Android DES Decrypt decode(String key, String data)

Description

decode

Declaration

public static String decode(String key, String data) 

Method Source Code

//package com.java2s;

import java.security.Key;
import java.security.spec.AlgorithmParameterSpec;

import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;

public class Main {
    public static final String ALGORITHM_DES = "DES/CBC/PKCS5Padding";

    public static String decode(String key, String data) {
        if (data == null)
            return null;
        try {/*from  w  w w .j a v a 2s  .c  o  m*/
            DESKeySpec dks = new DESKeySpec(key.getBytes());
            SecretKeyFactory keyFactory = SecretKeyFactory
                    .getInstance("DES");
            Key secretKey = keyFactory.generateSecret(dks);
            Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
            IvParameterSpec iv = new IvParameterSpec(key.getBytes());
            AlgorithmParameterSpec paramSpec = iv;
            cipher.init(Cipher.DECRYPT_MODE, secretKey, paramSpec);
            return new String(cipher.doFinal(hex2byte(data.getBytes())));
        } catch (Exception e) {
            e.printStackTrace();
            return data;
        }
    }

    private static byte[] hex2byte(byte[] b) {
        if ((b.length % 2) != 0)
            throw new IllegalArgumentException();
        byte[] b2 = new byte[b.length / 2];
        for (int n = 0; n < b.length; n += 2) {
            String item = new String(b, n, 2);
            b2[n / 2] = (byte) Integer.parseInt(item, 16);
        }
        return b2;
    }
}

Related

1. decode(String key, String data)
2. desDecodeCBC(byte[] key, byte[] keyiv, byte[] data)
3. desDecodeECB(byte[] key, byte[] data)
4. decryptDES(String decryptString, String decryptKey)
5. decryptDESFile(byte[] decryptData, String decryptKey)
6. decode(String key, byte[] data)
7. decrypt(byte[] key, byte[] src)
8. encode(String key, String data)
9. decryptBytes(String key, byte[] src)