PHP + Android XML 加密/解密

Question

我有一个应用程序正在下载一个 xml 并将其解析到一个 sql 数据库中。我的问题是，一旦部署了应用程序，来自 xml 的数据很容易被抓取，其他人可以将我来之不易的数据用于他们自己的邪恶目的/应用程序。基本上我需要使用 php 加密 xml，然后使用 android 解密它。我见过几个易于加密的 php 类，但我不完全确定哪种加密方法与 android 兼容。

解决后编辑：

起初我以为出于某种原因我不得不忽略括号，并打算遍历所有文本并吐出格式化的 xml 大声笑。比这简单得多。

$mcrypt = new MCrypt();
$datainxml = file_get_contents("data.xml");
$cipher = $mcrypt->encrypt($value);
echo $cipher;

Answer 1

以下代码可能对您有所帮助。使用它你可以加密/解密 PHP 和 Android 之间的字符串。

Java 部分：

import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class MCrypt {

    private String iv = "fedcba9876543210";//Dummy iv (CHANGE IT!)
    private IvParameterSpec ivspec;
    private SecretKeySpec keyspec;
    private Cipher cipher;

    private String SecretKey = "0123456789abcdef";//Dummy secretKey (CHANGE IT!)

    public MCrypt()
    {
        ivspec = new IvParameterSpec(iv.getBytes());

        keyspec = new SecretKeySpec(SecretKey.getBytes(), "AES");

        try {
            cipher = Cipher.getInstance("AES/CBC/NoPadding");
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public byte[] encrypt(String text) throws Exception
    {
        if(text == null || text.length() == 0)
            throw new Exception("Empty string");

        byte[] encrypted = null;

        try {
            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);

            encrypted = cipher.doFinal(padString(text).getBytes());
        } catch (Exception e)
        {           
            throw new Exception("[encrypt] " + e.getMessage());
        }

        return encrypted;
    }

    public byte[] decrypt(String code) throws Exception
    {
        if(code == null || code.length() == 0)
            throw new Exception("Empty string");

        byte[] decrypted = null;

        try {
            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);

            decrypted = cipher.doFinal(hexToBytes(code));
        } catch (Exception e)
        {
            throw new Exception("[decrypt] " + e.getMessage());
        }
        return decrypted;
    }



    public static String bytesToHex(byte[] data)
    {
        if (data==null)
        {
            return null;
        }

        int len = data.length;
        String str = "";
        for (int i=0; i<len; i++) {
            if ((data[i]&0xFF)<16)
                str = str + "0" + java.lang.Integer.toHexString(data[i]&0xFF);
            else
                str = str + java.lang.Integer.toHexString(data[i]&0xFF);
        }
        return str;
    }


    public static byte[] hexToBytes(String str) {
        if (str==null) {
            return null;
        } else if (str.length() < 2) {
            return null;
        } else {
            int len = str.length() / 2;
            byte[] buffer = new byte[len];
            for (int i=0; i<len; i++) {
                buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16);
            }
            return buffer;
        }
    }



    private static String padString(String source)
    {
      char paddingChar = ' ';
      int size = 16;
      int x = source.length() % size;
      int padLength = size - x;

      for (int i = 0; i < padLength; i++)
      {
          source += paddingChar;
      }

      return source;
    }
}

PHP部分：

<?php 

class MCrypt
{
    private $iv = 'fedcba9876543210'; #Same as in JAVA
    private $key = '0123456789abcdef'; #Same as in JAVA


    function __construct()
    {
    }

    function encrypt($str) {

      //$key = $this->hex2bin($key);    
      $iv = $this->iv;

      $td = mcrypt_module_open('rijndael-128', '', 'cbc', $iv);

      mcrypt_generic_init($td, $this->key, $iv);
      $encrypted = mcrypt_generic($td, $str);

      mcrypt_generic_deinit($td);
      mcrypt_module_close($td);

      return bin2hex($encrypted);
    }

    function decrypt($code) {
      //$key = $this->hex2bin($key);
      $code = $this->hex2bin($code);
      $iv = $this->iv;

      $td = mcrypt_module_open('rijndael-128', '', 'cbc', $iv);

      mcrypt_generic_init($td, $this->key, $iv);
      $decrypted = mdecrypt_generic($td, $code);

      mcrypt_generic_deinit($td);
      mcrypt_module_close($td);

      return utf8_encode(trim($decrypted));
    }

    protected function hex2bin($hexdata) {
      $bindata = '';

      for ($i = 0; $i < strlen($hexdata); $i += 2) {
        $bindata .= chr(hexdec(substr($hexdata, $i, 2)));
      }

      return $bindata;
    }

}

用法（Java）：

mcrypt = new MCrypt();
/* Encrypt */
String encrypted = MCrypt.bytesToHex( mcrypt.encrypt("Text to Encrypt") );
/* Decrypt */
String decrypted = new String( mcrypt.decrypt( encrypted ) );

用法（PHP）：

$mcrypt = new MCrypt();
#Encrypt
$encrypted = $mcrypt->encrypt("Text to encrypt");
#Decrypt
$decrypted = $mcrypt->decrypt($encrypted);