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Added Cryptographic and Video stream Examples
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‎CryptoGraphy/Android and Php.txt‎

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/***********/
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HOW TO USE IT (JAVA)
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mcrypt = new MCrypt();
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/* Encrypt */
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String encrypted = MCrypt.bytesToHex( mcrypt.encrypt("Text to Encrypt") );
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/* Decrypt */
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String decrypted = new String( mcrypt.decrypt( encrypted ) );
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/**JAVA**/
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import java.security.NoSuchAlgorithmException;
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import javax.crypto.Cipher;
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import javax.crypto.NoSuchPaddingException;
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import javax.crypto.spec.IvParameterSpec;
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import javax.crypto.spec.SecretKeySpec;
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public class MCrypt {
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private String iv = "fedcba9876543210";//Dummy iv (CHANGE IT!)
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private IvParameterSpec ivspec;
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private SecretKeySpec keyspec;
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private Cipher cipher;
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private String SecretKey = "0123456789abcdef";//Dummy secretKey (CHANGE IT!)
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public MCrypt()
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{
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ivspec = new IvParameterSpec(iv.getBytes());
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keyspec = new SecretKeySpec(SecretKey.getBytes(), "AES");
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try {
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cipher = Cipher.getInstance("AES/CBC/NoPadding");
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} catch (NoSuchAlgorithmException e) {
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// TODO Auto-generated catch block
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e.printStackTrace();
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} catch (NoSuchPaddingException e) {
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// TODO Auto-generated catch block
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e.printStackTrace();
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}
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}
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public byte[] encrypt(String text) throws Exception
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{
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if(text == null || text.length() == 0)
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throw new Exception("Empty string");
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byte[] encrypted = null;
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try {
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cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
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encrypted = cipher.doFinal(padString(text).getBytes());
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} catch (Exception e)
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{
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throw new Exception("[encrypt] " + e.getMessage());
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}
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return encrypted;
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}
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public byte[] decrypt(String code) throws Exception
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{
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if(code == null || code.length() == 0)
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throw new Exception("Empty string");
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byte[] decrypted = null;
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try {
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cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);
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decrypted = cipher.doFinal(hexToBytes(code));
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} catch (Exception e)
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{
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throw new Exception("[decrypt] " + e.getMessage());
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}
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return decrypted;
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}
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public static String bytesToHex(byte[] data)
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{
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if (data==null)
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{
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return null;
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}
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int len = data.length;
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String str = "";
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for (int i=0; i<len; i++) {
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if ((data[i]&amp;0xFF)&lt;16)
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str = str + "0" + java.lang.Integer.toHexString(data[i]&amp;0xFF);
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else
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str = str + java.lang.Integer.toHexString(data[i]&amp;0xFF);
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}
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return str;
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}
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public static byte[] hexToBytes(String str) {
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if (str==null) {
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return null;
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} else if (str.length() &lt; 2) {
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return null;
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} else {
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int len = str.length() / 2;
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byte[] buffer = new byte[len];
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for (int i=0; i&lt;len; i++) {
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buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16);
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}
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return buffer;
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}
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}
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private static String padString(String source)
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{
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char paddingChar = ' ';
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int size = 16;
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int x = source.length() % size;
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int padLength = size - x;
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for (int i = 0; i &lt; padLength; i++)
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{
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source += paddingChar;
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}
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return source;
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}
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}
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====================================================
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====================================================
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/**********/
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HOW TO USE IT (PHP)
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$mcrypt = new MCrypt();
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#Encrypt
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$encrypted = $mcrypt->encrypt("Text to encrypt");
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#Decrypt
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$decrypted = $mcrypt->decrypt($encrypted);
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/**PHP**/
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&lt;?php
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class MCrypt
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{
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private $iv = 'fedcba9876543210'; #Same as in JAVA
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private $key = '0123456789abcdef'; #Same as in JAVA
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function __construct()
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{
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}
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function encrypt($str) {
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//$key = $this->hex2bin($key);
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$iv = $this-&gt;iv;
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$td = mcrypt_module_open('rijndael-128', '', 'cbc', $iv);
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mcrypt_generic_init($td, $this-&gt;key, $iv);
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$encrypted = mcrypt_generic($td, $str);
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mcrypt_generic_deinit($td);
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mcrypt_module_close($td);
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return bin2hex($encrypted);
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}
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function decrypt($code) {
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//$key = $this-&gt;hex2bin($key);
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$code = $this-&gt;hex2bin($code);
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$iv = $this-&gt;iv;
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$td = mcrypt_module_open('rijndael-128', '', 'cbc', $iv);
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mcrypt_generic_init($td, $this-&gt;key, $iv);
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$decrypted = mdecrypt_generic($td, $code);
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mcrypt_generic_deinit($td);
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mcrypt_module_close($td);
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return utf8_encode(trim($decrypted));
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}
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protected function hex2bin($hexdata) {
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$bindata = '';
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for ($i = 0; $i &lt; strlen($hexdata); $i += 2) {
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$bindata .= chr(hexdec(substr($hexdata, $i, 2)));
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}
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return $bindata;
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}
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}
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// see http://androidsnippets.com/encrypt-decrypt-between-android-and-php

‎CryptoGraphy/AndroidActivityCrypto.java‎

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package com.aes_encrypt;
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import java.security.NoSuchAlgorithmException;
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import java.security.SecureRandom;
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import javax.crypto.Cipher;
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import javax.crypto.KeyGenerator;
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import javax.crypto.SecretKey;
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import javax.crypto.spec.SecretKeySpec;
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import android.app.Activity;
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import android.os.Bundle;
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import android.util.Base64;
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import android.widget.TextView;
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public class Main extends Activity {
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@Override
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public void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.main);
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String s = "This is my data I want to keep safe.";
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String encryptedText = encrypt(s);
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String clearText = decrypt(encryptedText);
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((TextView)findViewById(R.id.encrypted_text)).setText(encryptedText);
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((TextView)findViewById(R.id.clear_text)).setText(clearText);
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}
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private byte[] getKey() {
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byte[] seed = "here_is_your_aes_key".getBytes();
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KeyGenerator kg;
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try {
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kg = KeyGenerator.getInstance("AES");
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} catch (NoSuchAlgorithmException e) {
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return null;
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}
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SecureRandom sr;
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try {
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sr = SecureRandom.getInstance("SHA1PRNG");
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} catch (NoSuchAlgorithmException e) {
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return null;
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}
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sr.setSeed(seed);
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kg.init(128, sr);
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SecretKey sk = kg.generateKey();
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byte[] key = sk.getEncoded();
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return key;
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}
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private String encrypt(String clearText) {
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byte[] encryptedText = null;
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try {
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SecretKeySpec ks = new SecretKeySpec(getKey(), "AES");
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Cipher c = Cipher.getInstance("AES");
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c.init(Cipher.ENCRYPT_MODE, ks);
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encryptedText = c.doFinal(clearText.getBytes("UTF-8"));
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return Base64.encodeToString(encryptedText, Base64.DEFAULT);
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} catch (Exception e) {
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return null;
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}
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}
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private String decrypt (String encryptedText) {
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byte[] clearText = null;
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try {
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SecretKeySpec ks = new SecretKeySpec(getKey(), "AES");
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Cipher c = Cipher.getInstance("AES");
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c.init(Cipher.DECRYPT_MODE, ks);
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clearText = c.doFinal(Base64.decode(encryptedText, Base64.DEFAULT));
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return new String(clearText, "UTF-8");
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} catch (Exception e) {
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return null;
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}
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}
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}

‎CryptoGraphy/CipherDemoIVparam.java‎

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ciperDemo#cat CipherDemo.java
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import java.security.*;
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import javax.crypto.*;
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import javax.crypto.spec.IvParameterSpec;
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public class CipherDemo {
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public static void main(String [] args) {
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try {
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String[] algorithm = {“AES”,”Blowfish”,”DES”};//”3DES”,”RSA”
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String[] modes = {“ECB”,”CBC”,”CFB”,”OFB”,”OFB32?,”CFB8?};
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String[] padding = {“PKCS5Padding”};//”NoPadding”
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KeyGenerator kg = null;
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Cipher cipher = null;
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for(int i=0; i<algorithm.length; i++) {
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SecretKey sk = KeyGenerator.getInstance(algorithm[i]).generateKey();
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for(int j=0; j<modes.length; j++) {
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for(int k=0; k<padding.length; k++) {
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cipher = Cipher.getInstance(algorithm[i]+”/”+modes[j]+”/”+padding[k]);
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cipher.init(Cipher.ENCRYPT_MODE, sk);
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printeParam(cipher);
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System.out.println();
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byte[] encryptedText = cipher.doFinal(“data”.getBytes());
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if(cipher.getIV()!=null) {
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cipher.init(Cipher.DECRYPT_MODE, sk, new IvParameterSpec(cipher.getIV()));
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}else{
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cipher.init(Cipher.DECRYPT_MODE, sk);
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}
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System.out.println(“Decrypted data:”+new String(cipher.doFinal(encryptedText)));
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cipher = Cipher.getInstance(algorithm[i]+”/”+modes[j]+”/”+padding[k]);
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System.out.println();
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}
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}
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}
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KeyGenerator kg1 = KeyGenerator.getInstance(“AES”);//3DES, Blowfish
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Cipher cipher1 = Cipher.getInstance(“AES/ECB/PKCS5Padding”);//CBC,CFB,OFB
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} catch (NoSuchAlgorithmException e) {
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e.printStackTrace();
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} catch (NoSuchPaddingException e) {
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e.printStackTrace();
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} catch (InvalidKeyException e) {
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e.printStackTrace();
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} catch (IllegalBlockSizeException e) {
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e.printStackTrace();
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} catch (BadPaddingException e) {
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e.printStackTrace();
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} catch (InvalidAlgorithmParameterException e) {
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e.printStackTrace();
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}
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}
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private static void printeParam(Cipher ciper) {
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System.out.println(“ciper.getProvider(): “+ciper.getProvider());
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System.out.println(“ciper.getAlgorithm(): “+ciper.getAlgorithm());
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System.out.println(“ciper.getBlockSize(): “+ciper.getBlockSize());
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System.out.println(“ciper.getParameters(): “+ciper.getParameters());
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System.out.println(“ciper.getIV(): “+ciper.getIV());
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}
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}

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