using System; using System.Collections.Generic; using System.Text; class Safer { private string text; private string key; private int RoundValue; public int Round { get { return RoundValue; } set { RoundValue = value; } } public string Text { get{ return text; } set{ text = value; } } public string Key { get{ if (key.Length != 8) { throw new Exception("Encryption key must have 8 bytes"); } return key; } set{ if (value.Length != 8) { throw new Exception("Encryption key must have 8 bytes"); } key = value; } } // left cycling byte shift. For example, 111001 left cycling shift on 2 bytes = 100111 private uint LeftCicle(uint value, int count) { return (value >> count) + (((value << (32 - count)) >> (32 - count)) << count); } // get advanced encryption key private byte[] GetKey(int round, byte[] key) { char[,] b = new char[round + 1, 8]; for (int i = 0; i < round + 1; i++) { // const for advancing b[i, 0] = '1'; b[i, 1] = '6'; b[i, 2] = '7'; b[i, 3] = '3'; b[i, 4] = '3'; b[i, 5] = 'B'; b[i, 6] = '1'; b[i, 7] = 'E'; } for (int i = 2; i <= round; i++) { for (int j = 0; j < key.Length; j++) { uint uByte = LeftCicle(Convert.ToUInt32(key[j]), 3); uint specB = Convert.ToUInt32(Convert.ToByte(b[i, j])); // addition modulo 256 key[j] = Convert.ToByte((uByte + specB) % 256); } } return key; } // get 8 byte ration unencrypted data private byte[] GetTextBlock8Byte(string source, int blockNumber) { int eight = 8; byte[] b = Encoding.Default.GetBytes(source); byte[] resultBlock = new byte[eight]; int firstByte = blockNumber * eight; int j = 0; for (int i = firstByte; i < firstByte + eight; i++) { if (i >= b.Length) resultBlock[j] = 0; else resultBlock[j] = b[i]; j++; } return resultBlock; } private int GetTextBlockLength(string source) { byte[] b = Encoding.Default.GetBytes(source); if (b.Length % 8 == 0) return b.Length / 8; else return b.Length / 8 + 1; } // XOR private byte XOR(byte text, byte key) { return Convert.ToByte(Convert.ToInt32(text) ^ Convert.ToInt32(key)); } // addition modulo 256 private byte Mod256(byte text, byte key) { return Convert.ToByte((Convert.ToInt32(text) + Convert.ToInt32(key)) % 256); } // reverse for addition modulo 256 private byte DiffMod256(byte text, byte key) { int y = Convert.ToInt32(text); int k = Convert.ToInt32(key); if (y < k) y += 256; return Convert.ToByte(y - k % 256); } // operation E. using matrix map value. private byte E(byte text) { int[] replacement = new int[256] { 1, 45, 226, 147, 190, 69, 21, 174, 120, 3, 135, 164, 184, 56, 207, 63, 8, 103, 9, 148, 235, 38, 168, 107, 189, 24, 52, 27, 187, 191, 114, 247, 64, 53, 72, 156, 81, 47, 59, 85, 227, 192, 159, 216, 211, 243, 141, 177, 255, 167, 62, 220, 134, 119, 215, 166, 17, 251, 244, 186, 146, 145, 100, 131, 241, 51, 239, 218, 44, 181, 178, 43, 136, 209, 153, 203, 140, 132, 29, 20, 129, 151, 113, 202, 95, 163, 139, 87, 60, 130, 196, 82, 92, 28, 232, 160, 4, 180, 133, 74, 246, 19, 84, 182, 223, 12, 26, 142, 222, 224, 57, 252, 32, 155, 36, 78, 169, 152, 158, 171, 242, 96, 208, 108, 234, 250, 199, 217, 0, 212, 31, 110, 67, 188, 236, 83, 137, 254, 122, 93, 73, 201, 50, 194, 249, 154, 248, 109, 22, 219, 89, 150, 68, 233, 205, 230, 70, 66, 143, 10, 193, 204, 185, 101, 176, 210, 198, 172, 30, 65, 98, 41, 46, 14, 116, 80, 2, 90, 195, 37, 123, 138, 42, 91, 240, 6, 13, 71, 111, 112, 157, 126, 16, 206, 18, 39, 213, 76, 79, 214, 121, 48, 104, 54, 117, 125, 228, 237, 128, 106, 144, 55, 162, 94, 118, 170, 197, 127, 61, 175, 165, 229, 25, 97, 253, 77, 124, 183, 11, 238, 173, 75, 34, 245, 231, 115, 35, 33, 200, 5, 225, 102, 221, 179, 88, 105, 99, 86, 15, 161, 49, 149, 23, 7, 58, 40 }; int t = Convert.ToInt32(text); return Convert.ToByte(replacement[t]); } // operation L. using matrix map value. private byte L(byte text) { int[] replacement = new int[256] { 128, 0, 176, 9, 96, 239, 185, 253, 16, 18, 159, 228, 105, 186, 173, 248, 192, 56, 194, 101, 79, 6, 148, 252, 25, 222, 106, 27, 93, 78, 168, 130, 112, 237, 232, 236, 114, 179, 21, 195, 255, 171, 182, 71, 68, 1, 172, 37, 201, 250, 142, 65, 26, 33, 203, 211, 13, 110, 254, 38, 88, 218, 50, 15, 32, 169, 157, 132, 152, 5, 156, 187, 34, 140, 99, 231, 197, 225, 115, 198, 175, 36, 91, 135, 102, 39, 247, 87, 244, 150, 177, 183, 92, 139, 213, 84, 121, 223, 170, 246, 62, 163, 241, 17, 202, 245, 209, 23, 123, 147, 131, 188, 189, 82, 30, 235, 174, 204, 214, 53, 8, 200, 138, 180, 226, 205, 191, 217, 208, 80, 89, 63, 77, 98, 52, 10, 72, 136, 181, 86, 76, 46, 107, 158, 210, 61, 60, 3, 19, 251, 151, 81, 117, 74, 145, 113, 35, 190, 118, 42, 95, 249, 212, 85, 11, 220, 55, 49, 22, 116, 215, 119, 167, 230, 7, 219, 164, 47, 70, 243, 97, 69, 103, 227, 12, 162, 59, 28, 133, 24, 4, 29, 41, 160, 143, 178, 90, 216, 166, 126, 238, 141, 83, 75, 161, 154, 193, 14, 122, 73, 165, 44, 129, 196, 199, 54, 43, 127, 67, 149, 51, 242, 108, 104, 109, 240, 2, 40, 206, 221, 155, 234, 94, 153, 124, 20, 134, 207, 229, 66, 184, 64, 120, 45, 58, 233, 100, 31, 146, 144, 125, 57, 111, 224, 137, 48 }; int t = Convert.ToInt32(text); return Convert.ToByte(replacement[t]); } // reverse for operation PHT (Pseudo Hadamard Transform) private byte[] IPHT(byte x1, byte x2) { int intX1 = Convert.ToInt32(x1); int intX2 = Convert.ToInt32(x2); int diff1 = -intX1 + 2 * intX2; if (diff1 < 0) diff1 += 256; int diff2 = intX1 - intX2; if (diff2 < 0) diff2 += 256; int intY1 = diff1 % 256; int intY2 = diff2 % 256; byte[] b = new byte[2]; b[1] = Convert.ToByte(intY1); b[0] = Convert.ToByte(intY2); return b; } // operation PHT (Pseudo Hadamard Transform) private byte[] PHT(byte x1, byte x2) { int intX1 = Convert.ToInt32(x1); int intX2 = Convert.ToInt32(x2); int intY1 = (2 * intX1 + intX2) % 256; int intY2 = (intX1 + intX2) % 256; byte[] b = new byte[2]; b[0] = Convert.ToByte(intY1); b[1] = Convert.ToByte(intY2); return b; } public byte[] execPHTStage(byte[] x, int round) { byte[] b = new byte[8]; byte[] temp = new byte[2]; temp = this.PHT(x[0], x[1]); if (round != 0) { b[0] = temp[0]; b[4] = temp[1]; } else { Array.Copy(temp, 0, b, 0, 2); } temp = this.PHT(x[2], x[3]); if (round != 0) { b[1] = temp[0]; b[5] = temp[1]; } else { Array.Copy(temp, 0, b, 2, 2); } temp = this.PHT(x[4], x[5]); if (round != 0) { b[2] = temp[0]; b[6] = temp[1]; } else { Array.Copy(temp, 0, b, 4, 2); } temp = this.PHT(x[6], x[7]); if (round != 0) { b[3] = temp[0]; b[7] = temp[1]; } else { Array.Copy(temp, 0, b, 6, 2); } return b; } public byte[] execIPHTStage(byte[] x, int round) { byte[] b = new byte[8]; byte[] temp = new byte[2]; temp = this.IPHT(x[0], x[1]); if (round != 0) { b[0] = temp[0]; b[2] = temp[1]; } else Array.Copy(temp, 0, b, 0, 2); temp = this.IPHT(x[2], x[3]); if (round != 0) { b[4] = temp[0]; b[6] = temp[1]; } else Array.Copy(temp, 0, b, 2, 2); temp = this.IPHT(x[4], x[5]); if (round != 0) { b[1] = temp[0]; b[3] = temp[1]; } else Array.Copy(temp, 0, b, 4, 2); temp = this.IPHT(x[6], x[7]); if (round != 0) { b[5] = temp[0]; b[7] = temp[1]; } else Array.Copy(temp, 0, b, 6, 2); return b; } // SAFER K-64 encryption public byte[] encrypt() { int sourceLength = this.GetTextBlockLength(this.Text); byte[] key = Encoding.Default.GetBytes( this.Key ); byte[] bigKey; byte[] bigKey2; byte[] sourceBlock = new byte[8]; byte[] result = new byte[sourceLength * 8]; for (int round = 0; round < this.Round; round++) { int r = 0; for (int i = 0; i < sourceLength; i++) { sourceBlock = this.GetTextBlock8Byte(this.Text, i); // Encryption Key advancing bigKey = this.GetKey(2 * (i + 1) - 1, key); bigKey2 = this.GetKey(2 * (i + 1), key); for (int j = 0; j < sourceBlock.Length; j++) { switch (j + 1) { case 1: case 4: case 5: case 8: result[r] = this.XOR(sourceBlock[j], bigKey[j]); result[r] = this.E(result[r]); result[r] = this.Mod256(result[r], bigKey2[j]); break; default: result[r] = this.Mod256(sourceBlock[j], bigKey[j]); result[r] = this.L(result[r]); result[r] = this.XOR(result[r], bigKey2[j]); break; } r++; } byte[] temp = new byte[8]; Array.Copy(result, r - 8, temp, 0, 8); temp = this.execPHTStage(temp, 1); temp = this.execPHTStage(temp, 2); temp = this.execPHTStage(temp, 0); Array.Copy(temp, 0, result, r - 8, 8); } } return result; } // SAFER K-64 decryption public byte[] decrypt() { int sourceLength = this.GetTextBlockLength(this.Text); byte[] key = Encoding.Default.GetBytes(this.Key); byte[] bigKey; byte[] bigKey2; byte[] sourceBlock = new byte[8]; byte[] result = new byte[sourceLength * 8]; for (int round = 0; round < this.Round; round++) { int r = 0; for (int i = 0; i < sourceLength; i++) { sourceBlock = this.GetTextBlock8Byte(this.Text, i); byte[] temp = new byte[8]; Array.Copy(sourceBlock, 0, temp, 0, 8); temp = this.execIPHTStage(sourceBlock, 1); temp = this.execIPHTStage(temp, 2); temp = this.execIPHTStage(temp, 0); Array.Copy(temp, 0, result, r, 8); bigKey2 = this.GetKey(2 * (i + 1) - 1, key); bigKey = this.GetKey(2 * (i + 1), key); for (int j = 0; j < sourceBlock.Length; j++) { switch (j + 1) { case 1: case 4: case 5: case 8: result[r] = this.DiffMod256(result[r], bigKey2[j]); result[r] = this.L(result[r]); result[r] = this.XOR(result[r], bigKey[j]); break; default: result[r] = this.XOR(result[r], bigKey2[j]); result[r] = this.E(result[r]); result[r] = this.DiffMod256(result[r], bigKey[j]); break; } r++; } } } return result; } }
