JAVA实现AES加密

AES是美国联邦政府采用的商业及政府数据加密标准，预计将在未来几十年里代替DES在各个领域中得到广泛应用。AES提供128位密钥，因此，128位AES的加密强度是56位DES加密强度的1021倍还多。假设可以制造一部可以在1秒内破解DES密码的机器，那么使用这台机器破解一个128位AES密码需要大约149亿万年的时间。（更深一步比较而言，宇宙一般被认为存在了还不到200亿年）因此可以预计，美国国家标准局倡导的AES即将作为新标准取代DES。

package com.jshx.utils;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

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.spec.SecretKeySpec;

import org.apache.axis.encoding.Base64;

public class AES {
	/**
	  * 加密
	 * 
	  * @param content 需要加密的内容
	 * @param password  加密密码
	 * @return
	  */ 
	 public static byte[] encrypt(String content, String password) { 
	         try {            
	                 KeyGenerator kgen = KeyGenerator.getInstance("AES"); 
	                 kgen.init(128, new SecureRandom(password.getBytes())); 
	                 SecretKey secretKey = kgen.generateKey(); 
	                 byte[] enCodeFormat = secretKey.getEncoded(); 
	                 SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES"); 
	                 Cipher cipher = Cipher.getInstance("AES");// 创建密码器 
	                 byte[] byteContent = content.getBytes("utf-8"); 
	                 cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化 
	                 byte[] result = cipher.doFinal(byteContent); 
	                 return result; // 加密 
	         } catch (NoSuchAlgorithmException e) { 
	                 e.printStackTrace(); 
	         } catch (NoSuchPaddingException e) { 
	                 e.printStackTrace(); 
	         } catch (InvalidKeyException e) { 
	                 e.printStackTrace(); 
	         } catch (UnsupportedEncodingException e) { 
	                 e.printStackTrace(); 
	         } catch (IllegalBlockSizeException e) { 
	                 e.printStackTrace(); 
	         } catch (BadPaddingException e) { 
	                 e.printStackTrace(); 
	         } 
	         return null; 
	 } 
	 
	 /**解密
	  * @param content  待解密内容
	  * @param password 解密密钥
	  * @return
	   */ 
	  public static byte[] decrypt(byte[] content, String password) { 
	          try { 
	                   KeyGenerator kgen = KeyGenerator.getInstance("AES"); 
	                   kgen.init(128, new SecureRandom(password.getBytes())); 
	                   SecretKey secretKey = kgen.generateKey(); 
	                   byte[] enCodeFormat = secretKey.getEncoded(); 
	                   SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");             
	                   Cipher cipher = Cipher.getInstance("AES");// 创建密码器 
	                  cipher.init(Cipher.DECRYPT_MODE, key);// 初始化 
	                  byte[] result = cipher.doFinal(content); 
	                  return result; // 加密 
	          } catch (NoSuchAlgorithmException e) { 
	                  e.printStackTrace(); 
	          } catch (NoSuchPaddingException e) { 
	                  e.printStackTrace(); 
	          } catch (InvalidKeyException e) { 
	                  e.printStackTrace(); 
	          } catch (IllegalBlockSizeException e) { 
	                  e.printStackTrace(); 
	          } catch (BadPaddingException e) { 
	                  e.printStackTrace(); 
	          } 
	          return null; 
	  }
	  
	  
	  /**将二进制转换成16进制
	   * @param buf
	    * @return
	    */ 
	   public static String parseByte2HexStr(byte buf[]) { 
	           StringBuffer sb = new StringBuffer(); 
	           for (int i = 0; i < buf.length; i++) { 
	                   String hex = Integer.toHexString(buf[i] & 0xFF); 
	                   if (hex.length() == 1) { 
	                           hex = '0' + hex; 
	                   } 
	                   sb.append(hex.toUpperCase()); 
	           } 
	           return sb.toString(); 
	   } 
	   
	   /**将16进制转换为二进制
	    * @param hexStr
	     * @return
	     */ 
	    public static byte[] parseHexStr2Byte(String hexStr) { 
	            if (hexStr.length() < 1) 
	                    return null; 
	            byte[] result = new byte[hexStr.length()/2]; 
	            for (int i = 0;i< hexStr.length()/2; i++) { 
	                    int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16); 
	                    int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16); 
	                    result[i] = (byte) (high * 16 + low); 
	            } 
	            return result; 
	    } 
	    
	    /**
	       * 加密
	      *
	       * @param content 需要加密的内容
	      * @param password  加密密码
	      * @return
	       */ 
	      public static byte[] encrypt2(String content, String password) { 
	              try { 
	                      SecretKeySpec key = new SecretKeySpec(password.getBytes(), "AES"); 
	                      Cipher cipher = Cipher.getInstance("AES/ECB/NoPadding"); 
	                      byte[] byteContent = content.getBytes("utf-8"); 
	                      cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化 
	                      byte[] result = cipher.doFinal(byteContent); 
	                      return result; // 加密 
	              } catch (NoSuchAlgorithmException e) { 
	                      e.printStackTrace(); 
	              } catch (NoSuchPaddingException e) { 
	                      e.printStackTrace(); 
	              } catch (InvalidKeyException e) { 
	                      e.printStackTrace(); 
	              } catch (UnsupportedEncodingException e) { 
	                      e.printStackTrace(); 
	              } catch (IllegalBlockSizeException e) { 
	                      e.printStackTrace(); 
	              } catch (BadPaddingException e) { 
	                      e.printStackTrace(); 
	              } 
	              return null; 
	      } 
	  
	  public static void main(String[] args) {
		  String content = "test"; 
		  String password = "12345678"; 
		  //加密 
		 System.out.println("加密前：" + content); 
		 byte[] encryptResult = encrypt(content, password);
		 String tt4 = Base64.encode(encryptResult);
		 System.out.println(new String(tt4));
		 
		  //解密 
		 byte[] decryptResult = decrypt(encryptResult,password); 
		 System.out.println("解密后：" + new String(decryptResult)); 
	}
}

评论

1 楼 zcgewu 2015-08-21  

encrypt2()和encrypt()有什么区别