第七章 对称加密算法--DES

package com.util.des;import java.io.UnsupportedEncodingException;import java.security.InvalidKeyException;import java.security.Key;import java.security.NoSuchAlgorithmException;import java.security.spec.InvalidKeySpecException;import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import javax.crypto.KeyGenerator;import javax.crypto.NoSuchPaddingException;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESKeySpec;import org.apache.commons.codec.binary.Base64;/** * 基于JDK的DES算法 */public class DESJDK { private static final String ENCODING = "UTF-8"; private static final String KEY_ALGORITHM = "DES";//产生密钥的算法 private static final String CIPHER_ALGORITHM = "DES/ECB/PKCS5Padding";//加解密算法 格式：算法/工作模式/填充模式 /** * 产生密钥 */ public static byte[] getKey() throws NoSuchAlgorithmException{ KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_ALGORITHM); keyGenerator.init(56);//初始化密钥长度 SecretKey key =keyGenerator.generateKey();//产生密钥 return key.getEncoded(); } /** * 还原密钥：二进制字节数组转换为十六进制字符串 */ public static Key toKey(byte[] keyByte) throws InvalidKeyException, NoSuchAlgorithmException, InvalidKeySpecException{ DESKeySpec desKeySpec = new DESKeySpec(keyByte); return SecretKeyFactory.getInstance(KEY_ALGORITHM).generateSecret(desKeySpec); } /** * DES加密 * @param data 带加密数据 * @param keyByte 密钥 */ public static byte[] encrypt(String data, byte[] keyByte) throws InvalidKeyException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException{ Key key = toKey(keyByte);//还原密钥 Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM); cipher.init(Cipher.ENCRYPT_MODE, key);//设置加密模式并且初始化key return cipher.doFinal(data.getBytes(ENCODING)); } /** * DES加密，并转为16进制字符串或Base64编码字符串 */ public static String encryptDESHex(String data, byte[] keyByte) throws InvalidKeyException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException { byte[] encodedByte = encrypt(data, keyByte); //return new String(Hex.encode(encodedByte));//借助BC //return new String(org.apache.commons.codec.binary.Hex.encodeHexString(encodedByte));//借助CC return Base64.encodeBase64String(encodedByte);//借助CC的Base64编码 } /** * DES解密 * @param data 待解密数据为字节数组 * @param keyByte 密钥 */ public static byte[] decrypt(byte[] data, byte[] keyByte) throws InvalidKeyException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException { Key key = toKey(keyByte);//还原密钥 Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM); cipher.init(Cipher.DECRYPT_MODE, key);//设置解密模式（这是加解密的唯一不同的地方）并且初始化key return cipher.doFinal(data); } /** * DES解密 * @param data 待解密数据为字符串 * @param keyByte 密钥 */ public static byte[] decrypt(String data, byte[] keyByte) throws InvalidKeyException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException { Key key = toKey(keyByte);//还原密钥 Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM); cipher.init(Cipher.DECRYPT_MODE, key);//设置解密模式（这是加解密的唯一不同的地方）并且初始化key return cipher.doFinal(Base64.decodeBase64(data));//注意data不可以直接采用data.getByte()方法转化为字节数组，否则会抛异常 } /** * 测试 */ public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeyException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException { String data = "找一个好姑娘做老婆是我的梦 想!"; /*************测试encode()**************/ System.out.println("原文-->"+data); byte[] keyByte = DESJDK.getKey(); System.out.println("密钥-->"+Base64.encodeBase64String(keyByte));//这里将二进制的密钥使用base64加密保存，这也是在实际中使用的方式 byte[] encodedByte = DESJDK.encrypt(data, keyByte); System.out.println("加密后-->"+encodedByte); byte[] encodedByte2 = DESJDK.encrypt(data, keyByte); System.out.println("加密后-->"+encodedByte2); byte[] decodedByte = DESJDK.decrypt(encodedByte, keyByte); System.out.println("解密后-->"+decodedByte); for(int i=0;i<encodedByte.length;i++){ System.out.println(encodedByte[i]==encodedByte2[i]); } /*************测试encodeHmacMD5Hex()**************/ System.out.println("原文-->"+data); byte[] keyByte3 = DESJDK.getKey(); System.out.println("密钥-->"+Base64.encodeBase64String(keyByte3));//这里将二进制的密钥使用base64加密保存，这也是在实际中使用的方式 String encodedStr = DESJDK.encryptDESHex(data, keyByte3); System.out.println("加密后-->"+encodedStr); String encodedByte4 = DESJDK.encryptDESHex(data, keyByte3); System.out.println("加密后-->"+encodedByte4); byte[] decodedByte3 = DESJDK.decrypt(Base64.decodeBase64(encodedStr), keyByte3); System.out.println("解密Byte[]后-->"+decodedByte3); byte[] decodedByte4 = DESJDK.decrypt(encodedStr, keyByte3); System.out.println("解密String后-->"+decodedByte4); }}