1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.codec.digest;
19
20 class Binary {
21
22 private static final int RADIX = 2;
23
24 /**
25 * Converts a string of 0s and 1s to a byte array.
26 *
27 * @param binary a string of 0s and 1s to a byte array.
28 * @return a byte array
29 */
30 static byte[] toByteArray(final String binary) {
31 // Ensure the binary string length is a multiple of 8
32 final int inLen = binary.length();
33 if (inLen % Byte.SIZE != 0) {
34 throw new IllegalArgumentException(String.format("Binary string length must be a multiple of %,d.", Byte.SIZE));
35 }
36 final byte[] byteArray = new byte[inLen / Byte.SIZE];
37 for (int i = 0, j = 0; i < byteArray.length; i++, j += Byte.SIZE) {
38 byteArray[i] = (byte) Integer.parseInt(binary.substring(j, j + Byte.SIZE), RADIX);
39 }
40 return byteArray;
41 }
42 }