AES encryption CBC mode pkcs7padding filling Base64 encoding key 32byte iv16byte

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.Security;
import java.util.Arrays;


public class AES {



    public static void main(String[] args) throws IOException {
        AES aes = new AES();
        //  encryption   secret key 
//        String key = "1234567890qwertyuiopasdfghjklzxc";
//        b'\x87\xe9\x11\xfe\x82\xce\x8dS\x08;9\xd2\xbfx\x03\x95\x15\x99\xc2\x02\x9c\xcb\xaa\xd7G\x16\xd8\xae\x157U\xdb'

        byte[] keybytes = {(byte)0x87,(byte)0xe9,(byte)0x11,(byte)0xfe,(byte)0x82,(byte)0xce,(byte)0x8d,'S',(byte)0x08,';','9',(byte)0xd2,(byte)0xbf,'x',(byte)0x03,(byte)0x95,(byte)0x15,(byte)0x99,(byte)0xc2,(byte)0x02,(byte)0x9c,(byte)0xcb,(byte)0xaa,(byte)0xd7,'G',(byte)0x16,(byte)0xd8,(byte)0xae,(byte)0x15,'7','U',(byte)0xdb};
//         byte[] keybytes = { '1','2','3','4','5','6','7','8','9','0','q','w','e','r','t','y','u','i','o','p','a','s','d','f','g','h','j','k','l','z','x','c' };
//        byte[] keybytes = key.getBytes();
        byte[] iv = {(byte)0x87,(byte)0xe9,(byte)0x11,(byte)0xfe,(byte)0x82,(byte)0xce,(byte)0x8d,'S',(byte)0x08,';','9',(byte)0xd2,(byte)0xbf,'x',(byte)0x03,(byte)0x95};

        // Encrypted string 
        String content = "Hello,  Han -  mei  - mei ";
        System.out.println(" Before encryption ：" + content);
        System.out.println(" Encryption key ：" + new String(keybytes));
        //  Encryption method 
        String enc = aes.encrypt(content.getBytes(), keybytes,iv);
//        String encode = new BASE64Encoder().encode(enc);
        System.out.println(" Encrypted content ：" + enc);
//        System.out.println(" Encrypted content ：" + new String(Hex.encode(enc)));

        //  Decryption method 
//        byte[] bytes = new BASE64Decoder().decodeBuffer(enc);
        String dec = aes.decrypt(enc, keybytes,iv);
        System.out.println(" Decrypted content ：" + new String(dec));
    }




    /**
     *
     * @author ngh
     *
     * AES128  Algorithm 
     *
     * CBC  Pattern 
     *
     * PKCS7Padding  Fill mode 
     *
     * CBC The pattern needs to add a parameter iv
     *
     *  Be situated between java  I won't support it PKCS7Padding, Only support PKCS5Padding  however PKCS7Padding  and  PKCS5Padding  There's no difference 
     *  To be realized in java End use PKCS7Padding fill , Need to use bouncycastle Component to implement 
     */

    //  The algorithm name 
    final String KEY_ALGORITHM = "AES";
    //  Encryption and decryption algorithm / Pattern / fill style 
    final String algorithmStr = "AES/CBC/PKCS7Padding";
    //
    private Key key;
    private Cipher cipher;
    boolean isInited = false;

    //    String ivs = "1234567890qwerty";
//    byte[] iv = ivs.getBytes();
//    byte[] iv = {'1','2','3','4','5','6','7','8','9','0', 'q', 'w', 'e', 'r', 't', 'y' };
    public void init(byte[] keyBytes) {

        //  If you don't have enough keys 16 position , Then make up .   This if  The content in is very important 
        int base = 16;
        if (keyBytes.length % base != 0) {
            int groups = keyBytes.length / base + (keyBytes.length % base != 0 ? 1 : 0);
            byte[] temp = new byte[groups * base];
            Arrays.fill(temp, (byte) 0);
            System.arraycopy(keyBytes, 0, temp, 0, keyBytes.length);
            keyBytes = temp;
        }
        //  initialization 
        Security.addProvider(new BouncyCastleProvider());
        //  Turn it into JAVA The key format of 
        key = new SecretKeySpec(keyBytes, KEY_ALGORITHM);
        try {
            //  initialization cipher
            cipher = Cipher.getInstance(algorithmStr, "BC");
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (NoSuchProviderException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    /**
     *  Encryption method 
     *
     * @param content
     *             The string to encrypt 
     * @param keyBytes
     *             Encryption key 
     * @return
     */
    public String encrypt(byte[] content, byte[] keyBytes,byte[] iv) {
        byte[] encryptedText = null;
        init(keyBytes);
        System.out.println("IV：" + new String(iv));
        try {
            cipher.init(Cipher.ENCRYPT_MODE, key, new IvParameterSpec(iv));
            encryptedText = cipher.doFinal(content);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        String encode = new BASE64Encoder().encode(encryptedText);
        return encode;
    }
    /**
     *  Decryption method 
     *
     *
     *             String to decrypt 
     * @param keyBytes
     *             decryption key 
     * @return
     */
    public String decrypt(String enc, byte[] keyBytes,byte[] iv) throws IOException {
        byte[] encryptedData = new BASE64Decoder().decodeBuffer(enc);
        byte[] encryptedText = null;
        init(keyBytes);
        System.out.println("IV：" + new String(iv));
        try {
            cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
            encryptedText = cipher.doFinal(encryptedData);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
//        String encode = new BASE64Encoder().encode(encryptedText);
        String str = new String(encryptedText);
        return str;


    }

}