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DES
DES-Data Encryption Standard,即数据加密算法。是IBM公司于1975年研究成功并公开发表的。DES算法的入口参数有三个:Key、Data、Mode。其中Key为8个字节共64位,是DES算法的工作密钥;Data也为8个字节64位,是要被加密或被解密的数据;Mode为DES的工作方式,有两种:加密或解密。
DES算法把64位的明文输入块变为64位的密文输出块,它所使用的密钥也是64位。
![Java加密技术(二)——对称加密算法DES&AES_第1张图片](http://img.e-com-net.com/image/info8/ff6a3f6e07cb4bba87f6f249d6d9195d.jpg)
通过java代码实现如下: Coder类见 Java加密技术(一)
Java代码
![复制代码](http://img.e-com-net.com/image/info8/0e4e59eaad7340149d7ec4c555d2c667.jpg)
![收藏代码](http://img.e-com-net.com/image/info8/74c3ec61dbe54bd4a7eb67a36d03777a.jpg)
![27120508_PPHV.gif](http://img.e-com-net.com/image/info8/a8fdf87c9403405fbe4ab68a47b6d134.gif)
- import java.security.Key;
- import java.security.SecureRandom;
- import javax.crypto.Cipher;
- import javax.crypto.KeyGenerator;
- import javax.crypto.SecretKey;
- import javax.crypto.SecretKeyFactory;
- import javax.crypto.spec.DESKeySpec;
- /**
- * DES安全编码组件
- *
- *
- * 支持 DES、DESede(TripleDES,就是3DES)、AES、Blowfish、RC2、RC4(ARCFOUR)
- * DES key size must be equal to 56
- * DESede(TripleDES) key size must be equal to 112 or 168
- * AES key size must be equal to 128, 192 or 256,but 192 and 256 bits may not be available
- * Blowfish key size must be multiple of 8, and can only range from 32 to 448 (inclusive)
- * RC2 key size must be between 40 and 1024 bits
- * RC4(ARCFOUR) key size must be between 40 and 1024 bits
- * 具体内容 需要关注 JDK Document http://.../docs/technotes/guides/security/SunProviders.html
- *
- *
- * @author 梁栋
- * @version 1.0
- * @since 1.0
- */
- public abstract class DESCoder extends Coder {
- /**
- * ALGORITHM 算法
- * 可替换为以下任意一种算法,同时key值的size相应改变。
- *
- *
- * DES key size must be equal to 56
- * DESede(TripleDES) key size must be equal to 112 or 168
- * AES key size must be equal to 128, 192 or 256,but 192 and 256 bits may not be available
- * Blowfish key size must be multiple of 8, and can only range from 32 to 448 (inclusive)
- * RC2 key size must be between 40 and 1024 bits
- * RC4(ARCFOUR) key size must be between 40 and 1024 bits
- *
- *
- * 在Key toKey(byte[] key)方法中使用下述代码
- *
SecretKey secretKey = new SecretKeySpec(key, ALGORITHM);
替换 - *
- * DESKeySpec dks = new DESKeySpec(key);
- * SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
- * SecretKey secretKey = keyFactory.generateSecret(dks);
- *
- */
- public static final String ALGORITHM = "DES";
- /**
- * 转换密钥
- *
- * @param key
- * @return
- * @throws Exception
- */
- private static Key toKey(byte[] key) throws Exception {
- DESKeySpec dks = new DESKeySpec(key);
- SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
- SecretKey secretKey = keyFactory.generateSecret(dks);
- // 当使用其他对称加密算法时,如AES、Blowfish等算法时,用下述代码替换上述三行代码
- // SecretKey secretKey = new SecretKeySpec(key, ALGORITHM);
- return secretKey;
- }
- /**
- * 解密
- *
- * @param data
- * @param key
- * @return
- * @throws Exception
- */
- public static byte[] decrypt(byte[] data, String key) throws Exception {
- Key k = toKey(decryptBASE64(key));
- Cipher cipher = Cipher.getInstance(ALGORITHM);
- cipher.init(Cipher.DECRYPT_MODE, k);
- return cipher.doFinal(data);
- }
- /**
- * 加密
- *
- * @param data
- * @param key
- * @return
- * @throws Exception
- */
- public static byte[] encrypt(byte[] data, String key) throws Exception {
- Key k = toKey(decryptBASE64(key));
- Cipher cipher = Cipher.getInstance(ALGORITHM);
- cipher.init(Cipher.ENCRYPT_MODE, k);
- return cipher.doFinal(data);
- }
- /**
- * 生成密钥
- *
- * @return
- * @throws Exception
- */
- public static String initKey() throws Exception {
- return initKey(null);
- }
- /**
- * 生成密钥
- *
- * @param seed
- * @return
- * @throws Exception
- */
- public static String initKey(String seed) throws Exception {
- SecureRandom secureRandom = null;
- if (seed != null) {
- secureRandom = new SecureRandom(decryptBASE64(seed));
- } else {
- secureRandom = new SecureRandom();
- }
- KeyGenerator kg = KeyGenerator.getInstance(ALGORITHM);
- kg.init(secureRandom);
- SecretKey secretKey = kg.generateKey();
- return encryptBASE64(secretKey.getEncoded());
- }
- }
import java.security.Key;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
/**
* DES安全编码组件
*
*
* 支持 DES、DESede(TripleDES,就是3DES)、AES、Blowfish、RC2、RC4(ARCFOUR)
* DES key size must be equal to 56
* DESede(TripleDES) key size must be equal to 112 or 168
* AES key size must be equal to 128, 192 or 256,but 192 and 256 bits may not be available
* Blowfish key size must be multiple of 8, and can only range from 32 to 448 (inclusive)
* RC2 key size must be between 40 and 1024 bits
* RC4(ARCFOUR) key size must be between 40 and 1024 bits
* 具体内容 需要关注 JDK Document http://.../docs/technotes/guides/security/SunProviders.html
*
*
* @author 梁栋
* @version 1.0
* @since 1.0
*/
public abstract class DESCoder extends Coder {
/**
* ALGORITHM 算法
* 可替换为以下任意一种算法,同时key值的size相应改变。
*
*
* DES key size must be equal to 56
* DESede(TripleDES) key size must be equal to 112 or 168
* AES key size must be equal to 128, 192 or 256,but 192 and 256 bits may not be available
* Blowfish key size must be multiple of 8, and can only range from 32 to 448 (inclusive)
* RC2 key size must be between 40 and 1024 bits
* RC4(ARCFOUR) key size must be between 40 and 1024 bits
*
*
* 在Key toKey(byte[] key)方法中使用下述代码
* SecretKey secretKey = new SecretKeySpec(key, ALGORITHM);
替换
*
* DESKeySpec dks = new DESKeySpec(key);
* SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
* SecretKey secretKey = keyFactory.generateSecret(dks);
*
*/
public static final String ALGORITHM = "DES";
/**
* 转换密钥
*
* @param key
* @return
* @throws Exception
*/
private static Key toKey(byte[] key) throws Exception {
DESKeySpec dks = new DESKeySpec(key);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
SecretKey secretKey = keyFactory.generateSecret(dks);
// 当使用其他对称加密算法时,如AES、Blowfish等算法时,用下述代码替换上述三行代码
// SecretKey secretKey = new SecretKeySpec(key, ALGORITHM);
return secretKey;
}
/**
* 解密
*
* @param data
* @param key
* @return
* @throws Exception
*/
public static byte[] decrypt(byte[] data, String key) throws Exception {
Key k = toKey(decryptBASE64(key));
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, k);
return cipher.doFinal(data);
}
/**
* 加密
*
* @param data
* @param key
* @return
* @throws Exception
*/
public static byte[] encrypt(byte[] data, String key) throws Exception {
Key k = toKey(decryptBASE64(key));
Cipher cipher = Cipher.getInstance(ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, k);
return cipher.doFinal(data);
}
/**
* 生成密钥
*
* @return
* @throws Exception
*/
public static String initKey() throws Exception {
return initKey(null);
}
/**
* 生成密钥
*
* @param seed
* @return
* @throws Exception
*/
public static String initKey(String seed) throws Exception {
SecureRandom secureRandom = null;
if (seed != null) {
secureRandom = new SecureRandom(decryptBASE64(seed));
} else {
secureRandom = new SecureRandom();
}
KeyGenerator kg = KeyGenerator.getInstance(ALGORITHM);
kg.init(secureRandom);
SecretKey secretKey = kg.generateKey();
return encryptBASE64(secretKey.getEncoded());
}
}
延续上一个类的实现,我们通过MD5以及SHA对字符串加密生成密钥,这是比较常见的密钥生成方式。
再给出一个测试类:
Java代码
![复制代码](http://img.e-com-net.com/image/info8/0e4e59eaad7340149d7ec4c555d2c667.jpg)
![收藏代码](http://img.e-com-net.com/image/info8/74c3ec61dbe54bd4a7eb67a36d03777a.jpg)
![27120508_PPHV.gif](http://img.e-com-net.com/image/info8/a8fdf87c9403405fbe4ab68a47b6d134.gif)
- import static org.junit.Assert.*;
- import org.junit.Test;
- /**
- *
- * @author 梁栋
- * @version 1.0
- * @since 1.0
- */
- public class DESCoderTest {
- @Test
- public void test() throws Exception {
- String inputStr = "DES";
- String key = DESCoder.initKey();
- System.err.println("原文:\t" + inputStr);
- System.err.println("密钥:\t" + key);
- byte[] inputData = inputStr.getBytes();
- inputData = DESCoder.encrypt(inputData, key);
- System.err.println("加密后:\t" + DESCoder.encryptBASE64(inputData));
- byte[] outputData = DESCoder.decrypt(inputData, key);
- String outputStr = new String(outputData);
- System.err.println("解密后:\t" + outputStr);
- assertEquals(inputStr, outputStr);
- }
- }
import static org.junit.Assert.*;
import org.junit.Test;
/**
*
* @author 梁栋
* @version 1.0
* @since 1.0
*/
public class DESCoderTest {
@Test
public void test() throws Exception {
String inputStr = "DES";
String key = DESCoder.initKey();
System.err.println("原文:\t" + inputStr);
System.err.println("密钥:\t" + key);
byte[] inputData = inputStr.getBytes();
inputData = DESCoder.encrypt(inputData, key);
System.err.println("加密后:\t" + DESCoder.encryptBASE64(inputData));
byte[] outputData = DESCoder.decrypt(inputData, key);
String outputStr = new String(outputData);
System.err.println("解密后:\t" + outputStr);
assertEquals(inputStr, outputStr);
}
}
得到的输出内容如下:
Console代码
![复制代码](http://img.e-com-net.com/image/info8/0e4e59eaad7340149d7ec4c555d2c667.jpg)
![收藏代码](http://img.e-com-net.com/image/info8/74c3ec61dbe54bd4a7eb67a36d03777a.jpg)
![27120508_PPHV.gif](http://img.e-com-net.com/image/info8/a8fdf87c9403405fbe4ab68a47b6d134.gif)
- 原文: DES
- 密钥: f3wEtRrV6q0=
- 加密后: C6qe9oNIzRY=
- 解密后: DES
原文: DES
密钥: f3wEtRrV6q0=
加密后: C6qe9oNIzRY=
解密后: DES
由控制台得到的输出,我们能够比对加密、解密后结果一致。这是一种简单的加密解密方式,只有一个密钥。
其实DES有很多同胞兄弟,如DESede(TripleDES)、AES、Blowfish、RC2、RC4(ARCFOUR)。这里就不过多阐述了,大同小异,只要换掉ALGORITHM换成对应的值,同时做一个代码替换 SecretKey secretKey = new SecretKeySpec(key, ALGORITHM);就可以了,此外就是密钥长度不同了。
Java代码
![复制代码](http://img.e-com-net.com/image/info8/0e4e59eaad7340149d7ec4c555d2c667.jpg)
![收藏代码](http://img.e-com-net.com/image/info8/74c3ec61dbe54bd4a7eb67a36d03777a.jpg)
![27120508_PPHV.gif](http://img.e-com-net.com/image/info8/a8fdf87c9403405fbe4ab68a47b6d134.gif)
- /**
- * DES key size must be equal to 56
- * DESede(TripleDES) key size must be equal to 112 or 168
- * AES key size must be equal to 128, 192 or 256,but 192 and 256 bits may not be available
- * Blowfish key size must be multiple of 8, and can only range from 32 to 448 (inclusive)
- * RC2 key size must be between 40 and 1024 bits
- * RC4(ARCFOUR) key size must be between 40 and 1024 bits
- **/