blob: 4e4519e477045d9a319c6e9e5dc7aad93d2d27ad (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
/*
* Copyright © 2018 Samuel Holland <samuel@sholland.org>
* Copyright © 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
* SPDX-License-Identifier: GPL-2.0-or-later
*/
package com.wireguard.android.widget;
import android.text.InputFilter;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import com.wireguard.crypto.KeyEncoding;
/**
* InputFilter for entering WireGuard private/public keys encoded with base64.
*/
public class KeyInputFilter implements InputFilter {
private static boolean isAllowed(final char c) {
return Character.isLetterOrDigit(c) || c == '+' || c == '/';
}
public static InputFilter newInstance() {
return new KeyInputFilter();
}
@Override
public CharSequence filter(final CharSequence source,
final int sStart, final int sEnd,
final Spanned dest,
final int dStart, final int dEnd) {
SpannableStringBuilder replacement = null;
int rIndex = 0;
final int dLength = dest.length();
for (int sIndex = sStart; sIndex < sEnd; ++sIndex) {
final char c = source.charAt(sIndex);
final int dIndex = dStart + (sIndex - sStart);
// Restrict characters to the base64 character set.
// Ensure adding this character does not push the length over the limit.
if (((dIndex + 1 < KeyEncoding.KEY_LENGTH_BASE64 && isAllowed(c)) ||
(dIndex + 1 == KeyEncoding.KEY_LENGTH_BASE64 && c == '=')) &&
dLength + (sIndex - sStart) < KeyEncoding.KEY_LENGTH_BASE64) {
++rIndex;
} else {
if (replacement == null)
replacement = new SpannableStringBuilder(source, sStart, sEnd);
replacement.delete(rIndex, rIndex + 1);
}
}
return replacement;
}
}
|
