BadPaddingException

[Arpit Panwar]

 
package Encryption;
import java.io.*;
import java.security.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.crypto.Cipher.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public class EncMain {

    private Cipher cipher = null;
    private SecretKeySpec skeySpec;
    // private   String message = "asgfd";
    private IvParameterSpec iv;
    private byte[] rawBytes = {66, -56, -63, -97, -23, -9, 27, -3, 63, -115, 85, 81, -31, 127, -48, -92};
    private String Username = "";
    private String key = "";
    private String encrypted = "";
    private String decrypted = "";

    public EncMain() {
        Username = "arpitpanwar";//new UserBean.UserData().getUser();
        try {

            skeySpec = new GenKey().Gen(Username);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // public static void main(String[] args) throws Exception {
    public String getKey() throws Exception {
        byte[] gky = skeySpec.getEncoded();
        BASE64Encoder ecode = new BASE64Encoder();
        key = ecode.encodeBuffer(gky);
        //  key=ecode.encode(gky);
        return key;
    }

    public String doEncrypt(String message) {
        EncMain m = new EncMain();
        iv = new IvParameterSpec(rawBytes);
        //yaha par padding ho rahi hai
        String ec = Pad(message);
        byte[] btt = ec.getBytes();
        encrypted = m.encrypt(btt);
        return encrypted;
    }

    public String doDecrypt(String enc, int len, String key) {
        String s1=Pad(enc);
        String dec = new EncMain().decrpyt(s1, key);
        //remove padding
        //String decrypted=UnPad(dec,len);
        return dec;
    }

    //encryption ho gaya
    //  System.out.println("Encrypted string-:" + e);
    //decryption ho gaya
    // System.out.println("Decrypted string-:" +fi);
    // }
    private String encrypt(byte[] encrypted) {
        try {
            //instantiate the cipher
            cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
            byte[] encrypt = cipher.doFinal(encrypted);
            return new String(encrypt);
        } catch (Exception ex) {
            return "their is an error";
        }

    }

    private String decrpyt(String encrypted, String Key) {
        try {
            cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            iv = new IvParameterSpec(rawBytes);
            String retrivedbkey = Key;//from database
            BASE64Decoder dcode = new BASE64Decoder();
            byte[] dkey = dcode.decodeBuffer(retrivedbkey);
            SecretKeySpec skeySpec1 = new SecretKeySpec(dkey,"AES");
            cipher.init(Cipher.DECRYPT_MODE, skeySpec1, iv);
            byte[] original = cipher.doFinal(encrypted.getBytes());
            String ostring = new String(original);
            return ostring;
        } catch (Exception ex) {
            ex.printStackTrace();
            System.out.println(ex.getMessage());
            return "Their is an IllegleBlockSizeException ";
        }
    }

    private static String Pad(String src) {
        //  StringBuffer ms = null;
        StringBuffer s = new StringBuffer(src);
        int len = src.length();
        int padlen1 = len % 16;
        int padlen = 16 - padlen1;

        if (padlen != 16) {
            for (int i = 0; i < padlen; i++) {
                s.append("5");
            }
        }
        return s.toString();
    }

    private static String UnPad(String src, int ht) {
        StringBuffer ms = null;
        StringBuffer s = new StringBuffer(src);
        String de = s.toString();
        String re = de.substring(0, ht);
        return re.toString();
    }
    
}


MY MAIN CLASS CODE IS :
/*
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 * and open the template in the editor.
 */

package Encryption;

/**
 *
 * @author Administrator
 */
public class test {
    public static void main(String[] args)throws Exception{
        EncMain e = new EncMain();
       String key = e.getKey();
       //System.out.println(new String("This is amessage").length());
       String encrypted = e.doEncrypt("Thisamessage");
       System.out.println(key);
      // System.out.println(encrypted.getBytes().length);
       System.out.println("Excrypted:-   "+encrypted);
       String decrypt = e.doDecrypt(encrypted, 16,key);
       System.out.println("Decrypted:-  "+decrypt);
    }
    

}

   

[Ulf Dittmer]

You don't tell us what's happening, or in which line of code it's happening, but usually this exception is caused by treating encrypted data (which is binary data) as character data (by storing it in a String object). The code seems to be doing exactly that.