jZZPJDv5

1import java.security.SecureRandom;
2import java.security.spec.AlgorithmParameterSpec;
3import java.util.Arrays;
4import javax.crypto.Cipher;
5import javax.crypto.SecretKey;
6import javax.crypto.spec.IvParameterSpec;
7import javax.crypto.spec.SecretKeySpec;
8import sun.misc.BASE64Decoder;
9
10public class AESModel {
11
12    public static void main(String[] args) throws Exception {
13        doAES();
14        doAES1();
15    }
16
17    /**
18     * Шифрование AES.
19     */
20    private static void doAES() throws Exception {
21        String ct = "Y5JAfKCpb5mjw0ShdOEWhXAlQNdbxOBOqnqHt7kskPuswrw5LYG9C8Yab3d4m2SR";
22        String initVector = "9m/faAg9yXIQPiGlZE/0CA==";
23        String key = "r+H5ZvgM4cWJDOyyK5uXsw==";
24
25        BASE64Decoder decoder = new BASE64Decoder();
26
27        byte[] ctBytes = decoder.decodeBuffer(ct);
28        byte[] initVectorBytes = decoder.decodeBuffer(initVector);
29        byte[] keyBytes = decoder.decodeBuffer(key);
30
31        SecretKey secretKey = new SecretKeySpec(keyBytes, "AES");
32        Cipher cipher = Cipher.getInstance("AES/CBC/ISO10126Padding");
33        cipher.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(initVectorBytes));
34
35        byte[] openTextBytes = cipher.doFinal(ctBytes);
36        String openText = new String(openTextBytes);
37        System.out.println(openText);
38    }
39
40    /**
41     * Перебор AES.
42     */
43    private static void doAES1() throws Exception {
44        //final String ct = "Jg7QI1RrVRYNjREM2+KUnifcnQgFhv0gGQ41yquM1+0HAPdK+s/FfUAo";
45        final String ct = "bB0jXIKsr4F5Ir8LtvM8sWTBF5KHsn5zBkA3yW9zgg==";
46        //final String initVector = "b2Y+/uy/M6dtShDAGQaYzg==";
47        final String initVector = "jm/QEdqKgJ5WbE8gia9sjA==";
48
49        // нужно найти 7-й, 8-й байты
50        //final int i0 = 6;
51        //final int j0 = 7;
52        //
53        // нужно найти 5-й, 6-й байты
54        final int i0 = 4;
55        final int j0 = 5;
56
57        //final byte[] keyBytes = {-127, -82, -63, 75, 37, -34, 0, 0, -60, 94, 42, 101, 16, -65, 100, 101};
58        final byte[] keyBytes = {-80, -9, 83, 31, 0, 0, 61, -41, -33, 39, 46, 20, -48, -92, -44, 51};
59
60        BASE64Decoder decoder = new BASE64Decoder();
61
62        byte[] ctBytes = decoder.decodeBuffer(ct);
63        byte[] initVectorBytes = decoder.decodeBuffer(initVector);
64        AlgorithmParameterSpec iv = new IvParameterSpec(initVectorBytes);
65
66        Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");
67        for (int i = -128; i < 128; i++) {
68            for (int j = -128; j < 128; j++) {
69                //keyBytes[i0] = (byte) i;
70                //keyBytes[j0] = (byte) j;
71                keyBytes[i0] = (byte) i;
72                keyBytes[j0] = (byte) j;
73
74                SecretKey secretKey = new SecretKeySpec(keyBytes, "AES");
75                cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
76
77                byte[] openTextBytes = cipher.doFinal(ctBytes);
78                String openText = new String(openTextBytes);
79                long count = openText.chars().filter(Character::isLetter).count();
80
81				// в случае нахождения нескольких вариантов уменьшить коэффициент
82                // или выбрать осмысленный текст самостоятельно
83                if (count > openText.length() / 1.5) {
84                    System.out.println(openText);
85                    System.out.println(i0 + ": " + i);
86                    System.out.println(j0 + ": " + j);
87                }
88            }
89        }
90    }
91}