Initial data commit

Task/Password-generator/C-sharp/password-generator.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Linq;
+
+class Program
+{
+    const string Lower = "abcdefghijklmnopqrstuvwxyz";
+    const string Upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    const string Digits = "0123456789";
+    const string Symbols = "!\"#$%&'()*+,-./:;<=>?@[]^_{|}~";
+    static readonly string[] Full = {Lower, Upper, Digits, Symbols, Lower + Upper + Digits + Symbols};
+
+    const string Similar = "Il1O05S2Z";
+    static readonly string[] Excluded = Full.Select(x => new string(x.Except(Similar).ToArray())).ToArray();
+
+    static Random _rng = new Random();
+    static string[] _symbolSet = Full;
+
+    static void Main(string[] args)
+    {
+        int length = 12, count = 1;
+        try
+        {
+            foreach (var x in args.Select(arg => arg.Split(':')))
+            {
+                switch (x[0])
+                {
+                    case "-l": length = int.Parse(x[1]); break;
+                    case "-c": count = int.Parse(x[1]); break;
+                    case "-s": _rng = new Random(x[1].GetHashCode()); break;
+                    case "-x": _symbolSet = bool.Parse(x[1]) ? Excluded : Full; break;
+                    default: throw new FormatException("Could not parse arguments");
+                }
+            }
+        }
+        catch { ShowUsage(); return; }
+        try
+        {
+            for (int i = 0; i < count; i++)
+                Console.WriteLine(GeneratePass(length));
+        }
+        catch (Exception ex) { Console.WriteLine("Error: " + ex.Message); }
+    }
+
+    static void ShowUsage()
+    {
+        Console.WriteLine("Usage: PASSGEN [-l:length] [-c:count] [-s:seed] [-x:(true|false)]");
+        Console.WriteLine("\t-l: the length of the generated passwords");
+        Console.WriteLine("\t-c: the number of passwords to generate");
+        Console.WriteLine("\t-s: seed for the random number generator");
+        Console.WriteLine("\t-x: exclude similar characters: " + Similar);
+        Console.WriteLine("Example: PASSGEN -l:10 -c:5 -s:\"Sample Seed\" -x:true");
+    }
+
+    static string GeneratePass(int length)
+    {
+        var minLength = _symbolSet.Length - 1;
+        if(length < minLength)
+            throw new Exception("password length must be " + minLength + " or greater");
+
+        int[] usesRemaining = Enumerable.Repeat(1, _symbolSet.Length).ToArray();
+        usesRemaining[minLength] = length - minLength;
+        var password = new char[length];
+        for (int ii = 0; ii < length; ii++)
+        {
+            int set = _rng.Next(0, _symbolSet.Length);
+            if (usesRemaining[set] > 0)
+            {
+                usesRemaining[set]--;
+                password[ii] = _symbolSet[set][_rng.Next(0, _symbolSet[set].Length)];
+            }
+            else ii--;
+        }
+        return new string(password);
+    }
+}