I need to replicate the functionality of the following JAVA code that receives a string with the exponent and modulus of a public key to generate a public key with said parameters and encrypt a string:
package snippet;
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.Security;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.RSAPublicKeySpec;
import javax.crypto.Cipher;
public class Snippet {
public static void main(String ... strings) {
try {
// Needed if you don't have this provider
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
//String and received public key example
String ReceivedString = "1234";
String publicRSA = "010001|0097152d7034a8b48383d3dba20c43d049";
EncryptFunc(ReceivedString, publicRSA);
//The result obtained from the ReceivedString and the publicRSA is as follows:
//Result in hex [1234] -> [777786fe162598689a8dc172ed9418cb]
} catch (Exception ex) {
System.out.println("Error: " );
ex.printStackTrace();
}
}
public static String EncryptFunc(String ReceivedString, String clavePublica) throws Exception {
String result = "";
//We separate the received public string into exponent and modulus
//We receive it as "exponent|modulus"
String[] SplitKey = clavePublica.split("\\|");
KeyFactory keyFactory = KeyFactory.getInstance("RSA","BC");
RSAPublicKeySpec ks = new RSAPublicKeySpec(new BigInteger(hex2byte(SplitKey[1])), new BigInteger(hex2byte(SplitKey[0])));
//With these specs, we generate the public key
RSAPublicKey pubKey = (RSAPublicKey)keyFactory.generatePublic(ks);
//We instantiate the cypher, with the EncryptFunc and the obtained public key
Cipher cipher= Cipher.getInstance("RSA/None/NoPadding","BC");
cipher.init(Cipher.ENCRYPT_MODE, pubKey);
//We reverse the ReceivedString and encrypt it
String ReceivedStringReverse = reverse(ReceivedString);
byte[] cipherText2 = cipher.doFinal(ReceivedStringReverse.getBytes("UTF8"));
result = byte2hex(cipherText2);
System.out.println("result in hex ["+ReceivedString+"] -> ["+result+"]");
return result;
}
public static byte[] hex2byte(String s) {
int len = s.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
+ Character.digit(s.charAt(i+1), 16));
}
return data;
}
public static String byte2hex(byte[] bytes) {
StringBuilder result = new StringBuilder();
for (byte aByte : bytes) {
result.append(String.format("%02x", aByte));
// upper case
// result.append(String.format("%02X", aByte));
}
return result.toString();
}
public static String reverse(String source) {
int i, len = source.length();
StringBuilder dest = new StringBuilder(len);
for (i = (len - 1); i >= 0; i--){
dest.append(source.charAt(i));
}
return dest.toString();
}
}
I've tried several approaches with this one, And I have done some searching here, here, here, here and here.
I Managed to create the public key with the given parameters, but the results are always different when I encrypt the string:
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Digests;
using Org.BouncyCastle.Crypto.Encodings;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Paddings;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Security;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
namespace RSACypherTest
{
public class Program
{
public static RSACryptoServiceProvider rsa;
static void Main(string[] args)
{
string str = "1234";
string publicRSA = "010001|0097152d7034a8b48383d3dba20c43d049";
string encrypted = "";
Console.WriteLine("Original text: " + str);
encrypted = Encrypt(str, publicRSA);
Console.WriteLine("Encrypted text: " + encrypted);
Console.ReadLine();
}
public static string Encrypt(string str, string PublicRSA)
{
string[] Separated = PublicRSA.Split('|');
RsaKeyParameters pubParameters = MakeKey(Separated[1], Separated[0], false);
IAsymmetricBlockCipher eng = new Pkcs1Encoding(new RsaEngine());
eng.Init(true, pubParameters);
byte[] plaintext = Encoding.UTF8.GetBytes(Reverse(str));
byte[] encdata = eng.ProcessBlock(plaintext, 0, plaintext.Length);
return ByteArrayToString(encdata);
}
public static string Reverse(string s)
{
char[] charArray = s.ToCharArray();
Array.Reverse(charArray);
return new string(charArray);
}
public static string ByteArrayToString(byte[] ba)
{
return BitConverter.ToString(ba).Replace("-", "");
}
public static byte[] StringToByteArray(string hex)
{
int NumberChars = hex.Length;
byte[] bytes = new byte[NumberChars / 2];
for (int i = 0; i < NumberChars; i += 2)
bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
return bytes;
}
private static RsaKeyParameters MakeKey(string modulusHexString, string exponentHexString, bool isPrivateKey)
{
var modulus = new BigInteger(modulusHexString, 16);
var exponent = new BigInteger(exponentHexString, 16);
return new RsaKeyParameters(isPrivateKey, modulus, exponent);
}
}
}
I'm trying to use BouncyCastle because it seems to be the most effcient way of dealing with the key generation and everything. Any help concerning this would be very much appreciated.
Thanks in advance.
This is not the answer to your question but may help you in understanding RSA encryption.
I setup a sample encryption program in C# and used your given public key (converted the BigInteger modulus & exponent to Base64 values and further just wrote the XML-String representation of the public to use this key for encryption. The keylength is good for a length of maximum 5 byte data.
When running the encryption 5 times you will receive different encodedData (here in Base64 encoding) each run. So it's the expected behavior of the RSA encryption.
As C# allows me to "build" a short key it is not possible to generate a fresh keypair of such length and I doubt that Bouncy Castle would do (but here on SO there are many colleagues with a much better understanding of BC :-).
If you would like the program you can use the following external link to the program: https://jdoodle.com/ia/40.
Result:
load a pre created public key
publicKeyXML2: lxUtcDSotIOD09uiDEPQSQ==AQAB
encryptedData in Base64: JIFfO7HXCvdi0nSxKb0eLA==
encryptedData in Base64: dvtRw0U0KtT/pDJZW2X0FA==
encryptedData in Base64: CqJJKZevO6jWH6DQ1dnkhQ==
encryptedData in Base64: G7cL6BBwxysItvD/Rg0PuA==
encryptedData in Base64: HcfZJITu/PzN84WgI8yc6g==
code:
using System;
using System.Security.Cryptography;
using System.Text;
class RSACSPSample
{
static void Main()
{
try
{
//Create byte arrays to hold original, encrypted, and decrypted data.
byte[] dataToEncrypt = System.Text.Encoding.UTF8.GetBytes("1234");
byte[] encryptedData;
//Create a new instance of RSACryptoServiceProvider to generate
//public and private key data.
using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider())
{
Console.WriteLine("load a pre created public key");
string publicKeyXML = "<RSAKeyValue><Modulus>AJcVLXA0qLSDg9PbogxD0Ek=</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";
RSA.FromXmlString(publicKeyXML);
string publicKeyXML2 = RSA.ToXmlString(false);
Console.WriteLine("publicKeyXML2: " + publicKeyXML2);
Console.WriteLine();
//Pass the data to ENCRYPT, the public key information
//(using RSACryptoServiceProvider.ExportParameters(false),
//and a boolean flag specifying no OAEP padding.
for (int i = 0; i < 5; i++)
{
encryptedData = RSAEncrypt(dataToEncrypt, RSA.ExportParameters(false), false);
string encryptedDataBase64 = Convert.ToBase64String(encryptedData);
Console.WriteLine("encryptedData in Base64: " + encryptedDataBase64);
}
}
}
catch (ArgumentNullException)
{
//Catch this exception in case the encryption did
//not succeed.
Console.WriteLine("Encryption failed.");
}
}
public static byte[] RSAEncrypt(byte[] DataToEncrypt, RSAParameters RSAKeyInfo, bool DoOAEPPadding)
{
try
{
byte[] encryptedData;
//Create a new instance of RSACryptoServiceProvider.
using (RSACryptoServiceProvider RSA = new RSACryptoServiceProvider())
{
//Import the RSA Key information. This only needs
//toinclude the public key information.
RSA.ImportParameters(RSAKeyInfo);
//Encrypt the passed byte array and specify OAEP padding.
//OAEP padding is only available on Microsoft Windows XP or
//later.
encryptedData = RSA.Encrypt(DataToEncrypt, DoOAEPPadding);
}
return encryptedData;
}
//Catch and display a CryptographicException
//to the console.
catch (CryptographicException e)
{
Console.WriteLine(e.Message);
return null;
}
}
}
While I won't mark my own answer as the correct one, I've found that there's the possibility to recreate the entire functionality of the java code mentioned in my question.
As Michael Fehr mentions in his answer, Its absolutely logical that any encryption method will try to avoid creating repeating or predictable patterns, as this answer perfectly describes.
Since in this particular situation the aim is to replicate the java code functionality, and said functionality revolves around getting the same results when encrypting a string with a given public key, we can use the answer in this post to generate a pice of code like the following:
private static string EncryptMessage(string str, string publicRSA)
{
string[] Separated = publicRSA.Split('|');
RsaKeyParameters pubParameters = MakeKey(Separated[1], Separated[0], false);
var eng = new RsaEngine();
eng.Init(true, pubParameters);
string x = Reverse(str);
byte[] plaintext = Encoding.UTF8.GetBytes(x);
var encdata = ByteArrayToString(eng.ProcessBlock(plaintext, 0, plaintext.Length));
return encdata;
}
private static RsaKeyParameters MakeKey(string modulusHexString, string exponentHexString, bool isPrivateKey)
{
byte[] mod = StringToByteArray(modulusHexString);
byte[] exp = StringToByteArray(exponentHexString);
var modulus = new BigInteger(mod);
var exponent = new BigInteger(exp);
return new RsaKeyParameters(isPrivateKey, modulus, exponent);
}
To recap:
As Michael Fehr says, it is not only normal but expected of a crypyography engine to NOT generate repeatable/predictable patterns
To deliver on the previous point, they add random "padding" to the messages
It's possible (but not recommended) to use BouncyCastle to generate a No-padding engine, emulating the functionality of Java code such as this Cipher rsa = Cipher.getInstance("RSA/ECB/nopadding");
There is such code on C # and java, sha512 in them differs, whether it is possible to make somehow that the result sha512 was identical? I understand the problem in BaseConverter, analog Base64 in Java? Tried
Base64.getEncoder().encodeToString(str);
But I get an error because of getEncoder(). Do I need a library for this?
Code in C#:
public string Hash(string str)
{
string resultStr = String.Empty;
byte[] data = new UTF8Encoding().GetBytes(str);
byte[] result;
SHA512 shaM = new SHA512Managed();
result = shaM.ComputeHash(data);
resultStr = ReverseString(BitConverter.ToString(result).ToLower().Replace("-", String.Empty));
return resultStr.Substring(5, 25);
}
public static string ReverseString(string s)
{
char[] charArray = s.ToCharArray();
Array.Reverse(charArray);
return new string(charArray);
}
Code in Java:
public String Hash(String str) {
try {
MessageDigest digest = MessageDigest.getInstance("SHA-512");
digest.update(str.getBytes("UTF-16LE"));
byte messageDigest[] = digest.digest();
StringBuffer hexString = new StringBuffer();
for (int i = 0; i < messageDigest.length; i++) {
String h = Integer.toHexString(0xFF & messageDigest[i]);
while (h.length() < 2)
h = "0" + h;
hexString.append(h);
}
result = hexString.toString().toLowerCase();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return ReverseString(result).substring(5, 25);
}
public static String ReverseString(String s)
{
return new StringBuilder(s).reverse().toString();
}
You're hashing different data - in Java you're converting the string to UTF-16:
digest.update(str.getBytes("UTF-16LE"));
In C# you're using UTF-8:
byte[] data = new UTF8Encoding().GetBytes(str);
(I'm not sure why you're creating a new UTF8Encoding rather than using Encoding.UTF8, admittedly.)
With different input, you will get different hashes.
In general, the way to diagnose problems like this is to compare the data at every step of the transformation, whether that's through logging or debugging. In this case you have four transformations:
Message string to message bytes
Message bytes to hash bytes
Hash bytes to hash string (hex)
Reversed hash string (hex)
Next time, check the output of each step, and you'll work out where the problem is.
(It's not obvious why you'd want to reverse the hex output anyway, but that's a different matter.)
The problem was in the input line for hashing (the string was the salt without the rest of the data, the rest of the data was empty because there was an error in the definition of EditText (EditText returned an empty string) and also fixed the encoding in Java for UTF-8.
Is there any method to generate MD5 hash of a string in Java?
The MessageDigest class can provide you with an instance of the MD5 digest.
When working with strings and the crypto classes be sure to always specify the encoding you want the byte representation in. If you just use string.getBytes() it will use the platform default. (Not all platforms use the same defaults)
import java.security.*;
..
byte[] bytesOfMessage = yourString.getBytes("UTF-8");
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] theMD5digest = md.digest(bytesOfMessage);
If you have a lot of data take a look at the .update(xxx) methods which can be called repeatedly. Then call .digest() to obtain the resulting hash.
You need java.security.MessageDigest.
Call MessageDigest.getInstance("MD5") to get a MD5 instance of MessageDigest you can use.
The compute the hash by doing one of:
Feed the entire input as a byte[] and calculate the hash in one operation with md.digest(bytes).
Feed the MessageDigest one byte[] chunk at a time by calling md.update(bytes). When you're done adding input bytes, calculate the hash with
md.digest().
The byte[] returned by md.digest() is the MD5 hash.
If you actually want the answer back as a string as opposed to a byte array, you could always do something like this:
String plaintext = "your text here";
MessageDigest m = MessageDigest.getInstance("MD5");
m.reset();
m.update(plaintext.getBytes());
byte[] digest = m.digest();
BigInteger bigInt = new BigInteger(1,digest);
String hashtext = bigInt.toString(16);
// Now we need to zero pad it if you actually want the full 32 chars.
while(hashtext.length() < 32 ){
hashtext = "0"+hashtext;
}
You might also want to look at the DigestUtils class of the apache commons codec project, which provides very convenient methods to create MD5 or SHA digests.
Found this:
public String MD5(String md5) {
try {
java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
byte[] array = md.digest(md5.getBytes());
StringBuffer sb = new StringBuffer();
for (int i = 0; i < array.length; ++i) {
sb.append(Integer.toHexString((array[i] & 0xFF) | 0x100).substring(1,3));
}
return sb.toString();
} catch (java.security.NoSuchAlgorithmException e) {
}
return null;
}
on the site below, I take no credit for it, but its a solution that works!
For me lots of other code didnt work properly, I ended up missing 0s in the hash.
This one seems to be the same as PHP has.
source: http://m2tec.be/blog/2010/02/03/java-md5-hex-0093
Here is how I use it:
final MessageDigest messageDigest = MessageDigest.getInstance("MD5");
messageDigest.reset();
messageDigest.update(string.getBytes(Charset.forName("UTF8")));
final byte[] resultByte = messageDigest.digest();
final String result = new String(Hex.encodeHex(resultByte));
where Hex is: org.apache.commons.codec.binary.Hex from the Apache Commons project.
I've found this to be the most clear and concise way to do it:
MessageDigest md5 = MessageDigest.getInstance("MD5");
md5.update(StandardCharsets.UTF_8.encode(string));
return String.format("%032x", new BigInteger(1, md5.digest()));
I just downloaded commons-codec.jar and got perfect php like md5. Here is manual.
Just import it to your project and use
String Url = "your_url";
System.out.println( DigestUtils.md5Hex( Url ) );
and there you have it.
No need to make it too complicated.
DigestUtils works fine and makes you comfortable while working with md5 hashes.
DigestUtils.md5Hex(_hash);
or
DigestUtils.md5(_hash);
Either you can use any other encryption methods such as sha or md.
Found this solution which is much cleaner in terms of getting a String representation back from an MD5 hash.
import java.security.*;
import java.math.*;
public class MD5 {
public static void main(String args[]) throws Exception{
String s="This is a test";
MessageDigest m=MessageDigest.getInstance("MD5");
m.update(s.getBytes(),0,s.length());
System.out.println("MD5: "+new BigInteger(1,m.digest()).toString(16));
}
}
The code was extracted from here.
Another implementation:
import javax.xml.bind.DatatypeConverter;
String hash = DatatypeConverter.printHexBinary(
MessageDigest.getInstance("MD5").digest("SOMESTRING".getBytes("UTF-8")));
Another option is to use the Guava Hashing methods:
Hasher hasher = Hashing.md5().newHasher();
hasher.putString("my string");
byte[] md5 = hasher.hash().asBytes();
Handy if you are already using Guava (which if you're not, you probably should be).
I have a Class (Hash) to convert plain text in hash in formats: md5 or sha1, simillar that php functions (md5, sha1):
public class Hash {
/**
*
* #param txt, text in plain format
* #param hashType MD5 OR SHA1
* #return hash in hashType
*/
public static String getHash(String txt, String hashType) {
try {
java.security.MessageDigest md = java.security.MessageDigest.getInstance(hashType);
byte[] array = md.digest(txt.getBytes());
StringBuffer sb = new StringBuffer();
for (int i = 0; i < array.length; ++i) {
sb.append(Integer.toHexString((array[i] & 0xFF) | 0x100).substring(1,3));
}
return sb.toString();
} catch (java.security.NoSuchAlgorithmException e) {
//error action
}
return null;
}
public static String md5(String txt) {
return Hash.getHash(txt, "MD5");
}
public static String sha1(String txt) {
return Hash.getHash(txt, "SHA1");
}
}
Testing with JUnit and PHP
PHP Script:
<?php
echo 'MD5 :' . md5('Hello World') . "\n";
echo 'SHA1:' . sha1('Hello World') . "\n";
Output PHP script:
MD5 :b10a8db164e0754105b7a99be72e3fe5
SHA1:0a4d55a8d778e5022fab701977c5d840bbc486d0
Using example and Testing with JUnit:
public class HashTest {
#Test
public void test() {
String txt = "Hello World";
assertEquals("b10a8db164e0754105b7a99be72e3fe5", Hash.md5(txt));
assertEquals("0a4d55a8d778e5022fab701977c5d840bbc486d0", Hash.sha1(txt));
}
}
Code in GitHub
https://github.com/fitorec/java-hashes
My not very revealing answer:
private String md5(String s) {
try {
MessageDigest m = MessageDigest.getInstance("MD5");
m.update(s.getBytes(), 0, s.length());
BigInteger i = new BigInteger(1,m.digest());
return String.format("%1$032x", i);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return null;
}
There is a DigestUtils class in Spring also:
http://static.springsource.org/spring/docs/3.0.x/javadoc-api/org/springframework/util/DigestUtils.html
This class contains the method md5DigestAsHex() that does the job.
You can try following. See details and download codes here: http://jkssweetlife.com/java-hashgenerator-md5-sha-1/
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class MD5Example {
public static void main(String[] args) throws Exception {
final String inputString = "Hello MD5";
System.out.println("MD5 hex for '" + inputString + "' :");
System.out.println(getMD5Hex(inputString));
}
public static String getMD5Hex(final String inputString) throws NoSuchAlgorithmException {
MessageDigest md = MessageDigest.getInstance("MD5");
md.update(inputString.getBytes());
byte[] digest = md.digest();
return convertByteToHex(digest);
}
private static String convertByteToHex(byte[] byteData) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < byteData.length; i++) {
sb.append(Integer.toString((byteData[i] & 0xff) + 0x100, 16).substring(1));
}
return sb.toString();
}
}
Bombe's answer is correct, however note that unless you absolutely must use MD5 (e.g. forced on you for interoperability), a better choice is SHA1 as MD5 has weaknesses for long term use.
I should add that SHA1 also has theoretical vulnerabilities, but not as severe. The current state of the art in hashing is that there are a number of candidate replacement hash functions but none have yet emerged as the standard best practice to replace SHA1. So, depending on your needs you would be well advised to make your hash algorithm configurable so it can be replaced in future.
Another implementation: Fast MD5 Implementation in Java
String hash = MD5.asHex(MD5.getHash(new File(filename)));
I do not know if this is relevant for anyone reading this, but I just had the problem that I wanted to
download a file from a given URL and
compare its MD5 to a known value.
I wanted to do it with JRE classes only (no Apache Commons or similar). A quick web search did not show me sample code snippets doing both at the same time, only each task separately. Because this requires to read the same file twice, I figured it might be worth the while to write some code which unifies both tasks, calculating the checksum on the fly while downloading the file. This is my result (sorry if it is not perfect Java, but I guess you get the idea anyway):
import java.io.FileOutputStream;
import java.io.IOException;
import java.math.BigInteger;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.security.DigestOutputStream; // new
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
void downloadFile(String fromURL, String toFile, BigInteger md5)
throws IOException, NoSuchAlgorithmException
{
ReadableByteChannel in = Channels.newChannel(new URL(fromURL).openStream());
MessageDigest md5Digest = MessageDigest.getInstance("MD5");
WritableByteChannel out = Channels.newChannel(
//new FileOutputStream(toFile)); // old
new DigestOutputStream(new FileOutputStream(toFile), md5Digest)); // new
ByteBuffer buffer = ByteBuffer.allocate(1024 * 1024); // 1 MB
while (in.read(buffer) != -1) {
buffer.flip();
//md5Digest.update(buffer.asReadOnlyBuffer()); // old
out.write(buffer);
buffer.clear();
}
BigInteger md5Actual = new BigInteger(1, md5Digest.digest());
if (! md5Actual.equals(md5))
throw new RuntimeException(
"MD5 mismatch for file " + toFile +
": expected " + md5.toString(16) +
", got " + md5Actual.toString(16)
);
}
import java.security.*;
import javax.xml.bind.*;
byte[] bytesOfMessage = yourString.getBytes("UTF-8");
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] bytesOfDigest = md.digest(bytesOfMessage);
String digest = DatatypeConverter.printHexBinary(bytesOfDigest).toLowerCase();
Unlike PHP where you can do an MD5 hashing of your text by just calling md5 function ie md5($text), in Java it was made little bit complicated. I usually implemented it by calling a function which returns the md5 hash text.
Here is how I implemented it, First create a function named md5hashing inside your main class as given below.
public static String md5hashing(String text)
{ String hashtext = null;
try
{
String plaintext = text;
MessageDigest m = MessageDigest.getInstance("MD5");
m.reset();
m.update(plaintext.getBytes());
byte[] digest = m.digest();
BigInteger bigInt = new BigInteger(1,digest);
hashtext = bigInt.toString(16);
// Now we need to zero pad it if you actually want the full 32 chars.
while(hashtext.length() < 32 ){
hashtext = "0"+hashtext;
}
} catch (Exception e1)
{
// TODO: handle exception
JOptionPane.showMessageDialog(null,e1.getClass().getName() + ": " + e1.getMessage());
}
return hashtext;
}
Now call the function whenever you needed as given below.
String text = textFieldName.getText();
String pass = md5hashing(text);
Here you can see that hashtext is appended with a zero to make it match with md5 hashing in PHP.
For what it's worth, I stumbled upon this because I want to synthesize GUIDs from a natural key for a program that will install COM components; I want to syhthesize so as not to manage GUID lifecycle. I'll use MD5 and then use the UUID class to get a string out of it. (http://stackoverflow.com/questions/2190890/how-can-i-generate-guid-for-a-string-values/12867439 raises this issue).
In any case, java.util.UUID can get you a nice String from the MD5 bytes.
return UUID.nameUUIDFromBytes(md5Bytes).toString();
MD5 is perfectly fine if you don't need the best security, and if you're doing something like checking file integrity then security is not a consideration. In such as case you might want to consider something simpler and faster, such as Adler32, which is also supported by the Java libraries.
this one gives the exact md5 as you get from mysql's md5 function or php's md5 functions etc. This is the one I use (you can change according to your needs)
public static String md5( String input ) {
try {
java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
byte[] array = md.digest(input.getBytes( "UTF-8" ));
StringBuffer sb = new StringBuffer();
for (int i = 0; i < array.length; i++) {
sb.append( String.format( "%02x", array[i]));
}
return sb.toString();
} catch ( NoSuchAlgorithmException | UnsupportedEncodingException e) {
return null;
}
}
import java.security.MessageDigest
val digest = MessageDigest.getInstance("MD5")
//Quick MD5 of text
val text = "MD5 this text!"
val md5hash1 = digest.digest(text.getBytes).map("%02x".format(_)).mkString
//MD5 of text with updates
digest.update("MD5 ".getBytes())
digest.update("this ".getBytes())
digest.update("text!".getBytes())
val md5hash2 = digest.digest().map(0xFF & _).map("%02x".format(_)).mkString
//Output
println(md5hash1 + " should be the same as " + md5hash2)
You can generate MD5 hash for a given text by making use of the methods in the MessageDigest class in the java.security package. Below is the complete code snippet,
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import javax.xml.bind.DatatypeConverter;
public class MD5HashGenerator
{
public static void main(String args[]) throws NoSuchAlgorithmException
{
String stringToHash = "MyJavaCode";
MessageDigest messageDigest = MessageDigest.getInstance("MD5");
messageDigest.update(stringToHash.getBytes());
byte[] digiest = messageDigest.digest();
String hashedOutput = DatatypeConverter.printHexBinary(digiest);
System.out.println(hashedOutput);
}
}
The output from the MD5 function is a 128 bit hash represented by 32 hexadecimal numbers.
In case, if you are using a database like MySQL, you can do this in a more simpler way as well. The query Select MD5(“text here”) will return the MD5 hash of the text in the bracket.
try this:
public static String getHashMD5(String string) {
try {
MessageDigest md = MessageDigest.getInstance("MD5");
BigInteger bi = new BigInteger(1, md.digest(string.getBytes()));
return bi.toString(16);
} catch (NoSuchAlgorithmException ex) {
Logger.getLogger(MD5Utils.class
.getName()).log(Level.SEVERE, null, ex);
return "";
}
}
This is what I came here for- a handy scala function that returns string of MD5 hash:
def md5(text: String) : String = java.security.MessageDigest.getInstance("MD5").digest(text.getBytes()).map(0xFF & _).map { "%02x".format(_) }.foldLeft(""){_ + _}
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
* MD5 encryption
*
* #author Hongten
*
*/
public class MD5 {
public static void main(String[] args) {
System.out.println(MD5.getMD5("123456"));
}
/**
* Use md5 encoded code value
*
* #param sInput
* clearly
* # return md5 encrypted password
*/
public static String getMD5(String sInput) {
String algorithm = "";
if (sInput == null) {
return "null";
}
try {
algorithm = System.getProperty("MD5.algorithm", "MD5");
} catch (SecurityException se) {
}
MessageDigest md = null;
try {
md = MessageDigest.getInstance(algorithm);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
byte buffer[] = sInput.getBytes();
for (int count = 0; count < sInput.length(); count++) {
md.update(buffer, 0, count);
}
byte bDigest[] = md.digest();
BigInteger bi = new BigInteger(bDigest);
return (bi.toString(16));
}
}
There is an article on Codingkit about that. Check out: http://codingkit.com/a/JAVA/2013/1020/2216.html
You could try using Caesar.
First option:
byte[] hash =
new Hash(
new ImmutableMessageDigest(
MessageDigest.getInstance("MD5")
),
new PlainText("String to hash...")
).asArray();
Second option:
byte[] hash =
new ImmutableMessageDigest(
MessageDigest.getInstance("MD5")
).update(
new PlainText("String to hash...")
).digest();