android——實現AES加密

  1 package com.example.loadurlcode;
  2 
  3 
  4 import java.io.UnsupportedEncodingException;
  5 import java.security.InvalidKeyException;
  6 import java.security.NoSuchAlgorithmException;
  7 import java.security.SecureRandom;
  8 
  9 import javax.crypto.BadPaddingException;
 10 import javax.crypto.Cipher;
 11 import javax.crypto.IllegalBlockSizeException;
 12 import javax.crypto.KeyGenerator;
 13 import javax.crypto.NoSuchPaddingException;
 14 import javax.crypto.SecretKey;
 15 import javax.crypto.spec.SecretKeySpec;
 16 
 17 
 18 public class AES {
 19     /**
 20       * 加密
 21      * 
 22       * @param content 須要加密的內容
 23      * @param password  加密密碼
 24      * @return
 25       */ 
 26      public static byte[] encrypt(String content, String password) { 
 27              try {            
 28                      KeyGenerator kgen = KeyGenerator.getInstance("AES"); 
 29                      kgen.init(128, new SecureRandom(password.getBytes())); 
 30                      SecretKey secretKey = kgen.generateKey(); 
 31                      byte[] enCodeFormat = secretKey.getEncoded(); 
 32                      SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES"); 
 33                      Cipher cipher = Cipher.getInstance("AES");// 建立密碼器 
 34                      byte[] byteContent = content.getBytes("utf-8"); 
 35                      cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化 
 36                      byte[] result = cipher.doFinal(byteContent); 
 37                      return result; // 加密 
 38              } catch (NoSuchAlgorithmException e) { 
 39                      e.printStackTrace(); 
 40              } catch (NoSuchPaddingException e) { 
 41                      e.printStackTrace(); 
 42              } catch (InvalidKeyException e) { 
 43                      e.printStackTrace(); 
 44              } catch (UnsupportedEncodingException e) { 
 45                      e.printStackTrace(); 
 46              } catch (IllegalBlockSizeException e) { 
 47                      e.printStackTrace(); 
 48              } catch (BadPaddingException e) { 
 49                      e.printStackTrace(); 
 50              } 
 51              return null; 
 52      } 
 53      
 54      /**解密
 55       * @param content  待解密內容
 56       * @param password 解密密鑰
 57       * @return
 58        */ 
 59       public static byte[] decrypt(byte[] content, String password) { 
 60               try { 
 61                        KeyGenerator kgen = KeyGenerator.getInstance("AES"); 
 62                        kgen.init(128, new SecureRandom(password.getBytes())); 
 63                        SecretKey secretKey = kgen.generateKey(); 
 64                        byte[] enCodeFormat = secretKey.getEncoded(); 
 65                        SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");             
 66                        Cipher cipher = Cipher.getInstance("AES");// 建立密碼器 
 67                       cipher.init(Cipher.DECRYPT_MODE, key);// 初始化 
 68                       byte[] result = cipher.doFinal(content); 
 69                       return result; // 加密 
 70               } catch (NoSuchAlgorithmException e) { 
 71                       e.printStackTrace(); 
 72               } catch (NoSuchPaddingException e) { 
 73                       e.printStackTrace(); 
 74               } catch (InvalidKeyException e) { 
 75                       e.printStackTrace(); 
 76               } catch (IllegalBlockSizeException e) { 
 77                       e.printStackTrace(); 
 78               } catch (BadPaddingException e) { 
 79                       e.printStackTrace(); 
 80               } 
 81               return null; 
 82       }
 83       
 84       
 85       /**將二進制轉換成16進制
 86        * @param buf
 87         * @return
 88         */ 
 89        public static String parseByte2HexStr(byte buf[]) { 
 90                StringBuffer sb = new StringBuffer(); 
 91                for (int i = 0; i < buf.length; i++) { 
 92                        String hex = Integer.toHexString(buf[i] & 0xFF); 
 93                        if (hex.length() == 1) { 
 94                                hex = '0' + hex; 
 95                        } 
 96                        sb.append(hex.toUpperCase()); 
 97                } 
 98                return sb.toString(); 
 99        } 
100        
101        /**將16進制轉換爲二進制
102         * @param hexStr
103          * @return
104          */ 
105         public static byte[] parseHexStr2Byte(String hexStr) { 
106                 if (hexStr.length() < 1) 
107                         return null; 
108                 byte[] result = new byte[hexStr.length()/2]; 
109                 for (int i = 0;i< hexStr.length()/2; i++) { 
110                         int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16); 
111                         int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16); 
112                         result[i] = (byte) (high * 16 + low); 
113                 } 
114                 return result; 
115         } 
116         
117         /**
118            * 加密
119           *
120            * @param content 須要加密的內容
121           * @param password  加密密碼
122           * @return
123            */ 
124           public static byte[] encrypt2(String content, String password) { 
125                   try { 
126                           SecretKeySpec key = new SecretKeySpec(password.getBytes(), "AES"); 
127                           Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding"); 
128                           byte[] byteContent = content.getBytes("utf-8"); 
129                           cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化 
130                           byte[] result = cipher.doFinal(byteContent); 
131                           return result; // 加密 
132                   } catch (NoSuchAlgorithmException e) { 
133                           e.printStackTrace(); 
134                   } catch (NoSuchPaddingException e) { 
135                           e.printStackTrace(); 
136                   } catch (InvalidKeyException e) { 
137                           e.printStackTrace(); 
138                   } catch (UnsupportedEncodingException e) { 
139                           e.printStackTrace(); 
140                   } catch (IllegalBlockSizeException e) { 
141                           e.printStackTrace(); 
142                   } catch (BadPaddingException e) { 
143                           e.printStackTrace(); 
144                   } 
145                   return null; 
146           } 
147       
148       public static void main(String[] args) {
149           String content = "test"; 
150           String password = "12345678"; 
151           //加密 
152          System.out.println("加密前：" + content); 
153          byte[] encryptResult = encrypt(content, password);
154          System.out.println(new String(encryptResult));
155          
156           //解密 
157          byte[] decryptResult = decrypt(encryptResult,password); 
158          System.out.println("解密後：" + new String(decryptResult)); 
159     }
160 }

本文轉自http://duanfei.iteye.com/blog/1725613