1 files changed, 80 insertions, 0 deletions
diff --git a/DistributedPasswordCracker.Client/Utilities/PasswordFileHandler.cs b/DistributedPasswordCracker.Client/Utilities/PasswordFileHandler.cs
new file mode 100644
index 0000000..b078e97
--- /dev/null
+++ b/DistributedPasswordCracker.Client/Utilities/PasswordFileHandler.cs
@@ -0,0 +1,80 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Security.Cryptography;
+using DistributedPasswordCracker.Client.Models;
+
+namespace DistributedPasswordCracker.Client.Utilities
+{
+    class PasswordFileHandler
+    {
+        private static readonly Converter<char, byte> Converter = CharToByte;
+
+        /// <summary>
+        /// With this method you can make you own password file
+        /// </summary>
+        /// <param name="filename">Name of password file</param>
+        /// <param name="usernames">List of usernames</param>
+        /// <param name="passwords">List of passwords in clear text</param>
+        /// <exception cref="ArgumentException">if usernames and passwords have different lengths</exception>
+        public static void WritePasswordFile(String filename, String[] usernames, String[] passwords)
+        {
+            HashAlgorithm messageDigest = new SHA1CryptoServiceProvider();
+            if (usernames.Length != passwords.Length)
+            {
+                throw new ArgumentException("usernames and passwords must be same lengths");
+            }
+            using (FileStream fs = new FileStream(filename, FileMode.CreateNew, FileAccess.Write))
+            using (StreamWriter sw = new StreamWriter(fs))
+            {
+                for (int i = 0; i < usernames.Length; i++)
+                {
+                    byte[] passwordAsBytes = Array.ConvertAll(passwords[i].ToCharArray(), GetConverter());
+                    byte[] encryptedPassword = messageDigest.ComputeHash(passwordAsBytes);
+                    String line = usernames[i] + ":" + Convert.ToBase64String(encryptedPassword) + "\n";
+                    sw.WriteLine(line);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Reads all the username + encrypted password from the password file
+        /// </summary>
+        /// <param name="filename">the name of the password file</param>
+        /// <returns>A list of (username, encrypted password) pairs</returns>
+        public static List<UserInfo> ReadPasswordFile(String filename)
+        {
+            List<UserInfo> result = new List<UserInfo>();
+
+            FileStream fs = new FileStream(filename, FileMode.Open, FileAccess.Read);
+            using (StreamReader sr = new StreamReader(fs))
+            {
+
+                while (!sr.EndOfStream)
+                {
+                    String line = sr.ReadLine();
+                    String[] parts = line.Split(":".ToCharArray());
+                    UserInfo userInfo = new UserInfo(parts[0], parts[1]);
+                    result.Add(userInfo);
+                }
+                return result;
+            }
+        }
+
+        public static Converter<char, byte> GetConverter()
+        {
+            return Converter;
+        }
+
+        /// <summary>
+        /// Converting a char to a byte can be done in many ways.
+        /// This is one way ...
+        /// </summary>
+        /// <param name="ch"></param>
+        /// <returns></returns>
+        private static byte CharToByte(char ch)
+        {
+            return Convert.ToByte(ch);
+        }
+    }
+}
+\ No newline at end of file