Android AES Encryption Tool class sharing _android

1, AES Encryption tool class

Java does not support pkcs7padding and supports only pkcs5padding. We know that the encryption algorithm by the algorithm + mode + fill composition, the next introduction of iOS and Android general AES encryption, this article uses pkcs5padding encryption method.

Package Com.example.aesdemo;
Import java.io.UnsupportedEncodingException;
Import Javax.crypto.Cipher;
 
Import Javax.crypto.spec.SecretKeySpec; * * AES symmetric encryption decryption class **/public class Aeshelper {///** algorithm/mode/fill **/private static final String Ciphermode = "aes/ecb/pk
 
 Cs5padding ";
 * * Create key **/private static Secretkeyspec CreateKey (String password) {byte[] data = null;
 if (password = = null) {password = "";
 StringBuffer sb = new StringBuffer (32);
 Sb.append (password);
 while (Sb.length () <) {Sb.append ("0");
 } if (Sb.length () >) {sb.setlength (32);
 try {data = sb.tostring (). GetBytes ("UTF-8");
 catch (Unsupportedencodingexception e) {e.printstacktrace ();
 Return to new Secretkeyspec (data, "AES"); }///** encrypted byte data **/public static byte[] Encrypt (byte[] content, String password) {try {secretkeyspec key = creat
  EKey (password);
  SYSTEM.OUT.PRINTLN (key);
  Cipher Cipher = cipher.getinstance (Ciphermode); Cipher.init (Cipher.encrypt_mode, key);
  Byte[] result = cipher.dofinal (content);
 return result;
 catch (Exception e) {e.printstacktrace ();
 return null;
 ///** encryption (Result 16 binary string) **/public static string encrypt (string content, string password) {byte[] data = null;
 try {data = Content.getbytes ("UTF-8");
 catch (Exception e) {e.printstacktrace ();
 data = Encrypt (data, password);
 String result = Byte2hex (data);
 return result; }///** decrypt byte array **/public static byte[] Decrypt (byte[] content, String password) {try {secretkeyspec key = creat
  EKey (password);
  Cipher Cipher = cipher.getinstance (Ciphermode);
  Cipher.init (Cipher.decrypt_mode, key);
  Byte[] result = cipher.dofinal (content);
 return result;
 catch (Exception e) {e.printstacktrace ();
 return null;
 ///** decrypts the 16-binary string as a string **/public static string decrypt (string content, string password) {byte[] data = null;
 try {data = hex2byte (content);
 catch (Exception e) {e.printstacktrace (); } data = Decrypt (data, password);
 if (data = null) return null;
 String result = null;
 try {result = new String (data, "UTF-8");
 catch (Unsupportedencodingexception e) {e.printstacktrace ();
 return result; The///** byte array is converted to a 16 feed string **/public static string Byte2hex (byte[] b) {//number of bytes, stringbuffer sb = new StringBuffer (b.
 Length * 2);
 String tmp = "";
  for (int n = 0; n < b.length; n++) {//integer to hexadecimal indicates tmp = (java.lang.Integer.toHexString (b[n) & 0XFF));
  if (tmp.length () = = 1) {sb.append ("0");
 } sb.append (TMP); Return sb.tostring (). toUpperCase ();  Turn uppercase}///** hex string to byte array **/private static byte[] Hex2byte (string inputstring) {if (inputstring = null | |
 Inputstring.length () < 2) {return new byte[0];
 } inputstring = Inputstring.tolowercase ();
 int L = inputstring.length ()/2;
 Byte[] result = new Byte[l];
  for (int i = 0; i < L; ++i) {String tmp = inputstring.substring (2 * I, 2 * i + 2); Result[i] = (byte) (Integer.parseint (TMP,) & 0xFF);
 return result; }
}

2. Use

New Android Project

Package Com.example.aesdemo;
Import Android.os.Bundle;
Import android.app.Activity;
Import Android.view.Menu; 

Import Android.util.Log; public class Mainactivity extends activity {protected void OnCreate (Bundle savedinstancestate) {super.oncreate (SA
 		Vedinstancestate);
	
	 Setcontentview (R.layout.activity_main); 
	 String Masterpassword = "a"; 

	 String originaltext = "to"; 
try {String Encryptingcode = Aeshelper.encrypt (Originaltext,masterpassword); 
	  SYSTEM.OUT.PRINTLN ("Encrypted result is" + encryptingcode); 
	  LOG.I ("Encrypted result is", encryptingcode); 
String Decryptingcode = Aeshelper.decrypt (Encryptingcode,masterpassword); 
	  System.out.println ("decryption result is" + decryptingcode); 
	  LOG.I ("decryption result", decryptingcode); 
	 catch (Exception e) {//TODO auto-generated catch block E.printstacktrace (); } @Override Public boolean Oncreateoptionsmenu (Menu menu) {//Inflate the menu; This adds items to the action B
		Ar if it is present. Getmenuinflater (). Inflate (r.menu.mAin, menu);
	return true; }
}

3, printing results

09-19 10:41:05.467:i/Encryption Result (707): E55c24701f6380478e1940addfd08d22
09-19 10:41:05.467:i/decryption Result (707):