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 Log.d("xmppService",
48 "challenge="
49 + new String(Base64.decode(challenge,
50 Base64.DEFAULT)));
51 String[] challengeParts = new String(Base64.decode(challenge,
52 Base64.DEFAULT)).split(",");
53 String nonce = "";
54 for (int i = 0; i < challengeParts.length; ++i) {
55 String[] parts = challengeParts[i].split("=");
56 if (parts[0].equals("nonce")) {
57 nonce = parts[1].replace("\"", "");
58 } else if (parts[0].equals("rspauth")) {
59 return null;
60 }
61 }
62 String digestUri = "xmpp/"+account.getServer();
63 String nonceCount = "00000001";
64 String x = account.getUsername() + ":" + account.getServer() + ":"
65 + account.getPassword();
66 MessageDigest md = MessageDigest.getInstance("MD5");
67 byte[] y = md
68 .digest(x.getBytes(Charset.defaultCharset()));
69 String cNonce = new BigInteger(100, random).toString(32);
70 Log.d("xmppService", "conce=" + cNonce);
71 byte[] a1 = concatenateByteArrays(y,(":"+nonce+":"+cNonce).getBytes(Charset.defaultCharset()));
72 String a2 = "AUTHENTICATE:"+digestUri;
73 String ha1 = bytesToHex(md.digest(a1));
74 String ha2 = bytesToHex(md.digest(a2.getBytes(Charset
75 .defaultCharset())));
76 String kd = ha1 + ":" + nonce + ":"+nonceCount+":" + cNonce + ":auth:"
77 + ha2;
78 Log.d("xmppService", "kd=" + kd);
79 String response = bytesToHex(md.digest(kd.getBytes(Charset
80 .defaultCharset())));
81 String saslString = "username=\"" + account.getUsername()
82 + "\",realm=\"" + account.getServer() + "\",nonce=\""
83 + nonce + "\",cnonce=\"" + cNonce
84 + "\",nc="+nonceCount+",qop=auth,digest-uri=\""+digestUri+"\",response=" + response
85 + ",charset=utf-8";
86 Log.d("xmppService", "saslString=" + saslString);
87 return Base64.encodeToString(
88 saslString.getBytes(Charset.defaultCharset()),
89 Base64.NO_WRAP);
90 } catch (NoSuchAlgorithmException e) {
91 return null;
92 }
93 }
94
95 public static String randomMucName() {
96 Random random = new SecureRandom();
97 return randomWord(3, random) + "." + randomWord(7, random);
98 }
99
100 protected static String randomWord(int lenght, Random random) {
101 StringBuilder builder = new StringBuilder(lenght);
102 for (int i = 0; i < lenght; ++i) {
103 if (i % 2 == 0) {
104 builder.append(consonants[random.nextInt(consonants.length)]);
105 } else {
106 builder.append(vowels[random.nextInt(vowels.length)]);
107 }
108 }
109 return builder.toString();
110 }
111}