0.1.0

Author: AXiX-official

README.md

@@ -1,5 +1,7 @@
 # UnityAsset.NET
 
+---
+
 [![MIT](https://img.shields.io/github/license/AXiX-official/UnityAsset.NET)](https://github.com/AXiX-official/UnityAsset.NET/master/LICENSE)
 [![NuGet Stats](https://img.shields.io/nuget/v/UnityAsset.NET.svg)](https://www.nuget.org/packages/UnityAsset.NET)
 
@@ -9,11 +11,13 @@ Only support Unity 2017.x or later.
 
 ## Features
 
+---
+
 ### BundleFile
 
 - [x] Parse/Serialize
 - [ ] Patch
-- [ ] Calculate/Patch crc32
+- [x] Calculate/Patch crc32
 
 ### SerializedFile
 
@@ -25,7 +29,39 @@ Only support Unity 2017.x or later.
 - [x] Parse/Serialize
 - [ ] Patch
 
-## Acknowledgements
+## Examples
+
+---
+
+### Unity CN Decryption
+
+To load `BundleFile` with Unity CN Encryption, there are two ways.
+```csharp
+// Hex string format (32 characters)
+Setting.DefaultUnityCNKey = "587865636f6472506547616b61326536";  // Represents "XxecodrPeGaka2e6" in hex
+BundleFile bf = new BundleFile( @"path to your bundlefile");
+```
+or
+```csharp
+// Plain string format (16 characters)
+BundleFile bf = new BundleFile( @"path to your bundlefile", "XxecodrPeGaka2e6");
+```
+
+To remove Unity CN Encryption form File, you can simply save `BundleFile` without key
+```csharp
+bf.Serialize(@"path to save file", CompressionType.Lz4HC, CompressionType.Lz4HC);
+```
+
+### Stripped Version
+
+Some `BundleFile`'s version may be stripped, to load those file you can set a specific version
+```csharp
+Setting.DefaultUnityVerion = "2020.3.48f1"
+```
+
+## Credits
+
+---
 
 This project stands on the shoulders of these amazing open-source projects:
 

UnityAsset.NET/Files/BundleFileExtension.cs

@@ -1,4 +1,6 @@
-using UnityAsset.NET.Files.SerializedFiles;
+using UnityAsset.NET.Files.BundleFiles;
+using UnityAsset.NET.Files.SerializedFiles;
+using UnityAsset.NET.IO;
 
 namespace UnityAsset.NET.Files;
 
@@ -9,4 +11,13 @@ public static List<Asset> Assets(this BundleFile bf) =>
             .Where(file => file.File is SerializedFile)
             .SelectMany(file => ((SerializedFile)file.File).Assets)
             .ToList();
+
+    public static void PatchCrc32(this BundleFile bf, uint newCrc32)
+    {
+        if (bf.Crc32 != newCrc32)
+        {
+            var patchBytes = CRC32.rCRC(newCrc32, bf.Crc32);
+            bf.Files.Add(new FileWrapper(new HeapDataBuffer(patchBytes), new FileEntry(0, 4, 0, "crc32-patch-data")));
+        }
+    }
 }

UnityAsset.NET/Files/BundleFiles/BundleFile.cs

@@ -140,6 +140,8 @@ public BundleFile(string path, string? key = null)
         var db = DataBuffer.FromFile(path);
         UnityCnKey = key;
         Header = Header.Parse(ref db);
+        if (string.IsNullOrEmpty(Header.UnityRevision))
+            Header.UnityRevision = Setting.DefaultUnityVerion;
         UnityCnInfo = ParseUnityCnInfo(ref db, Header, UnityCnKey);
         AlignAfterHeader(ref db, Header);
         DataInfo = ParseDataInfo(ref db, Header);

UnityAsset.NET/Files/SerializedFiles/SerializedFile.cs

@@ -13,6 +13,8 @@ public SerializedFile(SerializedFileHeader header, SerializedFileMetadata metada
     {
         Header = header;
         Metadata = metadata;
+        if (string.IsNullOrEmpty(Metadata.UnityVersion))
+            Metadata.UnityVersion = Setting.DefaultUnityVerion;
         Assets = assets;
     }
 

UnityAsset.NET/IO/DataBuffer.cs

@@ -291,7 +291,7 @@ public void WriteUInt64(UInt64 value)
 
     public string ReadNullTerminatedString(int maxLength = 32767)
     {
-        var span = AsSpan().Slice(Position);
+        var span = SliceForward();
         int nullTerminator = span.IndexOf((byte)0);
         if (nullTerminator < 0 || nullTerminator > maxLength)
             nullTerminator = maxLength;

UnityAsset.NET/Setting.cs

@@ -4,4 +4,5 @@ public static class Setting
 {
     public static UInt32 DefaultChunkSize = 0x00020000;
     public static string? DefaultUnityCNKey = null;
+    public static string DefaultUnityVerion = "2019.4.40f1";
 }

UnityAsset.NET/UnityAsset.NET.csproj

@@ -5,15 +5,15 @@
         <ImplicitUsings>enable</ImplicitUsings>
         <Nullable>enable</Nullable>
         <Authors>AXiX</Authors>
-        <Description>A .NET library for reading and modifying Unity assets and bundles.</Description>
-        <Version>0.0.5</Version>
+        <Description>A work-in-progress .NET library for parsing/serializing/patching Unity Engine asset files.</Description>
+        <Version>0.1.0</Version>
         <Title>UnityAsset.NET</Title>
         <Copyright>AXiX</Copyright>
         <PackageProjectUrl>https://github.com/AXiX-official/UnityAsset.NET</PackageProjectUrl>
         <RepositoryUrl>https://github.com/AXiX-official/UnityAsset.NET</RepositoryUrl>
         <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
-        <AssemblyVersion>0.0.5.0</AssemblyVersion>
-        <FileVersion>0.0.5.0</FileVersion>
+        <AssemblyVersion>0.1.0.0</AssemblyVersion>
+        <FileVersion>0.1.0.0</FileVersion>
         <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
         <PackageReadmeFile>README.md</PackageReadmeFile>
         <PackageTags>Unity</PackageTags>