cipheroutputstream.java

纯java AES实现

package com.jrijndael.io;

import java.io.*;
import com.jrijndael.JRijndael;


public class CipherOutputStream {
    
    //The underlying BufferedOutputStream instance
    private BufferedOutputStream bos;
    
    //The underlying block cipher instance
    private JRijndael algorithm;
    
    /** Creates a new instance of CipherOutputStream */
    public CipherOutputStream(FileOutputStream fos, String passphrase, int keylength) {
        //Create a new instance of the BufferedOutputStream
        bos = new BufferedOutputStream(fos);
        
        //Create a new instance of the block cipher
        algorithm = new JRijndael();
        
        //Initialize the block cipher
        algorithm.generateKey(passphrase, keylength);
    }
    
    /** Encrypts then writes a byte array to the BufferedOutputStream */
    public void write(byte[] b) throws IOException {
        //Encrypt the supplyed byte array
        byte[] cipherText = algorithm.encryptByteArray(b);
        
        //Write the encrypted bytes to the BufferedOutputStream
        bos.write(cipherText);
    }
    
    /** Flushes the BufferedOutputStream */
    public void flush() throws IOException {
        //Flush the BufferedOutputStream
        bos.flush();
    }
    
    /** Clears the cipher, then closes the BufferedOutputStream */
    public void close() throws IOException {
        //Clear the block cipher
        algorithm.clear();
        
        //Close the BufferedOutputStream
        bos.close();
    }
}