加密算法（java版）_JAVA_编程开发_程序员俱乐部

先来一发最常用的消息摘要算法第五版←_←就是MD5：

class="java" name="code">package my.util.encryp.md5;

import java.security.MessageDigest;

public class MD5Utils {

	private String inStr;
	private MessageDigest md5;

	public MD5Utils(String inStr) {
		this.inStr = inStr;
		try {
			this.md5 = MessageDigest.getInstance("MD5");
		} catch (Exception e) {
			System.out.println(e.toString());
			e.printStackTrace();
		}
	}

	public String compute() {
		char[] charArray = this.inStr.toCharArray();
		byte[] byteArray = new byte[charArray.length];

		for (int i = 0; i < charArray.length; i++)
			byteArray[i] = (byte) charArray[i];

		byte[] md5Bytes = this.md5.digest(byteArray);
		StringBuffer hexValue = new StringBuffer();
		for (int i = 0; i < md5Bytes.length; i++) {
			int val = ((int) md5Bytes[i]) & 0xff;
			if (val < 16) hexValue.append("0");
			hexValue.append(Integer.toHexString(val));
		}
		return hexValue.toString();
	}

	public static void main(String[] args) {
		MD5Utils md5 = new MD5Utils("123456");
		String postString = md5.compute();
		System.out.println("→:" + postString);
	}
}

?高级加密标准AES：

package my.util.encryp.all;

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.Security;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;

public class EncrypAES {
	
	//KeyGenerator 提供对称密钥生成器的功能，支持各种算法
	private KeyGenerator keygen;
	//SecretKey 负责保存对称密钥
	private SecretKey deskey;
	//Cipher负责完成加密或解密工作
	private Cipher c;
	//该字节数组负责保存加密的结果
	private byte[] cipherByte;
	
	public EncrypAES() throws NoSuchAlgorithmException, NoSuchPaddingException{
		Security.addProvider(new com.sun.crypto.provider.SunJCE());
		//实例化支持DES算法的密钥生成器(算法名称命名需按规定，否则抛出异常)
		keygen = KeyGenerator.getInstance("AES");
		//生成密钥
		deskey = keygen.generateKey();
		//生成Cipher对象,指定其支持的DES算法
		c = Cipher.getInstance("AES");
	}
	
	/**
	 * 对字符串加密
	 * 
	 * @param str
	 * @return
	 * @throws InvalidKeyException
	 * @throws IllegalBlockSizeException
	 * @throws BadPaddingException
	 */
	public byte[] Encrytor(String str) throws InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		// 根据密钥，对Cipher对象进行初始化，ENCRYPT_MODE表示加密模式
		c.init(Cipher.ENCRYPT_MODE, deskey);
		byte[] src = str.getBytes();
		// 加密，结果保存进cipherByte
		cipherByte = c.doFinal(src);
		return cipherByte;
	}

	/**
	 * 对字符串解密
	 * 
	 * @param buff
	 * @return
	 * @throws InvalidKeyException
	 * @throws IllegalBlockSizeException
	 * @throws BadPaddingException
	 */
	public byte[] Decryptor(byte[] buff) throws InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		// 根据密钥，对Cipher对象进行初始化，DECRYPT_MODE表示加密模式
		c.init(Cipher.DECRYPT_MODE, deskey);
		cipherByte = c.doFinal(buff);
		return cipherByte;
	}

	/**
	 * @param args
	 * @throws NoSuchPaddingException 
	 * @throws NoSuchAlgorithmException 
	 * @throws BadPaddingException 
	 * @throws IllegalBlockSizeException 
	 * @throws InvalidKeyException 
	 */
	public static void main(String[] args) throws Exception {
		EncrypAES de1 = new EncrypAES();
		String msg ="呵呵";
		byte[] encontent = de1.Encrytor(msg);
		byte[] decontent = de1.Decryptor(encontent);
		System.out.println("明文是:" + msg);
		System.out.println("加密后:" + new String(encontent));
		System.out.println("解密后:" + new String(decontent));
	}

}

?数据加密标准DES：

package my.util.encryp.all;

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.Security;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;

public class EncrypDES {
	
	//KeyGenerator 提供对称密钥生成器的功能，支持各种算法
	private KeyGenerator keygen;
	//SecretKey 负责保存对称密钥
	private SecretKey deskey;
	//Cipher负责完成加密或解密工作
	private Cipher c;
	//该字节数组负责保存加密的结果
	private byte[] cipherByte;
	
	public EncrypDES() throws NoSuchAlgorithmException, NoSuchPaddingException{
		Security.addProvider(new com.sun.crypto.provider.SunJCE());
		//实例化支持DES算法的密钥生成器(算法名称命名需按规定，否则抛出异常)
		keygen = KeyGenerator.getInstance("DES");
		//生成密钥
		deskey = keygen.generateKey();
		//生成Cipher对象,指定其支持的DES算法
		c = Cipher.getInstance("DES");
	}
	
	/**
	 * 对字符串加密
	 * 
	 * @param str
	 * @return
	 * @throws InvalidKeyException
	 * @throws IllegalBlockSizeException
	 * @throws BadPaddingException
	 */
	public byte[] Encrytor(String str) throws InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		// 根据密钥，对Cipher对象进行初始化，ENCRYPT_MODE表示加密模式
		c.init(Cipher.ENCRYPT_MODE, deskey);
		byte[] src = str.getBytes();
		// 加密，结果保存进cipherByte
		cipherByte = c.doFinal(src);
		return cipherByte;
	}

	/**
	 * 对字符串解密
	 * 
	 * @param buff
	 * @return
	 * @throws InvalidKeyException
	 * @throws IllegalBlockSizeException
	 * @throws BadPaddingException
	 */
	public byte[] Decryptor(byte[] buff) throws InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		// 根据密钥，对Cipher对象进行初始化，DECRYPT_MODE表示加密模式
		c.init(Cipher.DECRYPT_MODE, deskey);
		cipherByte = c.doFinal(buff);
		return cipherByte;
	}

	/**
	 * @param args
	 * @throws NoSuchPaddingException 
	 * @throws NoSuchAlgorithmException 
	 * @throws BadPaddingException 
	 * @throws IllegalBlockSizeException 
	 * @throws InvalidKeyException 
	 */
	public static void main(String[] args) throws Exception {
		EncrypDES de1 = new EncrypDES();
		String msg ="呵呵";
		byte[] encontent = de1.Encrytor(msg);
		byte[] decontent = de1.Decryptor(encontent);
		System.out.println("明文是:" + msg);
		System.out.println("加密后:" + new String(encontent));
		System.out.println("解密后:" + new String(decontent));
	}

}

?DES升级版→DES3：

package my.util.encryp.all;

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.Security;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;

public class EncrypDES3 {

	// KeyGenerator 提供对称密钥生成器的功能，支持各种算法
	private KeyGenerator keygen;
	// SecretKey 负责保存对称密钥
	private SecretKey deskey;
	// Cipher负责完成加密或解密工作
	private Cipher c;
	// 该字节数组负责保存加密的结果
	private byte[] cipherByte;

	public EncrypDES3() throws NoSuchAlgorithmException, NoSuchPaddingException {
		Security.addProvider(new com.sun.crypto.provider.SunJCE());
		// 实例化支持DES算法的密钥生成器(算法名称命名需按规定，否则抛出异常)
		keygen = KeyGenerator.getInstance("DESede");
		// 生成密钥
		deskey = keygen.generateKey();
		// 生成Cipher对象,指定其支持的DES算法
		c = Cipher.getInstance("DESede");
	}

	/**
	 * 对字符串加密
	 * 
	 * @param str
	 * @return
	 * @throws InvalidKeyException
	 * @throws IllegalBlockSizeException
	 * @throws BadPaddingException
	 */
	public byte[] Encrytor(String str) throws InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		// 根据密钥，对Cipher对象进行初始化，ENCRYPT_MODE表示加密模式
		c.init(Cipher.ENCRYPT_MODE, deskey);
		byte[] src = str.getBytes();
		// 加密，结果保存进cipherByte
		cipherByte = c.doFinal(src);
		return cipherByte;
	}

	/**
	 * 对字符串解密
	 * 
	 * @param buff
	 * @return
	 * @throws InvalidKeyException
	 * @throws IllegalBlockSizeException
	 * @throws BadPaddingException
	 */
	public byte[] Decryptor(byte[] buff) throws InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		// 根据密钥，对Cipher对象进行初始化，DECRYPT_MODE表示加密模式
		c.init(Cipher.DECRYPT_MODE, deskey);
		cipherByte = c.doFinal(buff);
		return cipherByte;
	}

	/**
	 * @param args
	 * @throws NoSuchPaddingException 
	 * @throws NoSuchAlgorithmException 
	 * @throws BadPaddingException 
	 * @throws IllegalBlockSizeException 
	 * @throws InvalidKeyException 
	 */
	public static void main(String[] args) throws Exception {
		EncrypDES3 des = new EncrypDES3();
		String msg ="呵呵";
		byte[] encontent = des.Encrytor(msg);
		byte[] decontent = des.Decryptor(encontent);
		System.out.println("明文是:" + msg);
		System.out.println("加密后:" + new String(encontent));
		System.out.println("解密后:" + new String(decontent));

	}

}

?

?公钥加密算法RSA：

package my.util.encryp.all;

import java.security.InvalidKeyException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;

public class EncrypRSA {
	
	/**
	 * 加密
	 * @param publicKey
	 * @param srcBytes
	 * @return
	 * @throws NoSuchAlgorithmException
	 * @throws NoSuchPaddingException
	 * @throws InvalidKeyException
	 * @throws IllegalBlockSizeException
	 * @throws BadPaddingException
	 */
	protected byte[] encrypt(RSAPublicKey publicKey,byte[] srcBytes) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException{
		if(publicKey!=null){
			//Cipher负责完成加密或解密工作，基于RSA
			Cipher cipher = Cipher.getInstance("RSA");
			//根据公钥，对Cipher对象进行初始化
			cipher.init(Cipher.ENCRYPT_MODE, publicKey);
			byte[] resultBytes = cipher.doFinal(srcBytes);
			return resultBytes;
		}
		return null;
	}
	
	/**
	 * 解密 
	 * @param privateKey
	 * @param srcBytes
	 * @return
	 * @throws NoSuchAlgorithmException
	 * @throws NoSuchPaddingException
	 * @throws InvalidKeyException
	 * @throws IllegalBlockSizeException
	 * @throws BadPaddingException
	 */
	protected byte[] decrypt(RSAPrivateKey privateKey,byte[] srcBytes) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException{
		if(privateKey!=null){
			//Cipher负责完成加密或解密工作，基于RSA
			Cipher cipher = Cipher.getInstance("RSA");
			//根据公钥，对Cipher对象进行初始化
			cipher.init(Cipher.DECRYPT_MODE, privateKey);
			byte[] resultBytes = cipher.doFinal(srcBytes);
			return resultBytes;
		}
		return null;
	}

	/**
	 * @param args
	 * @throws NoSuchAlgorithmException 
	 * @throws BadPaddingException 
	 * @throws IllegalBlockSizeException 
	 * @throws NoSuchPaddingException 
	 * @throws InvalidKeyException 
	 */
	public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException {
		EncrypRSA rsa = new EncrypRSA();
		String msg = "夜月";
		//KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
		KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
		//初始化密钥对生成器，密钥大小为1024位
		keyPairGen.initialize(1024);
		//生成一个密钥对，保存在keyPair中
		KeyPair keyPair = keyPairGen.generateKeyPair();
		//得到私钥
		RSAPrivateKey privateKey = (RSAPrivateKey)keyPair.getPrivate();				
		//得到公钥
		RSAPublicKey publicKey = (RSAPublicKey)keyPair.getPublic();
		
		//用公钥加密
		byte[] srcBytes = msg.getBytes();
		byte[] resultBytes = rsa.encrypt(publicKey, srcBytes);
		
		//用私钥解密
		byte[] decBytes = rsa.decrypt(privateKey, resultBytes);
		
		System.out.println("明文是:" + msg);
		System.out.println("加密后是:" + new String(resultBytes));
		System.out.println("解密后是:" + new String(decBytes));
	}

}

?

?安全哈希算法?SHA：

package my.util.encryp.all;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class EncrypSHA {
	
	public byte[] eccrypt(String info) throws NoSuchAlgorithmException{
		MessageDigest md5 = MessageDigest.getInstance("SHA");
		byte[] srcBytes = info.getBytes();
		//使用srcBytes更新摘要
		md5.update(srcBytes);
		//完成哈希计算，得到result
		byte[] resultBytes = md5.digest();
		return resultBytes;
	}

	/**
	 * @param args
	 * @throws NoSuchAlgorithmException 
	 */
	public static void main(String[] args) throws NoSuchAlgorithmException {
		String msg = "夜月";
		EncrypSHA sha = new EncrypSHA();
		byte[] resultBytes = sha.eccrypt(msg);
		System.out.println("明文是：" + msg);
		System.out.println("密文是：" + new String(resultBytes));
		
	}

}

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