java对称加密算法的使用

package utils;

import java.io.UnsupportedEncodingException;

import java.security.MessageDigest;

import java.security.SecureRandom;

import java.security.spec.AlgorithmParameterSpec;

import java.security.spec.KeySpec;

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

import javax.crypto.spec.DESedeKeySpec;

import javax.crypto.spec.IvParameterSpec;

import javax.crypto.spec.SecretKeySpec;

 

/**

 * DES的密钥(key)长度是为8个字节,加密解密的速度是最快的<br>

 * DESede的密钥(key)长度是24个字节<br>

 * AES的密钥(key)长度是16个字节<br>

 * BlowFish的密钥(key)长度是可变的(1<=key<=16),加密最快,强度最高<br>

 */

public class AppCrypt {

 

    public final static String DES = "DES";

    public final static String DESEDE = "DESede";

    public final static String AES = "AES";

    public final static String BLOWFISH = "BlowFish";

    public final static String MD5 = "MD5";

 

    /**

     * md5加密

     * 

     * @param data

     * @return

     */

    public static String getMD5(String data) {

return null == data ? data : getMD5(string2byte(data));

    }

 

    private static String getMD5(byte str[]) {

try {

   MessageDigest md = MessageDigest.getInstance(MD5);

   md.update(str);

   byte b[] = md.digest();

   return byte2hex(b);

} catch (Exception e) {

   e.printStackTrace();

}

return null;

    }

 

    /**

     * 字符串加密

     * 

     * @param data

     *            字符串数据

     * @param key

     *            密钥

     * @param name

     *            算法名称

     * @throws Exception

     */

    public static String encrypt(String data, String key, String name) {

try {

   return byte2hex(encrypt(string2byte(data), string2byte(key), name));

} catch (Exception e) {

   e.printStackTrace();

}

return null;

    }

 

    /**

     * 字符串解密

     * 

     * @param data

     *            字符串加密数据

     * @param key

     *            密钥

     * @param name

     *            算法名称

     * @return

     * @throws Exception

     */

    public static String decrypt(String data, String key, String name) {

try {

   return byte2string(decrypt(hex2byte(string2byte(data)),

   string2byte(key), name));

} catch (Exception e) {

   e.printStackTrace();

}

return null;

    }

 

    /**

     * 对数据源进行加密

     * 

     * @param src

     *            数据源

     * @param key

     *            密钥

     * @param name

     *            算法的名称

     * @return 返回加密后的数据

     * @throws Exception

     */

    private static byte[] encrypt(byte[] src, byte[] key, String name)

   throws Exception {

SecretKey securekey = new SecretKeySpec(key, name);

Cipher cipher = Cipher.getInstance(name);

cipher.init(Cipher.ENCRYPT_MODE, securekey);

return cipher.doFinal(src);

    }

 

    /**

     * 对加密的数据源进行解密

     * 

     * @param src

     *            数据源

     * @param key

     *            密钥

     * @param name

     *            算法的名称

     * @return 返回解密后的原始数据

     * @throws Exception

     */

    private static byte[] decrypt(byte[] src, byte[] key, String name)

   throws Exception {

SecretKey securekey = new SecretKeySpec(key, name);

Cipher cipher = Cipher.getInstance(name);

cipher.init(Cipher.DECRYPT_MODE, securekey);

return cipher.doFinal(src);

    }

 

    /**

     * 二进制转十六进制

     * 

     * @param bytes

     * @return

     */

    private static String byte2hex(byte[] bytes) {

String hex = "";

if (bytes != null) {

   final int size = bytes.length;

   if (size > 0) {

String tmp;

StringBuilder sb = new StringBuilder();

for (int i = 0; i < size; i++) {

   tmp = (java.lang.Integer.toHexString(bytes[i] & 0XFF));

   if (tmp.length() == 1) {

sb.append("0" + tmp);

   } else {

sb.append(tmp);

   }

}

hex = sb.toString().toUpperCase();

   }

}

return hex;

    }

 

    /**

     * 十六进制转二进制

     * 

     * @param bytes

     * @return

     */

    private static byte[] hex2byte(byte[] bytes) {

if ((bytes.length % 2) != 0) {

   return null;

}

String item;

byte[] result = new byte[bytes.length / 2];

for (int i = 0; i < bytes.length; i += 2) {

   item = new String(bytes, i, 2);

   result[i / 2] = (byte) Integer.parseInt(item, 16);

}

return result;

    }

 

    /**

     * 把字符串转换成 Unicode Bytes.

     * 

     * @param s

     *            String

     * @return byte[]

     */

    private static byte[] string2byte(String s) {

byte[] bytes = null;

if (s != null) {

   try {

bytes = s.getBytes("utf-8");

   } catch (UnsupportedEncodingException e) {

e.printStackTrace();

   }

}

return bytes;

    }

 

    /**

     * 根据 Unicode Bytes 构造字符串.

     * 

     * @param bytes

     *            byte[]

     * @return String

     */

    private static String byte2string(byte[] bytes) {

String s = null;

if (bytes != null) {

   try {

s = new String(bytes, "utf-8");

   } catch (Exception e) {

e.printStackTrace();

   }

}

return s;

    }

 

    public static void main(String[] args) throws Exception {

/** DES算法 **/

String src = "你好！";

String key = "k>k2>&1&";

String enc = "", dec = "";

enc = encrypt(src, key, DES);

System.out.println("11加密后的数据为:" + enc);

dec = decrypt(enc, key, DES);

System.out.println("11解密后的数据:" + dec);

 

/* 若key的字节数大于8，则只取前8个字节 */

KeySpec keySpec = new DESKeySpec(string2byte(key));

SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);

SecretKey secretKey = keyFactory.generateSecret(keySpec);

/*

* 在JAVA中DES默认使用DES/ECB/PKCS5Padding，下面的写法Cipher.getInstance(

* "DES/ECB/PKCS5Padding")与 Cipher.getInstance("DES")等价

*/

Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("12加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("12解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

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

/* CBC模式下，需要传入IV向量 ，IV向量的字节长度必须等于8 */

AlgorithmParameterSpec paramSpec = new IvParameterSpec(string2byte(key));

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

System.out.println("13加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("13解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

/* NoPadding模式下，加密源数据的字节数必须是8的倍数 */

src = "12345678";

cipher = Cipher.getInstance("DES/ECB/NoPadding");

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("14加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("14解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

cipher = Cipher.getInstance("DES/CBC/NoPadding");

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

System.out.println("15加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("15解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

/** DESede算法 **/

src = "你好！";

key = "nohup command > f 2>&1 &";

enc = encrypt(src, key, DESEDE);

System.out.println("21加密后的数据为:" + enc);

dec = decrypt(enc, key, DESEDE);

System.out.println("21解密后的数据:" + dec);

 

/* 若key的字节数大于24，则只取前24个字节 */

keySpec = new DESedeKeySpec(string2byte(key));

keyFactory = SecretKeyFactory.getInstance(DESEDE);

secretKey = keyFactory.generateSecret(keySpec);

/*

* 在JAVA中DESede默认使用DESede/ECB/PKCS5Padding，下面的写法Cipher.getInstance(

* "DESede/ECB/PKCS5Padding")与 Cipher.getInstance("DESede")等价

*/

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

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("22加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("22解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

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

/* CBC模式下，需要传入IV向量 ，IV向量的字节长度必须等于8 */

paramSpec = new IvParameterSpec(string2byte("k>k2>&1&"));

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

System.out.println("23加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("23解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

/* NoPadding模式下，加密源数据的字节数必须是8的倍数 */

src = "12345678";

cipher = Cipher.getInstance("DESede/ECB/NoPadding");

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("24加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("24解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

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

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

System.out.println("25加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("25解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

/** AES算法 **/

src = "你好！";

key = "nohup cmd>f2>&1&";

enc = encrypt(src, key, AES);

System.out.println("31加密后的数据为:" + enc);

dec = decrypt(enc, key, AES);

System.out.println("31解密后的数据:" + dec);

/* key的字节数必须等于16 */

secretKey = new SecretKeySpec(string2byte(key), AES);

/*

* 在JAVA中AES默认使用AES/ECB/PKCS5Padding，下面的写法Cipher.getInstance(

* "AES/ECB/PKCS5Padding")与 Cipher.getInstance("AES")等价

*/

cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("32加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("32解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

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

/* CBC模式下，需要传入IV向量 ，IV向量的字节长度必须等于16 */

paramSpec = new IvParameterSpec(string2byte(key));

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

System.out.println("33加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("33解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

/* NoPadding模式下，加密源数据的字节数必须是16的倍数 */

src = "1234567812345678";

cipher = Cipher.getInstance("AES/ECB/NoPadding");

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("34加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("34解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

cipher = Cipher.getInstance("AES/CBC/NoPadding");

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

System.out.println("35加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("35解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

src = "你好！";

key = "nohup cmd>f2>&1&";

KeyGenerator kgen = KeyGenerator.getInstance(AES);

// ------------------------------

SecureRandom random = SecureRandom.getInstance("SHA1PRNG");

random.setSeed(string2byte(key));

kgen.init(128, random);

// ------------------------------

// 以上三行等价于kgen.init(128, new SecureRandom(string2byte(key)));

secretKey = kgen.generateKey();

secretKey = new SecretKeySpec(secretKey.getEncoded(), AES);// 这一行可以省略

cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("36加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("36解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

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

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

System.out.println("37加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("37解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

/* NoPadding模式下，加密源数据的字节数必须是16的倍数 */

src = "1234567812345678";

cipher = Cipher.getInstance("AES/ECB/NoPadding");

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("38加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("38解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

cipher = Cipher.getInstance("AES/CBC/NoPadding");

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

System.out.println("39加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("39解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

/** BlowFish算法 **/

src = "你好！";

key = "nohup cmd>f2>&1&";

enc = encrypt(src, key, BLOWFISH);

System.out.println("41加密后的数据为:" + enc);

dec = decrypt(enc, key, BLOWFISH);

System.out.println("41解密后的数据:" + dec);

/* key的字节数必须大于等于1小于等于16 */

secretKey = new SecretKeySpec(string2byte(key), BLOWFISH);

/*

* 在JAVA中BlowFish默认使用BlowFish/ECB/PKCS5Padding，下面的写法Cipher.getInstance(

* "BlowFish/ECB/PKCS5Padding")与 Cipher.getInstance("BlowFish")等价

*/

cipher = Cipher.getInstance("BlowFish/ECB/PKCS5Padding");

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("42加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("42解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

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

/* CBC模式下，需要传入IV向量 ，IV向量的字节长度必须等于8 */

paramSpec = new IvParameterSpec(string2byte("k>k2>&1&"));

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

System.out.println("43加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("43解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

/* NoPadding模式下，加密源数据的字节数必须是8的倍数 */

src = "12345678";

cipher = Cipher.getInstance("BlowFish/ECB/NoPadding");

cipher.init(Cipher.ENCRYPT_MODE, secretKey);

System.out.println("44加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

cipher.init(Cipher.DECRYPT_MODE, secretKey);

System.out.println("44解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

 

cipher = Cipher.getInstance("BlowFish/CBC/NoPadding");

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

System.out.println("45加密后的数据为:"

+ (enc = byte2hex(cipher.doFinal(string2byte(src)))));

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

System.out.println("45解密后的数据:"

+ byte2string(cipher.doFinal(hex2byte(string2byte(enc)))));

    }

}