用Bouncy Castle实现AES-128-CBC加密解密

Bouncy Castle Crypto APIs 是一个开源的轻量级Java 加密解密包，实现了JCE/JCA的provider，支持AES等多种加密解密算法。
详情请见主页：http://www.bouncycastle.org/java.html
本文的示例代码使用了http://www.bouncycastle.org/download/bcprov-jdk16-139.jar
1）使用JCE的AES-128-CBC加密解密

 package  com.albertsong.aes;

 import  java.security.Key;
 import  java.security.Security;

 import  javax.crypto.Cipher;
 import  javax.crypto.spec.IvParameterSpec;
 import  javax.crypto.spec.SecretKeySpec;

 import  org.bouncycastle.jce.provider.BouncyCastleProvider;
 import  org.bouncycastle.util.encoders.Hex;

 /**
  * @author Albert
  * @version 1.0
  *
  */
 public   class  AESWithJCE {

     /**
      * @param args
      */
     public   static   void  main(String[] args) {
         byte [] keybytes = {  0x31 ,  0x32 ,  0x33 ,  0x34 ,  0x35 ,  0x36 ,  0x37 ,  0x38 ,
                 0x31 ,  0x32 ,  0x33 ,  0x34 ,  0x35 ,  0x36 ,  0x37 ,  0x38  };
         byte [] iv = {  0x38 ,  0x37 ,  0x36 ,  0x35 ,  0x34 ,  0x33 ,  0x32 ,  0x31 ,  0x38 ,
                 0x37 ,  0x36 ,  0x35 ,  0x34 ,  0x33 ,  0x32 ,  0x31  };
         String content ="TEST1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ" ;
         System.out.println("Original content:" );
         System.out.println(content);
         try  {
             Security.addProvider(new  BouncyCastleProvider());
             Key key = new  SecretKeySpec(keybytes,  "AES" );
             Cipher in = Cipher.getInstance("AES/CBC/PKCS7Padding" , "BC" );
             in.init(Cipher.ENCRYPT_MODE, key, new  IvParameterSpec(iv));
             byte [] enc = in.doFinal(content.getBytes());
             System.out.println("Encrypted Content:" );
             System.out.println(new  String(Hex.encode(enc)));

             Cipher out = Cipher.getInstance("AES/CBC/PKCS7Padding" ,  "BC" );
             out.init(Cipher.DECRYPT_MODE, key, new  IvParameterSpec(iv));
             byte [] dec = out.doFinal(enc);
             System.out.println("Decrypted Content:" );
             System.out.println(new  String(dec));
         } catch  (Exception ex) {
             ex.printStackTrace();
         }

     }

 }

 2）不使用JCE的AES-128-CBC加密解密，可以用于J2ME程序中。

 package  com.albertsong.aes;

 import  org.bouncycastle.crypto.BufferedBlockCipher;
 import  org.bouncycastle.crypto.engines.AESFastEngine;
 import  org.bouncycastle.crypto.modes.CBCBlockCipher;
 import  org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
 import  org.bouncycastle.crypto.params.KeyParameter;
 import  org.bouncycastle.crypto.params.ParametersWithIV;
 import  org.bouncycastle.util.encoders.Hex;

 /**
  * @author Albert
  * @version 1.0
  *
  */
 public   class  AESWithoutJCE {

     /**
      * @param args
      */
     public   static   void  main(String[] args) {
         byte [] keybytes = {  0x31 ,  0x32 ,  0x33 ,  0x34 ,  0x35 ,  0x36 ,  0x37 ,  0x38 ,
                 0x31 ,  0x32 ,  0x33 ,  0x34 ,  0x35 ,  0x36 ,  0x37 ,  0x38  };
         byte [] iv = {  0x38 ,  0x37 ,  0x36 ,  0x35 ,  0x34 ,  0x33 ,  0x32 ,  0x31 ,  0x38 ,
                 0x37 ,  0x36 ,  0x35 ,  0x34 ,  0x33 ,  0x32 ,  0x31  };
         String content ="TEST1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ" ;
         System.out.println("Original content:" );
         System.out.println(content);
         try  {
             BufferedBlockCipher engine = new  PaddedBufferedBlockCipher( new  CBCBlockCipher( new  AESFastEngine()));
             engine.init(true ,  new  ParametersWithIV( new  KeyParameter(keybytes),iv));
             byte [] enc =  new   byte [engine.getOutputSize(content.getBytes().length)];
             int  size1 = engine.processBytes(content.getBytes(),  0 , content.getBytes().length, enc,  0 );
             int  size2 = engine.doFinal(enc, size1);
             System.out.println("size2 =" +size2);
             byte [] encryptedContent = new   byte [size1+size2];
             System.arraycopy(enc, 0 , encryptedContent,  0 , encryptedContent.length);
             System.out.println("Encrypted Content:" );
             System.out.println(new  String(Hex.encode(encryptedContent)));


             engine.init(false ,  new  ParametersWithIV( new  KeyParameter(keybytes),iv));
             byte [] dec =  new   byte [engine.getOutputSize(encryptedContent.length)];
             size1 = engine.processBytes(encryptedContent, 0 , encryptedContent.length, dec,  0 );
             size2 = engine.doFinal(dec, size1);
             System.out.println("size2 =" +size2);
             byte [] decryptedContent = new   byte [size1+size2];
             System.arraycopy(dec, 0 , decryptedContent,  0 , decryptedContent.length);
             System.out.println("Decrypted Content:" );
             System.out.println(new  String(decryptedContent));

         } catch  (Exception ex) {
             ex.printStackTrace();
         }

     }

 }