【转载】Android移动端与PHP服务端对称加密解密的实现

原文出处：Encryption between Java/Android And PHP 转载请注明原出处，尊重作者的原创，谢谢。

在网上找了很多实现，绝大多数都是不可用的，即android端和PHP端对同一字符串加密生成不一样的密文。但这个版本经测试是可用的，android版本：4.0.4，PHP5。

PHP类实现

<?
class ApiCrypter
{
    private $iv  = 'fdsfds85435nfdfs'; #与JAVA实现类中的设置必须一致
    private $key = '89432hjfsd891787'; #与JAVA实现类中的设置必须一致

    public function __construct() {
    }

    public function encrypt($str) { 
      $str = $this->pkcs5_pad($str);   
      $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);
    }

    public function decrypt($code) { 
      $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); 
      $ut =  utf8_encode(trim($decrypted));
      return $this->pkcs5_unpad($ut);
    }

    protected function hex2bin($hexdata) {
      $bindata = ''; 
      for ($i = 0; $i < strlen($hexdata); $i += 2) {
          $bindata .= chr(hexdec(substr($hexdata, $i, 2)));
      } 
      return $bindata;
    } 

    protected function pkcs5_pad ($text) {
      $blocksize = 16;
      $pad = $blocksize - (strlen($text) % $blocksize);
      return $text . str_repeat(chr($pad), $pad);
    }

    protected function pkcs5_unpad($text) {
      $pad = ord($text{strlen($text)-1});
      if ($pad > strlen($text)) {
          return false;    
      }
      if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) {
          return false;
      }
      return substr($text, 0, -1 * $pad);
    }
}
?>

JAVA类实现

package com.cwilldev.crypt;

import java.security.NoSuchAlgorithmException;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class ApiCrypter {

    private String iv              = "fdsfds85435nfdfs"; //根据实际需要更改
    private String secretkey       = "89432hjfsd891787"; //根据实际需要更改
    private IvParameterSpec ivspec;
    private SecretKeySpec keyspec;
    private Cipher cipher;

    public ApiCrypter()
    {
        ivspec = new IvParameterSpec(iv.getBytes());
        keyspec = new SecretKeySpec(secretkey.getBytes(), "AES");

        try {
            cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            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(text.getBytes("UTF-8"));
        }
        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;
        }
    }

}

PHP加密解密方法：

$original_text = 'test';
$mdes = new ApiCrypterUtil();
//加密
$encrypt_text = $mdes->encrypt($original_text);
$this->log($encrypt_text, LOG_DEBUG);
//解密
$this->log($mdes->decrypt($encrypt_text), LOG_DEBUG); 

Java加密解密方法：

//加密:
ApiCrypter apiCrypter = new ApiCrypter();
String originalText = "test";
String encryptedText = ApiCrypter.bytesToHex(apiCrypter.encrypt(jsonParams.toString()));
//解密:
String res = new String(apiCrypter.decrypt(encryptedText), "UTF-8"); 
String decryptedText = URLDecoder.decode(res, "UTF-8");