Data commit

Task/Chaocipher/C-sharp/chaocipher.cs

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+using System;
+
+namespace Chaocipher {
+    enum Mode {
+        ENCRYPT,
+        DECRYPT,
+    }
+
+    class Program {
+        const string L_ALPHABET = "HXUCZVAMDSLKPEFJRIGTWOBNYQ";
+        const string R_ALPHABET = "PTLNBQDEOYSFAVZKGJRIHWXUMC";
+
+        static string Exec(string text, Mode mode, bool showSteps = false) {
+            char[] left = L_ALPHABET.ToCharArray();
+            char[] right = R_ALPHABET.ToCharArray();
+            char[] eText = new char[text.Length];
+            char[] temp = new char[26];
+
+            for (int i = 0; i < text.Length; ++i) {
+                if (showSteps) Console.WriteLine("{0} {1}", string.Join("", left), string.Join("", right));
+                int index = 0;
+                if (mode == Mode.ENCRYPT) {
+                    index = Array.IndexOf(right, text[i]);
+                    eText[i] = left[index];
+                } else {
+                    index = Array.IndexOf(left, text[i]);
+                    eText[i] = right[index];
+                }
+                if (i == text.Length - 1) break;
+
+                // permute left
+
+                for (int j = index; j < 26; ++j) temp[j - index] = left[j];
+                for (int j = 0; j < index; ++j) temp[26 - index + j] = left[j];
+                var store = temp[1];
+                for (int j = 2; j < 14; ++j) temp[j - 1] = temp[j];
+                temp[13] = store;
+                temp.CopyTo(left, 0);
+
+                // permute right
+
+                for (int j = index; j < 26; ++j) temp[j - index] = right[j];
+                for (int j = 0; j < index; ++j) temp[26 - index + j] = right[j];
+                store = temp[0];
+                for (int j = 1; j < 26; ++j) temp[j - 1] = temp[j];
+                temp[25] = store;
+                store = temp[2];
+                for (int j = 3; j < 14; ++j) temp[j - 1] = temp[j];
+                temp[13] = store;
+                temp.CopyTo(right, 0);
+            }
+
+            return new string(eText);
+        }
+
+        static void Main(string[] args) {
+            var plainText = "WELLDONEISBETTERTHANWELLSAID";
+            Console.WriteLine("The original plaintext is : {0}", plainText);
+            Console.WriteLine("\nThe left and right alphabets after each permutation during encryption are :\n");
+            var cipherText = Exec(plainText, Mode.ENCRYPT, true);
+            Console.WriteLine("\nThe ciphertext is : {0}", cipherText);
+            var plainText2 = Exec(cipherText, Mode.DECRYPT);
+            Console.WriteLine("\nThe recovered plaintext is : {0}", plainText2);
+        }
+    }
+}