feat: correctly validate pdf signature and split open xml and odf validation

Updated readme, license and copyright notice, as well as nuget package information.

Author: ChristianHaase

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2025 ByteGuard
+Copyright (c) 2025 ByteGuard Contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -6,7 +6,7 @@ It helps you enforce consistent file upload rules by checking:
 -   Allowed file extensions
 -   File size limits
 -   File signatures (magic numbers) to detect spoofed types
--   Internal ZIP structure for Office Open XML / OpenDocument formats (`.docx`,  `.xlsx`,  `.pptx`,  `.odt`)
+-   Specification conformance for Office Open XML / Open Document Formats (`.docx`,  `.xlsx`,  `.pptx`,  `.odt`)
 
 > ⚠️ **Important:** This library should be part of a **defense-in-depth** strategy.  
 It does not replace antivirus scanning, sandboxing, or other security controls.
@@ -16,7 +16,7 @@ It does not replace antivirus scanning, sandboxing, or other security controls.
 - ✅ Validate files by **extension**
 - ✅ Validate files by **size**
 - ✅ Validate files by **signature (_magic-numbers_)**
-- ✅ Validate files by **internal ZIP structure** for archive-based formats (_Open XML and OpenDocument formats_)
+- ✅ Validate files by **specification conformance** for archive-based formats (_Open XML and Open Document Formats_)
 - ✅ Validate using file path, `Stream`, or `byte[]`
 - ✅ Configure which file types to support
 - ✅ Configure whether to **throw exceptions** or simply return a boolean
@@ -51,7 +51,7 @@ var isValid = fileValidator.IsValidFile("example.pdf", fileStream);
 ### Using the fluent builder
 
 ```csharp
-var  configuration = new FileValidatorConfigurationBuilder()
+var configuration = new FileValidatorConfigurationBuilder()
 	.AllowFileTypes(FileExtensions.Pdf, FileExtensions.Jpg, FileExtensions.Png)
 	.SetFileSizeLimit(ByteSize.MegaBytes(25))
 	.SetThrowExceptionOnInvalidFile(false)
@@ -71,13 +71,14 @@ The `FileValidator` class provides methods to validate specific aspects of a fil
 > 1.  Extension validation
 > 2.  File size validation
 > 3.  Signature (magic-number) validation
-> 4.  Optional Open XML / OpenDocument structure validation (for supported types)
+> 4.  Optional Open XML / Open Document Format specification conformance validation (for supported types)
 
 ```csharp
 bool isExtensionValid = fileValidator.IsValidFileType(fileName);
 bool isFileSizeValid = fileValidator.HasValidSize(fileStream);
 bool isSignatureValid = fileValidator.HasValidSignature(fileName, fileStream);
 bool isOpenXmlValid = fileValidator.IsValidOpenXmlDocument(fileName, fileStream);
+bool isOpenDocumentFormatValid = fileValidator.IsValidOpenDocumentFormat(fileName, fileStream);
 ```
 
 ### Example
@@ -137,11 +138,11 @@ The following file extensions are supported by the `FileValidator`:
 
 For some formats, additional checks are performed:
 
-- **Office Open XML / OpenDocument** (`.docx`, `.xlsx`, `.pptx`, `.odt`):  
+- **Office Open XML / Open Document Format** (`.docx`, `.xlsx`, `.pptx`, `.odt`):  
   - Extension
   - File size
   - Signature
-  - Internal ZIP structure (basic format sanity)
+  - Specification conformance
 
 - **Other binary formats** (e.g. images, audio, video such as `.jpg`, `.png`, `.mp3`, `.mp4`):  
   - Extension
@@ -164,10 +165,12 @@ When `ThrowExceptionOnInvalidFile` is set to `true`, validation functions will t
 
 | Exception type | Scenario |
 |--|--|
+| `EmptyFileException` | Thrown when the file content is `null` or empty, indicating a file without any content. |
 | `UnsupportedFileException` | Thrown when the file extension is not in the list of supported types. |
 | `InvalidFileSizeException` | Thrown when the file size exceeds the configured file size limit. |
 | `InvalidSignatureException` | Thrown when the file's signature does not match the expected signature for its type. |
 | `InvalidOpenXmlFormatException` | Thrown when the internal structure of an Open XML file is invalid (`.docx`, `.xlsx`, `.pptx`, etc.). |
+| `InvalidOpenDocumentFormatException` | Thrown when the specification conformance of an Open Document Format file is invalid (`.odt`, etc.). |
 
 ## When to use this package
 
@@ -176,4 +179,4 @@ When `ThrowExceptionOnInvalidFile` is set to `true`, validation functions will t
 - ✅ When you want **defense-in-depth** against spoofed or malicious files
 
 ## License
-_ByteGuard FileValidator is copyright © ByteGuard Contributors - Provided under the MIT license._
+_ByteGuard FileValidator is Copyright © ByteGuard Contributors - Provided under the MIT license._

src/ByteGuard.FileValidator/ByteGuard.FileValidator.csproj

@@ -3,21 +3,23 @@
     <PropertyGroup>
         <TargetFrameworks>netstandard2.0;net48;net8.0;net9.0;net10.0</TargetFrameworks>
         <VersionPrefix>0.1.0</VersionPrefix>
-        <Authors>ByteGuard, detilium</Authors>
-        <Owners>detilium</Owners>
-        <Description></Description>
+        <Authors>ByteGuard Contributors, detilium</Authors>
+        <Description>ByteGuard File Validator is a security-focused .NET library for validating user-supplied files, providing a configurable API to help you enforce safe and consistent file handling across your applications.</Description>
         <PackageProjectUrl>https://github.com/ByteGuard-HQ/byteguard-file-validator-net</PackageProjectUrl>
         <RepositoryUrl>https://github.com/ByteGuard-HQ/byteguard-file-validator-net</RepositoryUrl>
-        <PackageTags>byteguard, file-validator, security</PackageTags>
+        <RepositoryType>git</RepositoryType>
+        <PackageTags>byteguard file-validator file-validation file-upload upload-validation security application-security appsec</PackageTags>
         <PackageReadmeFile>README.md</PackageReadmeFile>
+        <Copyright>Copyright © ByteGuard Contributors</Copyright>
+        <PackageLicenseExpression>MIT</PackageLicenseExpression>
     </PropertyGroup>
 
     <ItemGroup Condition="'$(TargetFramework)' == 'net48'">
       <Reference Include="System.IO.Compression" />
     </ItemGroup>
 
     <ItemGroup>
-        <None Include="..\..\..\README.md" Pack="true" PackagePath="\" />
+        <None Include="..\..\README.md" Pack="true" PackagePath="\" />
     </ItemGroup>
 
     <ItemGroup>

src/ByteGuard.FileValidator/Exceptions/InvalidOpenDocumentFormatException.cs

@@ -0,0 +1,24 @@
+using System;
+
+namespace ByteGuard.FileValidator.Exceptions
+{
+    /// <summary>
+    /// Exception type used specifically when a given file, which is expected to be an Open Document Format (ODF) file,
+    /// does not adhere to the expected internal ODF structure.
+    /// /// </summary>
+    public class InvalidOpenDocumentFormatException : Exception
+    {
+        public InvalidOpenDocumentFormatException()
+            : base("Invalid Open Document Format file.")
+        {
+        }
+
+        public InvalidOpenDocumentFormatException(string message) : base(message)
+        {
+        }
+
+        public InvalidOpenDocumentFormatException(string message, Exception innerException) : base(message, innerException)
+        {
+        }
+    }
+}