18 lines
2.1 KiB
Java
18 lines
2.1 KiB
Java
// These pesky special agents keep reverse engineering our source code and then
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// breaking into our secret vaults. THIS will teach those sneaky sneaks a
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// lesson.
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//
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// -Minion #0891
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import java.util.*; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec;
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import java.security.*; class VaultDoor8 {public static void main(String args[]) {
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Scanner b = new Scanner(System.in); System.out.print("Enter vault password: ");
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String c = b.next(); String f = c.substring(8,c.length()-1); VaultDoor8 a = new VaultDoor8(); if (a.checkPassword(f)) {System.out.println("Access granted."); }
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else {System.out.println("Access denied!"); } } public char[] scramble(String password) {/* Scramble a password by transposing pairs of bits. */
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char[] a = password.toCharArray(); for (int b=0; b<a.length; b++) {char c = a[b]; c = switchBits(c,1,2); c = switchBits(c,0,3); /* c = switchBits(c,14,3); c = switchBits(c, 2, 0); */ c = switchBits(c,5,6); c = switchBits(c,4,7);
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c = switchBits(c,0,1); /* d = switchBits(d, 4, 5); e = switchBits(e, 5, 6); */ c = switchBits(c,3,4); c = switchBits(c,2,5); c = switchBits(c,6,7); a[b] = c; } return a;
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} public char switchBits(char c, int p1, int p2) {/* Move the bit in position p1 to position p2, and move the bit
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that was in position p2 to position p1. Precondition: p1 < p2 */ char mask1 = (char)(1 << p1);
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char mask2 = (char)(1 << p2); /* char mask3 = (char)(1<<p1<<p2); mask1++; mask1--; */ char bit1 = (char)(c & mask1); char bit2 = (char)(c & mask2); /* System.out.println("bit1 " + Integer.toBinaryString(bit1));
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System.out.println("bit2 " + Integer.toBinaryString(bit2)); */ char rest = (char)(c & ~(mask1 | mask2)); char shift = (char)(p2 - p1); char result = (char)((bit1<<shift) | (bit2>>shift) | rest); return result;
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} public boolean checkPassword(String password) {char[] scrambled = scramble(password); char[] expected = {
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0xF4, 0xC0, 0x97, 0xF0, 0x77, 0x97, 0xC0, 0xE4, 0xF0, 0x77, 0xA4, 0xD0, 0xC5, 0x77, 0xF4, 0x86, 0xD0, 0xA5, 0x45, 0x96, 0x27, 0xB5, 0x77, 0xC1, 0xC0, 0x95, 0x94, 0x94, 0xC1, 0xD1, 0xE1, 0xF1 }; return Arrays.equals(scrambled, expected); } } |