privatecrypto.java

数据库的加密以及密态查询

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import java.security.Key;
import java.security.SecureRandom;
import sun.misc.BASE64Encoder;
import sun.misc.BASE64Decoder;

public class PrivateCrypto {
        private Cipher cipher;
        private Key pkey;

        public PrivateCrypto() {
                try {
                        pkey = readKey();
                        //cipher=Cipher.getInstance("DES");
                        cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
                        //cipher = Cipher.getInstance("DES/ECB/NoPadding");
                } catch (Exception e) {
                        e.printStackTrace();
                }
        }

        public byte[] getKey() {
                return pkey.getEncoded();
        }

        public Key readKey() {
                try {
                        java.io.ObjectInputStream in = new java.io.ObjectInputStream(new java.io.FileInputStream("key.dat"));
                        pkey = (Key)in.readObject();
                        in.close();
                        return pkey;
                } catch (Exception ex) {
                        ex.printStackTrace();
                        return null;
                }
        }

        public byte[] encrypt(byte[] plainText) {

                try {
                        //byte[] keyInfo = pkey.getEncoded();
                        //System.out.println(new String(keyInfo));
                        //System.out.println(keyInfo.length);
                        //byte[] plainText=str.getBytes("UTF8");
                        cipher.init(Cipher.ENCRYPT_MODE, pkey);
                        byte[] cipherText = cipher.doFinal(plainText);
                        //return (new String(cipherText, "UTF8"));
                        //return (new BASE64Encoder().encode(cipherText));
                        return cipherText;
                } catch (Exception e) {
                        e.printStackTrace();
                        return null;
                }
        }

        //public byte[] decrypt(byte[] cipherText, byte[] keyInfo) {
        public byte[] decrypt(byte[] cipherText) {
                try {
                        //javax.crypto.spec.SecretKeySpec skey = new javax.crypto.spec.SecretKeySpec(keyInfo, "AES");
                        ///cipher.init(Cipher.DECRYPT_MODE,skey);
                        cipher.init(Cipher.DECRYPT_MODE, pkey);
                        byte[] newPlainText = cipher.doFinal(cipherText);
                        //System.out.println(newPlainText.length);
                        //return (new String(newPlainText,"UTF8"));
                        return newPlainText;
                } catch (Exception e) {
                        e.printStackTrace();
                        return null;
                }

        }

        public static void main(String[] args) throws Exception {

                byte[] plainText = "何利军，会议时间s^&*&*%%%".getBytes();
                PrivateCrypto pe = new PrivateCrypto();
                //String newStr;
                byte[] cipherText;
                //byte[] keyInfo = pe.getKey();
                cipherText = pe.encrypt(plainText);
                System.out.println(new String(cipherText));
                System.out.println(new String(pe.decrypt(cipherText)));
        }
}