Wenf4PC5

1package com.N0TrixPM;
2
3import sun.misc.BASE64Decoder;
4import sun.misc.BASE64Encoder;
5
6import javax.crypto.Cipher;
7import javax.crypto.NoSuchPaddingException;
8import javax.crypto.spec.IvParameterSpec;
9import javax.crypto.spec.SecretKeySpec;
10import java.math.BigInteger;
11import java.security.InvalidAlgorithmParameterException;
12import java.security.InvalidKeyException;
13import java.security.MessageDigest;
14import java.security.NoSuchAlgorithmException;
15
16public class Crypto {
17
18    private static String md5(final String input) throws NoSuchAlgorithmException {
19        final MessageDigest md = MessageDigest.getInstance("MD5");
20
21        final byte[] messageDigest = md.digest(input.getBytes());
22        final BigInteger number = new BigInteger(1, messageDigest);
23        return String.format("%032x", number);
24    }
25
26    private Cipher initCipher(final int mode, final String initialVectorString, final String secretKey)
27        throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException {
28
29        final SecretKeySpec skeySpec = new SecretKeySpec(md5(secretKey).getBytes(), "AES");
30
31        final IvParameterSpec initialVector = new IvParameterSpec(initialVectorString.getBytes());
32
33        final Cipher cipher = Cipher.getInstance("AES/CFB8/NoPadding");
34
35        cipher.init(mode, skeySpec, initialVector);
36
37        return cipher;
38
39    }
40
41
42    public String encrypt(final String dataToEncrypt, final String initialVector, final String secretKey) {
43        String encryptedData = null;
44        try {
45            // Initialize the cipher
46            final Cipher cipher = initCipher(Cipher.ENCRYPT_MODE, initialVector, secretKey);
47            // Encrypt the data
48            final byte[] encryptedByteArray = cipher.doFinal(dataToEncrypt.getBytes());
49            // Encode using Base64
50            encryptedData = (new BASE64Encoder()).encode(encryptedByteArray);
51        } catch (Exception e) {
52            System.err.println("Problem encrypting the data");
53            e.printStackTrace();
54        }
55        return encryptedData;
56    }
57
58    public String decrypt(final String encryptedData, final String initialVector, final String secretKey) {
59        String decryptedData = null;
60
61        try {
62
63            // Initialize the cipher
64
65            final Cipher cipher = initCipher(Cipher.DECRYPT_MODE, initialVector, secretKey);
66
67            // Decode using Base64
68
69            final byte[] encryptedByteArray = (new BASE64Decoder()).decodeBuffer(encryptedData);
70
71            // Decrypt the data
72
73            final byte[] decryptedByteArray = cipher.doFinal(encryptedByteArray);
74
75            decryptedData = new String(decryptedByteArray, "UTF8");
76
77        } catch (Exception e) {
78
79            System.err.println("Problem decrypting the data");
80
81            e.printStackTrace();
82
83        }
84
85        return decryptedData;
86
87    }
88
89
90
91    public static void main(final String[] args) {
92
93        final String iv = "0123456789123456"; // This has to be 16 characters
94
95        final String secretKey = "Replace this by your secret key";
96
97        final Crypto crypto = new Crypto();
98
99        final String encryptedData = crypto.encrypt("This is a test message.", iv, secretKey);
100
101        System.out.println(encryptedData);
102
103
104        final String decryptedData = crypto.decrypt(encryptedData, iv, secretKey);
105
106        System.out.println(decryptedData);
107
108    }
109
110}