android 使用des算法

转自：http://www.linuxidc.com/Linux/2011-08/41866.htm 稍有改动

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

import javax.crypto.Cipher;

importjavax.crypto.SecretKeyFactory;

importjavax.crypto.spec.DESKeySpec;

import android.util.Base64;

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

 /**

*DES算法，加密

*@paramdata待加密字符串

*@paramkey加密私钥，长度不能够小于8位

*@return加密后的字节数组，一般结合Base64编码使用

*@throwsCryptException异常

*/

publicstaticStringencode(Stringkey,Stringdata)throwsException{

returnencode(key,data.getBytes());

 /**

*DES算法，加密

*@paramdata待加密字符串

*@paramkey加密私钥，长度不能够小于8位

*@return加密后的字节数组，一般结合Base64编码使用

*@throwsCryptException

*异常

*/

privatestaticStringencode(Stringkey,byte[]data)throwsException{

try{

DESKeySpecdks=newDESKeySpec(key.getBytes());

SecretKeyFactorykeyFactory=SecretKeyFactory.getInstance("DES");

//key的长度不能够小于8位字节

KeysecretKey=keyFactory.generateSecret(dks);

Ciphercipher=Cipher.getInstance(ALGORITHM_DES);

IvParameterSpeciv=newIvParameterSpec("12345678".getBytes());

AlgorithmParameterSpecparamSpec=iv;

cipher.init(Cipher.ENCRYPT_MODE,secretKey,paramSpec);

byte[]bytes=cipher.doFinal(data);

returnBase64.encodeToString(bytes,0);

}catch(Exceptione){

thrownewException(e);

}

 /**

*DES算法，解密

*@paramdata待解密字符串

*@paramkey解密私钥，长度不能够小于8位

*@return解密后的字节数组

*@throwsException异常

*/

privatestaticbyte[]decode(Stringkey,byte[]data)throwsException{

try{

DESKeySpecdks=newDESKeySpec(key.getBytes());

SecretKeyFactorykeyFactory=SecretKeyFactory.getInstance("DES");

//key的长度不能够小于8位字节

KeysecretKey=keyFactory.generateSecret(dks);

Ciphercipher=Cipher.getInstance(ALGORITHM_DES);

IvParameterSpeciv=newIvParameterSpec("12345678".getBytes());

AlgorithmParameterSpecparamSpec=iv;

cipher.init(Cipher.DECRYPT_MODE,secretKey,paramSpec);

returncipher.doFinal(data);

}catch(Exceptione){

thrownewException(e);

}

}

 /**

*解密.

*@paramkey

*@paramdata

*@return

*@throwsException

*/

publicstaticStringdecode(Stringkey,Stringdata){

byte[]datas;

Stringvalue=null;

try{

if(System.getProperty("os.name")!=null

&&(System.getProperty("os.name").equalsIgnoreCase("sunos")||System

.getProperty("os.name").equalsIgnoreCase("linux"))){

datas=decode(key,Base64.decode(data,0));

}else{

datas=decode(key,Base64.decode(data,0));

   value = new String(datas);

}catch(Exceptione){

value="";

}

returnvalue;

}