jquery 加密到后端解密 js前端加密java后端解密

用RSA非对称加密方式实现。后台生成rsa密钥对，然后在页面设置rsa公钥，提交时用公钥加密密码，生成的密文传到后台，后台再用私钥解密，获取密码明文。
     这样客户端只需要知道rsa加密方式和公钥，前台不知道私钥是无法解密的，此解决方案还是相对比较安全的。
     需要到http://www.bouncycastle.org下载bcprov-jdk16-140.jar文件。
    缺陷： 由于进行的都是大数计算，使得RSA最快的情况也比DES慢上100倍，无论 是软件还是硬件实现。所以 一般来说只用于少               量数据 加密。
    下面我们就来一个实际的例子：

    1、前端加密需要引入Barrett.js、BigInt.js和RSA.js。

1.  <script src="/rsa/RSA.js" type="text/javascript"></script>
2.          <script src="/rsa/BigInt.js" type="text/javascript"></script>
3.          <script src="/rsa/Barrett.js" type="text/javascript"></script>

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2、前端加密代码：

1.  encryptedString : (function(paramStr, rsaKey){
2.      setMaxDigits(130);
3.      //第一个参数为加密指数、第二个参数为解密参数、第三个参数为加密系数
4.      key = new RSAKeyPair("10001", "", rsaKey); 
5.      //返回加密后的字符串
6.      return encryptedString(key, encodeURIComponent(paramStr));
7.          })

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其中的加密系数可以自定义，这里为：8246a46f44fc4d961e139fd70f4787d272d374532f4d2d9b7cbaad6a15a8c1301319aa6b3f30413b859351c71938aec516fa7147b69168b195e81df46b6bed7950cf3a1c719d42175f73d7c97a85d7d20a9e83688b92f05b3059bb2ff75cd7190a042cd2db97ebc2ab4da366f2a7085556ed613b5a39c9fdd2bb2595d1dc23b5

    3、后台RSA加密解密方法如下：

1.  import java.io.ByteArrayOutputStream;
2.  import java.io.FileInputStream;
3.  import java.io.FileOutputStream;
4.  import java.io.ObjectInputStream;
5.  import java.io.ObjectOutputStream;
6.  import java.math.BigInteger;
7.  import java.security.KeyFactory;
8.  import java.security.KeyPair;
9.  import java.security.KeyPairGenerator;
10.  import java.security.NoSuchAlgorithmException;
11.  import java.security.PrivateKey;
12.  import java.security.PublicKey;
13.  import java.security.SecureRandom;
14.  import java.security.interfaces.RSAPrivateKey;
15.  import java.security.interfaces.RSAPublicKey;
16.  import java.security.spec.InvalidKeySpecException;
17.  import java.security.spec.RSAPrivateKeySpec;
18.  import java.security.spec.RSAPublicKeySpec;
19.  
20.  import javax.crypto.Cipher;
21.  
22.  import org.apache.commons.lang.StringUtils;
23.  
24.  import com.jd.uwp.common.Constants;
25.  
26.  /**
27.  * RSA 工具类。提供加密，解密，生成密钥对等方法。
28.  * 需要bcprov-jdk16-140.jar包。
29.  * 
30.  */
31.  public class RSAUtil {
32.          
33.          private static String RSAKeyStore = "RSAKey.txt";
34.  
35.          /**
36.           * * 生成密钥对 *
37.           * @return KeyPair *
38.           * @throws EncryptException
39.           */
40.          public static KeyPair generateKeyPair(String basePath) throws Exception {
41.      try {
42.          KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA",
43.          new org.bouncycastle.jce.provider.BouncyCastleProvider());
44.          //大小
45.          final int KEY_SIZE = 1024;
46.          keyPairGen.initialize(KEY_SIZE, new SecureRandom());
47.          KeyPair keyPair = keyPairGen.generateKeyPair();
48.          saveKeyPair(keyPair, basePath);
49.          return keyPair;
50.      } catch (Exception e) {
51.          throw new Exception(e.getMessage());
52.      }
53.          }
54.  
55.          /**
56.           * 获取密钥对
57.           * @return
58.           * @throws Exception
59.           */
60.          public static KeyPair getKeyPair(String basePath) throws Exception {
61.      FileInputStream fis = new FileInputStream(StringUtils.isNotBlank(basePath) ? (basePath + RSAKeyStore) :     RSAKeyStore);
62.      ObjectInputStream oos = new ObjectInputStream(fis);
63.      KeyPair kp = (KeyPair) oos.readObject();
64.      oos.close();
65.      fis.close();
66.      return kp;
67.          }
68.  
69.          /**
70.           * 保存密钥
71.           * @param kp
72.           * @throws Exception
73.           */
74.          public static void saveKeyPair(KeyPair kp, String basePath) throws Exception {
75.      FileOutputStream fos = new FileOutputStream(StringUtils.isNotBlank(basePath) ? (basePath + RSAKeyStore) :     RSAKeyStore);
76.      ObjectOutputStream oos = new ObjectOutputStream(fos);
77.      // 生成密钥
78.      oos.writeObject(kp);
79.      oos.close();
80.      fos.close();
81.          }
82.  
83.          /**
84.           * * 生成公钥 *
85.           * @param modulus *
86.           * @param publicExponent *
87.           * @return RSAPublicKey *
88.           * @throws Exception
89.           */
90.          public static RSAPublicKey generateRSAPublicKey(byte[] modulus,
91.      byte[] publicExponent) throws Exception {
92.      KeyFactory keyFac = null;
93.      try {
94.          keyFac = KeyFactory.getInstance("RSA",
95.          new org.bouncycastle.jce.provider.BouncyCastleProvider());
96.      } catch (NoSuchAlgorithmException ex) {
97.          throw new Exception(ex.getMessage());
98.      }
99.      RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(new BigInteger(
100.          modulus), new BigInteger(publicExponent));
101.      try {
102.          return (RSAPublicKey) keyFac.generatePublic(pubKeySpec);
103.      } catch (InvalidKeySpecException ex) {
104.          throw new Exception(ex.getMessage());
105.      }
106.          }
107.  
108.          /**
109.           * * 生成私钥 *
110.           * @param modulus *
111.           * @param privateExponent *
112.           * @return RSAPrivateKey *
113.           * @throws Exception
114.           */
115.          public static RSAPrivateKey generateRSAPrivateKey(byte[] modulus,
116.      byte[] privateExponent) throws Exception {
117.      KeyFactory keyFac = null;
118.      try {
119.          keyFac = KeyFactory.getInstance("RSA",
120.          new org.bouncycastle.jce.provider.BouncyCastleProvider());
121.      } catch (NoSuchAlgorithmException ex) {
122.          throw new Exception(ex.getMessage());
123.      }
124.      RSAPrivateKeySpec priKeySpec = new RSAPrivateKeySpec(new BigInteger(
125.          modulus), new BigInteger(privateExponent));
126.      try {
127.          return (RSAPrivateKey) keyFac.generatePrivate(priKeySpec);
128.      } catch (InvalidKeySpecException ex) {
129.          throw new Exception(ex.getMessage());
130.                  }
131.          }
132.  
133.          /**
134.           * * 加密 *
135.           * @param key
136.           *            加密的密钥 *
137.           * @param data
138.           *            待加密的明文数据 *
139.           * @return 加密后的数据 *
140.           * @throws Exception
141.           */
142.          public static byte[] encrypt(PublicKey pk, byte[] data) throws Exception {
143.      try {
144.          Cipher cipher = Cipher.getInstance("RSA",
145.          new org.bouncycastle.jce.provider.BouncyCastleProvider());
146.          cipher.init(Cipher.ENCRYPT_MODE, pk);
147.          // 获得加密块大小，如：加密前数据为128个byte，而key_size=1024
148.          int blockSize = cipher.getBlockSize();
149.          // 加密块大小为127
150.          // byte,加密后为128个byte;因此共有2个加密块，第一个127
151.          // byte第二个为1个byte
152.          int outputSize = cipher.getOutputSize(data.length);// 获得加密块加密后块大小
153.          int leavedSize = data.length % blockSize;
154.          int blocksSize = leavedSize != 0 ? data.length / blockSize + 1 : data.length / blockSize;
155.          byte[] raw = new byte[outputSize * blocksSize];
156.          int i = 0;
157.          while (data.length - i * blockSize > 0) {
158.                  if (data.length - i * blockSize > blockSize) {
159.                      cipher.doFinal(data, i * blockSize, blockSize, raw, i * outputSize);
160.                  } else {
161.                      cipher.doFinal(data, i * blockSize, data.length - i * blockSize, raw, i * outputSize);
162.                  }
163.                  i++;
164.          }
165.          return raw;
166.      } catch (Exception e) {
167.          throw new Exception(e.getMessage());
168.      }
169.          }
170.  
171.          /**
172.           * * 解密 *
173.           * 
174.           * @param key
175.           *            解密的密钥 *
176.           * @param raw
177.           *            已经加密的数据 *
178.           * @return 解密后的明文 *
179.           * @throws Exception
180.           */
181.          @SuppressWarnings("static-access")
182.          public static byte[] decrypt(PrivateKey pk, byte[] raw) throws Exception {
183.      try {
184.          Cipher cipher = Cipher.getInstance("RSA", new org.bouncycastle.jce.provider.BouncyCastleProvider());
185.          cipher.init(cipher.DECRYPT_MODE, pk);
186.          int blockSize = cipher.getBlockSize();
187.          ByteArrayOutputStream bout = new ByteArrayOutputStream(64);
188.          int j = 0;
189.          while (raw.length - j * blockSize > 0) {
190.              bout.write(cipher.doFinal(raw, j * blockSize, blockSize));
191.              j++;
192.          }
193.          return bout.toByteArray();
194.      } catch (Exception e) {
195.          throw new Exception(e.getMessage());
196.      }
197.          }
198.          
199.  /**
200.  * 解密方法
201.  * paramStr    ->密文
202.  * basePath    ->RSAKey.txt所在的文件夹路径
203.  **/
204.          public static String decryptStr(String paramStr, String basePath) throws Exception{
205.      byte[] en_result = new BigInteger(paramStr, 16).toByteArray();
206.      byte[] de_result = decrypt(getKeyPair(basePath).getPrivate(), en_result);
207.      StringBuffer sb = new StringBuffer();
208.      sb.append(new String(de_result));
209.      //返回解密的字符串
210.      return sb.reverse().toString();
211.  }
212.  }
213.

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4、前端提交到后端解密调用:

1.  //前端 表单提交
2.  $.ajax({
3.      url : contextPath + "test.action",
4.      //加密传输
5.      data : {pwd:encryptedString ($("#pwd").val(), "adasdasdasdasdadsasdasdasdasd")},
6.      type  : "post",
7.      datatype : "json",
8.      success : function(retData){
9.      }
10.  });
11.  
12.  //后端解密代码
13.  RSAUtil.decryptStr(paramMap.getString("pwd"),  request.getSession().getServletContext().getRealPath("/"));

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