ArcToolkitCLI/ArcToolkitCLI/Commands/DecryptCommand.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using ArcToolkitCLI.Commands.Options;
using ArcToolkitCLI.Util;
using COM3D2.Toolkit.Arc;
using CommandLine;

namespace ArcToolkitCLI.Commands
{
    [Verb("decrypt", HelpText = "Decrypts the provided WARP files")]
    public class DecryptCommand : ICommand, IInputOptions, IDecryptionOptions, IOutputOptions
    {
        public int Run()
        {
            var errCode = Encryption.GetDecryptionKeys(this, out var keysDict);
            if (errCode != 0)
                return errCode;

            Directory.CreateDirectory(Output);

            foreach (var file in Glob.EnumerateFiles(Input))
            {
                if (!file.Exists)
                    return Errors.Error(Errors.ErrorCodes.NotAFile, file.Name);

                using var stream = File.OpenRead(file.FullName);
                var header = new byte[4];
                stream.Read(header, 0, header.Length);
                var headerString = Encoding.ASCII.GetString(header);
                stream.Position = 0;
                if (headerString == "warc")
                    Console.WriteLine($"{file.Name} is a WARC file, skipping...");
                else if (headerString == "warp")
                    try
                    {
                        var arcStream = WarpArc.DecryptWarp(stream, requestedFile =>
                        {
                            if (keysDict.TryGetValue("*", out var key))
                                return key;
                            if (keysDict.TryGetValue(requestedFile, out key))
                                return key;
                            if (Directory.Exists(ArcDirectory) &&
                                File.Exists(Path.Combine(ArcDirectory, requestedFile)))
                                return Encryption.ReadKeyFromFile(Path.Combine(ArcDirectory, requestedFile));
                            if (File.Exists(WarcFile))
                                return Encryption.ReadKeyFromFile(WarcFile);
                            throw new FileNotFoundException("No key found for the requested ARC", requestedFile);
                        });

                        Console.WriteLine($"Writing {Path.Combine(Output, file.Name)} with length {arcStream.Length}");
                        using (var output = File.Create(Path.Combine(Output, file.Name)))
                            arcStream.CopyTo(output);
                    }
                    catch (FileNotFoundException fe)
                    {
                        return Errors.Error(Errors.ErrorCodes.NoCorrectKey, file.Name, fe.FileName);
                    }
                else
                    return Errors.Error(Errors.ErrorCodes.UnknownArcType, file.Name);
            }

            return 0;
        }

        public string ArcDirectory { get; set; }
        public string DecryptionKey { get; set; }
        public string KeyFile { get; set; }
        public string WarcFile { get; set; }

        public IEnumerable<string> Input { get; set; }
        public string Output { get; set; }
    }
}