com.techempower.security.SimpleDigester Maven / Gradle / Ivy
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/*******************************************************************************
* Copyright (c) 2018, TechEmpower, Inc.
* All rights reserved.
*
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* contributors may be used to endorse or promote products derived from
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*
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package com.techempower.security;
import java.math.*;
import java.nio.charset.*;
import java.security.*;
import com.techempower.helper.*;
/**
* SimpleDigester provides a simplified abstraction on the java.security
* MessageDigest functionality. To use this class, just create an instance
* and then call getMD5 or getSHA. Try to keep a single instance of this
* class around at the scope of the application itself because it's undefined
* how long it takes to create the MessageDigest objects.
*
* The standard Sun Java Virtual Machine comes with MD5 and SHA algorithms.
* If a different security provider were to be used (fairly unlikely), the
* NoSuchAlgorithmException that is ignored below may be more important. Be
* aware that this class ignores that exception because it simply doesn't
* ever come up with the standard VM.
*/
public class SimpleDigester
{
//
// Constants.
//
public static final int MD5_LENGTH = 32;
public static final int HEXADECIMAL = 16;
//
// Member variables.
//
private MessageDigest shaDigest;
private MessageDigest md5Digest;
//
// Member methods.
//
/**
* Constructor.
*/
public SimpleDigester()
{
// Does nothing.
}
/**
* Gets the MD5 Digester.
*/
protected synchronized MessageDigest getMd5Digester()
{
if (this.md5Digest == null)
{
try
{
this.md5Digest = MessageDigest.getInstance("MD5");
}
catch (NoSuchAlgorithmException nsae)
{
// Do nothing.
}
}
return this.md5Digest;
}
/**
* Gets the SHA Digester.
*/
protected synchronized MessageDigest getShaDigester()
{
if (this.shaDigest == null)
{
try
{
this.shaDigest = MessageDigest.getInstance("SHA");
}
catch (NoSuchAlgorithmException nsae)
{
// Do nothing.
}
}
return this.shaDigest;
}
/**
* Digest a String using MD5.
*/
public synchronized String getMD5(String sourceString)
{
MessageDigest digest = getMd5Digester();
byte[] results = digest.digest(sourceString.getBytes());
digest.reset();
return new String(results);
}
/**
* Get the MD5 hash of a String in hex
* @param source The String to hash
* @return the hashed String
*/
public synchronized String getMD5Hex(String source) {
byte[] bytesOfMessage = source.getBytes(StandardCharsets.UTF_8);
MessageDigest digest = getMd5Digester();
digest.reset();
digest.update(bytesOfMessage);
byte[] digestArray = digest.digest(); // Gets the hash and resets
BigInteger bigInt = new BigInteger(1, digestArray);
String hashText = bigInt.toString(HEXADECIMAL);
return StringHelper.padZero(hashText, MD5_LENGTH); // Pad to 32 digits
}
/**
* Digest a String using SHA.
*/
public synchronized String getSHA(String sourceString)
{
MessageDigest digest = getShaDigester();
byte[] results = digest.digest(sourceString.getBytes());
digest.reset();
return new String(results);
}
/**
* Digest a String using SHA, and return as a raw byte array.
*/
public synchronized byte[] getSHAAsByteArray(String sourceString)
{
MessageDigest digest = getShaDigester();
byte[] results = digest.digest(sourceString.getBytes());
digest.reset();
return results;
}
/**
* Digest a String using SHA, and return as a hexadecimal String.
*/
public synchronized String getSHAHex(String sourceString)
{
byte[] bytesOfMessage = sourceString.getBytes(StandardCharsets.UTF_8);
MessageDigest digest = getShaDigester();
BigInteger result = new BigInteger(1, digest.digest(bytesOfMessage));
digest.reset();
return result.toString(HEXADECIMAL); // 16 radix = hexadecimal
}
/**
* Main tester method.
*/
public static void main(String[] args)
{
SimpleDigester sd = new SimpleDigester();
System.out.println("Simple digester. " + args.length + " arguments.");
for (String arg : args)
{
System.out.println(arg
+ " MD5: "
+ sd.getMD5Hex(arg)
+ " SHA: "
+ sd.getSHAHex(arg));
}
}
}