gui/Process/PasswordGen.cs

   1 /******************************************************************************/
   2 /* SlunkCrypt, by LoRd_MuldeR <MuldeR2@GMX.de>                                */
   3 /* This work has been released under the CC0 1.0 Universal license!           */
   4 /******************************************************************************/
   5
   6 using System;
   7 using System.Collections.Generic;
   8 using System.Diagnostics;
   9 using System.IO;
  10 using System.Text;
  11 using System.Threading.Tasks;
  12
  13 namespace com.muldersoft.slunkcrypt.gui.process
  14 {
  15     public static class PasswordGen
  16     {
  17         private static readonly TimeSpan TIMEOUT_MSEC = TimeSpan.FromSeconds(90);
  18
  19         private const string COMMAND_PASSWRD = "-p {0:D}";
  20
  21         // =============================================================================
  22         // Exception classes
  23         // =============================================================================
  24
  25         public class GenerationFailedException : IOException
  26         {
  27             public GenerationFailedException(string message, Exception innerException) : base(message, innerException)
  28             {
  29             }
  30         }
  31
  32         // =============================================================================
  33         // Public methods
  34         // =============================================================================
  35
  36         public static async Task<string> GeneratePassword(int length)
  37         {
  38             using (FileStream executableFile = ExecutableHelper.GetExecutableFile())
  39             {
  40                 try
  41                 {
  42                     string password = await StartProcess(executableFile, length);
  43                     if (IsWeakPassword(password))
  44                     {
  45                         throw new InvalidDataException("The generated password string is invalid!");
  46                     }
  47                     return password;
  48                 }
  49                 catch (Exception e)
  50                 {
  51                     throw new GenerationFailedException("Failed to generate password string!", e);
  52                 }
  53             }
  54         }
  55
  56         public static bool IsWeakPassword(string password)
  57         {
  58             int flags = 0;
  59             if (!string.IsNullOrEmpty(password))
  60             {
  61                 foreach (char c in password)
  62                 {
  63                     if (char.IsLetter(c))
  64                     {
  65                         flags |= char.IsUpper(c) ? 0x2 : 0x1;
  66                     }
  67                     else
  68                     {
  69                         flags |= char.IsDigit(c) ? 0x8 : 0x4;
  70                     }
  71                 }
  72             }
  73             return (flags != 0xF);
  74         }
  75
  76         // =============================================================================
  77         // Internal methods
  78         // =============================================================================
  79
  80         private static async Task<string> StartProcess(FileStream executableFile, int length)
  81         {
  82             using (Process process = new Process())
  83             {
  84                 process.StartInfo.UseShellExecute = false;
  85                 process.StartInfo.CreateNoWindow = true;
  86                 process.StartInfo.RedirectStandardOutput = true;
  87                 process.StartInfo.StandardOutputEncoding = Encoding.UTF8;
  88                 process.StartInfo.FileName = executableFile.Name;
  89                 process.StartInfo.Arguments = string.Format(COMMAND_PASSWRD, length);
  90                 process.Start();
  91
  92                 Stack<string> outputLines = await WaitForExit(process, TIMEOUT_MSEC);
  93
  94                 if (process.ExitCode == 0)
  95                 {
  96                     while (outputLines.Count > 0)
  97                     {
  98                         string line = outputLines.Pop();
  99                         if (line.Length >= length)
 100                         {
 101                             return line;
 102                         }
 103                     }
 104                 }
 105                 return string.Empty;
 106             }
 107         }
 108
 109         private static async Task<Stack<string>> WaitForExit(Process process, TimeSpan timeout)
 110         {
 111             Task<Stack<string>> readTask;
 112             await Task.WhenAny(readTask = Task.Run(() => ReadOutput(process)), Task.Delay(timeout));
 113             if (!process.WaitForExit(125))
 114             {
 115                 process.Kill();
 116                 process.WaitForExit();
 117             }
 118             return await readTask;
 119         }
 120
 121         private static Stack<string> ReadOutput(Process process)
 122         {
 123             Stack<string> result = new Stack<string>();
 124             using (StreamReader reader = process.StandardOutput)
 125             {
 126                 string line;
 127                 while ((line = reader.ReadLine()) != null)
 128                 {
 129                     line = line.Trim();
 130                     if (line.Length != 0)
 131                     {
 132                         result.Push(line.Trim());
 133                     }
 134                 }
 135             }
 136             return result;
 137         }
 138     }
 139 }