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私は完全な16ラウンドのDES暗号化を実行するこのプログラムを持っていますが、私は1回の完全ラウンドを実行する必要があります。私の問題は、完全な16ラウンドの実行を中止するためにコーディングをどこで切り詰めるべきかを理解できないように思えることです。ご協力ありがとうございました！あまりにも多くのラウンドに行くDESプログラム。
import javax.crypto.*;
import java.security.*;
import java.util.Scanner;
import java.util.*;
/**
* Performs encryption
*/
public class DESEncryption{
// Initial Permutation table
private static final byte[] InitialPermutation = {
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6,
64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7
};
// Permuted Choice 1 table
private static final byte[] PermutedChoice1 = {
57, 49, 41, 33, 25, 17, 9,
1, 58, 50, 42, 34, 26, 18,
10, 2, 59, 51, 43, 35, 27,
19, 11, 3, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15,
7, 62, 54, 46, 38, 30, 22,
14, 6, 61, 53, 45, 37, 29,
21, 13, 5, 28, 20, 12, 4
};
private static final byte[] PermutedChoice2 = {
14, 17, 11, 24, 1, 5,
3, 28, 15, 6, 21, 10,
23, 19, 12, 4, 26, 8,
16, 7, 27, 20, 13, 2,
41, 52, 31, 37, 47, 55,
30, 40, 51, 45, 33, 48,
44, 49, 39, 56, 34, 53,
46, 42, 50, 36, 29, 32
};
// Array to store the number of rotations that are to be done on each round
private static final byte[] rotations = {
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
};
private static final byte[] Expansion = {
32, 1, 2, 3, 4, 5,
4, 5, 6, 7, 8, 9,
8, 9, 10, 11, 12, 13,
12, 13, 14, 15, 16, 17,
16, 17, 18, 19, 20, 21,
20, 21, 22, 23, 24, 25,
24, 25, 26, 27, 28, 29,
28, 29, 30, 31, 32, 1
};
private static final byte[][] SubstitutionBoxes = { {
14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13
}, {
15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9
}, {
10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12
}, {
7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14
}, {
2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3
}, {
12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13
}, {
4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12
}, {
13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11
} };
private static final byte[] Permutation = {
16, 7, 20, 21,
29, 12, 28, 17,
1, 15, 23, 26,
5, 18, 31, 10,
2, 8, 24, 14,
32, 27, 3, 9,
19, 13, 30, 6,
22, 11, 4, 25
};
// Final permutation table
private static final byte[] FinalPermutation = {
40, 8, 48, 16, 56, 24, 64, 32,
39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30,
37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28,
35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25
};
private static int[] C = new int[28];
private static int[] D = new int[28];
private static int[][] subkey = new int[16][48];
public static void main(String args[]) {
System.out.println("Enter the plaintext in hexadecimal: ");
String input = new Scanner(System.in).nextLine();
int inputBits[] = new int[64];
for(int i=0 ; i < 16 ; i++) {
String s = Integer.toBinaryString(Integer.parseInt(input.charAt(i) + "", 16));
while(s.length() < 4) {
s = "0" + s;
}
for(int j=0 ; j < 4 ; j++) {
inputBits[(4*i)+j] = Integer.parseInt(s.charAt(j) + "");
}
}
System.out.println("Enter the key in hexadecimal: ");
String key = new Scanner(System.in).nextLine();
int keyBits[] = new int[64];
for(int i=0 ; i < 16 ; i++) {
String s = Integer.toBinaryString(Integer.parseInt(key.charAt(i) + "", 16));
while(s.length() < 4) {
s = "0" + s;
}
for(int j=0 ; j < 4 ; j++) {
keyBits[(4*i)+j] = Integer.parseInt(s.charAt(j) + "");
}
}
System.out.println("Encryption Rounds: ");
int outputBits[] = permute(inputBits, keyBits, false);
System.out.println("Decryption: ");
permute(outputBits, keyBits, true);
}
private static int[] permute(int[] inputBits, int[] keyBits, boolean isDecrypt) {
int newBits[] = new int[inputBits.length];
for(int i=0 ; i < inputBits.length ; i++) {
newBits[i] = inputBits[InitialPermutation[i]-1];
}
int L[] = new int[32];
int R[] = new int[32];
int i;
for(i=0 ; i < 28 ; i++) {
C[i] = keyBits[PermutedChoice1[i]-1];
}
for(; i < 56 ; i++) {
D[i-28] = keyBits[PermutedChoice1[i]-1];
}
for(int n=0 ; n < 16 ; n++) {
System.out.println("\n-------------");
System.out.println("Round " + (n+1) + ":");
int newR[] = new int[0];
if(isDecrypt) {
newR = fiestel(R, subkey[15-n]);
BitsDisplayed(subkey[15-n]);
} else {
newR = fiestel(R, KS(n, keyBits));
BitsDisplayed(subkey[n]);
}
int newL[] = xor(L, newR);
L = R;
R = newL;
System.out.print("L = ");
BitsDisplayed(L);
System.out.print("R = ");
BitsDisplayed(R);
}
int output[] = new int[64];
System.arraycopy(R, 0, output, 0, 32);
System.arraycopy(L, 0, output, 32, 32);
int finalOutput[] = new int[64];
for(i=0 ; i < 64 ; i++) {
finalOutput[i] = output[FinalPermutation[i]-1];
}
String hex = new String();
for(i=0 ; i < 16 ; i++) {
String bin = new String();
for(int j=0 ; j < 4 ; j++) {
bin += finalOutput[(4*i)+j];
}
int decimal = Integer.parseInt(bin, 2);
hex += Integer.toHexString(decimal);
}
if(isDecrypt) {
System.out.print("Decrypted text: ");
} else {
System.out.print("Encrypted text: ");
}
System.out.println(hex.toUpperCase());
return finalOutput;
}
private static int[] KS(int round, int[] key) {
int C1[] = new int[28];
int D1[] = new int[28];
int rotationTimes = (int) rotations[round];
C1 = leftShift(C, rotationTimes);
D1 = leftShift(D, rotationTimes);
int CnDn[] = new int[56];
System.arraycopy(C1, 0, CnDn, 0, 28);
System.arraycopy(D1, 0, CnDn, 28, 28);
int Kn[] = new int[48];
for(int i=0 ; i < Kn.length ; i++) {
Kn[i] = CnDn[PermutedChoice2[i]-1];
}
subkey[round] = Kn;
C = C1;
D = D1;
return Kn;
}
private static int[] fiestel(int[] R, int[] roundKey) {
int expandedR[] = new int[48];
for(int i=0 ; i < 48 ; i++) {
expandedR[i] = R[Expansion[i]-1];
}
int temp[] = xor(expandedR, roundKey);
int output[] = sBlock(temp);
return output;
}
private static int[] xor(int[] a, int[] b) {
int answer[] = new int[a.length];
for(int i=0 ; i < a.length ; i++) {
answer[i] = a[i]^b[i];
}
return answer;
}
private static int[] sBlock(int[] bits) {
// S-boxes applied in method.
int output[] = new int[32];
for(int i=0 ; i < 8 ; i++) {
int row[] = new int [2];
row[0] = bits[6*i];
row[1] = bits[(6*i)+5];
String sRow = row[0] + "" + row[1];
int column[] = new int[4];
column[0] = bits[(6*i)+1];
column[1] = bits[(6*i)+2];
column[2] = bits[(6*i)+3];
column[3] = bits[(6*i)+4];
String sColumn = column[0] +""+ column[1] +""+ column[2] +""+ column[3];
// Converting binary to decimal value
int iRow = Integer.parseInt(sRow, 2);
int iColumn = Integer.parseInt(sColumn, 2);
int x = SubstitutionBoxes[i][(iRow*16) + iColumn];
String s = Integer.toBinaryString(x);
while(s.length() < 4) {
s = "0" + s;
}
for(int j=0 ; j < 4 ; j++) {
output[(i*4) + j] = Integer.parseInt(s.charAt(j) + "");
}
}
int finalOutput[] = new int[32];
for(int i=0 ; i < 32 ; i++) {
finalOutput[i] = output[Permutation[i]-1];
}
return finalOutput;
}
private static int[] leftShift(int[] bits, int n) {
int answer[] = new int[bits.length];
System.arraycopy(bits, 0, answer, 0, bits.length);
for(int i=0 ; i < n ; i++) {
int temp = answer[0];
for(int j=0 ; j < bits.length-1 ; j++) {
answer[j] = answer[j+1];
}
answer[bits.length-1] = temp;
}
return answer;
}
private static void BitsDisplayed (int[] bits) {
for(int i=0 ; i < bits.length ; i+=4) {
String output = new String();
for(int j=0 ; j < 4 ; j++) {
output += bits[i+j];
}
System.out.print(Integer.toHexString(Integer.parseInt(output, 2)));
}
System.out.println();
}
}