Cryptography in PHP + Android

HOW TO USE IT (JAVA):


mcrypt = new MCrypt();

/*** encrypt */
String encrypted = MCrypt.bytesToHex(mcrypt.encrypt("plaintext"));

/*** decrypt */
String decrypted = new String(mcrypt.decrypt(encrypted));


HOW TO USE IT (PHP):



$mcrypt = new MCrypt();

#Encrypt
$encrypted = $mcrypt->encrypt("plaintext");

#Decrypt
$decrypted = $mcrypt->decrypt($encrypted);


Library Java:


import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class MCrypt {

private String iv = "fedcba9876543210"; //Dummy iv (CHANGE IT!)
private IvParameterSpec ivspec;
private SecretKeySpec keyspec;
private Cipher cipher;

private String SecretKey = "0123456789abcdef"; //Dummy secretKey (CHANGE IT!)

public MCrypt()
{
ivspec = new IvParameterSpec(iv.getBytes());
keyspec = new SecretKeySpec(SecretKey.getBytes(), "AES");

try {
cipher = Cipher.getInstance("AES/CBC/NoPadding");
}
catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (NoSuchPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

public byte[] encrypt(String text) throws Exception
{
if(text == null || text.length() == 0)
throw new Exception("Empty string");

byte[] encrypted = null;

try {
cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);

encrypted = cipher.doFinal(padString(text).getBytes());
}
catch (Exception e)
{
throw new Exception("[encrypt] " + e.getMessage());
}

return encrypted;
}

public byte[] decrypt(String code) throws Exception
{
if(code == null || code.length() == 0)
throw new Exception("Empty string");

byte[] decrypted = null;

try {
cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

decrypted = cipher.doFinal(hexToBytes(code));
}
catch (Exception e)
{
throw new Exception("[decrypt] " + e.getMessage());
}
return decrypted;
}

public static String bytesToHex(byte[] data)
{
if (data==null) return null;

int len = data.length;
String str = "";
for (int i=0; i
if ((data[i]&0xFF)<16)
str = str + "0" + java.lang.Integer.toHexString(data[i]&0xFF);
else
str = str + java.lang.Integer.toHexString(data[i]&0xFF);
}
return str;
}

public static byte[] hexToBytes(String str)
{
if (str==null) {
return null;
}
else if (str.length() < 2) {
return null;
}
else {
int len = str.length() / 2;
byte[] buffer = new byte[len];
for (int i=0; i
buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16);
}
return buffer;
}
}

private static String padString(String source)
{
char paddingChar = ' ';
int size = 16;
int x = source.length() % size;
int padLength = size - x;

for (int i = 0; i < padLength; i++)
{
source += paddingChar;
}

return source;
}
}


Library PHP:



class MCrypt
{
private $iv = 'fedcba9876543210'; #Same as in JAVA
private $key = '0123456789abcdef'; #Same as in JAVA

function __construct() {}

function encrypt($str)
{
//$key = $this->hex2bin($key);
$iv = $this->iv;

$td = mcrypt_module_open('rijndael-128', '', 'cbc', $iv);

mcrypt_generic_init($td, $this->key, $iv);
$encrypted = mcrypt_generic($td, $str);

mcrypt_generic_deinit($td);
mcrypt_module_close($td);

return bin2hex($encrypted);
}

function decrypt($code)
{
//$key = $this->hex2bin($key);
$code = $this->hex2bin($code);
$iv = $this->iv;

$td = mcrypt_module_open('rijndael-128', '', 'cbc', $iv);

mcrypt_generic_init($td, $this->key, $iv);
$decrypted = mdecrypt_generic($td, $code);

mcrypt_generic_deinit($td);
mcrypt_module_close($td);

return utf8_encode(trim($decrypted));
}

protected function hex2bin($hexdata)
{
$bindata = '';

for ($i = 0; $i < strlen($hexdata); $i += 2) {
$bindata .= chr(hexdec(substr($hexdata, $i, 2)));
}

return $bindata;
}

}

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The modes of operation currently available are: 

OFB
CBC
CFB
CTR