DES.zip_des_unioneaa

package algorithm; import algorithmUtil.DESUtil; /** * DES算法的实现类 */ public class DES { public byte[] desEncrypt(byte[] input, byte[][] loopKeys) { byte[] encryptResult; /* 加密结果 */ byte[] it = initialReplace(input); byte[] temp; temp = feistelFunction(it, loopKeys[0], true); for(int i = 1;i < 15;i++) { temp = feistelFunction(temp, loopKeys[i], true); } temp = feistelFunction(temp, loopKeys[15], false); encryptResult = initialReplaceReverse(temp); return encryptResult; } /** * 轮密钥生成函数 * @param initKey * @return */ public byte[][] getLoopKey(byte[] initKey) { byte[][] P1Result = new byte[16][56]; byte[][] loopKeyResult = new byte[16][48]; byte[] P1Key1 = PC1_KeyReplace(initKey); P1Result[0] = moveLeftLoop(P1Key1, DESUtil.MoveLeft[0]); for(int i = 1;i < 16;i++) { P1Result[i] = moveLeftLoop(P1Result[i - 1], DESUtil.MoveLeft[i]); } for (int i = 0;i < 16;i++) { loopKeyResult[i] = PC2_KeyReplace(P1Result[i]); } return loopKeyResult; } /** * 初始置换 * @param m * @return */ private byte[] initialReplace(byte[] m) { byte[] mResult = new byte[64]; for (int i = 0; i < 64; i++) { mResult[i] = m[DESUtil.IP[i] - 1]; } return mResult; } /** * F函数 * @param input * @param loopKey 轮密钥 * @param direction 控制左右两半 * @return */ private byte[] feistelFunction(byte[] inputData, byte[] roundKey, boolean direction) { byte[] result = new byte[64]; byte[] L = new byte[32]; byte[] R = new byte[32]; byte[] RResult; for(int i = 0;i < 32;i++) { L[i] = inputData[i]; R[i] = inputData[i + 32]; } byte[] eR = eExtend(R); byte[] xR48 = xor(eR, roundKey, 48); byte[] sR = sBoxReplace(xR48); byte[] pR = pReplace(sR); RResult = xor(L, pR, 32); if(direction) { for(int i = 0;i < 32;i++) { result[i] = R[i]; result[i + 32] = RResult[i]; } } else { for(int i = 0;i < 32;i++) { result[i] = RResult[i]; result[i + 32] = R[i]; } } return result; } /** * E盒扩展 * @param r * @return */ private byte[] eExtend(byte[] r) { byte[] eResult = new byte[48]; for (int i = 0; i < 48; i++) { eResult[i] = r[DESUtil.E[i] - 1]; } return eResult; } /** * S盒代替 * @param rResult * @return */ private byte[] sBoxReplace(byte[] rResult) { byte[][] input = new byte[8][6]; byte[] result = new byte[32]; for(int i = 0;i < 8;i++) { for(int j = 0;j < 6;j++) { input[i][j] = rResult[6 * i + j]; } int column = 2*input[i][0] + input[i][5]; int row = 8*input[i][1] + 4*input[i][2] + 2*input[i][3] + input[i][4]; int temp = DESUtil.SBox[i][column][row]; result[4 * i + 3] = (byte) (temp % 2); temp /= 2; result[4 * i + 2] = (byte) (temp % 2); temp /= 2; result[4 * i + 1] = (byte) (temp % 2); temp /= 2; result[4 * i] = (byte) (temp % 2); } return result; } /** * P盒置换 * @param sResult * @return */ private byte[] pReplace(byte[] sResult) { byte[] pResult = new byte[32]; for (int i = 0;i < 32;i++) { pResult[i] = sResult[DESUtil.P[i] - 1]; } return pResult; } private byte[] initialReplaceReverse(byte[] rl) { byte[] mResult = new byte[64]; for (int i = 0; i < 64; i++){ mResult[i] = rl[DESUtil.InverseIP[i] - 1]; } return mResult; } /** * 轮密钥生成的置换选择1 * @param initKey * @return */ private byte[] PC1_KeyReplace(byte[] initKey) { byte[] PC1_Key = new byte[56]; for(int i = 0;i < 56;i++) { PC1_Key[i] = initKey[DESUtil.PC1[i] - 1]; } return PC1_Key; } /** * 轮密钥生成的置换选择2 * @param PC1_Result * @return */ private byte[] PC2_KeyReplace(byte[] PC1_Result) { byte[] PC2_Key = new byte[48]; for(int i = 0;i < 48;i++) { PC2_Key[i] = PC1_Result[DESUtil.PC2[i] - 1]; } return PC2_Key; } /** * 轮密钥生成的循环左移 * @param input * @param index * @return */ private byte[] moveLeftLoop(byte[] input,int index) { byte[] moveResult = new byte[56]; for (int i = 0;i < 28;i++) { moveResult[i] = input[(i + index) % 28]; } for (int i = 28;i < 56;i++) { moveResult[i] = input[(i + index) % 28 + 28]; } return moveResult; } /** * 异或 * @param leftOp * @param rightOp * @param length * @return */ private byte[] xor(byte[] leftOp,byte[] rightOp,int length) { byte[] x = new byte[length]; for (int i = 0; i < length; i++){ x[i] = (byte)(leftOp[i] ^ rightOp[i]); } return x; } /** * 二进制字节数组转换为字符串 * @param bytes * @return */ public String byte2BinaryStr(byte[] bytes) { String result = ""; for (byte b: bytes) { result += b == 0 ?"0":"1"; } return result; } }