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ByteGuard.FileValidator

ByteGuard.FileValidator is a lightweight security-focused library for validating user-supplied files in .NET applications.
It helps you enforce consistent file upload rules by checking:

• Allowed file extensions
• File size limits
• File signatures (magic numbers) to detect spoofed types
• Specification conformance for Office Open XML / Open Document Formats (.docx, .xlsx, .pptx, .odt)
• Malware scan result using a varity of scanners (requires the addition of a specific ByteGuard.FileValidator scanner package)

⚠️ Important: This package is one layer in a defense-in-depth strategy.
It does not replace endpoint protection, sandboxing, input validation, or other security controls.

Features

• ✅ Validate files by extension
• ✅ Validate files by size
• ✅ Validate files by signature (magic-numbers)
• ✅ Validate files by specification conformance for archive-based formats (Open XML and Open Document Formats)
• ✅ Ensure no malware through a variety of antimalware scanners
• ✅ Validate using file path, Stream, or byte[]
• ✅ Configure which file types to support
• ✅ Configure whether to throw exceptions or simply return a boolean
• ✅ Fluent configuration API for easy setup