initial commit of a worker skeleton

MalwareMultiScan.Backends/Backends/Abstracts/AbstractLocalProcessScanBackend.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Text.RegularExpressions;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+
+namespace MalwareMultiScan.Backends.Backends.Abstracts
+{
+    public abstract class AbstractLocalProcessScanBackend : AbstractScanBackend
+    {
+        private readonly ILogger _logger;
+        
+        protected virtual Regex MatchRegex { get; }
+        protected virtual string BackendPath { get; }
+        protected virtual bool ParseStdErr { get; }
+
+        protected virtual string GetBackendArguments(string path)
+        {
+            throw new NotImplementedException();
+        }
+
+        protected AbstractLocalProcessScanBackend(ILogger logger)
+        {
+            _logger = logger;
+        }
+
+        public override async Task<string[]> ScanAsync(string path, CancellationToken cancellationToken)
+        {
+            var process = new Process
+            {
+                StartInfo = new ProcessStartInfo(BackendPath, GetBackendArguments(path))
+                {
+                    RedirectStandardError = true,
+                    RedirectStandardOutput = true,
+                    WorkingDirectory = Path.GetDirectoryName(BackendPath) ?? Directory.GetCurrentDirectory()
+                }
+            };
+            
+            _logger.LogInformation(
+                $"Starting process {process.StartInfo.FileName} " +
+                $"with arguments {process.StartInfo.Arguments} " +
+                $"in working directory {process.StartInfo.WorkingDirectory}");
+            
+            process.Start();
+
+            cancellationToken.Register(() =>
+            {
+                if (!process.HasExited)
+                    process.Kill(true);
+            });
+            
+            process.WaitForExit();
+
+            _logger.LogInformation($"Process has exited with code {process.ExitCode}");
+
+            var standardOutput = await process.StandardOutput.ReadToEndAsync();
+            var standardError = await process.StandardError.ReadToEndAsync();
+            
+            _logger.LogDebug($"Process standard output: {standardOutput}");
+            _logger.LogDebug($"Process standard error: {standardError}");
+
+            return MatchRegex
+                .Matches(ParseStdErr ? standardError : standardOutput)
+                .Where(x => x.Success)
+                .Select(x => x.Groups["threat"].Value)
+                .ToArray();
+        }
+    }
+}