Java-web中利用RSA進行加密解密操作的方法示例

2024-07-14 08:41:58

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前言

最近在看，網絡安全方面的問題，我們可以使用RSA進行非對稱加密防止，獲取用戶信息。首先我們看下java下操作RSA進行加密解密算法，代碼如下：

package com.jb.test; import java.security.InvalidKeyException;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.NoSuchAlgorithmException;import java.security.PrivateKey;import java.security.PublicKey;import java.security.SecureRandom; import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import javax.crypto.NoSuchPaddingException; import org.apache.commons.codec.binary.Hex; public class RSAEntry {  /** * @Title: main * @Description: RSA加密算法，解密算法 * @param args * void * @throws NoSuchAlgorithmException  * @throws NoSuchPaddingException  * @throws InvalidKeyException  * @throws BadPaddingException  * @throws IllegalBlockSizeException  *  * @throws */ public static void main(String[] args) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {// Security.getProviders();//獲取所有支持的加密算法 //采用非對稱加密解密算法 //生成密鑰實例 KeyPairGenerator keygen = KeyPairGenerator.getInstance("RSA"); SecureRandom random = new SecureRandom(); random.setSeed(System.currentTimeMillis());//設置隨機種子 keygen.initialize(512, random);//設置密鑰長度，應為64的整數倍 //生成密鑰公鑰對 KeyPair keyPair = keygen.generateKeyPair(); //獲取公鑰 PublicKey pubkey = keyPair.getPublic(); //獲取私鑰 PrivateKey prikey = keyPair.getPrivate(); //測試數據 String data = "測試數據"; //使用公鑰進行加密 //構建加密解密類 Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, pubkey);//設置為加密模式 byte[] jmdata = cipher.doFinal(data.getBytes()); //打印加密后數據 System.out.println(new String(Hex.encodeHex(jmdata))); //改為解密模式進行解密 cipher.init(Cipher.DECRYPT_MODE, prikey);//會用私鑰解密 jmdata = cipher.doFinal(jmdata); System.out.println(new String(jmdata));  }}

在web應用中，我們可以通過js進行前端加密，java進行后臺解密，已達到我們的目的。這里需要注意的是，要想實現正確的加密解密算法，需要使用bcprov-ext-jdk15on-147.jar。

首先創建系統的密鑰提供者：

package com.jb.test; import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.PrivateKey;import java.security.PublicKey;import java.security.SecureRandom; import org.apache.commons.codec.binary.Hex;import org.bouncycastle.jcajce.provider.asymmetric.rsa.BCRSAPublicKey;import org.bouncycastle.jce.provider.BouncyCastleProvider; /** * RSA初始化類 * @author nmm * 結合前臺的js使用的話，主要需要指定密鑰提供者，即引入bcprov-ext-jdk15on-147.jar并使用其中的提供者 */public class RsaInitUtil {  private static KeyPair keyPair;  private static RsaInitUtil util;  private RsaInitUtil(){ try { if(keyPair == null) { //如果想要能夠解密js的加密文件，使用此提供者是必須的 KeyPairGenerator keygen = KeyPairGenerator.getInstance("RSA", new BouncyCastleProvider()); SecureRandom random = new SecureRandom(); random.setSeed(System.currentTimeMillis()); keygen.initialize(512, random);//設置512位長度 keyPair = keygen.generateKeyPair(); } } catch (Exception e) { e.printStackTrace(); } }  public static RsaInitUtil getInstance(){ synchronized ("rsa") { if(util == null) { util = new RsaInitUtil(); } } return util; }  /** *  * 功能說明：[獲取公鑰] * @return * 創建者:Nmm, Aug 19, 2013 */ public PublicKey getPublicKey(){ return keyPair.getPublic(); }  public PrivateKey getPrivateKey(){ return keyPair.getPrivate(); }  /** *  * 功能說明：[獲取公鑰字符串] * @return * 創建者:Nmm, Aug 19, 2013 */ public String getPublicKeyStr(){ //根據我們的提供者，這里獲取的是該類型公鑰 BCRSAPublicKey pk = (BCRSAPublicKey) getPublicKey(); String str = new String(Hex.encodeHex(pk.getModulus().toByteArray())); System.out.println(str); //獲取入口10001一般都為這個 String ss = new String(Hex.encodeHex(pk.getPublicExponent().toByteArray())); //獲取轉換字符串 System.out.println(b2Hex(pk.getModulus().toByteArray())); return ss + str; } /** *  * 功能說明：[手動轉換] * @param byteArray * @return * 創建者:Nmm, Aug 19, 2013 */ private String b2Hex(byte[] byteArray) { StringBuilder sb = new StringBuilder(); for(int i = 0; i < byteArray.length; i++ ) { int zhz = byteArray[i]; if(zhz < 0) { zhz += 256; } if(zhz < 16) { sb.append("0"); } sb.append(Integer.toHexString(zhz)); } return sb.toString(); }}

前臺引入RSA.js,BigInt.js和Barrett.js并采用如下方法加密：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@page import="com.jb.test.RsaInitUtil"%><%  RsaInitUtil rsa = RsaInitUtil.getInstance(); String my = rsa.getPublicKeyStr(); String exp = my.substring(0,6); String mou = my.substring(6);%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <title>RSA測試</title> <script type="text/javascript" src="RSA.js"></script> <script type="text/javascript" src="BigInt.js"></script> <script type="text/javascript" src="Barrett.js"></script> </head>  <body> </body></html><script type="text/javascript">  var m = '<%=mou%>'; var e = '<%=exp%>';  var key = ''; setMaxDigits(128); alert(e); key = new RSAKeyPair(e,'',m); var res = encryptedString(key,encodeURIComponent('測試數據'));  window.location.href = 'rsaDecTry.do?res=' + res; </script>

后臺解密算法為：

package com.jb.test; import java.net.URLDecoder;import java.security.NoSuchAlgorithmException; import javax.crypto.Cipher;import javax.crypto.NoSuchPaddingException; import org.apache.commons.codec.binary.Hex;import org.bouncycastle.jce.provider.BouncyCastleProvider;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping; /** * Rsa加密的控制層 * @author nmm * */@Controller("rsaController")public class RsaController {  private RsaInitUtil rsaUtil = RsaInitUtil.getInstance();  /** *  * 功能說明：[解密方法] * @param res * 創建者:Nmm, Aug 19, 2013 * @throws NoSuchPaddingException  * @throws NoSuchAlgorithmException  */ @RequestMapping("rsaDecTry.do") public void decodeTry(String res) throws Exception { Cipher cipher = Cipher.getInstance("RSA",new BouncyCastleProvider());//必須指定此提供者 cipher.init(Cipher.DECRYPT_MODE, rsaUtil.getPrivateKey()); System.out.println(res); byte[] buff = cipher.doFinal(Hex.decodeHex(res.toCharArray())); //將字符串轉為字符 StringBuilder sb = new StringBuilder(new String(buff,"UTF-8")); //解密后的內容是倒敘的 sb.reverse(); //進行URL解密，主要是為了中文亂碼問題 String result = URLDecoder.decode(sb.toString(), "UTF-8"); System.out.println(result);  }}

至此可完成，整個加密解密過程，下面大家可以把rsa相關的內容全部整合到一個工具類中，不用想這里處理。

下面為RSA加密解密工具類：

package com.jb.framework.filter; import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.math.BigInteger;import java.net.URLDecoder;import java.security.KeyFactory;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.NoSuchAlgorithmException;import java.security.PrivateKey;import java.security.PublicKey;import java.security.SecureRandom;import java.security.spec.RSAPrivateKeySpec;import java.security.spec.RSAPublicKeySpec;import java.util.Calendar; import javax.crypto.Cipher; import org.apache.commons.codec.binary.Hex;import org.bouncycastle.jcajce.provider.asymmetric.rsa.BCRSAPublicKey;import org.bouncycastle.jce.provider.BouncyCastleProvider; /** *  * @Package: com.jb.framework.filter<br> * @ClassName: RSAUtil<br> * @Description: RSA加密工具類，這里我們是每次系統啟動時聲稱一套公鑰，私鑰，因此不能將加密串存入數據庫中，如果要這么做可以預先生成密鑰隊寫入到文件中<br> */public class RSAUtil {  private RSAUtil(){}  public static final String keyPubFile = "rsaPubKey.bin"; public static final String keyPriFile = "rsaPriKey.bin";  private static RSAUtil rsa; //密鑰生成器 private PublicKey publicKey; //密鑰隊 private PrivateKey privateKey;    public static RSAUtil getInstance(){ synchronized ("rsa") { if(rsa == null) { rsa = new RSAUtil(); rsa.init(); } } return rsa; } /** *  * @Title: init * @Description: 初始化方法 * void * @throws */ private void init() { //構建RSA算法 try { KeyPairGenerator kengen = KeyPairGenerator.getInstance("RSA",new BouncyCastleProvider()); //構建隨機種子 SecureRandom random = new SecureRandom(); random.setSeed(Calendar.getInstance().getTimeInMillis()); kengen.initialize(512, random);//采用512位加密 KeyPair keyPair = kengen.generateKeyPair(); publicKey = keyPair.getPublic(); privateKey = keyPair.getPrivate(); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } } /** *  * @Title: getPublicKey * @Description: 獲取公鑰 * @return * PublicKey * @throws */ public PublicKey getPublicKey(){ return this.publicKey; } /** *  * @Title: getPrivateKey * @Description: 獲取私鑰 * @return * PrivateKey * @throws */ public PrivateKey getPrivateKey(){ return this.privateKey; } /** *  * @Title: getPublicKeyStr * @Description: 獲取系統公鑰字符串，前6位為exponentk,后面為modlus * @return * String * @throws */ public String getPublicKeyStr(){ BCRSAPublicKey pk = (BCRSAPublicKey) getPublicKey(); String pubStr = ""; pubStr += b2hex(pk.getPublicExponent().toByteArray()); pubStr += b2hex(pk.getModulus().toByteArray()); return pubStr; } /** *  * @Title: entryText * @Description: 使用默認公鑰進行加密 * @param text * @return * String * @throws */ public String encryText(String text) { return encryText(text,getPublicKey()); } /** *  * @Title: entryText * @Description: 使用指定公鑰進行加密，解決長字符串加密 * @param text * @param publicKey2 * @return * String * @throws */ public String encryText(String text, PublicKey pk) { try { Cipher cipher = Cipher.getInstance("RSA",new BouncyCastleProvider()); cipher.init(Cipher.ENCRYPT_MODE, pk); int block = cipher.getBlockSize();//獲取最大加密塊 int j = 0; StringBuilder sb = new StringBuilder(); byte[] targetData = text.getBytes("UTF-8"); while (targetData.length - j*block > 0) { byte[] jmdata = cipher.doFinal(targetData,j*block,Math.min(targetData.length - j*block, block)); sb.append(b2hex(jmdata)); j++; } return sb.toString(); } catch (Exception e) { e.printStackTrace(); } return null; } /** *  * @Title: decryText * @Description: 使用默認的私鑰進行解密解密算法 * @param text * @return * String * @throws */ public String decryText(String text) { return decryText(text,getPrivateKey()); } /** *  * @Title: decryText * @Description: 指定私鑰進行解密，增加對于大字符串的解密操作 * @param text * @param privateKey2 * @return * String * @throws */ public String decryText(String text, PrivateKey pk) { try { Cipher cipher = Cipher.getInstance("RSA", new BouncyCastleProvider()); cipher.init(Cipher.DECRYPT_MODE, pk); byte[] targetBuff = Hex.decodeHex(text.replace(" ", "").toCharArray()); int block = cipher.getBlockSize(); int j = 0; StringBuilder sb = new StringBuilder(); while (targetBuff.length - j * block > 0) { byte[] jmdata = cipher.doFinal(targetBuff,j*block,block); sb.append(new String(jmdata,"UTF-8")); j++; } return sb.toString();  } catch (Exception e) { e.printStackTrace(); } return null; } /** *  * @Title: decryTextByUrl * @Description: 解密前臺傳遞的加密串，為防止中文亂碼，前臺字符串最好使用encodeURIComponent方法進行url編碼 * @param text * @return * String * @throws */ public String decryTextByUrl(String text) { try { Cipher cipher = Cipher.getInstance("RSA", new BouncyCastleProvider()); cipher.init(Cipher.DECRYPT_MODE, getPrivateKey()); byte[] targetBuff = Hex.decodeHex(text.replace(" ", "").toCharArray()); int block = cipher.getBlockSize(); int j = 0; StringBuilder sb = new StringBuilder(); while (targetBuff.length - j * block > 0) {//處理大字符串的加密解密處理 byte[] jmdata = cipher.doFinal(targetBuff,j*block,block); sb.append(new StringBuilder(new String(jmdata,"UTF-8")).reverse()); j++; } String res = URLDecoder.decode(sb.toString(), "UTF-8"); return res;  } catch (Exception e) { e.printStackTrace(); } return null; } /** *  * @Title: createPubKey * @Description: 根據指定的冪和模式生成公鑰 * @param exponent * @param modules * @return * PublicKey * @throws */ public PublicKey createPubKey(byte[] exponent,byte[]modules) { try { KeyFactory keyFactory = KeyFactory.getInstance("RSA", new BouncyCastleProvider()); RSAPublicKeySpec rsaKs = new RSAPublicKeySpec(new BigInteger(modules),new BigInteger(exponent)); return keyFactory.generatePublic(rsaKs);  } catch (Exception e) { e.printStackTrace(); }  return null; } /** *  * @Title: createPubKey * @Description: 根據指定的冪和模式生成公鑰 * @param exponent * @param modules * @return * PublicKey * @throws */ public PrivateKey createPriKey(byte[] exponent,byte[]modules) { try { KeyFactory keyFactory = KeyFactory.getInstance("RSA", new BouncyCastleProvider()); RSAPrivateKeySpec rsaKs = new RSAPrivateKeySpec(new BigInteger(modules),new BigInteger(exponent)); return keyFactory.generatePrivate(rsaKs);  } catch (Exception e) { e.printStackTrace(); } return null; } /** *  * @Title: saveKeyToFile * @Description: 保存公鑰和私鑰到文件中 * void * @throws */ public void saveKeyToFile() { PublicKey pk = getPublicKey(); PrivateKey prik = getPrivateKey();  String path = RSAUtil.class.getClassLoader().getResource("").getPath(); ObjectOutputStream outPub = null; ObjectOutputStream outPri = null; try { System.out.println(path + keyPubFile); outPub = new ObjectOutputStream(new FileOutputStream(path + keyPubFile)); outPri = new ObjectOutputStream(new FileOutputStream(path + keyPriFile)); outPub.writeObject(pk); outPri.writeObject(prik); } catch (Exception e) { e.printStackTrace(); }finally { try { outPub.close(); outPri.close(); } catch (IOException e) { e.printStackTrace(); }  } } /** *  * @Title: readKey * @Description: 讀取密鑰 * @param isPub * @return * Object * @throws */ public Object readKey(boolean isPub) { String path = RSAUtil.class.getClassLoader().getResource("").getPath(); ObjectInputStream in = null; try { if(isPub) { path += keyPubFile; in = new ObjectInputStream(new FileInputStream(path)); PublicKey pk = (PublicKey) in.readObject(); return pk; }else { path += keyPriFile; in = new ObjectInputStream(new FileInputStream(path)); PrivateKey pk = (PrivateKey) in.readObject(); return pk; } } catch (Exception e) { e.printStackTrace(); }finally { try { in.close(); } catch (IOException e) { e.printStackTrace(); } } return null; }   /** *  * @Title: b2hex * @Description: 將二進制轉為16進制字符串 * @param buff * @return * String * @throws */ public String b2hex(byte[] buff) { StringBuilder sb = new StringBuilder(); for(int i = 0; i < buff.length; i++) { int z = buff[i]; if(z < 0) { z+= 256; } if(z < 16) { sb.append("0"); } sb.append(Integer.toHexString(z)); } return sb.toString(); }}

總結

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