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Java使用RSA加密解密签名及校验

news 来源：原创 2024/4/29 1:25:31

RSA加密解密类：

package com.ihep;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;

import com.fcplay.Base64;

public class RSAEncrypt {
   /**
   * 字节数据转字符串专用集合
   */
   private static final char[] HEX_CHAR = { '0', '1', '2', '3', '4', '5', '6',
           '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

   /**
   * 随机生成密钥对
   */
   public static void genKeyPair(String filePath) {
       // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
       KeyPairGenerator keyPairGen = null;
       try {
           keyPairGen = KeyPairGenerator.getInstance("RSA");
       } catch (NoSuchAlgorithmException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
       }
       // 初始化密钥对生成器，密钥大小为96-1024位
       keyPairGen.initialize(1024,new SecureRandom());
       // 生成一个密钥对，保存在keyPair中
       KeyPair keyPair = keyPairGen.generateKeyPair();
       // 得到私钥
       RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
       // 得到公钥
       RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
       try {
           // 得到公钥字符串
           String publicKeyString = Base64.encode(publicKey.getEncoded());
           // 得到私钥字符串
           String privateKeyString = Base64.encode(privateKey.getEncoded());
           // 将密钥对写入到文件
           FileWriter pubfw = new FileWriter(filePath + "/publicKey.keystore");
           FileWriter prifw = new FileWriter(filePath + "/privateKey.keystore");
           BufferedWriter pubbw = new BufferedWriter(pubfw);
           BufferedWriter pribw = new BufferedWriter(prifw);
           pubbw.write(publicKeyString);
           pribw.write(privateKeyString);
           pubbw.flush();
           pubbw.close();
           pubfw.close();
           pribw.flush();
           pribw.close();
           prifw.close();
       } catch (Exception e) {
           e.printStackTrace();
       }
   }

   /**
   * 从文件中输入流中加载公钥
   *
   * @param in
   *            公钥输入流
   * @throws Exception
   *             加载公钥时产生的异常
   */
   public static String loadPublicKeyByFile(String path) throws Exception {
       try {
           BufferedReader br = new BufferedReader(new FileReader(path
                   + "/publicKey.keystore"));
           String readLine = null;
           StringBuilder sb = new StringBuilder();
           while ((readLine = br.readLine()) != null) {
               sb.append(readLine);
           }
           br.close();
           return sb.toString();
       } catch (IOException e) {
           throw new Exception("公钥数据流读取错误");
       } catch (NullPointerException e) {
           throw new Exception("公钥输入流为空");
       }
   }

   /**
   * 从字符串中加载公钥
   *
   * @param publicKeyStr
   *            公钥数据字符串
   * @throws Exception
   *             加载公钥时产生的异常
   */
   public static RSAPublicKey loadPublicKeyByStr(String publicKeyStr)
           throws Exception {
       try {
           byte[] buffer = Base64.decode(publicKeyStr);
           KeyFactory keyFactory = KeyFactory.getInstance("RSA");
           X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);
           return (RSAPublicKey) keyFactory.generatePublic(keySpec);
       } catch (NoSuchAlgorithmException e) {
           throw new Exception("无此算法");
       } catch (InvalidKeySpecException e) {
           throw new Exception("公钥非法");
       } catch (NullPointerException e) {
           throw new Exception("公钥数据为空");
       }
   }

   /**
   * 从文件中加载私钥
   *
   * @param keyFileName
   *            私钥文件名
   * @return 是否成功
   * @throws Exception
   */
   public static String loadPrivateKeyByFile(String path) throws Exception {
       try {
           BufferedReader br = new BufferedReader(new FileReader(path
                   + "/privateKey.keystore"));
           String readLine = null;
           StringBuilder sb = new StringBuilder();
           while ((readLine = br.readLine()) != null) {
               sb.append(readLine);
           }
           br.close();
           return sb.toString();
       } catch (IOException e) {
           throw new Exception("私钥数据读取错误");
       } catch (NullPointerException e) {
           throw new Exception("私钥输入流为空");
       }
   }

   public static RSAPrivateKey loadPrivateKeyByStr(String privateKeyStr)
           throws Exception {
       try {
           byte[] buffer = Base64.decode(privateKeyStr);
           PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
           KeyFactory keyFactory = KeyFactory.getInstance("RSA");
           return (RSAPrivateKey) keyFactory.generatePrivate(keySpec);
       } catch (NoSuchAlgorithmException e) {
           throw new Exception("无此算法");
       } catch (InvalidKeySpecException e) {
           throw new Exception("私钥非法");
       } catch (NullPointerException e) {
           throw new Exception("私钥数据为空");
       }
   }

   /**
   * 公钥加密过程
   *
   * @param publicKey
   *            公钥
   * @param plainTextData
   *            明文数据
   * @return
   * @throws Exception
   *             加密过程中的异常信息
   */
   public static byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData)
           throws Exception {
       if (publicKey == null) {
           throw new Exception("加密公钥为空, 请设置");
       }
       Cipher cipher = null;
       try {
           // 使用默认RSA
           cipher = Cipher.getInstance("RSA");
           // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
           cipher.init(Cipher.ENCRYPT_MODE, publicKey);
           byte[] output = cipher.doFinal(plainTextData);
           return output;
       } catch (NoSuchAlgorithmException e) {
           throw new Exception("无此加密算法");
       } catch (NoSuchPaddingException e) {
           e.printStackTrace();
           return null;
       } catch (InvalidKeyException e) {
           throw new Exception("加密公钥非法,请检查");
       } catch (IllegalBlockSizeException e) {
           throw new Exception("明文长度非法");
       } catch (BadPaddingException e) {
           throw new Exception("明文数据已损坏");
       }
   }

   /**
   * 私钥加密过程
   *
   * @param privateKey
   *            私钥
   * @param plainTextData
   *            明文数据
   * @return
   * @throws Exception
   *             加密过程中的异常信息
   */
   public static byte[] encrypt(RSAPrivateKey privateKey, byte[] plainTextData)
           throws Exception {
       if (privateKey == null) {
           throw new Exception("加密私钥为空, 请设置");
       }
       Cipher cipher = null;
       try {
           // 使用默认RSA
           cipher = Cipher.getInstance("RSA");
           cipher.init(Cipher.ENCRYPT_MODE, privateKey);
           byte[] output = cipher.doFinal(plainTextData);
           return output;
       } catch (NoSuchAlgorithmException e) {
           throw new Exception("无此加密算法");
       } catch (NoSuchPaddingException e) {
           e.printStackTrace();
           return null;
       } catch (InvalidKeyException e) {
           throw new Exception("加密私钥非法,请检查");
       } catch (IllegalBlockSizeException e) {
           throw new Exception("明文长度非法");
       } catch (BadPaddingException e) {
           throw new Exception("明文数据已损坏");
       }
   }

   /**
   * 私钥解密过程
   *
   * @param privateKey
   *            私钥
   * @param cipherData
   *            密文数据
   * @return 明文
   * @throws Exception
   *             解密过程中的异常信息
   */
   public static byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData)
           throws Exception {
       if (privateKey == null) {
           throw new Exception("解密私钥为空, 请设置");
       }
       Cipher cipher = null;
       try {
           // 使用默认RSA
           cipher = Cipher.getInstance("RSA");
           // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
           cipher.init(Cipher.DECRYPT_MODE, privateKey);
           byte[] output = cipher.doFinal(cipherData);
           return output;
       } catch (NoSuchAlgorithmException e) {
           throw new Exception("无此解密算法");
       } catch (NoSuchPaddingException e) {
           e.printStackTrace();
           return null;
       } catch (InvalidKeyException e) {
           throw new Exception("解密私钥非法,请检查");
       } catch (IllegalBlockSizeException e) {
           throw new Exception("密文长度非法");
       } catch (BadPaddingException e) {
           throw new Exception("密文数据已损坏");
       }
   }

   /**
   * 公钥解密过程
   *
   * @param publicKey
   *            公钥
   * @param cipherData
   *            密文数据
   * @return 明文
   * @throws Exception
   *             解密过程中的异常信息
   */
   public static byte[] decrypt(RSAPublicKey publicKey, byte[] cipherData)
           throws Exception {
       if (publicKey == null) {
           throw new Exception("解密公钥为空, 请设置");
       }
       Cipher cipher = null;
       try {
           // 使用默认RSA
           cipher = Cipher.getInstance("RSA");
           // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
           cipher.init(Cipher.DECRYPT_MODE, publicKey);
           byte[] output = cipher.doFinal(cipherData);
           return output;
       } catch (NoSuchAlgorithmException e) {
           throw new Exception("无此解密算法");
       } catch (NoSuchPaddingException e) {
           e.printStackTrace();
           return null;
       } catch (InvalidKeyException e) {
           throw new Exception("解密公钥非法,请检查");
       } catch (IllegalBlockSizeException e) {
           throw new Exception("密文长度非法");
       } catch (BadPaddingException e) {
           throw new Exception("密文数据已损坏");
       }
   }

   /**
   * 字节数据转十六进制字符串
   *
   * @param data
   *            输入数据
   * @return 十六进制内容
   */
   public static String byteArrayToString(byte[] data) {
       StringBuilder stringBuilder = new StringBuilder();
       for (int i = 0; i < data.length; i++) {
           // 取出字节的高四位作为索引得到相应的十六进制标识符注意无符号右移
           stringBuilder.append(HEX_CHAR[(data[i] & 0xf0) >>> 4]);
           // 取出字节的低四位作为索引得到相应的十六进制标识符
           stringBuilder.append(HEX_CHAR[(data[i] & 0x0f)]);
           if (i < data.length - 1) {
               stringBuilder.append(' ');
           }
       }
       return stringBuilder.toString();
   }
}

最后是一个MainTest：

package com.ihep;

public class MainTest {

   public static void main(String[] args) throws Exception {
       String filepath="G:/tmp/";

       //RSAEncrypt.genKeyPair(filepath);


       System.out.println("--------------公钥加密私钥解密过程-------------------");
       String plainText="ihep_公钥加密私钥解密";
       //公钥加密过程
       byte[] cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)),plainText.getBytes());
       String cipher=Base64.encode(cipherData);
       //私钥解密过程
       byte[] res=RSAEncrypt.decrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)), Base64.decode(cipher));
       String restr=new String(res);
       System.out.println("原文："+plainText);
       System.out.println("加密："+cipher);
       System.out.println("解密："+restr);
       System.out.println();

       System.out.println("--------------私钥加密公钥解密过程-------------------");
       plainText="ihep_私钥加密公钥解密";
       //私钥加密过程
       cipherData=RSAEncrypt.encrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(filepath)),plainText.getBytes());
       cipher=Base64.encode(cipherData);
       //公钥解密过程
       res=RSAEncrypt.decrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(filepath)), Base64.decode(cipher));
       restr=new String(res);
       System.out.println("原文："+plainText);
       System.out.println("加密："+cipher);
       System.out.println("解密："+restr);
       System.out.println();

       System.out.println("---------------私钥签名过程------------------");
       String content="ihep_这是用于签名的原始数据";
       String signstr=RSASignature.sign(content,RSAEncrypt.loadPrivateKeyByFile(filepath));
       System.out.println("签名原串："+content);
       System.out.println("签名串："+signstr);
       System.out.println();

       System.out.println("---------------公钥校验签名------------------");
       System.out.println("签名原串："+content);
       System.out.println("签名串："+signstr);

       System.out.println("验签结果："+RSASignature.doCheck(content, signstr, RSAEncrypt.loadPublicKeyByFile(filepath)));
       System.out.println();

   }
}