java RSAUtils 加密工具类操作

java RSAUtils 加密工具类操作

1.RSA加密算法是一种非对称加密算法。在公开密钥加密和电子商业中RSA被广泛使用。RSA公开密钥密码体制。所谓的公开密钥密码体制就是使用不同的加密密钥与解密密钥，是一种“由已知加密密钥推导出解密密钥在计算上是不可行的”密码体制。在公开密钥密码体制中，加密密钥（即公开密钥）PK是公开信息，而解密密钥（即秘密密钥）SK是需要保密的。加密算法E和解密算法D也都是公开的。虽然解密密钥SK是由公开密钥PK决定的，但却不能根据PK计算出SK。

2.本工具类涉及到BASE64编码，所以先展示出BASE64Utils：

package com.example.springboottest.common.util;

import sun.misc.BASE64Decoder;

import sun.misc.BASE64Encoder;

import java.security.MessageDigest;

/**

* BASE64的加解密

* @author Neo

* @date 2018-4-15 22:21:51

*

*/

@SuppressWarnings("restriction")

public class Base64Utils {

public static final String KEY_SHA = "SHA";

public static final String KEY_MD5 = "MD5";

/**

* BASE64解密

*

* @param key

* @return

* @throws Exception

*/

public static byte[] decryptBASE64(String key) throws Exception {

return (new BASE64Decoder()).decodeBuffer(key);

}

/**

* BASE64加密

*

* @param key

* @return

* @throws Exception

*/

public static String encryptBASE64(byte[] key) throws Exception {

return (new BASE64Encoder()).encodeBuffer(key);

}

/**

* MD5加密

*

* @param data

* @return

* @throws Exception

*/

public static byte[] encryptMD5(byte[] data) throws Exception {

MessageDigest md5 = MessageDigest.getInstance(KEY_MD5);

md5.update(data);

return md5.digest();

}

/**

* SHA加密

*

* @param data

* @return

* @throws Exception

*/

public static byte[] encryptSHA(byte[] data) throws Exception {

MessageDigest sha = MessageDigest.getInstance(KEY_SHA);

sha.update(data);

return sha.digest();

}

}

3.然后我们展示RSAUtils：

package com.example.springboottest.common.util;

import javax.crypto.Cipher;

import java.security.*;

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;

/**

* RSA安全编码组件

*

* @version 1.0

* @desc 公钥和私钥存放在properties文件的时候每行的末尾加上“\r\n\”

* “\r\n” 起到换行的作用,最后的“\”在properties在里表示连接

*

* @author Neo

* @date 2018-4-15 22:23:19

* @since 1.0

*/

public class RSAUtils extends Base64Utils {

public static final String KEY_ALGORITHM = "RSA";

public static final String SIGNATURE_ALGORITHM = "MD5withRSA";

private static final String PUBLIC_KEY = "RSAPublicKey";

private static final String PRIVATE_KEY = "RSAPrivateKey";

/**

* 用私钥对信息生成数字签名

*

* @param data 加密数据

* @param privateKey 私钥

* @return

* @throws Exception

*/

public static String sign(String data, String privateKey) throws Exception {

return sign(data.getBytes(), privateKey);

}

/**

* 用私钥对信息生成数字签名

*

* @param data 加密数据

* @param privateKey 私钥

* @return

* @throws Exception

*/

public static String sign(byte[] data, String privateKey) throws Exception {

// 解http://密由base64编码的私钥

byte[] keyBytes = decryptBASE64(privateKey);

// 构造PKCS8EncodedKeySpec对象

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

// KEY_ALGORITHM 指定的加密算法

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

// 取私钥匙对象

PrivateKey priKey = keyFactory.generatePrivate(pkcs8KeySpec);

// 用私钥对信息生成数字签名

Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

signature.initSign(priKey);

signature.update(data);

return encryptBASE64(signature.sign());

}

/**

* 校验数字签名

*

* @param data 加密数据

* @param publicKey 公钥

* @param sign 数字签名

* @return 校验成功返回true 失败返回false

* @throws Exception

*/

public static boolean verify(String data, String publicKey, String sign) throws Exception {

return verify(data.getBytes(), publicKey, sign);

}

/**

* 校验数字签名

*

* @param data 加密数据

* @param publicKey 公钥

* @param sign 数字签名

* @return 校验成功返回true 失败返回false

* @throws Exception

*/

public static boolean verify(byte[] data, String publicKey, String sign) throws Exception {

// 解密由base64编码的公钥

byte[] keyBytes = decryptBASE64(publicKey);

// 构造X509EncodedKeySpec对象

X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);

// KEY_ALGORITHM 指定的加密算法

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

// 取公钥匙对象

PublicKey pubKey = keyFactory.generatePublic(keySpec);

Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

signature.initVerify(pubKey);

signature.update(data);

// 验证签名是否正常

return signature.verify(decryptBASE64(sign));

}

/**

* 解密

* 用私钥解密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static String decryptByPrivateKey(String data, String key) throws Exception {

return new String(decryptByPrivateKey(Base64Utils.decryptBASE64(data), key));

}

/**

* 解密

* 用私钥解密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] decryptByPrivateKey(byte[] data, String key) throws Exception {

// 对密钥解密

byte[] keyBytes = decryptBASE64(key);

// 取得私钥

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);

// 对数据解密

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

cipher.init(Cipher.DECRYPT_MODE, privateKey);

return cipher.doFinal(data);

}

/**

* 解密

* 用私钥解密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static String decryptByPublicKey(String data, String key) throws Exception {

return new String(decryptByPublicKey(Base64Utils.decryptBASE64(data), key));

}

/**

* 解密

* 用私钥解密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] decryptByPublicKey(byte[] data, String key) throws Exception {

// 对密钥解密

byte[] keyBytes = decryptBASE64(key);

// 取得公钥

X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key publicKey = keyFactory.generatePublic(x509KeySpecaqhtz);

// 对数据解密

Cipher cihttp://pher = Cipher.getInstance(keyFactory.getAlgorithm());

cipher.init(Cipher.DECRYPT_MODE, publicKey);

return cipher.doFinal(data);

}

/**

* 加密

* 用公钥加密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static String encryptByPublicKey(String data, String key) throws Exception {

return Base64Utils.encryptBASE64(encryptByPublicKey(data.getBytes(), key));

}

/**

* 加密

* 用公钥加密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] encryptByPublicKey(byte[] data, String key) throws Exception {

// 对公钥解密

byte[] keyBytes = decryptBASE64(key);

// 取得公钥

X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key publicKey = keyFactory.generatePublic(x509KeySpec);

// 对数据加密

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

cipher.init(Cipher.ENCRYPT_MODE, publicKey);

return cipher.doFinal(data);

}

/**

* 加密

* 用私钥加密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static String encryptByPrivateKey(String data, String key) throws Exception {

return Base64Utils.encryptBASE64(encryptByPrivateKey(data.getBytes(), key));

}

/**

* 加密

* 用私钥加密

*

* @param data

* @param key

* @return

* @throws Exception

*/

public static byte[] encryptByPrivateKey(byte[] data, String key) throws Exception {

// 对密钥解密

byte[] keyBytes = decryptBASE64(key);

// 取得私钥

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key privateKey = keyFactory.generatePrivate(pkcs8KeySpec);

// 对数据加密

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

cipher.init(Cipher.ENCRYPT_MODE, privateKey);

return cipher.doFinal(data);

}

/**

* 取得私钥

*

* @param keyMap

* @return

* @throws Exception

*/

public static String getPrivateKey(Map keyMap) throws Exception {

Key key = (Key) keyMap.get(PRIVATE_KEY);

return encryptBASE64(key.getEncoded());

}

/**

* 取得公钥

*

* @param keyMap

* @return

* @throws Exception

*/

public static String getPublicKey(Map keyMap) throws Exception {

Key key = (Key) keyMap.get(PUBLIC_KEY);

return encryptBASE64(key.getEncoded());

}

/**

* 初始化密钥

*

* @return

* @throws Exception

*/

public static Map initKey() throws Exception {

KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);

keyPairGen.initialize(1024);

KeyPair keyPair = keyPairGen.generateKeyPair();

// 公钥

RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();

// 私钥

RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

Map keyMap = new HashMap(2);

keyMap.put(PUBLIC_KEY, publicKey);

keyMap.put(PRIVATE_KEY, privateKey);

return keyMap;

}

public static void main(String[] args) {

try {

Map map = RSAUtils.initKey();

String publicKey = RSAUtils.getPublicKey(map);

String privateKey = RSAUtils.getPrivateKey(map);

System.out.println("公钥：" + publicKey);

System.out.println("私钥：" + privateKey);

String data = "Java是世界上最好的编程语言";

String encryptData = RSAUtils.encryptByPublicKey(data, publicKey);

System.out.println("加密后：" + encryptData);

String decryptData = RSAUtils.decryptByPrivateKey(encryptData, privateKey);

System.out.println("解密后：" + decryptData);

} catch (Exception e) {

e.printStackTrace();

}

}

}

4.最后展示测试结果：

补充知识：java使用RSA生成公钥和私钥，并进行加解密

废话不多说，上代码：

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