java using AES and RSA encryption and decryption

Others 2019-06-28 14:26:15 views: null

  • At first understand, what is piled encryption, what is asymmetric encryption?

　　Symmetric encryption: encryption and decryption keys are the same, very fast encryption, such as AES

　　Asymmetric encryption: encryption and decryption keys are different, slower, such as RSA

 

  • Look at the code (to be used in the study) 

　　Its dependencies:

   　　<dependency>
          <groupId>org.bouncycastle</groupId>
          <artifactId>bcprov-jdk15on</artifactId>
          <version>1.58</version>
      </dependency>

 

　　

       1, RSA tools:

package cn.wangtao.utils;

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;

/**
 * @ClassName RSAUtils
 * @Auth 桃子
 * @Date 2019-6-25 15:15
 * @Version 1.0
 * @Description
 **/
public class RSAUtils {

    private static final String RSA = "RSA "; // encryption 

    Private static Logger Logger = Final LoggerFactory.getLogger (RSAUtils.class); 

    // acquire the key 
    public static KeyPair getKey () throws Exception { 
        the try { 
            the KeyPairGenerator KeyPairGenerator = the KeyPairGenerator. the getInstance (the RSA, new new BouncyCastleProvider ()); 
            keyPairGenerator.initialize (2048); // initialization key length 
            KeyPair keyPair = keyPairGenerator.generateKeyPair (); // generate a key pair 
            return KeyPair; 
        } the catch (Exception E) { 
            Logger. error ( "RSA key acquired abnormality", E); 
            the throw new new exception ( "RSA key acquired abnormality", E); 
        } 
    }
 
    // public key encrypting
    encryptStr static String public (RSAPublicKey publicKey, String STR) throws Exception { 
        the try { 
            the Cipher cipher = Cipher.getInstance (the RSA, new new BouncyCastleProvider ()); 
            cipher.init (Cipher.ENCRYPT_MODE, publicKey); 
            // encrypted 
            byte [] bytes = the getBytes (str.getBytes (), cipher); 
            // 2 converted to hexadecimal 
            String Result = CommonUtils.parseByte2HexStr (bytes); 
            return Result; 
        } the catch (Exception E) { 
            logger.error ( "using RSA public key encryption abnormal ", E); 
            the throw new new exception (" RSA public key encryption using abnormal ", E); 
        } 
    }



 
    // private key to decrypt
    decryptStr static String public (RSAPrivateKey The privateKey, String STR) throws Exception { 
        the try { 
            Cipher cipher = Cipher.getInstance (the RSA, new new BouncyCastleProvider ()); 
            cipher.init (Cipher.DECRYPT_MODE, privateKey); // initialized with a key of this Cipher Object 
            // hexadecimal is converted into binary 
            byte [] bytes = CommonUtils.parseHexStr2Byte (STR); 
            // decryption 
            byte [] BS = the getBytes (bytes, cipher); 
            String Content = new new String (BS, "UTF-. 8 "); 
            return Content; 
        } the catch (exception E) { 
            logger.error (" using the RSA private key to decrypt abnormal ", E); 
            the throw new new exception (" using the RSA private key to decrypt abnormal ", E); 
        } 
    }


    //通过cipher获取字节数组
    public static byte[] getBytes(byte[] bytes,Cipher cipher) throws Exception {
        int blockSize = cipher.getBlockSize(); // 返回块的大小
        int j = 0;
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        while (bytes.length - j * blockSize > 0) { // 将二进制数据分块写入ByteArrayOutputStream中
            if(bytes.length-j*blockSize>blockSize){
                baos.write(cipher.doFinal(bytes, j * blockSize, blockSize));
            }else{
                baos.write(cipher.doFinal(bytes, j * blockSize,bytes.length-j*blockSize));
            }
            j++;
        }
        baos.close();
        byte [] = byteArray The baos.toByteArray (); 
        return byteArray The; 
    } 

    // save the file to the secret key of the 
    public void saveRSAKey (fileName String) throws Exception { 
        a FileOutputStream fos = null; 
        the ObjectOutputStream OOS = null; 
        the try { 
            KeyPair KeyPair getKey = ( ); 
            fos = new new a FileOutputStream (fileName); 
            OOS the ObjectOutputStream new new = (fos); // number sequence to 
            oos.writeObject (KeyPair); 
        } the catch (exception E) { 
            logger.error ( "secret key of the RSA abnormality saved to a file [{}] ", fileName, E); 
            the throw new new exception (" secret key of the RSA abnormality saved to a file ", E); 
        } the finally { 
            ! IF (OOS = null) { 
                the try { 
                    oos.close ();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
            if(fos!=null){
                try {
                    fos.close();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        }
    }

}

　　2, CommonUtils common tools:

package cn.wangtao.utils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

/**
 * @ClassName CommonUtils
 * @Auth 桃子
 * @Date 2019-6-27 12:51
 * @Version 1.0
 * @Description
 **/
public class CommonUtils {

    private static final Logger logger= LoggerFactory.getLogger(CommonUtils.class);
    //编码方式
    public static final String CODE_TYPE = "UTF-8";

    //字符补全
    private static final String[] consult = new String[]{"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","G"};

    //关流
    public static void closeReaderandWriter(Reader reader, Writer writer){
        if(writer!=null){
            try {
                writer.close();
            } catch (IOException e) {
                logger.error("关闭输出流失败",e);
            }
        }
        if(reader!=null){
            try {
                reader.close();
            } catch (IOException e) {
                logger.error("关闭输出流失败",e);
            }
        }
    }

    //将16进制转换为二进制
    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1)
            return null;
        byte[] result = new byte[hexStr.length()/2];
        for (int i = 0;i< hexStr.length()/2; i++) {
            int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);
            int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }

    //将二进制转换成16进制
    public static String parseByte2HexStr(byte buf[]) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < buf.length; i++) {
            String hex = Integer.toHexString(buf[i] & 0xFF);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return sb.toString();
    }

    //补全字符
    public static String completionCodeFor16Bytes(String str) throws Exception {
        try{
            int num = str.getBytes(CODE_TYPE).length;
            int index = num%16;
            //进行加密内容补全操作, 加密内容应该为 16字节的倍数, 当不足16*n字节是进行补全, 差一位时 补全16+1位
            //补全字符 以 $ 开始,$后一位代表$后补全字符位数,之后全部以0进行补全;
            if(index != 0){
                StringBuffer sbBuffer = new StringBuffer(str);
                if(16-index == 1){
                    sbBuffer.append("$" + consult[16-1] + addStr(16-1-1));
                }else{
                    sbBuffer.append("$" + consult[16-index-1] + addStr(16-index-1-1));
                }
                str = sbBuffer.toString();
            }
            return str;
        }catch (Exception e){
            logger.error("使用AES加密前补全字符异常",e);
            throw new Exception("使用AES加密前补全字符异常",e);
        }
    }

    //追加字符
    public static String addStr(int num){
        StringBuffer sbBuffer = new StringBuffer("");
        for (int i = 0; i < num; i++) {
            sbBuffer.append("0");
        }
        return sbBuffer.toString();
    }

    //还原字符(进行字符判断)
    public static String resumeCodeOf16Bytes(String str) throws Exception{
        int indexOf = str.lastIndexOf("$");
        if(indexOf == -1){
            return str;
        }
        String trim = str.substring(indexOf+1,indexOf+2).trim();
        int num = 0;
        for (int i = 0; i < consult.length; i++) {
            if(trim.equals(consult[i])){
                num = i;
            }
        }
        if(num == 0){
            return str;
        }
        return str.substring(0,indexOf).trim();
    }

}

　　

3，AESUtils通用工具类：package cn.wangtao.utilsimport org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.io.*;
import java.security.interfaces.RSAPrivateKey;
import java.util.Map;

/**
 * @ClassName AESUtils
 * @Auth 桃子
 * @Date 2019-6-27 12:05
 * @Version 1.0
 * @Description
 **/
public class AESUtils {

    private static final Logger logger= LoggerFactory.getLogger(AESUtils.class);

    //填充类型
    public static final String AES_TYPE = "AES/ECB/PKCS5Padding";

    private static final String AES = "AES"; // 加密方式


    public static final String DES_TYPE = "DES/ECB/PKCS5Padding";

    private static final String DES = "DES"; // 加密方式

    private final  String defaultDesKey="11112222";//8位

    //对字符串加密
    public static String encryptStr(String content,String aesKey) throws Exception {
        try {
            SecretKeySpec key = new SecretKeySpec(aesKey.getBytes(),AES );
            Cipher cipher = Cipher.getInstance(AES_TYPE);
            cipher.init(Cipher.ENCRYPT_MODE, key);
            //字符补全
            String content16Str = CommonUtils.completionCodeFor16Bytes(content);
            byte[] encryptedData = cipher.doFinal(content16Str.getBytes(CommonUtils.CODE_TYPE));
            //2进制转换成16进制
            String hexStr = CommonUtils.parseByte2HexStr(encryptedData);
            return hexStr;
        } catch (Exception e) {
            logger.error("使用AES对字符串加密异常",e);
            throw new Exception("使用AES对字符串加密异常",e);
        }

    }
    //对字符串解密
    public static String  decryptStr(String content,String aesKey) throws Exception {
        try {
            //16进制转换成2进制
            byte[] bytes = CommonUtils.parseHexStr2Byte(content);
            SecretKeySpec key = new SecretKeySpec(
                    aesKey.getBytes(), AES);
            Cipher cipher = Cipher.getInstance(AES_TYPE);
            cipher.init(Cipher.DECRYPT_MODE, key);
            byte[] decryptedData = cipher.doFinal(bytes);
            String result=new String(decryptedData, CommonUtils.CODE_TYPE);
            //还原字符
            String orgResult = CommonUtils.resumeCodeOf16Bytes(result);
            return orgResult;
        } catch (Exception e) {
            logger.error("使用AES对字符串解密异常",e);
            throw new Exception("使用AES对字符串解密异常",e);
        }
    }

    //对文件加密
    public static File encryptFile(File orgFile, File encryptFile, Map<String,Object> context) throws Exception {
        logger.info("使用AES对文件加密开始，源文件地址[{}]加密后文件地址[{}]",orgFile.getPath(),encryptFile.getPath());
        BufferedReader br=null;
        BufferedWriter bw=null;
        try{
            //获取AESKEY ，如果没有为默认
            String aesKey = (String) context.get(Dirt.AES_KEY);
            br=new BufferedReader(new FileReader(orgFile));

            bw=(BufferedWriter)context.get(Dirt.BUFFEREDWRITER);
            if(null==bw){
                bw=new BufferedWriter(new FileWriter(encryptFile));
            }
            String len=null;
            while (null!=(len=br.readLine())){
                String encrypt= encryptStr(len,aesKey);
                bw.write(encrypt);
                bw.newLine();
                bw.flush();
            }
            logger.info("使用AES对文件加密结束，源文件地址[{}]加密后文件地址[{}]",orgFile.getPath(),encryptFile.getPath());
            return encryptFile;
        }catch (Exception e){
            logger.error("使用AES对文件加密异常,源文件地址[{}]加密后文件地址[{}]",orgFile.getPath(),encryptFile.getPath(),e);
            throw new Exception("使用AES对文件加密异常",e);
        }finally {
            CommonUtils.closeReaderandWriter(br,bw);
        }
    }

    //对文本解密，返回解密文件后的文件
    public static File decryptFile(File decryptfile,  File encryptFile,Map<String,Object> context) throws Exception {
        logger.info("使用AES对文件解密开始，源加密文件地址[{}]解密后文件地址[{}]",encryptFile.getPath(),decryptfile.getPath());
        BufferedReader br=null;
        BufferedWriter bw=null;
        try{
            if(decryptfile.exists()){
                decryptfile.delete();
            }
            //边读边加密边写
            br=new BufferedReader(new FileReader(encryptFile));
            bw=new BufferedWriter(new FileWriter(decryptfile));

            String len=null;
            String aesKey=null;
            //判断是否加密
            RSAPrivateKey privateKey= (RSAPrivateKey) context.get(Dirt.RSAPRIVATEKEY);
            if(null!=privateKey){
                StringBuffer sb=new StringBuffer();
                while ((len=br.readLine())!=null){
                    sb.append(len);
                    if(len.equals("\n")||len.equals("")||len.equals("\r\n")||len.equals("\r")){ //AES密文以空行结束，RSA使用Base64加密写入时，会换行
                        aesKey=RSAUtils.decryptStr(privateKey,sb.toString());
                        break;
                    }
                }
            }
            if(null==aesKey){
                aesKey=(String) context.get(Dirt.AES_KEY);
            }
           logger.info("aesKey[{}]",aesKey);
            if(aesKey!=null){
                while ((len=br.readLine())!=null){
                    String decrypt= decryptStr(len,aesKey);
                    bw.write(decrypt);
                    bw.flush();
                    bw.newLine();
                }
            }
            logger.info("使用AES对文件解密结束，源加密文件地址[{}]解密后文件地址[{}]",encryptFile.getPath(),decryptfile.getPath());
            return decryptfile;
        }catch (Exception e){
            logger.error("使用AES对文件解密异常,源加密文件地址[{}]解密后文件地址[{}]",encryptFile.getPath(),decryptfile.getPath(),e);
            throw new Exception("使用AES对文件解密异常",e);
        }finally {
            CommonUtils.closeReaderandWriter(br,bw);
        }
    }
}

　　4，Dirt常量

package cn.wangtao.utils;

import java.security.interfaces.RSAPublicKey;

/**
 * @ClassName Dirt
 * @Auth 桃子
 * @Date 2019-6-27 14:20
 * @Version 1.0
 * @Description
 **/
public class Dirt {
    public  static  final String UPLOADFILEURL="uploadFileUrl";
    public static final String AES_KEY="aesKey";
    public static final String RSAPUBLICKEY="rsaPublicKey";
    public static final String RSAPRIVATEKEY="rsaPrivateKey";


    public final static String RETURNCODE="returnCode";
    public final static String RETURNMSG="returnMsg";
    public final static String FILENAME="fileName";
    public final static String ORGFILENAME="orgFileName";
    public final static String ENCRYPTFILE="encryptFile";


    public static final String BUFFEREDWRITER="bufferedWriter"; //是为了在原始文件中进行补充加密

    //返回码
    public final static String SUCCESSCODE="000000";
    public final static String FAILEDCODE="999999";

    //加密文件所放的目录
    public final static String BASELOCALDIR="XXX"; //基本目录路径
    public final static String ENCRYPTLOCALDIR="encrypt"; //加密文件目录


}

 

 

  • AES的介绍

　　　详情请参考：https://blog.csdn.net/qq_28205153/article/details/55798628

  • RSA的介绍

 　　     详情请参考：https://www.cnblogs.com/jiftle/p/7903762.html

Guess you like

Origin www.cnblogs.com/gdhzdbh/p/11101540.html
Recommended
Linus is the most active in "eating dog food"!
Ranking
Share good programmer web front-end array and sorting, de-duplication and random roll call
Compilation error caused by cv_bridge and python version problems error: return-statement with no value, in function returning'void*' [-fpe
魔众帮助中心系统 v3.1.0 首页切换器，界面优化
Die beim Millimeterwellenradar-Integrationstest aufgetretene Grube (Multiprozessbindung an einen UDP-Port verursacht Probleme)
How to suppress the "requires transitive directive for an automatic module" warning properly?
LeetCode-1743. Restore the Array From Adjacent Pairs-Analysis and Code (Java)
Summer 2019 Summer soft essay 7 workers
Python中Assert断言的使用语法和例子
LeetCode one question per day (2021-2-3 sliding window median)
Fairchild, the ancestor of semiconductors, the legend of the first trillion-dollar start-up
Daily
More
2024-05-20(5)
2024-05-19(0)
2024-05-18(31)
2024-05-17(6)
2024-05-16(23)
2024-05-15(5)
2024-05-14(9)
2024-05-13(8)
2024-05-12(28)
2024-05-11(32)

Code World

© 2018 codetd.com