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KSI Java SDK common module
/*
* Copyright 2013-2016 Guardtime, Inc.
*
* This file is part of the Guardtime client SDK.
*
* 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, CONDITIONS, OR OTHER LICENSES OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
* "Guardtime" and "KSI" are trademarks or registered trademarks of
* Guardtime, Inc., and no license to trademarks is granted; Guardtime
* reserves and retains all trademark rights.
*/
package com.guardtime.ksi.util;
import com.guardtime.ksi.exceptions.KSIException;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CodingErrorAction;
import java.security.GeneralSecurityException;
import java.security.InvalidKeyException;
import java.security.KeyStore;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Collection;
import java.util.Random;
import java.util.zip.CRC32;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
/**
* A collection of miscellaneous, commonly used utility functions.
*/
public final class Util {
/**
* The default buffer size for the data read/copy operations in this class.
*/
public static final int DEFAULT_BUFFER_SIZE = 8192;
/**
* Random source.
*/
private static final Random RANDOM = new SecureRandom();
/**
* Computes the CRC32 checksum for the given data.
*
* The checksum is appended to the original data and the result returned in a newly allocated array.
*
* @param b
* the data to compute the checksum for.
* @return an array containing the original data with the CRC appended to it.
* @throws NullPointerException
* if {@code b} is {@code null}.
* @throws ArrayIndexOutOfBoundsException
* if the half-range {@code [off..off+len)} is not in {@code [0..b.length)}.
*/
public static byte[] addCrc32(byte[] b) throws NullPointerException, ArrayIndexOutOfBoundsException {
return addCrc32(b, 0, b.length);
}
/**
* Computes the CRC32 checksum for {@code len} bytes of the given data, starting from {@code off}.
*
* The checksum is appended to the original data and the result returned in a newly allocated array.
*
* @param b
* the buffer containing the data to compute the checksum for.
* @param off
* the buffer containing the data to compute the checksum for.
* @param len
* number of bytes to include in the checksum.
* @return an array containing specified data bytes with CRC appended to it.
* @throws NullPointerException
* if {@code b} is {@code null}.
* @throws ArrayIndexOutOfBoundsException
* if the half-range {@code [off..off+len)} is not in {@code [0..b.length)}.
*/
public static byte[] addCrc32(byte[] b, int off, int len) throws NullPointerException, ArrayIndexOutOfBoundsException {
byte[] res = new byte[len + 4];
byte[] crc = calculateCrc32(b, off, len);
System.arraycopy(b, off, res, 0, len);
System.arraycopy(crc, 0, res, len, 4);
return res;
}
/**
* Computes the CRC32 checksum for {@code length} bytes of the given data, starting from {@code off}.
*
* @param b
* the buffer containing the data to compute the checksum for.
* @param off
* the buffer containing the data to compute the checksum for.
* @param length
* number of bytes to include in the checksum.
* @return an array containing calculated CRC32 value.
*/
public static byte[] calculateCrc32(byte[] b, int off, int length) {
CRC32 crc32 = new CRC32();
crc32.update(b, off, length);
return toByteArray((int) (crc32.getValue() & 0xffffffffL));
}
/**
* Decodes UTF-8 string from the given buffer.
*
* @param buf
* the buffer.
* @param ofs
* offset of the UTF-8 data in the buffer.
* @param len
* length of the UTF-8 data to decode.
* @return the decoded string.
* @throws CharacterCodingException
* when the specified data is not in valid UTF-8 format.
*/
public static String decodeString(byte[] buf, int ofs, int len) throws CharacterCodingException {
if (ofs < 0 || len < 0 || ofs + len < 0 || ofs + len > buf.length) {
throw new IndexOutOfBoundsException();
}
CharsetDecoder decoder = Charset.forName("UTF-8").newDecoder().onMalformedInput(CodingErrorAction.REPORT)
.onUnmappableCharacter(CodingErrorAction.REPORT);
return decoder.decode(ByteBuffer.wrap(buf, ofs, len)).toString();
}
/**
* Encodes the given string in UTF-8.
*
* @param value
* the string to encode.
* @return a newly allocated array containing the encoding result.
*/
public static byte[] toByteArray(String value) {
if (value == null) {
return null;
}
try {
CharsetEncoder encoder = Charset.forName("UTF-8").newEncoder().onMalformedInput(CodingErrorAction.REPORT)
.onUnmappableCharacter(CodingErrorAction.REPORT);
ByteBuffer buf = encoder.encode(CharBuffer.wrap(value));
// don't use ByteBuffer.array(), as it returns internal, and
// possibly larger, byte array
byte[] res = new byte[buf.remaining()];
buf.get(res);
return res;
} catch (CharacterCodingException e) {
throw new RuntimeException("Unexpected exception", e);
}
}
/**
* Copies all available data from {@code in} to byte array.
*
* @param in
* input stream to copy data from.
* @return array of bytes read from input stream
* @throws IOException
*/
public static byte[] toByteArray(InputStream in) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
copyData(in, out);
return out.toByteArray();
}
/**
* Copies all available data from {@code in} to byte array.
*
* @param in
* input stream to copy data from.
* @param bufferSize
* buffer size to use
* @return array of bytes read from input stream
* @throws IOException
*/
public static byte[] toByteArray(InputStream in, int bufferSize) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
copyData(in, out, bufferSize);
return out.toByteArray();
}
/**
* Creates a copy of the given byte array.
*
* @param b
* the array to copy.
* @return copy of {@code b}, or {@code null} if {@code b} is {@code null}.
*/
public static byte[] copyOf(byte[] b) {
if (b == null) {
return null;
}
return copyOf(b, 0, b.length);
}
/**
* Creates a copy of a section of the given byte array.
*
* @param b
* the array to copy.
* @param off
* the start offset of the data within {@code b}.
* @param len
* the number of bytes to copy.
* @return copy of the requested section of {@code b}.
* @throws NullPointerException
* if {@code b} is {@code null}.
* @throws ArrayIndexOutOfBoundsException
* if the half-range {@code [off..off+len)} is not in {@code [0..b.length)}.
*/
public static byte[] copyOf(byte[] b, int off, int len) throws NullPointerException, ArrayIndexOutOfBoundsException {
if (b == null) {
throw new NullPointerException();
}
if (off < 0 || len < 0 || off > b.length - len) {
throw new ArrayIndexOutOfBoundsException();
}
byte[] copy = new byte[len];
System.arraycopy(b, off, copy, 0, len);
return copy;
}
/**
* Joins two byte arrays to one
*
* @param a
* first byte array to join. not null
* @param b
* second byte array to join. not null.
* @return joined byte array.
*/
public static byte[] join(byte[] a, byte[] b) {
byte[] result = new byte[a.length + b.length];
System.arraycopy(a, 0, result, 0, a.length);
System.arraycopy(b, 0, result, a.length, b.length);
return result;
}
/**
* Computes the least common multiple (LCM) of two integers.
*
* Least common multiple is the smallest positive integer that can be divided by both numbers without a remainder.
*
* @param a
* the first integer.
* @param b
* the second integer.
* @return the least common multiple of {@code a} and {@code b}, or {@code 0}, if either {@code a} or {@code b} is
* {@code 0}.
* @throws ArithmeticException
* when the result is too big to fit into an {@code int}.
*/
public static int lcm(int a, int b) throws ArithmeticException {
if (a == 0 || b == 0) {
return 0;
}
a = Math.abs(a) / gcd(a, b);
b = Math.abs(b);
if (a > Integer.MAX_VALUE / b) {
throw new ArithmeticException("Integer overflow");
}
return a * b;
}
/**
* Computes the greatest common divisor (GCD) of two integers.
*
* Greatest common divisor is the largest integer that divides both numbers without remainder.
*
* @param a
* the first integer.
* @param b
* the second integer.
* @return the greatest common divisor of {@code a} and {@code b}, or {@code 0}, if both {@code a} and {@code b} are
* {@code 0}.
*/
public static int gcd(int a, int b) {
a = Math.abs(a);
b = Math.abs(b);
while (a > 0) {
int c = b % a;
b = a;
a = c;
}
return b;
}
/**
* Converts {@code value} to two-byte array.
*
* Bytes are returned in network byte order (ordered from the most to the least significant byte).
*
* @param value
* the value to convert.
* @return the converted bytes as an array.
*/
public static byte[] toByteArray(short value) {
return new byte[]{(byte) (value >>> 8), (byte) value};
}
/**
* Converts {@code value} to four-byte array.
*
* Bytes are returned in network byte order (ordered from the most to the least significant byte).
*
* @param value
* the value to convert.
* @return the converted bytes as an array.
*/
public static byte[] toByteArray(int value) {
return new byte[]{(byte) (value >>> 24), (byte) (value >>> 16), (byte) (value >>> 8), (byte) value};
}
/**
* Converts {@code value} to eight-byte array.
*
* Bytes are returned in network byte order (ordered from the most to the least significant byte).
*
* @param value
* the value to convert.
* @return the converted bytes as an array.
*/
public static byte[] toByteArray(long value) {
return new byte[]{(byte) (value >>> 56), (byte) (value >>> 48), (byte) (value >>> 40), (byte) (value >>> 32), (byte) (value >>> 24),
(byte) (value >>> 16), (byte) (value >>> 8), (byte) value};
}
/**
* Converts the first two bytes of {@code b} to a 16-bit signed integer.
*
* Assumes network byte order (ordered from the most to the least significant byte).
*
* @param b
* the buffer to read from.
* @return the converted value.
*/
public static short toShort(byte[] b) {
return toShort(b, 0);
}
/**
* Converts two bytes of {@code b}, starting from {@code offset}, to a 16-bit signed integer.
*
* Assumes network byte order (ordered from the most to the least significant byte).
*
* @param b
* the buffer to read from.
* @param offset
* start offset in the buffer.
* @return the converted value.
*/
public static short toShort(byte[] b, int offset) {
return (short) ((b[offset++] << 8) + (b[offset++] & 0xff));
}
/**
* Converts the first four bytes of {@code b} to a 32-bit signed integer.
*
* Assumes network byte order (ordered from the most to the least significant byte).
*
* @param b
* the buffer to read from.
* @return the converted value.
*/
public static int toInt(byte[] b) {
return toInt(b, 0);
}
/**
* Converts four bytes of {@code b}, starting from {@code offset}, to a 32-bit signed integer.
*
* Assumes network byte order (ordered from the most to the least significant byte).
*
* @param b
* the buffer to read from.
* @param offset
* start offset in the buffer.
* @return the converted value.
*/
public static int toInt(byte[] b, int offset) {
return (toShort(b, offset) << 16) + (toShort(b, offset + 2) & 0xffff);
}
/**
* Converts the first eight bytes of {@code b} to a 64-bit signed integer.
*
* Assumes network byte order (ordered from the most to the least significant byte).
*
* @param b
* the buffer to read from.
* @return the converted value.
*/
public static long toLong(byte[] b) {
return toLong(b, 0);
}
/**
* Converts eight bytes of {@code b}, starting from {@code offset}, to a 64-bit signed integer.
*
* Assumes network byte order (ordered from the most to the least significant byte).
*
* @param b
* the buffer to read from.
* @param offset
* start offset in the buffer.
* @return the converted value.
*/
public static long toLong(byte[] b, int offset) {
return ((long) toInt(b, offset) << 32) + (toInt(b, offset + 4) & 0xffffffffL);
}
/**
* Decodes an unsigned integer from the given buffer.
*
* @param buf
* the buffer.
* @param ofs
* offset of the data in the buffer.
* @param len
* length of the data to decode.
* @return the decoded value.
* @throws IllegalArgumentException
* when result does not fit into 63-bit unsigned integer.
*/
public static long decodeUnsignedLong(byte[] buf, int ofs, int len) throws IllegalArgumentException {
if (ofs < 0 || len < 0 || ofs + len < 0 || ofs + len > buf.length) {
throw new IndexOutOfBoundsException();
}
if (len > 8 || len == 8 && buf[ofs] < 0) {
throw new IllegalArgumentException("Integers of at most 63 unsigned bits supported by this implementation");
}
long t = 0;
for (int i = 0; i < len; ++i) {
t = (t << 8) | ((long) buf[ofs + i] & 0xff);
}
return t;
}
/**
* Encodes the given value in a minimal number of bytes, in network byte order (most significant bits first).
*
* @param value
* the value to encode (the encoding is unsigned, so only non-negative values are supported).
* @return a newly allocated array containing the encoding result.
*/
public static byte[] encodeUnsignedLong(long value) {
if (value < 0) {
throw new IllegalArgumentException("Only non-negative integer values are allowed");
}
int n = 0;
for (long t = value; t > 0; t >>>= 8) {
++n;
}
byte[] res = new byte[n];
for (long t = value; t > 0; t >>>= 8) {
res[--n] = (byte) t;
}
return res;
}
/**
* Calculates the RFC 2104 compatible HMAC for the given message, key and algorithm.
*
* @param message
* message for which the MAC is to be calculated
* @param keyBytes
* key for calculation
* @param algorithm
* algorithm to be used (MD5, SHA1, SHA256)
* @return hmac as byte array
* @throws NoSuchAlgorithmException
* if invalid algorithm is provided
* @throws InvalidKeyException
* if invalid key is provided
* @throws IllegalArgumentException
* if hmac key is nll
*/
public static byte[] calculateHMAC(byte[] message, byte[] keyBytes, String algorithm) throws NoSuchAlgorithmException, InvalidKeyException {
if (keyBytes == null) {
throw new IllegalArgumentException("Invalid HMAC key: null");
}
String hmacAlgorithmName = "Hmac" + algorithm.toUpperCase().replaceAll("[^\\p{Alnum}]", "");
SecretKeySpec key = new SecretKeySpec(keyBytes, hmacAlgorithmName);
Mac mac = Mac.getInstance(hmacAlgorithmName);
mac.init(key);
return mac.doFinal(message);
}
/**
* Copies all available data from {@code in} to {@code out}.
*
* Allocates a temporary memory buffer of {@link #DEFAULT_BUFFER_SIZE} bytes for this.
*
* @param in
* input stream to copy data from.
* @param out
* output stream to copy data to.
* @return the number of bytes actually copied.
* @throws IOException
* if one is thrown by either {@code in} or {@code out}.
*/
public static int copyData(InputStream in, OutputStream out) throws IOException {
return copyData(in, out, -1, DEFAULT_BUFFER_SIZE);
}
/**
* Copies up to {@code limit} bytes of data from {@code in} to {@code out}.
*
* May copy less than {@code limit} bytes if {@code in} does not have that much data available.
*
* Allocates a temporary memory buffer of {@code bufSize} bytes for this.
*
* @param in
* input stream to copy data from.
* @param out
* output stream to copy data to.
* @param limit
* maximum number of bytes to copy ({@code -1} to copy all bytes).
* @param bufSize
* size of the buffer to allocate (larger buffer may speed up the process).
* @return the number of bytes actually copied.
* @throws IOException
* if one is thrown by either {@code in} or {@code out}.
*/
public static int copyData(InputStream in, OutputStream out, int limit, int bufSize) throws IOException {
if (bufSize < 1) {
throw new IllegalArgumentException("Invalid buffer size: " + bufSize);
}
byte[] buf = new byte[bufSize];
int total = 0;
while (limit < 0 || total < limit) {
int maxRead = ((limit < 0) ? buf.length : Math.min(limit - total, buf.length));
int count = in.read(buf, 0, maxRead);
if (count < 1) {
break;
}
out.write(buf, 0, count);
total += count;
}
return total;
}
/**
* Copies up to {@code limit} bytes of data from {@code in} to {@code out}.
*
* May copy less than {@code limit} bytes if {@code in} does not have that much data available.
*
* Allocates a temporary memory buffer of {@link #DEFAULT_BUFFER_SIZE} bytes for this.
*
* @param in
* input stream to copy data from.
* @param out
* output stream to copy data to.
* @param limit
* maximum number of bytes to copy.
* @return the number of bytes actually copied.
* @throws IOException
* if one is thrown by either {@code in} or {@code out}.
*/
public static int copyData(InputStream in, OutputStream out, int limit) throws IOException {
return copyData(in, out, limit, DEFAULT_BUFFER_SIZE);
}
/**
* Closes an {@code InputStream} unconditionally.
*
* Equivalent to {@code InputStream.close()}, except any exceptions will be ignored. This is typically used in
* {@code finally} blocks.
*
* @param input
* {@link InputStream} to close
*/
public static void closeQuietly(InputStream input) {
if (input != null) {
try {
input.close();
} catch (IOException e) {
}
}
}
/**
* Closes an {@code OutputStream} unconditionally.
*
* Equivalent to {@code OutputStream.close()}, except any exceptions will be ignored. This is typically used in
* {@code finally} blocks.
*
* @param output
* {@link OutputStream} to close
*/
public static void closeQuietly(OutputStream output) {
if (output != null) {
try {
output.close();
} catch (IOException e) {
}
}
}
/**
* Returns the next pseudorandom, uniformly distributed long value from the Math.random() sequence.
N!B!
* All values are greater than or equal to zero.
*
* @return the random long
*/
public static Long nextLong() {
long randomLong = RANDOM.nextLong();
if (randomLong < 0) {
randomLong = randomLong + 1;
randomLong = Math.abs(randomLong);
}
return randomLong;
}
/**
* Checks if the input object is null or not.
* @param o input object
* @param name input object name
*/
public static void notNull(Object o, String name) {
if (o == null) {
throw new NullPointerException(name + " can not be null");
}
}
/**
* Checks if two objects are equal. It's safe to pass null objects.
* @param o1 first input object
* @param o2 second input object
* @return true if both inputs are null or equal to each other
*/
public static boolean equals(Object o1, Object o2) {
return (o1 == null && o2 == null) || (o1 != null && o2 != null && o1.equals(o2));
}
/**
* Checks if two collections are equal ignoring the order of components. It's safe to pass collections that might be null.
* @param c1 first collection
* @param c2 second collection
* @return true if both lists are null or if they have exactly the same components.
*/
public static boolean equalsIgnoreOrder(Collection c1, Collection c2) {
return (c1 == null && c2 == null) || (c1 != null && c2 != null && c1.size() == c2.size() && c1.containsAll(c2) && c2.containsAll(c1));
}
/**
* Method for checking if an element is present in int array.
*
* @param array an array of int values
* @param key a primitive int value
* @return if element is present in array
*/
public static boolean containsInt(final int[] array, final int key) {
for (int element : array) {
if (element == key) {
return true;
}
}
return false;
}
/**
* Creates a URL object from the String representation.
*
* @param url the String to parse as a URL.
* @return a Uniform Resource Locator object
*/
public static URL toUrl(String url) {
try {
return new URL(url);
} catch (MalformedURLException e) {
throw new IllegalArgumentException("Malformed URL '" + url + "'", e);
}
}
/**
* Returns the default location of Java Runtime Environment certificate store.
*
* @return default certificate store location
*/
public static String getDefaultTrustStore() {
return System.getProperty("java.home") + File.separatorChar + "lib" + File.separatorChar
+ "security" + File.separatorChar + "cacerts";
}
/**
* Loads and returns the {@link java.security.KeyStore} from the file system.
*/
public static KeyStore loadKeyStore(File file, String password) throws KSIException {
notNull(file, "Trust store file");
FileInputStream input = null;
KeyStore keyStore = null;
try {
keyStore = KeyStore.getInstance("JKS");
char[] passwordCharArray = password == null ? null : password.toCharArray();
input = new FileInputStream(file);
keyStore.load(input, passwordCharArray);
} catch (GeneralSecurityException e) {
throw new KSIException("Loading java key store with path " + file + " failed", e);
} catch (IOException e) {
throw new KSIException("Loading java key store with path " + file + " failed", e);
} finally {
closeQuietly(input);
}
return keyStore;
}
/**
* This class should not be instantiated.
*/
private Util() {}
}
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