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字符串加密解密种

发布时间: 2012-11-12 12:31:57 作者: rapoo

字符串加密解密类
import javax.crypto.*;

import javax.crypto.spec.*;

import java.security.*;



public class EncryptData {



DESedeKeySpec spec;

SecretKeyFactory keyFactory;

SecretKey theKey;

Cipher cipher;

IvParameterSpec IvParameters;



public EncryptData() {

byte[] encryptKey;

try {

// 检测是否有 TripleDES 加密的供应程序

// 如无,明确地安装SunJCE 供应程序

try {

Cipher c = Cipher.getInstance("DESede");

} catch (Exception e) {

System.err.println("Installling SunJCE provider.");

Provider sunjce = new com.sun.crypto.provider.SunJCE();

Security.addProvider(sunjce);

}

// 创建一个密钥

encryptKey = "This is a test DESede Key".getBytes();



// 为上一密钥创建一个指定的 DESSede key

spec = new DESedeKeySpec(encryptKey);



// 得到 DESSede keys

keyFactory = SecretKeyFactory.getInstance("DESede");



// 生成一个 DESede 密钥对象

theKey = keyFactory.generateSecret(spec);



// 创建一个 DESede 密码

cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");



// 为 CBC 模式创建一个用于初始化的 vector 对象

IvParameters = new IvParameterSpec(new byte[] { 12, 34, 56, 78, 90, 87, 65, 43 });

} catch (Exception exc) {

// 记录加密或解密操作错误

}

}



private String encrypt(String password) {

String encrypted_password = null;

byte[] encrypted_pwd = null;



try {

// 以加密模式初始化密钥

cipher.init(Cipher.ENCRYPT_MODE, theKey, IvParameters);



// 加密前的密码(旧)

byte[] plainttext = password.getBytes();



// 加密密码

encrypted_pwd = cipher.doFinal(plainttext);



// 转成字符串,得到加密后的密码(新)

encrypted_password = new String(encrypted_pwd);

} catch (Exception ex) {

// 记录加密错误

}



StringBuffer tempString = new StringBuffer();

for (int i = 0; i < encrypted_pwd.length; i++) {

tempString.append(encrypted_pwd[i] + ",");

}



String aa = new String(tempString);

return aa;

}



private String decrypt(String spassword) {

String[] ss = spassword.split(",");

byte[] password = new byte[ss.length];

for (int i = 0; i < ss.length; i++) {

password[i] = (byte) (new Integer(ss[i]).intValue());

}

String decrypted_password = null;

try {

// 以解密模式初始化密钥

cipher.init(Cipher.DECRYPT_MODE, theKey, IvParameters);



// 构造解密前的密码

byte[] decryptedPassword = password;



// 解密密码

byte[] decrypted_pwd = cipher.doFinal(decryptedPassword);

// 得到结果

decrypted_password = new String(decrypted_pwd);

} catch (Exception ex) {

// 记录解密错误

}

return decrypted_password;

}



/**

* 加密算法

* @param password 未加密的密码

* @return 加密后的密码

*/

public static String s_encrypt(String password) {

String encrypted_pwd = null;

EncryptData encryptData = new EncryptData();

encrypted_pwd = encryptData.encrypt(password);

return encrypted_pwd;

}



/**

* 解密算法

* @param password 加过密的密码

* @return 解密后的密码

*/

public static String b_decrypt(String password) {

String decrypted_password = null;

EncryptData encryptData = new EncryptData();

decrypted_password = encryptData.decrypt(password);

return decrypted_password;

}



}

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