1package eu.siacs.conversations.utils;
2
3import java.math.BigInteger;
4import java.nio.charset.Charset;
5import java.security.MessageDigest;
6import java.security.NoSuchAlgorithmException;
7import java.security.SecureRandom;
8import java.util.Random;
9
10import eu.siacs.conversations.entities.Account;
11
12import android.util.Base64;
13import android.util.Log;
14
15public class CryptoHelper {
16 final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();
17 final protected static char[] vowels = "aeiou".toCharArray();
18 final protected static char[] consonants = "bcdfghjklmnpqrstvwxyz"
19 .toCharArray();
20
21 public static String bytesToHex(byte[] bytes) {
22 char[] hexChars = new char[bytes.length * 2];
23 for (int j = 0; j < bytes.length; j++) {
24 int v = bytes[j] & 0xFF;
25 hexChars[j * 2] = hexArray[v >>> 4];
26 hexChars[j * 2 + 1] = hexArray[v & 0x0F];
27 }
28 return new String(hexChars).toLowerCase();
29 }
30
31 public static String saslPlain(String username, String password) {
32 String sasl = '\u0000' + username + '\u0000' + password;
33 return Base64.encodeToString(sasl.getBytes(Charset.defaultCharset()),
34 Base64.NO_WRAP);
35 }
36
37 private static byte[] concatenateByteArrays(byte[] a, byte[] b) {
38 byte[] result = new byte[a.length + b.length];
39 System.arraycopy(a, 0, result, 0, a.length);
40 System.arraycopy(b, 0, result, a.length, b.length);
41 return result;
42 }
43
44 public static String saslDigestMd5(Account account, String challenge) {
45 try {
46 Random random = new SecureRandom();
47 String[] challengeParts = new String(Base64.decode(challenge,
48 Base64.DEFAULT)).split(",");
49 String nonce = "";
50 for (int i = 0; i < challengeParts.length; ++i) {
51 String[] parts = challengeParts[i].split("=");
52 if (parts[0].equals("nonce")) {
53 nonce = parts[1].replace("\"", "");
54 } else if (parts[0].equals("rspauth")) {
55 return null;
56 }
57 }
58 String digestUri = "xmpp/"+account.getServer();
59 String nonceCount = "00000001";
60 String x = account.getUsername() + ":" + account.getServer() + ":"
61 + account.getPassword();
62 MessageDigest md = MessageDigest.getInstance("MD5");
63 byte[] y = md
64 .digest(x.getBytes(Charset.defaultCharset()));
65 String cNonce = new BigInteger(100, random).toString(32);
66 byte[] a1 = concatenateByteArrays(y,(":"+nonce+":"+cNonce).getBytes(Charset.defaultCharset()));
67 String a2 = "AUTHENTICATE:"+digestUri;
68 String ha1 = bytesToHex(md.digest(a1));
69 String ha2 = bytesToHex(md.digest(a2.getBytes(Charset
70 .defaultCharset())));
71 String kd = ha1 + ":" + nonce + ":"+nonceCount+":" + cNonce + ":auth:"
72 + ha2;
73 String response = bytesToHex(md.digest(kd.getBytes(Charset
74 .defaultCharset())));
75 String saslString = "username=\"" + account.getUsername()
76 + "\",realm=\"" + account.getServer() + "\",nonce=\""
77 + nonce + "\",cnonce=\"" + cNonce
78 + "\",nc="+nonceCount+",qop=auth,digest-uri=\""+digestUri+"\",response=" + response
79 + ",charset=utf-8";
80 return Base64.encodeToString(
81 saslString.getBytes(Charset.defaultCharset()),
82 Base64.NO_WRAP);
83 } catch (NoSuchAlgorithmException e) {
84 return null;
85 }
86 }
87
88 public static String randomMucName() {
89 Random random = new SecureRandom();
90 return randomWord(3, random) + "." + randomWord(7, random);
91 }
92
93 protected static String randomWord(int lenght, Random random) {
94 StringBuilder builder = new StringBuilder(lenght);
95 for (int i = 0; i < lenght; ++i) {
96 if (i % 2 == 0) {
97 builder.append(consonants[random.nextInt(consonants.length)]);
98 } else {
99 builder.append(vowels[random.nextInt(vowels.length)]);
100 }
101 }
102 return builder.toString();
103 }
104}