io.netty.handler.codec.http.websocketx.WebSocketUtil Maven / Gradle / Ivy
/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you 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 io.netty.handler.codec.http.websocketx;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.handler.codec.base64.Base64;
import io.netty.util.CharsetUtil;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
* A utility class mainly for use by web sockets
*/
final class WebSocketUtil {
/**
* Performs a MD5 hash on the specified data
*
* @param data The data to hash
* @return The hashed data
*/
static byte[] md5(byte[] data) {
try {
//Try to get a MessageDigest that uses MD5
MessageDigest md = MessageDigest.getInstance("MD5");
//Hash the data
return md.digest(data);
} catch (NoSuchAlgorithmException e) {
//This shouldn't happen! How old is the computer?
throw new InternalError("MD5 not supported on this platform - Outdated?");
}
}
/**
* Performs a SHA-1 hash on the specified data
*
* @param data The data to hash
* @return The hashed data
*/
static byte[] sha1(byte[] data) {
try {
//Attempt to get a MessageDigest that uses SHA1
MessageDigest md = MessageDigest.getInstance("SHA1");
//Hash the data
return md.digest(data);
} catch (NoSuchAlgorithmException e) {
//Alright, you might have an old system.
throw new InternalError("SHA-1 is not supported on this platform - Outdated?");
}
}
/**
* Performs base64 encoding on the specified data
*
* @param data The data to encode
* @return An encoded string containing the data
*/
static String base64(byte[] data) {
ByteBuf encodedData = Unpooled.wrappedBuffer(data);
return Base64.encode(encodedData).toString(CharsetUtil.UTF_8);
}
/**
* Creates an arbitrary number of random bytes
*
* @param size the number of random bytes to create
* @return An array of random bytes
*/
static byte[] randomBytes(int size) {
byte[] bytes = new byte[size];
for (int index = 0; index < size; index++) {
bytes[index] = (byte) randomNumber(0, 255);
}
return bytes;
}
/**
* Generates a pseudo-random number
*
* @param minimum The minimum allowable value
* @param maximum The maximum allowable value
* @return A pseudo-random number
*/
static int randomNumber(int minimum, int maximum) {
return (int) (Math.random() * maximum + minimum);
}
/**
* A private constructor to ensure that instances of this class cannot be made
*/
private WebSocketUtil() {
// Unused
}
}