文件加密解密算法(Java源码)

文件加密解密算法(Java源码) java,file,算法,加密解密,java源码 package com.crypto.encrypt; import java.security.SecureRandom; import java.io.*; import javax.crypto.spec.DESKeySpec; import javax.crypto.SecretKey; import javax.crypto.SecretKeyFactory; import javax.crypto.Cipher; import java.security.InvalidKeyException; import java.security.NoSuchAlgorithmException; import java.security.spec.InvalidKeySpecException; import javax.crypto.NoSuchPaddingException; import javax.crypto.BadPaddingException; import javax.crypto.IllegalBlockSizeException; import java.lang.reflect.Constructor; import java.security.spec.KeySpec; import java.lang.reflect.InvocationTargetException; public class EncryptData { private String keyfile=null; public EncryptData() { } public EncryptData(String keyfile) { this.keyfile=keyfile; } /** * 加密文件 * @param filename String 源路径 * @param filenamekey String 加密后的路径 */ public void createEncryptData(String filename,String filenamekey) throws IllegalStateException, IllegalBlockSizeException, BadPaddingException, NoSuchPaddingException, InvalidKeySpecException, NoSuchAlgorithmException, InvalidKeyException, IOException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException, ClassNotFoundException, IllegalStateException, IllegalBlockSizeException, BadPaddingException, NoSuchPaddingException, InvalidKeySpecException, NoSuchAlgorithmException, InvalidKeyException, IOException { //验证keyfile if(keyfile==null || keyfile.equals("")) { throw new NullPointerException("无效的key文件路径"); } encryptData(filename,filenamekey); } /** * 加密类文件 * @param filename String 原始的类文件 * @param encryptfile String 加密后的类文件 * @throws IOException * @throws InvalidKeyException * @throws NoSuchAlgorithmException * @throws InvalidKeySpecException * @throws NoSuchPaddingException * @throws NoSuchAlgorithmException * @throws BadPaddingException * @throws IllegalBlockSizeException * @throws IllegalStateException */ private void encryptData(String filename,String encryptfile) throws IOException, InvalidKeyException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, NoSuchAlgorithmException, BadPaddingException, IllegalBlockSizeException, IllegalStateException, ClassNotFoundException, SecurityException, NoSuchMethodException, InvocationTargetException, IllegalArgumentException, IllegalAccessException, InstantiationException { byte data[]=Util.readFile(filename); // 执行加密操作 byte encryptedClassData[] = getencryptData(data); // 保存加密后的文件，覆盖原有的类文件。 Util.writeFile(encryptedClassData,encryptfile); } /** * 直接获得加密数据 * @param bytes byte[] * @throws IllegalStateException * @throws IllegalBlockSizeException * @throws BadPaddingException * @throws InvalidKeyException * @throws NoSuchPaddingException * @throws InvalidKeySpecException * @throws NoSuchAlgorithmException * @throws InstantiationException * @throws IllegalAccessException * @throws IllegalArgumentException * @throws InvocationTargetException * @throws NoSuchMethodException * @throws SecurityException * @throws ClassNotFoundException * @throws IOException * @return byte[] */ public byte[] createEncryptData(byte[] bytes) throws IllegalStateException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException, NoSuchPaddingException, InvalidKeySpecException, NoSuchAlgorithmException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException, ClassNotFoundException, IOException { bytes=getencryptData(bytes); return bytes; } private byte[] getencryptData(byte[] bytes) throws IOException, ClassNotFoundException, SecurityException, NoSuchMethodException, InvocationTargetException, IllegalArgumentException, IllegalAccessException, InstantiationException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, IllegalStateException { // 产生一个可信任的随机数源 SecureRandom sr = new SecureRandom(); //从密钥文件key Filename中得到密钥数据 byte[] rawKeyData = Util.readFile(keyfile); // 从原始密钥数据创建DESKeySpec对象 Class classkeyspec=Class.forName(Util.getValue("keyspec")); Constructor constructor = classkeyspec.getConstructor(new Class[]{byte[].class}); KeySpec dks = (KeySpec) constructor.newInstance(new Object[]{rawKeyData}); // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象 SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(Util.getAlgorithm()); SecretKey key = keyFactory.generateSecret(dks); // Cipher对象实际完成加密操作 Cipher cipher = Cipher.getInstance(Util.getAlgorithm()); // 用密钥初始化Cipher对象 cipher.init(Cipher.ENCRYPT_MODE, key, sr); // 执行加密操作 bytes = cipher.doFinal(bytes); // 返回字节数组 return bytes; } /** * 设置key文件路径 * @param keyfile String */ public void setKeyFile(String keyfile) { this.keyfile=keyfile; } }