RSA加密解密-实例

最新推荐文章于 2024-12-01 18:40:16 发布
原创最新推荐文章于 2024-12-01 18:40:16 发布 · 788 阅读
0 ·
CC 4.0 BY-SA版权
文章标签：
#RSA 加密解密
java 专栏收录该内容
36 篇文章
订阅专栏

package com.service;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.security.Key;
import java.security.KeyFactory;
import java.security.spec.PKCS8EncodedKeySpec;
import java.util.Map;
import javax.crypto.Cipher;
import org.apache.axiom.util.base64.Base64Utils;

/**
 * 类名： RSAService
 * 描述：
 * @author admin
 * @date 2013-2-20 下午1:31:16
 *
 *
 */
public class RSAService {
 private static final String SPLIT_STRING="--";
 public static void main(String[] args) {
  try {
//   SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
//   System.out.println(sdf.format(new Date()));
//   encryptFile("D:\\test\\admin.rar","D:\\test\\admin0.rar");
//   decryptFile("D:\\test\\admin0.rar","D:\\test\\admin1.rar");
//   System.out.println(sdf.format(new Date()));
   /*********运行命令执行*********/
   System.out.println("参数个数："+args.length);
   if(args.length==3){         
    if(args[0].equals("e")){
     System.out.println("操作类型：加密"); 
    }else if(args[0].equals("d")){
     System.out.println("操作类型：解密"); 
    }
    System.out.println("源文件路径："+args[1]); 
    System.out.println("目标文件路径："+args[2]); 
     
    if(args[0].equals("e")){
     encryptFile(args[1],args[2]);
    }else if(args[0].equals("d")){
     decryptFile(args[1],args[2]);
    }else{
     System.out.println("标识符错误，e表示加密，d表示解密");
    }
   }else{
    System.out.println("第一个参数：e表示加密，d表示解密");
    System.out.println("第二个参数：源文件路径，如：c:\\src.txt");
    System.out.println("第三个参数：目标文件路径，如：c:\\dest.txt");
   }
  } catch (Exception e) {
   System.out.println("第一个参数：e表示加密，d表示解密");
   System.out.println("第二个参数：源文件路径，如：c:\\src.txt");
   System.out.println("第三个参数：目标文件路径，如：c:\\dest.txt");
   e.printStackTrace();
  }
 }
 
 /**
  * 
  * 方法描述： 
  * @param srcFileName 要加密的文件
  * @param destFileName 加密后存放的文件名
  * @throws Exception
  * void
  * @author admin
  * @date 2013-2-20 下午2:52:29
  */
 public static boolean encryptFile(String srcFileName,
            String destFileName) throws Exception {
      OutputStream outputWriter = null;
      InputStream inputReader = null;
      boolean bool=true;
      try {
        Map<String, Object> keyMap = RSAUtils.genKeyPair();
        String  publicKey = RSAUtils.getPublicKey(keyMap);
        String  privateKey = RSAUtils.getPrivateKey(keyMap);
          byte[] srcfilebyte=fileToByte(srcFileName);
          byte[] tep=RSAUtils.encryptByPublicKey(srcfilebyte,publicKey);
          OutputStreamWriter os = new OutputStreamWriter( new FileOutputStream(destFileName));
      os.write(privateKey+SPLIT_STRING+Base64Utils.encode(tep));                                                                
      os.close();
      } catch (Exception e) {
        bool=false;
            throw e;
      } finally {
            try {
                if (outputWriter != null) {
                    outputWriter.close();
                }
                if (inputReader != null) {
                    inputReader.close();
                }
            } catch (Exception e) {
             e.printStackTrace();
            }
      }
      return bool;
  }
 /**
  * 
  * 方法描述： 解密
  * @param srcFileName 要解密的文件
  * @param destFileName 解密后存放的文件名
  * @throws Exception
  * void
  * @author admin
  * @date 2013-2-20 下午2:51:18
  */
 public static boolean decryptFile(String srcFileName,
            String destFileName) throws Exception {
      OutputStream outputWriter = null;
      InputStream inputReader = null;
      boolean bool=true;
      try {
         Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding",
                 new org.bouncycastle.jce.provider.BouncyCastleProvider());
         FileInputStream in = new FileInputStream(srcFileName);
          byte[] data_ = new byte[0];
            ByteArrayOutputStream out_ = new ByteArrayOutputStream(2048);
            byte[] cache1_ = new byte[1024];
            int nRead_ = 0;
            while ((nRead_ = in.read(cache1_)) != -1) {
                out_.write(cache1_, 0, nRead_);
                out_.flush();
            }
            out_.close();
            in.close();
            data_ = out_.toByteArray();
//            System.out.println(new String(data_));
            String result=new String(data_);
            String[] strKey=result.split(SPLIT_STRING);
          byte[] content=Base64Utils.decode(strKey[1]);//内容
            byte[] keyBytes = Base64Utils.decode(strKey[0]);//密钥-私钥
            PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
            
            cipher.init(Cipher.DECRYPT_MODE, privateK);
            
            outputWriter = new FileOutputStream(destFileName);
            inputReader = new FileInputStream(srcFileName);
            int inputLen = content.length;
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int offSet = 0;
            byte[] cache;
            int i = 0;
            // 对数据分段解密
            while (inputLen - offSet > 0) {
                if (inputLen - offSet > 128) {
                    cache = cipher.doFinal(content, offSet, 128);
                } else {
                    cache = cipher.doFinal(content, offSet, inputLen - offSet);
                }
                out.write(cache, 0, cache.length);
                i++;
                offSet = i * 128;
            }
            byte[] decryptedData = out.toByteArray();
            out.close();
            outputWriter.write(decryptedData);
            outputWriter.flush();
            outputWriter.close();
      } catch (Exception e) {
       bool=true;
            throw e;
      } finally {
            try {
                if (outputWriter != null) {
                    outputWriter.close();
                }
                if (inputReader != null) {
                    inputReader.close();
                }
            } catch (Exception e) {
            }
      }
      return bool;
  }
 /**
  * 
  * 方法描述： 转化为字节
  * @param filePath 文件路径
  * @return
  * @throws Exception
  * byte[]
  * @author admin
  * @date 2013-2-26 下午5:30:28
  */
 public static byte[] fileToByte(String filePath) throws Exception {
        byte[] data = new byte[0];
        File file = new File(filePath);
        if (file.exists()) {
            FileInputStream in = new FileInputStream(file);
            ByteArrayOutputStream out = new ByteArrayOutputStream(2048);
            byte[] cache = new byte[1024];
            int nRead = 0;
            while ((nRead = in.read(cache)) != -1) {
                out.write(cache, 0, nRead);
                out.flush();
            }
            out.close();
            in.close();
            data = out.toByteArray();
         }
        return data;
    }
}
 

package com.service;
import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.Cipher;
import org.apache.axiom.util.base64.Base64Utils;
/**
 * 类名： RSAUtils
 * 描述：
 * @author admin
 * @date 2013-2-19 下午4:15:20
 *
 *
 */
public class RSAUtils {
    /** *//**
     * 加密算法RSA
     */
    public static final String KEY_ALGORITHM = "RSA";
    
    /** *//**
     * 签名算法
     */
    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
    /** *//**
     * 获取公钥的key
     */
    private static final String PUBLIC_KEY = "RSAPublicKey";
    
    /** *//**
     * 获取私钥的key
     */
    private static final String PRIVATE_KEY = "RSAPrivateKey";
    
    /** *//**
     * RSA最大加密明文大小
     */
    private static final int MAX_ENCRYPT_BLOCK = 117;
    
    /** *//**
     * RSA最大解密密文大小
     */
    private static final int MAX_DECRYPT_BLOCK = 128;
    /** *//**
     * <p>
     * 生成密钥对(公钥和私钥)
     * </p>
     * 
     * @return
     * @throws Exception
     */
    public static Map<String, Object> genKeyPair() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
        keyPairGen.initialize(1024);
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        Map<String, Object> keyMap = new HashMap<String, Object>(2);
        keyMap.put(PUBLIC_KEY, publicKey);
        keyMap.put(PRIVATE_KEY, privateKey);
        return keyMap;
    }
    /** *//**
     * <P>
     * 私钥解密
     * </p>
     * 
     * @param encryptedData 已加密数据
     * @param privateKey 私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, privateK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;
    }

    /** *//**
     * <p>
     * 公钥加密
     * </p>
     * 
     * @param data 源数据
     * @param publicKey 公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPublicKey(byte[] data, String publicKey)
            throws Exception {
        byte[] keyBytes = Base64Utils.decode(publicKey);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
        // 对数据加密
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, publicK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
    }
    /** *//**
     * <p>
     * 获取私钥
     * </p>
     * 
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPrivateKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PRIVATE_KEY);
        return Base64Utils.encode(key.getEncoded());
    }
    /** *//**
     * <p>
     * 获取公钥
     * </p>
     * 
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPublicKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PUBLIC_KEY);
        return Base64Utils.encode(key.getEncoded());
    }
}