第九章 对称加密算法--IDEA

  1 package com.util.idea;
  2 
  3 import java.io.UnsupportedEncodingException;
  4 import java.security.InvalidAlgorithmParameterException;
  5 import java.security.InvalidKeyException;
  6 import java.security.Key;
  7 import java.security.NoSuchAlgorithmException;
  8 import java.security.NoSuchProviderException;
  9 import java.security.Security;
 10 import java.security.spec.InvalidKeySpecException;
 11 
 12 import javax.crypto.BadPaddingException;
 13 import javax.crypto.Cipher;
 14 import javax.crypto.IllegalBlockSizeException;
 15 import javax.crypto.KeyGenerator;
 16 import javax.crypto.NoSuchPaddingException;
 17 import javax.crypto.SecretKey;
 18 import javax.crypto.spec.SecretKeySpec;
 19 
 20 import org.apache.commons.codec.binary.Base64;
 21 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 22 
 23 /**
 24  * 基于BC的IDEA算法，工作模式只有ECB
 25  */
 26 public class IDEABC {
 27     private static final String ENCODING = "UTF-8";
 28     private static final String KEY_ALGORITHM = "IDEA";//产生密钥的算法
 29     private static final String CIPHER_ALGORITHM = "IDEA/ECB/PKCS5Padding";//加解密算法 格式：算法/工作模式/填充模式
 30     /**
 31      * 产生密钥
 32      */
 33     public static byte[] getKey() throws NoSuchAlgorithmException{
 34         Security.addProvider(new BouncyCastleProvider());//在BC中用，JDK下去除
 35         KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_ALGORITHM);
 36         keyGenerator.init(128);//初始化密钥长度,128
 37         SecretKey key =keyGenerator.generateKey();//产生密钥
 38         return key.getEncoded();
 39     }
 40     
 41     /**
 42      * 还原密钥：二进制字节数组转换为Java对象
 43      */
 44     public static Key toKey(byte[] keyByte){
 45         return new SecretKeySpec(keyByte, KEY_ALGORITHM);
 46     }
 47     
 48     /**
 49      * IDEA加密
 50      * @param data     带加密数据
 51      * @param keyByte  密钥
 52      */
 53     public static byte[] encrypt(String data, byte[] keyByte) throws NoSuchAlgorithmException, 
 54                                                                      NoSuchProviderException, 
 55                                                                      NoSuchPaddingException, 
 56                                                                      InvalidKeyException, 
 57                                                                      IllegalBlockSizeException, 
 58                                                                      BadPaddingException, 
 59                                                                      UnsupportedEncodingException {
 60         Key key = toKey(keyByte);//还原密钥
 61         Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM,"BC");//BC下用
 62         cipher.init(Cipher.ENCRYPT_MODE, key);//设置加密模式并且初始化key
 63         return cipher.doFinal(data.getBytes(ENCODING));
 64     }
 65     
 66     /**
 67      * IDEA加密，并转为16进制字符串或Base64编码字符串
 68      */
 69     public static String encryptIDEAHex(String data, byte[] keyByte) throws NoSuchAlgorithmException, 
 70                                                                            NoSuchProviderException, 
 71                                                                            NoSuchPaddingException, 
 72                                                                            InvalidKeyException, 
 73                                                                            IllegalBlockSizeException, 
 74                                                                            BadPaddingException, 
 75                                                                            UnsupportedEncodingException {
 76         byte[] encodedByte = encrypt(data, keyByte);
 77         //return new String(Hex.encode(encodedByte));//借助BC
 78         //return new String(org.apache.commons.codec.binary.Hex.encodeHexString(encodedByte));//借助CC
 79         return Base64.encodeBase64String(encodedByte);//借助CC的Base64编码
 80     }
 81     
 82     /**
 83      * IDEA解密
 84      * @param data        待解密数据为字节数组
 85      * @param keyByte    密钥
 86      */
 87     public static byte[] decrypt(byte[] data, byte[] keyByte) throws NoSuchAlgorithmException, 
 88                                                                      NoSuchProviderException, 
 89                                                                      NoSuchPaddingException, 
 90                                                                      InvalidKeyException, 
 91                                                                      IllegalBlockSizeException, 
 92                                                                      BadPaddingException {
 93         Key key = toKey(keyByte);//还原密钥
 94         Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM,"BC");//BC下用
 95         cipher.init(Cipher.DECRYPT_MODE, key);
 96         return cipher.doFinal(data);
 97     }
 98     
 99     /**
100      * IDEA解密
101      * @param data        待解密数据为字符串
102      * @param keyByte    密钥
103      */
104     public static byte[] decrypt(String data, byte[] keyByte) throws NoSuchAlgorithmException, 
105                                                                      NoSuchProviderException, 
106                                                                      NoSuchPaddingException, 
107                                                                      InvalidKeyException, 
108                                                                      IllegalBlockSizeException, 
109                                                                      BadPaddingException  {
110         Key key = toKey(keyByte);//还原密钥
111         Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM,"BC");//BC下用
112         cipher.init(Cipher.DECRYPT_MODE, key);
113         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
114     }
115     
116     /**
117      * 测试
118      */
119     public static void main(String[] args) throws NoSuchAlgorithmException, 
120                                                   InvalidKeyException, 
121                                                   InvalidKeySpecException, 
122                                                   NoSuchPaddingException, 
123                                                   IllegalBlockSizeException, 
124                                                   BadPaddingException, 
125                                                   UnsupportedEncodingException, 
126                                                   NoSuchProviderException, 
127                                                   InvalidAlgorithmParameterException {
128         String data = "找一个好姑娘做老婆是我的梦 想!";
129         /*************测试encrypt()、decrypt()**************/
130         System.out.println("原文-->"+data);
131         byte[] keyByte = IDEABC.getKey(); 
132         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
133         byte[] encodedByte = IDEABC.encrypt(data, keyByte);
134         System.out.println("加密后-->"+encodedByte);
135         byte[] encodedByte2 = IDEABC.encrypt(data, keyByte);
136         System.out.println("加密后-->"+encodedByte2);
137         byte[] decodedByte = IDEABC.decrypt(encodedByte, keyByte);
138         System.out.println("解密后-->"+decodedByte);
139         for(int i=0;i<encodedByte.length;i++){
140             System.out.println(encodedByte[i]==encodedByte2[i]);
141         }
142         /*************测试encryptIDEAHex()、decrypt()**************/
143         System.out.println("原文-->"+data);
144         byte[] keyByte3 = IDEABC.getKey(); 
145         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
146         String encodedStr = IDEABC.encryptIDEAHex(data, keyByte3);
147         System.out.println("加密后-->"+encodedStr);
148         String encodedByte4 = IDEABC.encryptIDEAHex(data, keyByte3);
149         System.out.println("加密后-->"+encodedByte4);
150         byte[] decodedByte3 = IDEABC.decrypt(Base64.decodeBase64(encodedStr), keyByte3);
151         System.out.println("解密Byte[]后-->"+decodedByte3);
152         byte[] decodedByte4 = IDEABC.decrypt(encodedStr, keyByte3);
153         System.out.println("解密String后-->"+decodedByte4);
154     }
155 }