4muLFGP6

1package id.co.sat.helper;
2
3import java.security.SecureRandom;
4
5import javax.crypto.Cipher;
6import javax.crypto.KeyGenerator;
7import javax.crypto.SecretKey;
8import javax.crypto.spec.SecretKeySpec;
9
10/**
11 * Created by Asus User on 22/11/2017.
12 */
13
14public class AESEncrypt {
15
16    public String encryption(String strNormalText){
17        String seedValue = "4Learning";
18        String normalTextEnc="";
19        try {
20            normalTextEnc = encrypt(seedValue, strNormalText);
21        } catch (Exception e) {
22            e.printStackTrace();
23        }
24        return normalTextEnc;
25    }
26    public String decryption(String strEncryptedText){
27        String seedValue = "4Learning";
28        String strDecryptedText="";
29        try {
30            strDecryptedText = decrypt(seedValue, strEncryptedText);
31        } catch (Exception e) {
32            e.printStackTrace();
33        }
34        return strDecryptedText;
35    }
36
37    public static String encrypt(String seed, String cleartext) throws Exception {
38        byte[] rawKey = getRawKey(seed.getBytes());
39        byte[] result = encrypt(rawKey, cleartext.getBytes());
40        return toHex(result);
41    }
42
43    public static String decrypt(String seed, String encrypted) throws Exception {
44        byte[] rawKey = getRawKey(seed.getBytes());
45        byte[] enc = toByte(encrypted);
46        byte[] result = decrypt(rawKey, enc);
47        return new String(result);
48    }
49
50    private static byte[] getRawKey(byte[] seed) throws Exception {
51        KeyGenerator kgen = KeyGenerator.getInstance("AES");
52        SecureRandom sr = SecureRandom.getInstance("SHA1PRNG","Crypto");
53        sr.setSeed(seed);
54        kgen.init(128, sr); // 192 and 256 bits may not be available
55        SecretKey skey = kgen.generateKey();
56        byte[] raw = skey.getEncoded();
57        return raw;
58    }
59
60
61    private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
62        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
63        Cipher cipher = Cipher.getInstance("AES");
64        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
65        byte[] encrypted = cipher.doFinal(clear);
66        return encrypted;
67    }
68
69    private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {
70        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
71        Cipher cipher = Cipher.getInstance("AES");
72        cipher.init(Cipher.DECRYPT_MODE, skeySpec);
73        byte[] decrypted = cipher.doFinal(encrypted);
74        return decrypted;
75    }
76
77    public static byte[] toByte(String hexString) {
78        int len = hexString.length()/2;
79        byte[] result = new byte[len];
80        for (int i = 0; i < len; i++)
81            result[i] = Integer.valueOf(hexString.substring(2*i, 2*i+2), 16).byteValue();
82        return result;
83    }
84
85    public static String toHex(byte[] buf) {
86        if (buf == null)
87            return "";
88        StringBuffer result = new StringBuffer(2*buf.length);
89        for (int i = 0; i < buf.length; i++) {
90            appendHex(result, buf[i]);
91        }
92        return result.toString();
93    }
94
95    private final static String HEX = "0123456789ABCDEF";
96    private static void appendHex(StringBuffer sb, byte b) {
97        sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
98    }
99}