rsa加密

pom:

commons-codec
commons-codec
1.10

import org.apache.commons.codec.binary.Base64;
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;

public class RSAUtil {

public static void main(String[] args) {
    Map<String, String> keyPair = RSAUtil.generateKeyPair();
    String publicKey = keyPair.get("publicKey");
    String privateKey = keyPair.get("privateKey");
    String string = "啦啦啦11";
    String encrypt = RSAUtil.encrypt(string, publicKey);
    String decryptedString = RSAUtil.decrypt(encrypt, privateKey);
    System.out.println("publicKey:"+publicKey);
    System.out.println("privateKey:"+privateKey);
    System.out.println("string:"+string);
    System.out.println("decryptedString:"+decryptedString);
}

/**
 * 生成秘钥对
 * @return
 * @throws NoSuchAlgorithmException
 */
public static Map<String, String> generateKeyPair(){
    KeyPairGenerator keyPairGen = null;
    try {
        keyPairGen = KeyPairGenerator.getInstance("RSA");
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    }
    keyPairGen.initialize(1024,new SecureRandom());
    KeyPair keyPair = keyPairGen.generateKeyPair();
    RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();
    RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();
    String publicKey = new String(Base64.encodeBase64(rsaPublicKey.getEncoded()));
    String privateKey = new String(Base64.encodeBase64((rsaPrivateKey.getEncoded())));
    Map<String, String> keyMap = new HashMap<>();
    keyMap.put("publicKey", publicKey);
    keyMap.put("privateKey", privateKey);
    return keyMap;
}

/**
 * 加密
 * @param string
 * @param publicKey
 * @return
 * @throws Exception
 */
public static String encrypt(String string, String publicKey){
    byte[] decoded = Base64.decodeBase64(publicKey);
    RSAPublicKey pubKey = null;
    try {
        pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
        Cipher cipher = null;
        cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, pubKey);
        return Base64.encodeBase64String(cipher.doFinal(string.getBytes("UTF-8")));
    } catch (Exception e) {
        e.printStackTrace();
    }
    return "";
}

/**
 *
 * @param string
 * @param privateKey
 * @return
 * @throws Exception
 */
public static String decrypt(String string, String privateKey){
    try {
        RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(Base64.decodeBase64(privateKey)));
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, rsaPrivateKey);
        return new String(cipher.doFinal(Base64.decodeBase64(string)));
    } catch (Exception e) {
        e.printStackTrace();
    }
    return "";
}

}