be.atbash.ee.security.octopus.nimbus.util.ByteUtils Maven / Gradle / Ivy
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/*
* Copyright 2017-2022 Rudy De Busscher (https://www.atbash.be)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package be.atbash.ee.security.octopus.nimbus.util;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* Byte utilities.
*
* Based on code by Vladimir Dzhuvinov
*/
public final class ByteUtils {
/**
* Concatenates the specified byte arrays.
*
* @param byteArrays The byte arrays to concatenate, may be
* {@code null}.
* @return The resulting byte array.
*/
public static byte[] concat(byte[]... byteArrays) {
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
for (byte[] bytes : byteArrays) {
if (bytes == null) {
continue; // skip
}
baos.write(bytes);
}
return baos.toByteArray();
} catch (IOException e) {
// Should never happen
throw new IllegalStateException(e.getMessage(), e);
}
}
/**
* Returns a portion of the specified byte array.
*
* @param byteArray The byte array. Must not be {@code null}.
* @param beginIndex The beginning index, inclusive. Must be zero or
* positive.
* @param length The length. Must be zero or positive.
* @return The byte array portion.
*/
public static byte[] subArray(byte[] byteArray, int beginIndex, int length) {
byte[] subArray = new byte[length];
System.arraycopy(byteArray, beginIndex, subArray, 0, subArray.length);
return subArray;
}
/**
* Returns the bit length of the specified byte length.
*
* @param byteLength The byte length.
* @return The bit length.
*/
public static int bitLength(int byteLength) {
return byteLength * 8;
}
/**
* Returns the bit length of the specified byte length, preventing
* integer overflow.
*
* @param byteLength The byte length.
* @return The bit length.
* @throws IntegerOverflowException On a integer overflow.
*/
public static int safeBitLength(int byteLength)
throws IntegerOverflowException {
long longResult = (long) byteLength * (long) 8;
if ((long) ((int) longResult) != longResult) {
throw new IntegerOverflowException();
} else {
return (int) longResult;
}
}
/**
* Returns the byte length of the specified byte array.
*
* @param byteArray The byte array. May be {@code null}.
* @return The bite length, zero if the array is {@code null}.
*/
public static int bitLength(byte[] byteArray) {
if (byteArray == null) {
return 0;
} else {
return bitLength(byteArray.length);
}
}
/**
* Returns the byte length of the specified byte array, preventing
* integer overflow.
*
* @param byteArray The byte array. May be {@code null}.
* @return The bite length, zero if the array is {@code null}.
* @throws IntegerOverflowException On a integer overflow.
*/
public static int safeBitLength(byte[] byteArray)
throws IntegerOverflowException {
if (byteArray == null) {
return 0;
} else {
return safeBitLength(byteArray.length);
}
}
/**
* Returns the byte length of the specified bit length.
*
* @param bitLength The bit length.
* @return The byte byte length.
*/
public static int byteLength(int bitLength) {
return bitLength / 8;
}
/**
* Read all bytes from the inputstream. The stream is closed after it is fully read.
*
* @param inputStream The stream to read from
* @return The byte array contained in the stream.
* @throws IOException When exception occurred during reading of the Stream.
*/
public static byte[] readAllBytes(InputStream inputStream) throws IOException {
final int bufLen = 4 * 0x400; // 4KB
byte[] buf = new byte[bufLen];
int readLen;
try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
while ((readLen = inputStream.read(buf, 0, bufLen)) != -1) {
outputStream.write(buf, 0, readLen);
}
return outputStream.toByteArray();
} finally {
inputStream.close();
}
}
/**
* Returns {@code true} if the specified byte array is zero filled.
*
* @param byteArray the byte array. Must not be {@code null}.
* @return {@code true} if zero filled, else {@code false}.
*/
public static boolean isZeroFilled(byte[] byteArray) {
for (final byte b : byteArray) {
if (b != 0) {
return false;
}
}
return true;
}
}