1
|
|
|
/* |
2
|
|
|
* This file is part of ArakneUtils. |
3
|
|
|
* |
4
|
|
|
* ArakneUtils is free software: you can redistribute it and/or modify |
5
|
|
|
* it under the terms of the GNU Lesser General Public License as published by |
6
|
|
|
* the Free Software Foundation, either version 3 of the License, or |
7
|
|
|
* (at your option) any later version. |
8
|
|
|
* |
9
|
|
|
* ArakneUtils is distributed in the hope that it will be useful, |
10
|
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
11
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
12
|
|
|
* GNU Lesser General Public License for more details. |
13
|
|
|
* |
14
|
|
|
* You should have received a copy of the GNU Lesser General Public License |
15
|
|
|
* along with ArakneUtils. If not, see <https://www.gnu.org/licenses/>. |
16
|
|
|
* |
17
|
|
|
* Copyright (c) 2017-2020 Vincent Quatrevieux |
18
|
|
|
*/ |
19
|
|
|
|
20
|
|
|
package fr.arakne.utils.encoding; |
21
|
|
|
|
22
|
|
|
import org.checkerframework.checker.index.qual.LTLengthOf; |
23
|
|
|
import org.checkerframework.dataflow.qual.Pure; |
24
|
|
|
import org.checkerframework.dataflow.qual.SideEffectFree; |
25
|
|
|
|
26
|
|
|
/** |
27
|
|
|
* The password encoding algorithm for Dofus |
28
|
|
|
* The algo is a pseudo base 64 vigenere cypher implementation |
29
|
|
|
* |
30
|
|
|
* Note: This is not a safe method for store or communicate password. |
31
|
|
|
* You must use this algo only for compatibility with Dofus 1. |
32
|
|
|
* |
33
|
|
|
* Usage: |
34
|
|
|
* <code> |
35
|
|
|
* PasswordEncoder encoder = new PasswordEncoder("my connection key"); |
36
|
|
|
* |
37
|
|
|
* encoder.encode("my password"); // Encode password for send to the server |
38
|
|
|
* encoder.decode(encodedPassword); // Decode the password |
39
|
|
|
* </code> |
40
|
|
|
* |
41
|
|
|
* https://github.com/Emudofus/Dofus/blob/1.29/ank/utils/Crypt.as#L20 |
42
|
|
|
*/ |
43
|
|
|
public final class PasswordEncoder { |
44
|
|
|
private final String key; |
45
|
|
|
|
46
|
|
|
/** |
47
|
|
|
* @param key The key to use. It must be long enough to encode the password. |
48
|
|
|
*/ |
49
|
1 |
|
public PasswordEncoder(String key) { |
50
|
1 |
|
this.key = key; |
51
|
1 |
|
} |
52
|
|
|
|
53
|
|
|
/** |
54
|
|
|
* Get the encoding key |
55
|
|
|
* |
56
|
|
|
* @return The key |
57
|
|
|
*/ |
58
|
|
|
@Pure |
59
|
|
|
public String key() { |
60
|
1 |
|
return key; |
61
|
|
|
} |
62
|
|
|
|
63
|
|
|
/** |
64
|
|
|
* Decode given string using key |
65
|
|
|
* |
66
|
|
|
* @param encoded Encoded string |
67
|
|
|
* |
68
|
|
|
* @return Decoded string, in Dofus base 64 format |
69
|
|
|
* |
70
|
|
|
* @throws IllegalArgumentException When the encoded string is invalid, or the key is too small |
71
|
|
|
*/ |
72
|
|
|
@SideEffectFree |
73
|
|
|
@SuppressWarnings("assignment") // i / 2 is not resolved as key and decoded length |
74
|
|
|
public String decode(String encoded) { |
75
|
1 |
|
if (encoded.length() % 2 != 0) { |
76
|
1 |
|
throw new IllegalArgumentException("Invalid encoded string"); |
77
|
|
|
} |
78
|
|
|
|
79
|
1 |
|
if (key.length() * 2 < encoded.length()) { |
80
|
1 |
|
throw new IllegalArgumentException("Encoded string is too long for the key"); |
81
|
|
|
} |
82
|
|
|
|
83
|
1 |
|
final char[] decoded = new char[encoded.length() / 2]; |
84
|
|
|
|
85
|
|
|
// Iterate over pair chars |
86
|
1 |
|
for (int i = 0; i < encoded.length() - 1; i += 2) { |
87
|
1 |
|
final @LTLengthOf({"key", "decoded"}) int p = i / 2; |
88
|
1 |
|
final int k = key.charAt(p) % 64; // Get key char |
89
|
|
|
|
90
|
|
|
// Get two chars int value (divider and modulo) |
91
|
1 |
|
int d = Base64.ord(encoded.charAt(i)); |
92
|
1 |
|
int r = Base64.ord(encoded.charAt(i + 1)); |
93
|
|
|
|
94
|
|
|
// Remove key value |
95
|
1 |
|
d -= k; |
96
|
1 |
|
r -= k; |
97
|
|
|
|
98
|
|
|
// if values are negative (due to modulo), reverse the module |
99
|
1 |
|
while (d < 0) { |
100
|
1 |
|
d += 64; |
101
|
|
|
} |
102
|
|
|
|
103
|
1 |
|
while (r < 0) { |
104
|
1 |
|
r += 64; |
105
|
|
|
} |
106
|
|
|
|
107
|
|
|
// retrieve the original value |
108
|
1 |
|
final int v = d * 16 + r; |
109
|
|
|
|
110
|
1 |
|
decoded[p] = (char) v; |
111
|
|
|
} |
112
|
|
|
|
113
|
1 |
|
return new String(decoded); |
114
|
|
|
} |
115
|
|
|
|
116
|
|
|
/** |
117
|
|
|
* Encode the password using the key |
118
|
|
|
* |
119
|
|
|
* @param password The raw password |
120
|
|
|
* @return The encoded password |
121
|
|
|
* |
122
|
|
|
* @throws IllegalArgumentException When the password is too long |
123
|
|
|
*/ |
124
|
|
|
@SideEffectFree |
125
|
|
|
@SuppressWarnings({"argument", "array.access.unsafe.high"}) // Length are not resolved |
126
|
|
|
public String encode(String password) { |
127
|
1 |
|
if (key.length() < password.length()) { |
128
|
1 |
|
throw new IllegalArgumentException("The password is too long for the key"); |
129
|
|
|
} |
130
|
|
|
|
131
|
1 |
|
final char[] encoded = new char[password.length() * 2]; |
132
|
|
|
|
133
|
1 |
|
for (int i = 0; i < password.length(); ++i) { |
134
|
|
|
// Password char and key |
135
|
1 |
|
final char c = password.charAt(i); |
136
|
1 |
|
final char k = key.charAt(i); |
137
|
|
|
|
138
|
|
|
// Get the divider and modulo values |
139
|
1 |
|
final int d = c / 16; |
140
|
1 |
|
final int r = c % 16; |
141
|
|
|
|
142
|
|
|
// Encode into base64 |
143
|
1 |
|
encoded[i * 2] = Base64.chrMod(d + k); |
144
|
1 |
|
encoded[i * 2 + 1] = Base64.chrMod(r + k); |
145
|
|
|
} |
146
|
|
|
|
147
|
1 |
|
return new String(encoded); |
148
|
|
|
} |
149
|
|
|
} |
150
|
|
|
|