andreacristaldi-DefenderRuleParser/Parsers/GenericBinarySignatureParser.cs

// DefenderRuleParser
// Author: Andrea Cristaldi 2025 - https://github.com/andreacristaldi/DefenderRuleParser
// This project is licensed under the Apache 2.0 License.
/*
 * Summary: Generic fixed-layout binary parser for small atomized records.
 * Origin: dump-driven; field sizes/endianness inferred empirically.
 * Role: Provides a reusable path when the structure is regular but unnamed.
 */

using System;
using System.Collections.Generic;
using System.IO;
using DefenderRuleParser2.Models;

namespace DefenderRuleParser2.Parsers
{
    public class GenericBinarySignatureParser : ISignatureParser
    {
        private readonly string _signatureType;

        public GenericBinarySignatureParser(string signatureType)
        {
            _signatureType = signatureType;
        }

        public void Parse(BinaryReader reader, int size, uint threatId)
        {
            long offset = reader.BaseStream.Position;

            try
            {
                byte[] data = reader.ReadBytes(size);
                string hex = BitConverter.ToString(data).Replace("-", " ");

                Logger.Info($"[{_signatureType}] Threat ID: {threatId}, Size: {size} bytes");
                Logger.Info($"  > Hex: {hex}");

                if (ThreatDatabase.TryGetThreat(threatId, out var threat))
                {
                    threat.Signatures.Add(new SignatureEntry
                    {
                        Type = _signatureType,
                        Offset = offset,
                        Pattern = new List<string> { hex },
                        Parsed = true,
                        ConditionType = "PRESENT",
                        ConditionValue = 1
                    });
                }
            }
            catch (Exception ex)
            {
                Logger.Error($"[!] {_signatureType} Error parsing at offset 0x{offset:X}: {ex.Message}");
            }
            finally
            {
                reader.BaseStream.Seek(offset + size, SeekOrigin.Begin);
            }

        }
    }
}