Java加密算法RSA代码实例

Java加密算法RSA代码实例

这篇文章主要介绍了java加密算法RSA代码实例,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

代码如下

import javax.crypto.BadPaddingException;

import javax.crypto.Cipher;

import javax.crypto.IllegalBlockSizeException;

import javax.crypto.NoSuchPaddingException;

import java.security.*;

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 java.util.HashMap;

import java.util.Map;

public class RSADecrypt {

public static Map createKeyPair() throws NoSuchAlgorithmException {

//创建秘钥对生成器

KeyPairGenerator generator = KeyPairGenerator.getInstance("rsa");

//初始化密钥对生成器

generator.initialize(1024);

//生成密钥对

KeyPair keyPair = generator.generateKeyPair();

//获取公钥私钥

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

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

String publicKeyStr = new String(publicKey.getEncoded());

String privateKeyStr = new String(privateKey.getEncoded());

//公钥私钥存放map

Map keyMap = new HashMap<>();

keyMap.put("publicKey", publicKeyStr);

keyMap.put("privateKey", privateKeyStr);

return keyMap;

}

/**

* 获取公钥

* @param publicKey

* @return

*/

public static RSAPublicKey getPublicKey(String publicKey) throws NoSuchAlgorithmException, InvalidKeySpecException {

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

//X509编码

X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(publicKey.getBytes());

RSAPublicKey rsaPublicKey = (RSAPublicKey) keyFactory.generatePublic(x509EncodedKeySpec);

return rsaPublicKey;

}

/**

* 获取私钥

* @param privateKey

* @return

*/

public static RSAPrivateKey getPrivateKey(String privateKey) throws NoSuchAlgorithmException, InvalidKeySpecException {

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

//PKCS#8编码

PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(privateKey.getBytes());

RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyFactory.generatePrivate(pkcs8EncodedKeySpec);

return rsaPrivateKey;

}

/**

* 公钥加密

* @param src

* @param publicKey

* @return

*/

public static byte[] publicEncrypt(String src, RSAPublicKey publicKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {

Cipher cipher = Cipher.getInstance("rsa");

cipher.init(Cipher.ENCRYPT_MODE,publicKey);

byte[] encryptedData = cipher.doFinal(src.getBytes());

return encryptedData;

}

/**

* 私钥解密

* @param data

* @param privateKey

* @return

* @throws NoSuchPaddingException

* @throws NoSuchAlgorithmException

* @throws InvalidKeyException

* @throws BadPaddingException

* @throws IllegalBlockSizeException

*/

public static String privateDecrypt(byte[] data, RSAPrivateKey privateKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {

Cipher cipher = Cipher.getInstance("rsa");

cipher.init(Cipher.DECRYPT_MODE,privateKey);

byte[] result = cipher.doFinal(data);

return new String(result);

}

public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, IllegalBlockSizeException, InvalidKeyException, BadPaddingException, NoSuchPaddingException {

Map keyPair = createKeyPair();

RSAPublicKey publicKey = getPublicKey(keyPair.get("publicKey"));http://

RSAPrivateKey privateKey = getPrivateKey(keyPair.get("privateKey"));

String str = "hello world";

/**

* 公钥加密，私钥解密

*/

byte[] encryptedData = publicEncrypt(str,publicKey);

String result = privateDecrypt(encryptedData, privateKey);

/**

* 私钥加密，公钥解密

*/

byte[] encrypted = privateEncrypt(str, privateKey);

String source = publicDecrypt(encrypted, publicKey);

}

/**

* 私钥加密

* @param src

* @param privateKey

* @return

* @throws NoSuchPaddingException

* @throws NoSuchAlgorithmException

* @throws InvalidKeyException

* @throws BadPaddingException

* @throws IllegalBlockSizeException

*/

public static byte[] privateEncrypt(String src, RSAPrivateKey privateKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {

Cipher cipher = Cipher.getInstance("rsa");

cipher.init(Cipher.DECRYPT_MODE,privateKey);

byte[] result = cipher.doFinal(src.getBytes());

return result;

}

/**

* 公钥解密

* @param data

* @param publicKey

* @return

* @throws NoSuchPaddingException

* @throws NoSuchAlgorithmException

* @throws InvalidKeyException

* @throws BadPaddingException

* @throws IllegalBlockSizeException

*/

public static String publicDecrypt(byte[] data, RSAPublicKey publicKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {

Cipher cipher = Cipher.getInstance("rsa");

cipher.init(Cipher.DECRYPT_MODE,publicKey);

byte[] result = cipher.doFinal(data);

return new String(result);

}

}

上面例子使用密钥长度1024，如果想使用2048密钥，只需要在初始化密钥对生成器做一些变动，其他部分可以复用。

generator.initialize(2048);

这个例子只是基本常用的RSA加解密，也可加入base64，签名。

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