JAVA实现RSA算法

1、数据结构:JAV A实现RSA算法实现一对密钥对整个项目所有加密解密文件都适用的方法,采用先生成一对密钥.保存到xml文件中,以后获得私匙和公钥只需要从xml文件中取得就可以了./* 把成生的一对密钥保存到RSAKey.xml文件中*/public void saveRSAKey( try SecureRandom sr = new SecureRandom(;KeyPairGenerator kg = KeyPairGenerator.getInstance("RSA",/注意密钥大小最好为1024,否则解密会有乱码情况.kg.initialize(1024, sr;Fi

2、leOutputStream fos = new FileOutputStream("C:/RSAKey.xml"ObjectOutputStream oos = new ObjectOutputStream(fos;/生成密钥oos.writeObject(kg.generateKeyPair(;oos.close(; catch (Exception e e.printStackTrace(;获取密钥方法如下:/* 获得RSA加密的密钥。* return KeyPair返回对称密钥*/public static KeyPair getKeyPair( /产生新密钥对Ke

3、yPair kp;try String fileName = "conf/RASKey.xml".getResourceAsStream(fileName;ObjectInputStream oos = new ObjectInputStream(is;kp = (KeyPair oos.readObject(;oos.close(; catch (Exception e throw new EprasRuntimeException("读取加密文件出错.", e;return kp;文件采用RSA算法加密文件/* 文件file进行加密并保存目标文件de

4、stFile中* param srcFileName* 要加密的文件如c:/test/srcFile.txt* param destFileName* 加密后存放的文件名如c:/加密后文件.txt*/public static void encryptFile(String srcFileName,String destFileName throws Exception OutputStream outputWriter = null;InputStream inputReader = null;try byte buf = new byte100;int bufl;cipher.init(C

5、ipher.ENCRYPT_MODE, getKeyPair(.getPublic(; outputWriter = new FileOutputStream(destFileName; inputReader = new FileInputStream(srcFileName;while (bufl = inputReader.read(buf != -1 byte encText = null;byte newArr = null;if (buf.length = bufl newArr = buf; else newArr = new bytebufl;for (int i = 0; i

6、 < bufl; i+ newArr = (byte buf;encText = cipher.doFinal(newArr;outputWriter.write(encText;outputWriter.flush(; catch (Exception e throw e; finally try if (outputWriter != null outputWriter.close(;if (inputReader != null inputReader.close(; catch (Exception e 文件采用RSA算法解密文件/* 文件file进行加密并保存目标文件destF

7、ile中* param srcFileName* 已加密的文件如c:/加密后文件.txt* param destFileName* 解密后存放的文件名如c:/ test/解密后文件.txt*/public static void decryptFile(String srcFileName,String destFileName throws Exception OutputStream outputWriter = null;InputStream inputReader = null;try byte buf = new byte128;int bufl;cipher.init(Ciphe

8、r.DECRYPT_MODE, getKeyPair(.getPrivate(; outputWriter = new FileOutputStream(destFileName; inputReader = new FileInputStream(srcFileName;while (bufl = inputReader.read(buf != -1 byte encText = null;byte newArr = null;if (buf.length = bufl newArr = buf; else newArr = new bytebufl;for (int i = 0; i < bufl; i+ newArr = (byte buf;encText = cipher.doFinal(newArr;outputWriter.write(encText;outputWriter.flush(; catch (Exception e throw e; finally try i