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@SimoneStefani
Last active August 17, 2021 14:03
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Example of AES encryption and decryption in Java
/**
* Code written by P. Gajland
* https://github.com/GaPhil
*
* IMPORTANT:
* This code is for educational and demonstrative purpose only.
* If you need to do serious encryption for "production" it is
* recommended to investigate more traditional libraries and
* gain some specific knowledge on cryptography and security.
*/
import java.security.Key;
import javax.crypto.Cipher;
import sun.misc.BASE64Encoder;
import sun.misc.BASE64Decoder;
import javax.crypto.spec.SecretKeySpec;
public class AESenc {
private static final String ALGO = "AES";
private static final byte[] keyValue =
new byte[]{'T', 'h', 'e', 'B', 'e', 's', 't', 'S', 'e', 'c', 'r', 'e', 't', 'K', 'e', 'y'};
/**
* Encrypt a string with AES algorithm.
*
* @param data is a string
* @return the encrypted string
*/
public static String encrypt(String data) throws Exception {
Key key = generateKey();
Cipher c = Cipher.getInstance(ALGO);
c.init(Cipher.ENCRYPT_MODE, key);
byte[] encVal = c.doFinal(data.getBytes());
return new BASE64Encoder().encode(encVal);
}
/**
* Decrypt a string with AES algorithm.
*
* @param encryptedData is a string
* @return the decrypted string
*/
public static String decrypt(String encryptedData) throws Exception {
Key key = generateKey();
Cipher c = Cipher.getInstance(ALGO);
c.init(Cipher.DECRYPT_MODE, key);
byte[] decordedValue = new BASE64Decoder().decodeBuffer(encryptedData);
byte[] decValue = c.doFinal(decordedValue);
return new String(decValue);
}
/**
* Generate a new encryption key.
*/
private static Key generateKey() throws Exception {
return new SecretKeySpec(keyValue, ALGO);
}
}
@RZMiRaN
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RZMiRaN commented Apr 28, 2018

@merugu
it must be 16 characters length because each character is 8 bits, which means 16 characters will make 128 bits

@cristianprofile
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10000 thanks for your code!!!!! It works like a charm!!!!!

@SuganV
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SuganV commented Nov 26, 2018

Isnt it possible to have keyValue byte in a String Datatype ???

@aayush9333
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What will be the main class?

@ahmedalfakih97
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dosn't hava a main method

@Uyagi
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Uyagi commented Mar 15, 2019

What will be the main class?

Added what would make a potential main method work

import java.util.Scanner;


public class AESenc {

    private static Scanner input = new Scanner(System.in);
    private static String data = input.nextLine();


    /** 
     * Main
     */
    public static void main(String[] args) throws Exception
    { 
        AESenc cipher = new AESenc();
        System.out.println(cipher.encrypt(data));
    } 

}

@networkspyghana
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please how can i convert this code to php. i want to encrypte with php and decrypt with java

@ApoorvaOjha
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I am getting this exception when I run the same code in decryption process... please help!

Exception in thread "main" javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:934)
at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:845)
at com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:446)
at javax.crypto.Cipher.doFinal(Cipher.java:2165)
at ae1.Ae1.decrypt(Ae1.java:40)
at ae1.Ae1.main(Ae1.java:60)
C:\Users\apoor\AppData\Local\NetBeans\Cache\8.2\executor-snippets\run.xml:53: Java returned: 1

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