(java 基础知识) java 加密操作---java.crypto

妖狐艹你老母 2023-10-10 11:55 21阅读 0赞

#### [java对文件进行加密解密操作 ][java_] ####

#### 接口类：  package JFFileEncrypt;  import java.security.Key;   import java.security.NoSuchAlgorithmException;   import java.security.SecureRandom;  import javax.crypto.KeyGenerator;   import javax.crypto.spec.SecretKeySpec;   /\*\*   \* 功能：对文件加密解密操作   \* @author jiangfeng   \*   \*/   public interface FileEncryptInterface   \{   /\*\*   \* 加密算法   \* @param key   \* @param FileName   \* @return   \*/   public boolean DESEncrypt(Key key, String FileName);   /\*\*   \* 解密算法   \* @param FileName   \* @param key   \* @return   \*/   public boolean DESDecrypt(String FileName, Key key);   /\*\*   \* 自定义一个key   \*/   public Key getKey(String keyRule);   /\*\*   \* 第二种产生key的方法   \* @return   \*/   public Key getKey2();   \}   接口实现类：  package JFFileEncrypt;  import java.io.BufferedWriter;   import java.io.FileInputStream;   import java.io.FileOutputStream;   import java.io.IOException;   import java.io.OutputStreamWriter;   import java.security.InvalidKeyException;   import java.security.Key;   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.spec.SecretKeySpec;   /\*\*   \* 功能：对文件加密解密操作   \* @author jiangfeng   \*   \*/   public class FileEncryptImpal implements FileEncryptInterface   \{   /\*\*   \* 功能：加密文件   \*/   public boolean DESEncrypt(Key key, String FileName)   \{   boolean result = false;   StringBuffer sb = null;   try   \{   /\*   \* Cipher类无构造方法，调用getInstance()方法将所请求转换的名称传递给它 参数为 转换的名称，例如   \* DES/CBC/PKCS5Padding，这里我们使用DES转换。   \*/   Cipher encriptCipher = Cipher.getInstance("DES");   // 用密钥初始化此 Cipher   encriptCipher.init(Cipher.ENCRYPT\_MODE, key);   FileInputStream in = new FileInputStream(FileName);   int size = in.available();   byte\[\] encode = new byte\[size\];   in.read(encode);   String srcCode = new String(encode);   // 按单部分操作加密数据   byte\[\] desCode = encriptCipher.doFinal(srcCode.getBytes());   // 将加密后的数据转换成16进制的字符串返回   sb = new StringBuffer(desCode.length \* 2);   for (int i = 0; i < desCode.length; i++)   \{   int temp = desCode\[i\];   // 把负数转换为正数   if (temp < 0)   \{   temp = temp + 256;// byte的最小值为-256,最大值为255   \}   // 小于 0F 的数需要在前面补0   if (temp < 16)   \{   sb.append("0");   \}   sb.append(Integer.toString(temp, 16));   \}   BufferedWriter out = new BufferedWriter(new OutputStreamWriter(   new FileOutputStream(FileName)));   out.write(sb.toString(), 0, sb.length());   out.close();   result = true;   \}   catch (NoSuchAlgorithmException e)   \{   e.printStackTrace();   \}   catch (NoSuchPaddingException e)   \{   e.printStackTrace();   \}   catch (InvalidKeyException e)   \{   e.printStackTrace();   \}   catch (IllegalBlockSizeException e)   \{   e.printStackTrace();   \}   catch (IOException e)   \{   e.printStackTrace();   \}   catch (BadPaddingException e)   \{   e.printStackTrace();   \}   return result;   \}   /\*\*   \* 功能：解密文件   \*/   public boolean DESDecrypt(String FileName, Key key)   \{   Cipher decriptCipher = null;   String decriptString = null;   boolean result = false;   try   \{   FileInputStream in = new FileInputStream(FileName);   int size = in.available();   byte\[\] encode = new byte\[size\];   in.read(encode);   String encriptCode = new String(encode);   byte\[\] encriptByte = encriptCode.getBytes();   byte\[\] decriptByte = new byte\[encriptByte.length / 2\];   for (int i = 0; i < encriptByte.length; i += 2)   \{   String strTmp = new String(encriptByte, i, 2);   decriptByte\[i / 2\] = (byte) Integer.parseInt(strTmp, 16);   \}   decriptCipher = Cipher.getInstance("DES");   decriptCipher.init(Cipher.DECRYPT\_MODE, key);   byte\[\] outByte = decriptCipher.doFinal(decriptByte);   decriptString = new String(outByte);   BufferedWriter out = new BufferedWriter(new OutputStreamWriter(   new FileOutputStream(FileName)));   out.write(decriptString.toString(), 0, decriptString.length());   out.close();   \}   catch (NoSuchAlgorithmException e)   \{   e.printStackTrace();   \}   catch (NoSuchPaddingException e)   \{   e.printStackTrace();   \}   catch (InvalidKeyException e)   \{   e.printStackTrace();   \}   catch (IllegalBlockSizeException e)   \{   e.printStackTrace();   \}   catch (BadPaddingException e)   \{   System.out.println("密钥错误！");   e.printStackTrace();   \}   catch (IOException e)   \{   e.printStackTrace();   \}   return result;   \}   /\*\*   \* 自定义一个key   \*/   public Key getKey(String keyRule)   \{   Key key = null;   byte\[\] keyByte = keyRule.getBytes();   // 创建一个空的八位数组,默认情况下为0   byte\[\] byteTemp = new byte\[8\];   // 将用户指定的规则转换成八位数组   for (int i = 0; i < byteTemp.length && i < keyByte.length; i++)   \{   byteTemp\[i\] = keyByte\[i\];   \}   key = new SecretKeySpec(byteTemp, "DES");   return key;   \}   /\*\*   \* 第二种产生key的方法   \*   \* @return   \*/   public Key getKey2()   \{   Key key = null;   // 创建一个可信任的随机数源，DES算法需要   SecureRandom sr = new SecureRandom();   try   \{   // 用DES算法创建一个KeyGenerator对象   KeyGenerator kg = KeyGenerator.getInstance("DES");   // 初始化此密钥生成器,使其具有确定的密钥长度   kg.init(sr);   // 生成密匙   key = kg.generateKey();   \}   catch (NoSuchAlgorithmException e)   \{   e.printStackTrace();   \}   return key;   \}   \}   测试方法：  package JFFileEncrypt;  import java.security.Key;  public class Test   \{   public static void main(String\[\] args)   \{   FileEncryptInterface encrypt = new FileEncryptImpal();   // 要加密的原文   String FileName = "[FTP.xml][]";   // 自己指定的密钥   String keyRule = "jiangfeng861016shanghaigongzuo";   Key key = encrypt.getKey(keyRule);   encrypt.DESEncrypt(key, FileName);   encrypt.DESDecrypt(FileName, key);   \}  \} ####

[java_]: http://blog.csdn.net/jiangfeng861016/article/details/4755675
[FTP.xml]: ftp://ftp.xml/