decrydata2function.java

这是用java写的三个源码

package mircoenorde.grade2;

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import javax.crypto.SecretKey;
import java.security.Security;
import javax.crypto.spec.SecretKeySpec;
import java.io.ObjectInputStream;
import javax.crypto.Cipher;
import java.io.FileOutputStream;
import java.security.MessageDigest;
import java.io.File;
import mircoenorde.common.exception.MircoenordeException;

/**
 * <p>Title: </p>
 *
 * <p>Description: </p>
 *
 * <p>Copyright: Copyright (c) 2005</p>
 *
 * <p>Company: </p>
 *
 * @author not attributable
 * @version 1.0
 */
public class DecryData2Function {
    public void decryData2Funtion(String fileIN, String fileOUT,
                                  String userpassword,
                                  int grade, int delFile) throws
            MircoenordeException {
        try {
            if (grade == 2) { //首先匹配加密级别;
                //第一步,从指定目录读入加密文件;
                ObjectInputStream objIN = new ObjectInputStream(new
                        BufferedInputStream(new FileInputStream(fileIN)));
                EncryData2 degrade2 = (EncryData2) objIN.readObject();
                objIN.close();
                String filename = degrade2.getfilename();
                //第二步,得到userpassword的摘要值,并取其前面128位用来构造AES对称密钥；
                Security.addProvider(new BouncyCastleProvider()); //加入算法提供者;
                MessageDigest passwordhash = MessageDigest.getInstance("SHA1",
                        "BC");
                //passwordhash.update(userpassword.getBytes());
                byte[] passwordhashbyte = passwordhash.digest(userpassword.
                        getBytes());
                byte[] mesdigest = degrade2.getmesdigest();

                //第三步,比较Hash值,如果一致就解密,否则就报出错信息;
                boolean hashboolean = true; //注意口令匹配方式;
                for (int i = 0; i < 20; i++) {
                    if (passwordhashbyte[i] == mesdigest[i]) {

                    } else {
                        hashboolean = false;
                        throw new MircoenordeException(1, "密码错误，请重新输入！！！");
                    }
                }
                System.out.println(hashboolean);
                if (hashboolean) {

                    //第四步,得到userpassword的摘要值，并取其前面128位用来构造AES对称密钥；
                    byte[] passwordhash128 = new byte[16];
                    for (int i = 0; i < 16; i++) {
                        passwordhash128[i] = passwordhashbyte[i];
                    }
                    SecretKey passwordhash128AES = new SecretKeySpec(
                            passwordhash128,
                            "DES"); //将passwordhash64变幻成DES密钥；

                    //第五步,解密aeskey1
                    Cipher userCipher = Cipher.getInstance(
                            "AES/ECB/PKCS5Padding",
                            "BC");
                    userCipher.init(Cipher.DECRYPT_MODE, passwordhash128AES);
                    //userCipher.update(degrade1.getenaeskeybyte());
                    SecretKey aeskey1 = new SecretKeySpec(userCipher.doFinal(
                            degrade2.getenaeskeybyte()),
                            "AES"); //至此已将aeskey1解密；下面就用它把content解密；

                    //第六步,使用刚解密的aeskey1来解密content;
                    //这里不必重新定义加密机；
                    // Cipher secondCipher = Cipher.getInstance("DES","BC");
                    userCipher.init(Cipher.DECRYPT_MODE, aeskey1); //重新初始化；
                    // userCipher.update(degrade1.getcontent());
                    byte[] content = userCipher.doFinal(degrade2.getcontent());

                    //第七步，将文件写到指定目录；
                    FileOutputStream fout = new FileOutputStream(fileOUT +
                            filename);
                    fout.write(content);
                    fout.close();
                    if (delFile == 1) {
                        File file = new File(fileIN);
                        file.delete();
                    }

                } else {
                    System.out.println("口令出错！！！");
                    System.out.println("你最多只有三次机会！！！");
                }
            } else {
                System.out.println("***********出错***********");

            }
        } catch (MircoenordeException ex) {
            throw new MircoenordeException(1, "密码错误，请重新输入！！！");
        } catch (Exception ex) {
            System.out.println(ex);
            ex.printStackTrace();
        }
    }


}