RSA 签名、验证、加密、解密帮助类

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.PrivateKey;

import java.security.PublicKey;

import java.security.Signature;

import java.security.SignatureException;

import java.security.spec.EncodedKeySpec;

import java.security.spec.InvalidKeySpecException;

import java.security.spec.PKCS8EncodedKeySpec;

import java.security.spec.X509EncodedKeySpec;

 

import javax.crypto.Cipher;

 

import sun.misc.BASE64Decoder;

import sun.misc.BASE64Encoder;

 

/**

 * RSA 签名、验证、加密、解密帮助类

 *

 * @author sam

 *

 */

public class RsaHelper

{

   // 签名对象

   private Signature sign;

   private static final RsaHelper rsaHelper = new RsaHelper();

  

   private String pubkey;

   private String prikey;

  

   private RsaHelper()

   {

      try

      {

        sign = Signature.getInstance("SHA1withRSA");

      }

      catch (NoSuchAlgorithmException nsa)

      {

        System.out.println("" + nsa.getMessage());

      }

   }

  

   public static RsaHelper getInstance()

   {

      return rsaHelper;

   }

  

   private PrivateKey getPrivateKey(String privateKeyStr)

   {

      try

      {

        byte[] privateKeyBytes = b64decode(privateKeyStr);

        KeyFactory keyFactory = KeyFactory.getInstance("RSA");

        EncodedKeySpec privateKeySpec = new PKCS8EncodedKeySpec(privateKeyBytes);

        return keyFactory.generatePrivate(privateKeySpec);

      }

      catch (InvalidKeySpecException e)

      {

        System.out.println("Invalid Key Specs. Not valid Key files." + e.getCause());

        return null;

      }

      catch (NoSuchAlgorithmException e)

      {

        System.out.println("There is no such algorithm. Please check the JDK ver." + e.getCause());

        return null;

      }

   }

  

   private PublicKey getPublicKey(String publicKeyStr)

   {

      try

      {

        byte[] publicKeyBytes = b64decode(publicKeyStr);

        KeyFactory keyFactory = KeyFactory.getInstance("RSA");

        EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(publicKeyBytes);

        return keyFactory.generatePublic(publicKeySpec);

      }

      catch (InvalidKeySpecException e)

      {

        System.out.println("Invalid Key Specs. Not valid Key files." + e.getCause());

        return null;

      }

      catch (NoSuchAlgorithmException e)

      {

        System.out.println("There is no such algorithm. Please check the JDK ver." + e.getCause());

        return null;

      }

   }

  

   /**

    * RSA 数据签名

    *

    * @param toBeSigned

    *            (待签名的原文)

    * @param priKey

    *            (RSA私钥)

    * @return (返回RSA签名后的数据签名数据base64编码)

    */

   public String signData(String toBeSigned, String priKey)

   {

     

      try

      {

        PrivateKey privateKey = getPrivateKey(priKey);

        byte[] signByte = toBeSigned.getBytes("utf-8");

        Signature rsa = Signature.getInstance("SHA1withRSA");

        rsa.initSign(privateKey);

        rsa.update(signByte);

        return b64encode(rsa.sign());

      }

      catch (NoSuchAlgorithmException ex)

      {

        System.out.println(ex);

      }

      catch (InvalidKeyException in)

      {

        System.out.println("Invalid Key file.Please check the key file path" + in.getCause());

      }

      catch (Exception se)

      {

        System.out.println(se);

      }

      return null;

   }

  

   /**

    * RSA 数据签名验证

    *

    * @param signature

    *            (RSA签名数据(base64编码)

    * @param data

    *            (待验证的数据原文)

    * @param pubKey

    *            (RSA公钥数据)

    * @return 返回验证结果(TRUE:验证成功;FALSE:验证失败)

    */

   public boolean verifySignature(String signature, String data, String pubKey)

   {

      try

      {

        byte[] signByte = b64decode(signature);

        byte[] dataByte = data.getBytes("utf-8");

        PublicKey publicKey = getPublicKey(pubKey);

        sign.initVerify(publicKey);

        sign.update(dataByte);

        return sign.verify(signByte);

      }

      catch (SignatureException e)

      {

        e.printStackTrace();

      }

      catch (Exception e)

      {

        e.printStackTrace();

      }

      return false;

   }

  

   /**

    * base64编码

    *

    * @param data

    * @return

    */

   private String b64encode(byte[] data)

   {

      return new BASE64Encoder().encode(data);

   }

  

   /**

    * base64解码

    *

    * @param data

    * @return

    */

   private byte[] b64decode(String data)

   {

      try

      {

        return new BASE64Decoder().decodeBuffer(data);

      }

      catch (Exception ex)

      {

      }

      return null;

   }

  

   /**

    * RSA数据加密

    *

    * @param data

    *            (需要加密的数据)

    * @param pubKey

    *            (RSA公钥)

    * @return 返回加密后的密文(BASE64编码)

    */

   public String encryptData(String data, String pubKey)

   {

      try

      {

        byte[] dataByte = data.getBytes("utf-8");

        PublicKey publicKey = getPublicKey(pubKey);

        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

        cipher.init(Cipher.ENCRYPT_MODE, publicKey);

        return b64encode(cipher.doFinal(dataByte));

      }

      catch (Exception e)

      {

        return null;

      }

   }

  

   /**

    * RSA数据解密

    *

    * @param encryptedData

    *            (需要解密的数据base64编码数据)

    * @param priKey

    *            (RSA的私钥)

    * @return 返回解密后的原始明文

    */

   public String decryptData(String encryptedData, String priKey)

   {

      try

      {

        byte[] encryData = b64decode(encryptedData);

        PrivateKey privateKey = getPrivateKey(priKey);

        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

        cipher.init(Cipher.DECRYPT_MODE, privateKey);

        return new String(cipher.doFinal(encryData), "utf-8");

      }

      catch (Exception e)

      {

        return null;

      }

   }

  

   /**

    * 得到私钥字符串(经过base64编码)

    *

    * @return

    */

   public static String getPriKeyString(PrivateKey key) throws Exception

   {

      byte[] keyBytes = key.getEncoded();

      String s = (new BASE64Encoder()).encode(keyBytes);

      return s;

   }

  

   /**

    * 得到公钥字符串(经过base64编码)

    *

    * @return

    */

   public static String getPubKeyString(PublicKey key) throws Exception

   {

      byte[] keyBytes = key.getEncoded();

      String s = (new BASE64Encoder()).encode(keyBytes);

      return s;

   }

  

   /**

    * 生成密钥 自动产生RSA1024位密钥

    *

    * @throws NoSuchAlgorithmException

    * @throws IOException

    */

   public void getAutoCreateRSA() throws NoSuchAlgorithmException, IOException

   {

      try

      {

        KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");

        kpg.initialize(1024);

        KeyPair kp = kpg.genKeyPair();

        PublicKey puk = kp.getPublic();

        PrivateKey prk = kp.getPrivate();

       

        pubkey = getPubKeyString(puk);

        prikey = getPriKeyString(prk);

         System.out.print("pubkey==:"+pubkey.replaceAll(" ", "").replaceAll(" ", ""));

         System.out.print("prikey==:"+prikey.replaceAll(" ", "").replaceAll(" ", ""));

      }

      catch (Exception e)

      {

        e.printStackTrace();

      }

   }

  

   public String getPubkey()

   {

      return pubkey;

   }

  

   public void setPubkey(String pubkey)

   {

      this.pubkey = pubkey;

   }

  

   public String getPrikey()

   {

      return prikey;

   }

  

   public void setPrikey(String prikey)

   {

      this.prikey = prikey;

   }

  

}

 

原文地址:https://www.cnblogs.com/chinaifae/p/10400571.html