RC4

Author: zeyadetman

SecurityLibrary/DES/DES.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SecurityLibrary.ElGamal
+{
+    public class ElGamal
+    {
+        /// <summary>
+        /// Encryption
+        /// </summary>
+        /// <param name="alpha"></param>
+        /// <param name="q"></param>
+        /// <param name="y"></param>
+        /// <param name="k"></param>
+        /// <returns>list[0] = C1, List[1] = C2</returns>
+        public List<long> Encrypt(int q, int alpha, int y, int k, int m)
+        {
+            throw new NotImplementedException();
+
+        }
+        public int Decrypt(int c1, int c2, int x, int q)
+        {
+            throw new NotImplementedException();
+
+        }
+    }
+}

SecurityLibrary/DES/TripleDES.cs

@@ -13,12 +13,75 @@ public class RC4 : CryptographicTechnique
     {
         public override string Decrypt(string cipherText, string key)
         {
-            throw new NotImplementedException();
+            return Encrypt(cipherText, key);
         }
 
         public override  string Encrypt(string plainText, string key)
         {
-            throw new NotImplementedException();
+            bool flag = false;
+            if (plainText[1] == 'x' && plainText[0] == '0')
+            {
+                flag = true;
+                string tmpP = "";
+                for (int i = 2; i < plainText.Length; i+=2)
+                {
+                    tmpP += char.ConvertFromUtf32(Convert.ToInt32(plainText[i].ToString()+plainText[i+1].ToString(), 16));
+                }
+                plainText = tmpP;
+            }
+
+            if (key[0] == '0' && key[1] == 'x')
+            {
+                string tmpK = "";
+                for (int i = 2; i < key.Length; i+=2)
+                {
+                    tmpK += char.ConvertFromUtf32(Convert.ToInt32(key[i].ToString()+key[i+1].ToString(), 16));
+                }
+                key = tmpK;
+            }
+            int[] S = new int[256];
+            int[] T = new int[256];
+            for (int i = 0; i < 256; i++)
+            {
+                S[i] = i;
+                T[i] = key[i % key.Length];
+            }
+
+            int j = 0;
+            for (int i = 0; i < 256; i++)
+            {
+                j = (j + S[i] + T[i]) % 256;
+                int tmp = S[i];
+                S[i] = S[j];
+                S[j] = tmp;
+            }
+
+            int a=0, l=0, k = 0;
+            int plLength = plainText.Length;
+            int t;
+            
+            string C = "";
+            for (int i = 0; i < plainText.Length; i++)
+            {
+                a = (a + 1) % 256;
+                l = (l + S[a]) % 256;
+                int tmp;
+                tmp = S[a];
+                S[a] = S[l];
+                S[l] = tmp;
+                t = (S[a] + S[l]) % 256;
+                k = S[t];
+                Console.WriteLine(plainText[i].ToString() + k.ToString());
+                C += char.ConvertFromUtf32((plainText[i] ^ k));
+            }
+
+            if (flag)
+            {
+                C = string.Join("", C.Select(c => ((int)c).ToString("x2")));
+                C = "0x" + C;
+            }
+            Console.WriteLine(C);
+            return C;
         }
     }
 }

SecurityLibrary/ElGamal/ELGAMAL.cs

@@ -0,0 +1,62 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using SecurityLibrary.RC4;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SecurityPackageTest
+{
+    [TestClass]
+    public class RC4Test
+    {
+        [TestMethod]
+        public void RC4TestEnc1()
+        {
+            RC4 algorithm = new RC4();
+            string cipher = algorithm.Encrypt("abcd", "test");
+            Assert.IsTrue(cipher.Equals("ÏíDu"));
+        }
+
+        [TestMethod]
+        public void RC4TestDec1()
+        {
+            RC4 algorithm = new RC4();
+            string cipher = algorithm.Decrypt("ÏíDu", "test");
+            Assert.IsTrue(cipher.Equals("abcd"));
+        }
+
+        [TestMethod]
+        public void RC4TestEnc2()
+        {
+            RC4 algorithm = new RC4();
+            string cipher = algorithm.Encrypt("0x61626364", "0x74657374");
+            Assert.IsTrue(cipher.Equals("0xcfed4475", StringComparison.InvariantCultureIgnoreCase));
+        }
+
+        [TestMethod]
+        public void RC4TestDec2()
+        {
+            RC4 algorithm = new RC4();
+            string cipher = algorithm.Encrypt("0xcfed4475", "0x74657374");
+            Assert.IsTrue(cipher.Equals("0x61626364", StringComparison.InvariantCultureIgnoreCase));
+        }
+
+        [TestMethod]
+        public void RC4TestNewEnc()
+        {
+            RC4 algorithm = new RC4();
+            string cipher = algorithm.Encrypt("aaaa", "test");
+            Assert.IsTrue(cipher.Equals("ÏîFp"));
+        }
+
+        [TestMethod]
+        public void RC4TestNewDec()
+        {
+            RC4 algorithm = new RC4();
+            string cipher = algorithm.Decrypt("ÏîFp", "test");
+            Assert.IsTrue(cipher.Equals("aaaa"));
+        }
+    }
+}