puspensi.general.validation 1.0.1

puspensi.general.validation

A comprehensive .NET Standard 2.0 library for file validation and MIME type detection, providing extension methods for IFormFile and MemoryStream objects.

🚀 Features

• File Type Validation: Validate PDF, Word documents, images, spreadsheets, presentations, and compressed archives
• Security Validation: Check PDF files for potentially malicious JavaScript content
• MIME Type Detection: Advanced content-based file type detection using MimeDetective
• Dual Support: Works with both IFormFile (ASP.NET Core uploads) and MemoryStream objects
• Lightweight: Targets .NET Standard 2.0 for broad compatibility

📦 Installation

Install the package via NuGet Package Manager:

Install-Package puspensi.general.validation

Or via .NET CLI:

dotnet add package puspensi.general.validation

Or via PackageReference in your .csproj file:

<PackageReference Include="puspensi.general.validation" Version="1.0.0" />

🔧 Dependencies

• Microsoft.AspNetCore.Http (>= 2.3.9)
• Mime-Detective (>= 24.5.1)
• Mime-Detective.Definitions.Exhaustive (>= 24.5.1)

📖 Usage

Basic File Validation

using puspensi.general.validation;
using Microsoft.AspNetCore.Http;

// In your controller action
[HttpPost]
public IActionResult UploadFile(IFormFile file)
{
    // Check if file is of any allowed type
    if (!file.AllowedFile())
    {
        return BadRequest("File type not allowed");
    }
    
    // Specific validations
    if (file.IsPdfFile())
    {
        // Handle PDF file
        if (file.IsPdfSecured())
        {
            // PDF is secure (no JavaScript)
            // Process the file...
        }
        else
        {
            return BadRequest("PDF contains potentially malicious content");
        }
    }
    
    return Ok("File uploaded successfully");
}

Working with MemoryStream

using puspensi.general.validation;
using System.IO;

public void ProcessFileFromMemory(MemoryStream fileStream)
{
    if (fileStream.IsImageFile())
    {
        // Handle image file
        Console.WriteLine("Processing image file...");
    }
    else if (fileStream.IsDocumentFile())
    {
        // Handle document file
        Console.WriteLine("Processing document file...");
    }
    else if (fileStream.IsCompressFile())
    {
        // Handle compressed archive
        Console.WriteLine("Processing archive file...");
    }
}

File Type Specific Validation

// Check for Word documents
if (file.IsWordFile())
{
    // Supports: DOC, DOCX, ODT, MS Works
}

// Check for images
if (file.IsImageFile())
{
    // Supports: JPEG, PNG, GIF, BMP, TIFF, WebP, SVG, PostScript
}

// Check for spreadsheets and presentations (part of IsDocumentFile)
if (file.IsDocumentFile())
{
    // Includes PDFs, Word docs, Excel files, PowerPoint, etc.
}

// Check for compressed files
if (file.IsCompressFile())
{
    // Supports: ZIP, RAR, 7Z, TAR, GZIP, BZIP2
}

📋 API Reference

Extension Methods for IFormFile

Extension Methods for MemoryStream

All the above methods are also available for MemoryStream objects with the same signatures and functionality. MemoryStream validation uses advanced content analysis for more accurate detection.

🗂️ Supported File Types

PDF Files

• application/pdf

Word Documents

• application/msword (DOC)
• application/vnd.openxmlformats-officedocument.wordprocessingml.document (DOCX)
• application/vnd.oasis.opendocument.text (ODT)
• application/vnd.ms-works (Works)

Spreadsheets

• application/vnd.ms-excel (XLS)
• application/vnd.openxmlformats-officedocument.spreadsheetml.sheet (XLSX)
• application/vnd.oasis.opendocument.spreadsheet (ODS)
• text/csv (CSV)

Presentations

• application/vnd.ms-powerpoint (PPT)
• application/vnd.openxmlformats-officedocument.presentationml.presentation (PPTX)
• application/vnd.oasis.opendocument.presentation (ODP)

Images

• image/jpeg (JPEG/JPG)
• image/png (PNG)
• image/gif (GIF)
• image/bmp (BMP)
• image/tiff (TIFF)
• image/webp (WebP)
• image/svg+xml (SVG)
• application/postscript (PostScript)

Text Documents

• text/plain (TXT)
• application/rtf (RTF)

Compressed Archives

• application/zip (ZIP)
• application/x-rar-compressed (RAR)
• application/x-7z-compressed (7Z)
• application/x-tar (TAR)
• application/gzip (GZIP)
• application/x-bzip2 (BZIP2)

🔒 Security Features

The IsPdfSecured() method provides basic security validation for PDF files by checking for:

• JavaScript content (/s /javascript)
• JavaScript execution patterns (/js ()

Note: This is a basic security check and should not be considered a complete security solution. Always implement additional security measures for file uploads in production environments.

🎯 Use Cases

• File Upload Validation: Validate user uploads in web applications
• Content Management: Ensure only allowed file types are processed
• Document Processing: Identify and route different document types
• Security Screening: Basic malware detection for PDF files
• File Organization: Categorize files by type for storage systems

🏗️ Framework Compatibility

• .NET Standard 2.0
• .NET Framework 4.6.1+
• .NET Core 2.0+
• .NET 5.0+
• .NET 6.0+
• .NET 7.0+
• .NET 8.0+

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🔧 Advanced Usage

Custom Validation Logic

public bool IsAllowedDocument(IFormFile file)
{
    // Custom validation combining multiple checks
    return file.IsPdfFile() && file.IsPdfSecured() || 
           file.IsWordFile() || 
           file.IsImageFile();
}

Error Handling

public async Task<IActionResult> ValidateAndProcessFile(IFormFile file)
{
    try
    {
        if (!file.AllowedFile())
        {
            return BadRequest(new { error = "File type not supported" });
        }

        if (file.IsPdfFile() && !file.IsPdfSecured())
        {
            return BadRequest(new { error = "PDF file contains potentially unsafe content" });
        }

        // Process file...
        return Ok(new { message = "File processed successfully" });
    }
    catch (Exception ex)
    {
        return StatusCode(500, new { error = "File validation failed", details = ex.Message });
    }
}

⚠️ Important Notes

1. Content vs Header Validation: IFormFile methods rely on the ContentType header, while MemoryStream methods analyze actual file content for more accurate detection.

2. Performance: Content-based detection (MemoryStream methods) is more accurate but slightly slower than header-based validation.

3. Security: The PDF security check is basic. Implement additional security measures for production use.

4. Licensing: The MimeDetective library is configured for personal/non-commercial use. Check licensing requirements for commercial applications.