yLt7g4SM

1import java.io.UnsupportedEncodingException;
2import java.security.InvalidKeyException;
3import java.security.NoSuchAlgorithmException;
4import java.security.SecureRandom;
5import java.util.Base64;
6
7import javax.crypto.Mac;
8import javax.crypto.spec.SecretKeySpec;
9
10public class EncryptionUtility {
11
12	final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();
13	
14	public static String calculateHash(String secret, String url, String encryption) {
15
16		Mac shaHmac = null;
17
18		try {
19
20			shaHmac = Mac.getInstance(encryption);
21
22		} catch (NoSuchAlgorithmException e) {
23
24			e.printStackTrace();
25		}
26
27		SecretKeySpec secretKey = new SecretKeySpec(secret.getBytes(), encryption);
28
29		try {
30
31			shaHmac.init(secretKey);
32
33		} catch (InvalidKeyException e) {
34
35			e.printStackTrace();
36		}
37
38		byte[] hash = shaHmac.doFinal(url.getBytes());
39		String check = bytesToHex(hash);
40
41		return check;
42	}
43
44	public static String generateNonce() {
45
46		SecureRandom random = null;
47		
48		try {
49
50			random = SecureRandom.getInstance("SHA1PRNG");
51
52		} catch (NoSuchAlgorithmException e) {
53
54			e.printStackTrace();
55		}
56
57		random.setSeed(System.currentTimeMillis()); 
58
59		byte[] nonceBytes = new byte[16]; 
60		random.nextBytes(nonceBytes); 
61
62		String nonce = null;
63
64		try {
65
66			nonce = new String(Base64.getEncoder().encode(nonceBytes), "UTF-8");
67
68		} catch (UnsupportedEncodingException e) {
69
70			e.printStackTrace();
71		}
72
73		return nonce;
74	}
75	
76	private static String bytesToHex(byte[] bytes) {
77		
78	    char[] hexChars = new char[bytes.length * 2];
79	    
80	    for(int j = 0; j < bytes.length; j++) {
81	    	
82	        int v = bytes[j] & 0xFF;
83	        
84	        hexChars[j * 2] = hexArray[v >>> 4];
85	        hexChars[j * 2 + 1] = hexArray[v & 0x0F];
86	    }
87	    
88	    return new String(hexChars);
89	}
90	
91
92    public static String getHmacDigest(Mac mac, String postData)throws Exception {
93        byte[] bytes = mac.doFinal(postData.getBytes("ASCII"));
94        StringBuilder hash = new StringBuilder();
95        for (int i = 0; i < bytes.length; i++) {
96            String hex = Integer.toHexString(0xFF & bytes[i]);
97            if (hex.length() == 1) {
98                hash.append('0');
99            }
100            hash.append(hex);
101        }
102        return hash.toString();
103    }
104
105}