Android AES encryption tool and androidaes Tool

Android AES encryption tool and androidaes Tool

1. AES encryption tool

Java does not support PKCS7Padding. Only PKCS5Padding is supported. We know that the encryption algorithm consists of algorithm + mode + fill. This article uses the PKCS5Padding encryption method.

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Package com. example. aesdemo; import java. io. unsupportedEncodingException; import javax. crypto. cipher; import javax. crypto. spec. secretKeySpec; /// ** AES symmetric encryption and decryption class **/public class AESHelper {// ** algorithm/mode/fill **/private static final String CipherMode = "AES/ECB /PKCS5Padding "; /// ** 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 () <32) {sb. append ("0");} if (sb. length ()> 32) {sb. setLength (32);} try {data = sb. toString (). getBytes ("UTF-8");} catch (UnsupportedEncodingException e) {e. printStackTrace ();} return new SecretKeySpec (data, "AES");} // ** encrypt byte data **/public static byte [] encrypt (byte [] content, string password) {try {SecretKeySpec key = createKey (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;} // ** encrypted (the result is a hexadecimal 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 the byte array **/public static byte [] decrypt (byte [] content, String password) {try {SecretKeySpec key = createKey (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;} // ** decrypt the hexadecimal 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;} // ** convert the byte array to a hexadecimal 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 ++) {// The integer is converted to hexadecimal to indicate tmp = (java. lang. integer. toHexString (B [n] & 0XFF); if (tmp. length () = 1) {sb. append ("0");} sb. append (tmp);} return sb. toString (). toUpperCase (); // convert to uppercase} // ** convert the hex String to a 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, 16) & 0xFF);} return result ;}}

Use ~~~~~~~~~~~~~~~~ ··

String masterPassword = "a"; String originalText = "on"; try {String encryptingCode = AESHelper. encrypt (originalText, masterPassword); // System. out. println ("encrypted Result:" + encryptingCode); Log. I ("the encryption result is", encryptingCode); String decryptingCode = AESHelper. decrypt (encryptingCode, masterPassword); // System. out. println ("decryption Result:" + decryptingCode); Log. I ("decryption result", decryptingCode);} catch (Exception e) {// TODO Auto-generated catch block e. printStackTrace ();}}

Result

The encrypted result is (707): E55C24701F6380478E1940ADDFD08D22

Decryption result ( 707 ): Yu