression.LZ4 | MiloszKrajewski/K4os.Compression.LZ4 | https://github.com/MiloszKrajewski/K4os.Compression.LZ4/ (MIT) |
-| Xamarin.LibZipSharp | xamarin/LibZipSharp | https://github.com/xamarin/LibZipSharp/ (MIT) |
 | Irony | IronyProject/Irony | https://github.com/IronyProject/Irony (MIT) |
 | Newtonsoft.Json | JamesNK/Newtonsoft.Json | https://github.com/JamesNK/Newtonsoft.Json (MIT) |
 | NuGet.ProjectModel | NuGet/NuGet.Client | https://github.com/NuGet/NuGet.Client (Apache 2.0) |
@@ -111,13 +110,6 @@ These are downloaded and shipped with the SDK:
 | r8 | google/r8 | https://r8.googlesource.com/r8/ (BSD-3-Clause) |
 | binutils | gnu/binutils | https://sourceware.org/git/?p=binutils-gdb.git;a=tree;hb=HEAD (GPLv3) |
 
-#### libzip (via LibZipSharp NuGet)
-LibZipSharp bundles libzip internally:
-
-| Source | Name in TPN | License Location |
-|--------|------------|-----------------|
-| libzip (in LibZipSharp NuGet) | nih-at/libzip | LibZipSharp NuGet `Licences/libzip/LICENSE` or https://github.com/nih-at/libzip/ (BSD-3-Clause) |
-
 ### Step 2 — Cross-reference
 
 Compare the inventory against the current entries in `THIRD-PARTY-NOTICES.TXT`:

@@ -39,7 +39,6 @@
 
   <!-- Common <PackageReference/> versions -->
   <PropertyGroup>
-    <LibZipSharpVersion>3.3.0</LibZipSharpVersion>
     <MicroBuildCoreVersion>1.0.0</MicroBuildCoreVersion>
     <NewtonsoftJsonPackageVersion>13.0.3</NewtonsoftJsonPackageVersion>
     <NuGetApiPackageVersion>5.4.0</NuGetApiPackageVersion>

@@ -30,10 +30,8 @@ implication, estoppel or otherwise.
 19. MiloszKrajewski/K4os.Compression.LZ4 (https://github.com/MiloszKrajewski/K4os.Compression.LZ4/)
 20. mono/cecil (https://github.com/mono/cecil/)
 21. mono/linker (https://github.com/mono/linker/)
-22. nih-at/libzip (https://github.com/nih-at/libzip/)
-23. NuGet/NuGet.Client (https://github.com/NuGet/NuGet.Client)
-24. tessil/robin-map (https://github.com/Tessil/robin-map)
-25. xamarin/LibZipSharp (https://github.com/xamarin/LibZipSharp/)
+22. NuGet/NuGet.Client (https://github.com/NuGet/NuGet.Client)
+23. tessil/robin-map (https://github.com/Tessil/robin-map)
 
 %% Android API documentation NOTICES AND INFORMATION BEGIN HERE
 ================================================================
@@ -2401,45 +2399,6 @@ SOFTWARE.
 END OF mono/linker NOTICES AND INFORMATION
 
 
-%% nih-at/libzip NOTICES AND INFORMATION BEGIN HERE
-===================================================
-Copyright (C) 1999-2020 Dieter Baron and Thomas Klausner
-
-The authors can be contacted at <info@libzip.org>
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions
-are met:
-
-1. Redistributions of source code must retain the above copyright
-  notice, this list of conditions and the following disclaimer.
-
-2. Redistributions in binary form must reproduce the above copyright
-  notice, this list of conditions and the following disclaimer in
-  the documentation and/or other materials provided with the
-  distribution.
-
-3. The names of the authors may not be used to endorse or promote
-  products derived from this software without specific prior
-  written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
-OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
-DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
-GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
-IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
-OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
-IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
-===================================================
-END OF nih-at/libzip NOTICES AND INFORMATION
-
-
 %% NuGet/NuGet.Client NOTICES AND INFORMATION BEGIN HERE
 ========================================================
 Copyright (c) .NET Foundation and Contributors.
@@ -2491,33 +2450,3 @@ SOFTWARE.
 ======================================================
 END OF tessil/robin-map NOTICES AND INFORMATION
 
-
-%% xamarin/LibZipSharp NOTICES AND INFORMATION BEGIN HERE
-=========================================================
-The MIT License (MIT)
-
-Copyright (c) 2016 Marek Habersack
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
-
-
-=========================================================
-END OF xamarin/LibZipSharp NOTICES AND INFORMATION
-
-
@@ -4,7 +4,6 @@
 
   <PropertyGroup>
     <TargetFramework>$(DotNetStableTargetFramework)</TargetFramework>
-    <LibZipSharpBundleAllNativeLibraries>true</LibZipSharpBundleAllNativeLibraries>
     <OutputPath>$(BootstrapOutputDirectory)</OutputPath>
   </PropertyGroup>
 

@@ -2,10 +2,11 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.IO.Compression;
 using System.Linq;
 using Microsoft.Build.Framework;
 using Microsoft.Build.Utilities;
-using Xamarin.Tools.Zip;
+using Microsoft.Android.Build.Tasks;
 
 namespace Xamarin.Android.Tools.BootstrapTasks
 {
@@ -133,11 +134,12 @@ public override bool Execute ()
 				var zipFiles = Directory.GetFiles (referenceContractPath.Parent.FullName, "*.zip");
 				foreach (var zipFile in zipFiles) {
 					var zipDateTime = File.GetLastWriteTimeUtc (zipFile);
-					using (var zip = ZipArchive.Open (zipFile, FileMode.Open)) {
-						foreach (var entry in zip) {
-							var path = Path.Combine (referenceContractPath.FullName, entry.NativeFullName);
+					using (var zip = ZipArchiveExtensions.OpenZipRead (zipFile)) {
+						foreach (var entry in zip.Entries) {
+							var path = Path.Combine (referenceContractPath.FullName, entry.FullName.Replace ('/', Path.DirectorySeparatorChar));
 							if (!File.Exists (path) || File.GetLastWriteTimeUtc (path) < zipDateTime) {
 								Log.LogMessage ($"Extracting: {path}");
+								Directory.CreateDirectory (Path.GetDirectoryName (path));
 								using (var fileStream = File.Create (path)) {
 									entry.Extract (fileStream);
 								}