加密解密整理

MD5加密算法:
Message Digest Algorithm MD5(中文名为消息摘要算法第五版)为计算机安全领域广泛使用的一种散列函数,用以提供消息的完整性保护。该算法的文件号为RFC 1321(R.Rivest,MIT Laboratory for Computer Science and RSA Data Security Inc. April 1992)
public final class MD5Crypt {

/**
*
* Command line test rig.
 * @throws NoSuchAlgorithmException 
*
*/

static public void main(String argv[]) throws NoSuchAlgorithmException
{
	System.out.println(crypt("daliantan0v0"));;
// if ((argv.length < 1) || (argv.length > 2))
//   {
//	System.err.println("Usage: MD5Crypt password salt");
//	System.exit(1);
//   }
//
// if (argv.length == 2)
//   {
//	System.err.println(MD5Crypt.crypt(argv[0], argv[1]));
//   }
// else
//   {
//	System.err.println(MD5Crypt.crypt(argv[0]));
//   }
// 
// System.exit(0);
}

static private final String SALTCHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";

static private final String itoa64 = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

static private final String to64(long v, int size)
{
 StringBuffer result = new StringBuffer();

 while (--size >= 0)
   {
	result.append(itoa64.charAt((int) (v & 0x3f)));
	v >>>= 6;
   }

 return result.toString();
}

static private final void clearbits(byte bits[])
{
 for (int i = 0; i < bits.length; i++)
   {
	bits[i] = 0;
   }
}



/**
* convert an encoded unsigned byte value into a int
* with the unsigned value.
*/

static private final int bytes2u(byte inp)
{
 return (int) inp & 0xff;
}

/**
* <p>This method actually generates a OpenBSD/FreeBSD/Linux PAM compatible
* md5-encoded password hash from a plaintext password and a
* salt.</p>
*
* <p>The resulting string will be in the form '$1$&lt;salt&gt;$&lt;hashed mess&gt;</p>
*
* @param password Plaintext password
*
* @return An OpenBSD/FreeBSD/Linux-compatible md5-hashed password field.
 * @throws NoSuchAlgorithmException 
*/

static public final String crypt(String password) throws NoSuchAlgorithmException
{
 StringBuffer salt = new StringBuffer();
 java.util.Random randgen = new java.util.Random();

 /* -- */

  while (salt.length() < 8)
    {
	 int index = (int) (randgen.nextFloat() * SALTCHARS.length());
      salt.append(SALTCHARS.substring(index, index+1));
    }

  return MD5Crypt.crypt(password, salt.toString());
}

/**
* <p>This method actually generates a OpenBSD/FreeBSD/Linux PAM compatible
* md5-encoded password hash from a plaintext password and a
* salt.</p>
*
* <p>The resulting string will be in the form '$1$&lt;salt&gt;$&lt;hashed mess&gt;</p>
*
* @param password Plaintext password
* @param salt A short string to use to randomize md5.  May start with $1$, which
*             will be ignored.  It is explicitly permitted to pass a pre-existing
*             MD5Crypt'ed password entry as the salt.  crypt() will strip the salt
*             chars out properly.
*
* @return An OpenBSD/FreeBSD/Linux-compatible md5-hashed password field.
 * @throws NoSuchAlgorithmException 
*/

static public final String crypt(String password, String salt) throws NoSuchAlgorithmException
{
 /* This string is magic for this algorithm.  Having it this way,
  * we can get get better later on */

 String magic = "$1$";
 byte finalState[];
 MessageDigest ctx, ctx1;
 long l;

 /* -- */

 /* Refine the Salt first */

 /* If it starts with the magic string, then skip that */
 
 if (salt.startsWith(magic))
   {
	salt = salt.substring(magic.length());
   }

 /* It stops at the first '$', max 8 chars */

 if (salt.indexOf('$') != -1)
   {
	salt = salt.substring(0, salt.indexOf('$'));
   }

 if (salt.length() > 8)
   {
	salt = salt.substring(0, 8);
   }

 ctx = MessageDigest.getInstance("MD5");

 ctx.update(password.getBytes());    // The password first, since that is what is most unknown
 ctx.update(magic.getBytes());    // Then our magic string
 ctx.update(salt.getBytes());    // Then the raw salt

 /* Then just as many characters of the MD5(pw,salt,pw) */

 ctx1 = MessageDigest.getInstance("MD5");
 ctx1.update(password.getBytes());
 ctx1.update(salt.getBytes());
 ctx1.update(password.getBytes());
 finalState = ctx1.digest();

 for (int pl = password.length(); pl > 0; pl -= 16)
   {
	for( int i=0; i< (pl > 16 ? 16 : pl); i++ )
	  ctx.update(finalState[i] );
   }

 /* the original code claimed that finalState was being cleared
    to keep dangerous bits out of memory, but doing this is also
    required in order to get the right output. */

 clearbits(finalState);
 
 /* Then something really weird... */

 for (int i = password.length(); i != 0; i >>>=1)
   {
	if ((i & 1) != 0)
	  {
	    ctx.update(finalState[0]);
	  }
	else
	  {
	    ctx.update(password.getBytes()[0]);
	  }
   }

 finalState = ctx.digest();

 /*
  * and now, just to make sure things don't run too fast
  * On a 60 Mhz Pentium this takes 34 msec, so you would
  * need 30 seconds to build a 1000 entry dictionary...
  *
  * (The above timings from the C version)
  */

 for (int i = 0; i < 1000; i++)
   {
	ctx1 = MessageDigest.getInstance("MD5");

	if ((i & 1) != 0)
	  {
	    ctx1.update(password.getBytes());
	  }
	else
	  {
	    for( int c=0; c<16; c++ )
	      ctx1.update(finalState[c]);
	  }

	if ((i % 3) != 0)
	  {
	    ctx1.update(salt.getBytes());
	  }

	if ((i % 7) != 0)
	  {
	    ctx1.update(password.getBytes());
	  }

	if ((i & 1) != 0)
	  {
	    for( int c=0; c<16; c++ )
	      ctx1.update(finalState[c]);
	  }
	else
	  {
	    ctx1.update(password.getBytes());
	  }

	finalState = ctx1.digest();
   }

 /* Now make the output string */

 StringBuffer result = new StringBuffer();

 result.append(magic);
 result.append(salt);
 result.append("$");

 l = (bytes2u(finalState[0]) << 16) | (bytes2u(finalState[6]) << 8) | bytes2u(finalState[12]);
 result.append(to64(l, 4));

 l = (bytes2u(finalState[1]) << 16) | (bytes2u(finalState[7]) << 8) | bytes2u(finalState[13]);
 result.append(to64(l, 4));

 l = (bytes2u(finalState[2]) << 16) | (bytes2u(finalState[8]) << 8) | bytes2u(finalState[14]);
 result.append(to64(l, 4));

 l = (bytes2u(finalState[3]) << 16) | (bytes2u(finalState[9]) << 8) | bytes2u(finalState[15]);
 result.append(to64(l, 4));

 l = (bytes2u(finalState[4]) << 16) | (bytes2u(finalState[10]) << 8) | bytes2u(finalState[5]);
 result.append(to64(l, 4));

 l = bytes2u(finalState[11]);
 result.append(to64(l, 2));

 /* Don't leave anything around in vm they could use. */
 clearbits(finalState);

 return result.toString();
}
}


DES加密与解密:
/**  
 *   
 * 使用DES加密与解密,可对byte[],String类型进行加密与解密 密文可使用String,byte[]存储.  
 *   
 * 方法: void getKey(String strKey)从strKey的字条生成一个Key  
 *   
 * String getEncString(String strMing)对strMing进行加密,返回String密文 String  
 * getDesString(String strMi)对strMin进行解密,返回String明文  
 *   
 * byte[] getEncCode(byte[] byteS)byte[]型的加密 byte[] getDesCode(byte[]  
 * byteD)byte[]型的解密  
 */  
  
public class ThreeDES {   
    Key key;   
  
    /**  
     * 根据参数生成KEY  
     *   
     * @param strKey  
     */  
    public void getKey(String strKey) {   
        try {   
            KeyGenerator _generator = KeyGenerator.getInstance("DES");   
            _generator.init(new SecureRandom(strKey.getBytes()));   
            this.key = _generator.generateKey(); 
            _generator = null;   
        } catch (Exception e) {   
            e.printStackTrace();   
        }   
    }   
  
    /**  
     * 加密String明文输入,String密文输出  
     *   
     * @param strMing  
     * @return  
     */  
    public String getEncString(String strMing) {   
        byte[] byteMi = null;   
        byte[] byteMing = null;   
        String strMi = "";   
        BASE64Encoder base64en = new BASE64Encoder();   
        try {   
            byteMing = strMing.getBytes("UTF8");   
            byteMi = this.getEncCode(byteMing);   
            strMi = base64en.encode(byteMi);   
        } catch (Exception e) {   
            e.printStackTrace();   
        } finally {   
            base64en = null;   
            byteMing = null;   
            byteMi = null;   
        }   
        return strMi;   
    }   
  
    /**  
     * 解密 以String密文输入,String明文输出  
     *   
     * @param strMi  
     * @return  
     */  
    public String getDesString(String strMi) {   
        BASE64Decoder base64De = new BASE64Decoder();   
        byte[] byteMing = null;   
        byte[] byteMi = null;   
        String strMing = "";   
        try {   
            byteMi = base64De.decodeBuffer(strMi);   
            byteMing = this.getDesCode(byteMi);   
            strMing = new String(byteMing, "UTF8");   
        } catch (Exception e) {   
            e.printStackTrace();   
        } finally {   
            base64De = null;   
            byteMing = null;   
            byteMi = null;   
        }   
        return strMing;   
    }   
  
    /**  
     * 加密以byte[]明文输入,byte[]密文输出  
     *   
     * @param byteS  
     * @return  
     */  
    private byte[] getEncCode(byte[] byteS) {   
        byte[] byteFina = null;   
        Cipher cipher;   
        try {   
            cipher = Cipher.getInstance("DES");   
            cipher.init(Cipher.ENCRYPT_MODE, key);   
            byteFina = cipher.doFinal(byteS);   
        } catch (Exception e) {   
            e.printStackTrace();   
        } finally {   
            cipher = null;   
        }   
        return byteFina;   
    }   
  
    /**  
     * 解密以byte[]密文输入,以byte[]明文输出  
     *   
     * @param byteD  
     * @return  
     */  
    private byte[] getDesCode(byte[] byteD) {   
        Cipher cipher;   
        byte[] byteFina = null;   
        try {   
            cipher = Cipher.getInstance("DES");   
            cipher.init(Cipher.DECRYPT_MODE, key);   
            byteFina = cipher.doFinal(byteD);   
        } catch (Exception e) {   
            e.printStackTrace();   
        } finally {   
            cipher = null;   
        }   
        return byteFina;   
  
    }   
  
    public static void main(String[] args) {   
        ThreeDES des = new ThreeDES();// 实例化一个对像   
        des.getKey("daliantan0v0");// 生成密匙   
        
        String strEnc = des.getEncString("ss = 00-13-77-5A-B2-F4=2010-10-10");// 加密字符串,返回String的密文   
        System.out.println(strEnc);   
  
        String strDes = des.getDesString("d6LhO6+II12wjY+JzushFtC4II8wVDOI");// 把String 类型的密文解密    
        System.out.println(strDes);   
    }   
  
}  


RSA加密解密:
  RSA算法是第一个能同时用于加密和数字签名的算法,也易于理解和操作。 RSA是被研究得最广泛的公钥算法,从提出到现在已近二十年,经历了各种攻击的考验,逐渐为人们接受,普遍认为是目前最优秀的公钥方案之一。
public class RSAEncrypt {   
  
    public static void main(String[] args) {   
        try {   
               
            RSAEncrypt encrypt = new RSAEncrypt();   
            String encryptText = "ganlisxn1104";   
            KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");   
            keyPairGen.initialize(1024);   
            KeyPair keyPair = keyPairGen.generateKeyPair();   
            // Generate keys   
               
            RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();   
            RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();   
               
            byte[] e = encrypt.encrypt(publicKey,encryptText.getBytes());   
               
            byte[] de = encrypt.decrypt(privateKey, e);   
               
            System.out.println("加密:"+encrypt.bytesToString(e));   
               
            System.out.println("解密:"+encrypt.bytesToString(de));   
           
        } catch (Exception e) {   
            e.printStackTrace();   
        }   
    }   
  public void doDecrypt(String encryptText) throws NoSuchAlgorithmException{
	   RSAEncrypt encrypt = new RSAEncrypt();   
       KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");  
       keyPairGen.initialize(1024);   
       KeyPair keyPair = keyPairGen.generateKeyPair();   
       RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();   
       RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();   
          
      // byte[] e = ' &r? ????gf??¦?_???(?)Z!-Dl?tA/??rl???`l???????iR?"|$?;D?I???|?F?JH???h???S?)u-?H??"`?M?2?#¢]?¬?6r?(??Y??:?b ';
    	   //encrypt.encrypt(publicKey,encryptText.getBytes());   
          
       byte[] de = encrypt.decrypt(privateKey, encryptText.getBytes());   
          
      // System.out.println("加密:"+encrypt.bytesToString(e));   
          System.out.println("11111111111111");
       System.out.println("解密:"+encrypt.bytesToString(de)); 
  }
    /** */  
    /**  
     * Change byte array to String.  
     *   
     * @return byte[]  
     */  
    protected String bytesToString(byte[] encrytpByte) {   
        String result = "";   
        for (Byte bytes : encrytpByte) {   
            result += (char) bytes.intValue();   
        }   
        return result;   
    }   
  
    /** */  
    /**  
     * Encrypt String.  
     *   
     * @return byte[]  
     */  
    protected byte[] encrypt(RSAPublicKey publicKey, byte[] obj) {   
        if (publicKey != null) {   
            try {   
                Cipher cipher = Cipher.getInstance("RSA");   
                cipher.init(Cipher.ENCRYPT_MODE, publicKey);   
                return cipher.doFinal(obj);   
            } catch (Exception e) {   
                e.printStackTrace();   
            }   
        }   
        return null;   
    }   
  
    /** */  
    /**  
     * Basic decrypt method  
     *   
     * @return byte[]  
     */  
    protected byte[] decrypt(RSAPrivateKey privateKey, byte[] obj) {   
        if (privateKey != null) {   
            try {   
                Cipher cipher = Cipher.getInstance("RSA");   
                cipher.init(Cipher.DECRYPT_MODE, privateKey);   
                return cipher.doFinal(obj);   
            } catch (Exception e) {   
                e.printStackTrace();   
            }   
        }   
        return null;   
    }   
}


DES加密
数据加密算法(Data Encryption Algorithm,DEA)的数据加密标准(Data Encryption Standard,DES)是规范的描述,它出自IBM 的研究工作,并在 1977 年被美国政府正式采纳。它很可能是使用最广泛的密钥系统,特别是在保护金融数据的安全中,最初开发的 DES 是嵌入硬 件中的。通常,自动取款机(Automated Teller Machine,ATM)都使用 DES。

安全散列算法SHA
  (Secure Hash Algorithm,SHA)
  是美国国家标准和技术局发布的国家标准FIPS PUB 180-1,一般称为SHA-1。其对长度不超过264二进制位的消息产生160位的消息摘要输出,按512比特块处理其输入。
  SHA是一种数据加密算法,该算法经过加密专家多年来的发展和改进已日益完善,现在已成为公认的最安全的散列算法之一,并被广泛使用。该算法的思想是接收一段明文,然后以一种不可逆的方式将它转换成一段(通常更小)密文,也可以简单的理解为取一串输入码(称为预映射或信息),并把它们转化为长度较短、位数固定的输出序列即散列值(也称为信息摘要或信息认证代码)的过程。散列函数值可以说时对明文的一种“指纹”或是“摘要”所以对散列值的数字签名就可以视为对此明文的数字签名。
/**  
 * 加密解密  
 *   
 * @author shy.qiu  
 * @since  http://blog.csdn.net/qiushyfm  
 */  
public class Crypt {   
       /**  
     * 进行SHA加密  
     *   
     * @param info  
     *            要加密的信息  
     * @return String 加密后的字符串  
     */  
    public String encryptToSHA(String info) {   
        byte[] digesta = null;   
        try {   
            // 得到一个SHA-1的消息摘要   
            MessageDigest alga = MessageDigest.getInstance("SHA-1");   
            // 添加要进行计算摘要的信息   
            alga.update(info.getBytes());   
            // 得到该摘要   
            digesta = alga.digest();   
        } catch (NoSuchAlgorithmException e) {   
            e.printStackTrace();   
        }   
        // 将摘要转为字符串   
        String rs = byte2hex(digesta);   
        return rs;   
    }   
    // //////////////////////////////////////////////////////////////////////////   
    /**  
     * 创建密匙  
     *   
     * @param algorithm  
     *            加密算法,可用 DES,DESede,Blowfish  
     * @return SecretKey 秘密(对称)密钥  
     */  
    public SecretKey createSecretKey(String algorithm) {   
        // 声明KeyGenerator对象   
        KeyGenerator keygen;   
        // 声明 密钥对象   
        SecretKey deskey = null;   
        try {   
            // 返回生成指定算法的秘密密钥的 KeyGenerator 对象   
            keygen = KeyGenerator.getInstance(algorithm);   
            // 生成一个密钥   
            deskey = keygen.generateKey();   
        } catch (NoSuchAlgorithmException e) {   
            e.printStackTrace();   
        }   
        // 返回密匙   
        return deskey;   
    }   
    /**  
     * 根据密匙进行DES加密  
     *   
     * @param key  
     *            密匙  
     * @param info  
     *            要加密的信息  
     * @return String 加密后的信息  
     */  
    public String encryptToDES(SecretKey key, String info) {   
        // 定义 加密算法,可用 DES,DESede,Blowfish   
        String Algorithm = "DES";   
        // 加密随机数生成器 (RNG),(可以不写)   
        SecureRandom sr = new SecureRandom();   
        // 定义要生成的密文   
        byte[] cipherByte = null;   
        try {   
            // 得到加密/解密器   
            Cipher c1 = Cipher.getInstance(Algorithm);   
            // 用指定的密钥和模式初始化Cipher对象   
            // 参数:(ENCRYPT_MODE, DECRYPT_MODE, WRAP_MODE,UNWRAP_MODE)   
            c1.init(Cipher.ENCRYPT_MODE, key, sr);   
            // 对要加密的内容进行编码处理,   
            cipherByte = c1.doFinal(info.getBytes());   
        } catch (Exception e) {   
            e.printStackTrace();   
        }   
        // 返回密文的十六进制形式   
        return byte2hex(cipherByte);   
    }   
    /**  
     * 根据密匙进行DES解密  
     *   
     * @param key  
     *            密匙  
     * @param sInfo  
     *            要解密的密文  
     * @return String 返回解密后信息  
     */  
    public String decryptByDES(SecretKey key, String sInfo) {   
        // 定义 加密算法,   
        String Algorithm = "DES";   
        // 加密随机数生成器 (RNG)   
        SecureRandom sr = new SecureRandom();   
        byte[] cipherByte = null;   
        try {   
            // 得到加密/解密器   
            Cipher c1 = Cipher.getInstance(Algorithm);   
            // 用指定的密钥和模式初始化Cipher对象   
            c1.init(Cipher.DECRYPT_MODE, key, sr);   
            // 对要解密的内容进行编码处理   
            cipherByte = c1.doFinal(hex2byte(sInfo));   
        } catch (Exception e) {   
            e.printStackTrace();   
        }   
        // return byte2hex(cipherByte);   
        return new String(cipherByte);   
    }   
    // /////////////////////////////////////////////////////////////////////////////   
    /**  
     * 创建密匙组,并将公匙,私匙放入到指定文件中  
     *   
     * 默认放入mykeys.bat文件中  
     * @throws IOException 
     */  
    public void createPairKey() throws IOException {   
        try {   
            // 根据特定的算法一个密钥对生成器   
            KeyPairGenerator keygen = KeyPairGenerator.getInstance("DSA");   
            // 加密随机数生成器 (RNG)   
            SecureRandom random = new SecureRandom();   
            // 重新设置此随机对象的种子   
            random.setSeed(1000);   
            // 使用给定的随机源(和默认的参数集合)初始化确定密钥大小的密钥对生成器   
            keygen.initialize(512, random);// keygen.initialize(512);   
            // 生成密钥组   
            KeyPair keys = keygen.generateKeyPair();   
            // 得到公匙   
            PublicKey pubkey = keys.getPublic();   
            // 得到私匙   
            PrivateKey prikey = keys.getPrivate(); 
            //取得公司名称,写入公钥中
            GetProperties gp = new GetProperties();
            String company = gp.getCompany();
            // 将公匙私匙写入到文件当中   
            doObjToFile("mykeys.bat", new Object[] { prikey, pubkey ,company});   
        } catch (NoSuchAlgorithmException e) {   
            e.printStackTrace();   
        }   
    }   
    /**  
     * 利用私匙对信息进行签名 把签名后的信息放入到指定的文件中  
     *   
     * @param info  
     *            要签名的信息  
     * @param signfile  
     *            存入的文件  
     */  
    public void signToInfo(String info, String signfile) {   
        // 从文件当中读取私匙   
        PrivateKey myprikey = (PrivateKey) getObjFromFile("mykeys.bat", 1);   
        // 从文件中读取公匙   
        PublicKey mypubkey = (PublicKey) getObjFromFile("mykeys.bat", 2); 
        String in = (String) getObjFromFile("mykeys.bat", 3);
        System.out.println("****"+in);
        try {   
            // Signature 对象可用来生成和验证数字签名   
            Signature signet = Signature.getInstance("DSA");   
            // 初始化签署签名的私钥   
            signet.initSign(myprikey);   
            // 更新要由字节签名或验证的数据   
            signet.update(info.getBytes());   
            // 签署或验证所有更新字节的签名,返回签名   
            byte[] signed = signet.sign();   
            // 将数字签名,公匙,信息放入文件中   
            doObjToFile("d:\\"+signfile, new Object[] { signed, mypubkey, info ,in});   
        } catch (Exception e) {   
            e.printStackTrace();   
        }   
    }   
    /**  
     * 读取数字签名文件 根据公匙,签名,信息验证信息的合法性  
     *   
     * @return true 验证成功 false 验证失败  
     */  
    public boolean validateSign(String signfile) {   
        // 读取公匙   
        PublicKey mypubkey = (PublicKey) getObjFromFile(signfile, 2); 
        System.out.println("mypubkey==="+mypubkey);
        // 读取签名   
        byte[] signed = (byte[]) getObjFromFile(signfile, 1);   
        // 读取信息   
        String info = (String) getObjFromFile(signfile, 3); 
        System.out.println("info==="+info);
        try {   
            // 初始一个Signature对象,并用公钥和签名进行验证   
            Signature signetcheck = Signature.getInstance("DSA");   
            // 初始化验证签名的公钥   
            signetcheck.initVerify(mypubkey);   
            // 使用指定的 byte 数组更新要签名或验证的数据   
            signetcheck.update(info.getBytes());     
            // 验证传入的签名   
            return signetcheck.verify(signed);   
        } catch (Exception e) {   
            e.printStackTrace();   
            return false;   
        }   
    }   
    /**  
     * 将二进制转化为16进制字符串  
     *   
     * @param b  
     *            二进制字节数组  
     * @return String  
     */  
    public String byte2hex(byte[] b) {   
        String hs = "";   
        String stmp = "";   
        for (int n = 0; n < b.length; n++) {   
            stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));   
            if (stmp.length() == 1) {   
                hs = hs + "0" + stmp;   
            } else {   
                hs = hs + stmp;   
            }   
        }   
        return hs.toUpperCase();   
    }   
    /**  
     * 十六进制字符串转化为2进制  
     *   
     * @param hex  
     * @return  
     */  
    public byte[] hex2byte(String hex) {   
        byte[] ret = new byte[8];   
        byte[] tmp = hex.getBytes();   
        for (int i = 0; i < 8; i++) {   
            ret[i] = uniteBytes(tmp[i * 2], tmp[i * 2 + 1]);   
        }   
        return ret;   
    }   
    /**  
     * 将两个ASCII字符合成一个字节; 如:"EF"--> 0xEF  
     *   
     * @param src0  
     *            byte  
     * @param src1  
     *            byte  
     * @return byte  
     */  
    public static byte uniteBytes(byte src0, byte src1) {   
        byte _b0 = Byte.decode("0x" + new String(new byte[] { src0 }))   
                .byteValue();   
        _b0 = (byte) (_b0 << 4);   
        byte _b1 = Byte.decode("0x" + new String(new byte[] { src1 }))   
                .byteValue();   
        byte ret = (byte) (_b0 ^ _b1);   
        return ret;   
    }   
    /**  
     * 将指定的对象写入指定的文件  
     *   
     * @param file  
     *            指定写入的文件  
     * @param objs  
     *            要写入的对象  
     */  
    public void doObjToFile(String file, Object[] objs) {   
        ObjectOutputStream oos = null;   
        try {   
            FileOutputStream fos = new FileOutputStream(file);   
            oos = new ObjectOutputStream(fos);   
            for (int i = 0; i < objs.length; i++) {   
                oos.writeObject(objs[i]);   
            }   
        } catch (Exception e) {   
            e.printStackTrace();   
        } finally {   
            try {   
                oos.close();   
            } catch (IOException e) {   
                e.printStackTrace();   
            }   
        }   
    }   
    /**  
     * 返回在文件中指定位置的对象  
     *   
     * @param file  
     *            指定的文件  
     * @param i  
     *            从1开始  
     * @return  
     */  
    public Object getObjFromFile(String file, int i) {   
        ObjectInputStream ois = null;   
        Object obj = null;   
        try {   
            FileInputStream fis = new FileInputStream(file);   
            ois = new ObjectInputStream(fis);   
            for (int j = 0; j < i; j++) {   
                obj = ois.readObject();   
            }   
        } catch (Exception e) {   
            e.printStackTrace();   
        } finally {   
            try {   
                ois.close();   
            } catch (IOException e) {   
                e.printStackTrace();   
            }   
        }   
        return obj;   
    }   
    /**  
     * 测试  
     *   
     * @param args  
     * @throws IOException 
     */  
    public static void main(String[] args) throws IOException {   
        Crypt jiami = new Crypt();   
        // 执行MD5加密"Hello world!"   
        System.out.println("Hello经过MD5:" + jiami.encryptToMD5("tanovo"));   
        // 生成一个DES算法的密匙   
        SecretKey key = jiami.createSecretKey("DES");   
        // 用密匙加密信息"Hello world!"   
        String str1 = jiami.encryptToDES(key, "tanovo");   
        System.out.println("使用des加密信息tanovo为:" + str1);   
        // 使用这个密匙解密   
        String str2 = jiami.decryptByDES(key, str1);   
        System.out.println("解密后为:" + str2);   
        // 创建公匙和私匙   
        jiami.createPairKey();   
        // 对Hello world!使用私匙进行签名   
        jiami.signToInfo("Hello", "mysign.bat");   
        // 利用公匙对签名进行验证。   
        if (jiami.validateSign("mysign.bat")) {   
            System.out.println("Success!");   
        } else {   
            System.out.println("Fail!");   
        }   
    }   
}  


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