1/*
2 * Copyright 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package org.conscrypt;
18
19/**
20 *
21 * Helper class for dealing with hexadecimal strings.
22 *
23 */
24// public for testing by TrustedCertificateStoreTest
25public class Hex {
26    private Hex() {}
27
28    private final static char[] DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
29
30    public static String bytesToHexString(byte[] bytes) {
31        char[] buf = new char[bytes.length * 2];
32        int c = 0;
33        for (byte b : bytes) {
34            buf[c++] = DIGITS[(b >> 4) & 0xf];
35            buf[c++] = DIGITS[b & 0xf];
36        }
37        return new String(buf);
38    }
39
40    public static String intToHexString(int i, int minWidth) {
41        int bufLen = 8;  // Max number of hex digits in an int
42        char[] buf = new char[bufLen];
43        int cursor = bufLen;
44
45        do {
46            buf[--cursor] = DIGITS[i & 0xf];
47        } while ((i >>>= 4) != 0 || (bufLen - cursor < minWidth));
48
49        return new String(buf, cursor, bufLen - cursor);
50    }
51
52}
53