2 rsa加密

import com.alibaba.fastjson.JSON;
import org.apache.logging.log4j.util.Base64Util;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.yaml.snakeyaml.external.biz.base64Coder.Base64Coder;

import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.ArrayList;
import java.util.Base64;
import java.util.List;


@Component
public class RSAUtils {

    //定义加密方式
    public static final String KEY_RSA = "RSA";


    /**
     * **
     * RSA最大加密大小
     */
    private final static int MAX_ENCRYPT_BLOCK = 117;

    /**
     * **
     * RSA最大解密大小
     */
    private final static int MAX_DECRYPT_BLOCK = 128;

    @Value("${rsa.public_key}")
    private String PUBLIC_KEY;

    @Value("${rsa.private_key}")
    private String PRIVATE_KEY;

    /**
     * BASE64 解码
     *
     * @param key 需要Base64解码的字符串
     * @return 字节数组
     */
    public static byte[] decryptBase64(String key) {
        return Base64.getDecoder().decode(key);
    }

    /**
     * BASE64 编码
     *
     * @param key 需要Base64编码的字节数组
     * @return 字符串
     */
    public static String encryptBase64(byte[] key) {
        return new String(Base64.getEncoder().encode(key));
    }

    /**
     * 公钥加密（分段）
     *
     * @return
     */
    public String publicEncrypt(Object obj) {
        try {

            String encryptingStr = JSON.toJSONString(obj);
            encryptingStr=java.net.URLEncoder.encode(encryptingStr);
            // 将公钥由字符串转为UTF-8格式的字节数组
            byte[] publicKeyBytes = decryptBase64(PUBLIC_KEY);
            // 获得公钥
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
            // 取得待加密数据
            byte[] data = encryptingStr.getBytes("UTF-8");
            KeyFactory factory;
            factory = KeyFactory.getInstance(KEY_RSA);
            PublicKey publicKey = factory.generatePublic(keySpec);
            // 对数据加密
            Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            // 返回加密后由Base64编码的加密信息
            int inputLen = data.length;
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int offSet = 0;
            byte[] cache;
            int i = 0;
            // 对数据分段解密
            while (inputLen - offSet > 0) {
                if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                    cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
                } else {
                    cache = cipher.doFinal(data, offSet, inputLen - offSet);
                }
                out.write(cache, 0, cache.length);
                i++;
                offSet = i * MAX_ENCRYPT_BLOCK;
            }
            byte[] decryptedData = out.toByteArray();
            out.close();
            return encryptBase64(decryptedData);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * 私钥解密（分段）
     *
     * @param encryptedStr
     * @return
     */
    public String decryptByPrivateKey(String encryptedStr) {
        try {
            // 对私钥解密
            byte[] privateKeyBytes = decryptBase64(PRIVATE_KEY);
            // 获得私钥
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
            // 获得待解密数据
            byte[] data = decryptBase64(encryptedStr);
            KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
            PrivateKey privateKey = factory.generatePrivate(keySpec);
            // 对数据解密
            Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            // 返回UTF-8编码的解密信息
            int inputLen = data.length;
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int offSet = 0;
            byte[] cache;
            int i = 0;
            // 对数据分段解密
            while (inputLen - offSet > 0) {
                if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                    cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
                } else {
                    cache = cipher.doFinal(data, offSet, inputLen - offSet);
                }
                out.write(cache, 0, cache.length);
                i++;
                offSet = i * MAX_DECRYPT_BLOCK;
            }
            byte[] decryptedData = out.toByteArray();
            out.close();
            return new String(decryptedData, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * 公钥加密（分段）
     *
     * @param encryptingStr
     * @param publicKeyStr
     * @return
     */
    public static String encryptByPublicKey(String encryptingStr, String publicKeyStr) {
        try {
            // 将公钥由字符串转为UTF-8格式的字节数组
            byte[] publicKeyBytes = decryptBase64(publicKeyStr);
            // 获得公钥
            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
            // 取得待加密数据
            byte[] data = encryptingStr.getBytes("UTF-8");
            KeyFactory factory;
            factory = KeyFactory.getInstance(KEY_RSA);
            PublicKey publicKey = factory.generatePublic(keySpec);
            // 对数据加密
            Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
            cipher.init(Cipher.ENCRYPT_MODE, publicKey);
            // 返回加密后由Base64编码的加密信息
            int inputLen = data.length;
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int offSet = 0;
            byte[] cache;
            int i = 0;
            // 对数据分段解密
            while (inputLen - offSet > 0) {
                if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                    cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
                } else {
                    cache = cipher.doFinal(data, offSet, inputLen - offSet);
                }
                out.write(cache, 0, cache.length);
                i++;
                offSet = i * MAX_ENCRYPT_BLOCK;
            }
            byte[] decryptedData = out.toByteArray();
            out.close();
            return encryptBase64(decryptedData);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * 私钥解密（分段）
     *
     * @param encryptedStr
     * @param privateKeyStr
     * @return
     */
    public static String decryptByPrivateKey(String encryptedStr, String privateKeyStr) {
        try {
            // 对私钥解密
            byte[] privateKeyBytes = decryptBase64(privateKeyStr);
            // 获得私钥
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
            // 获得待解密数据
            byte[] data = decryptBase64(encryptedStr);
            KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
            PrivateKey privateKey = factory.generatePrivate(keySpec);
            // 对数据解密
            Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
            cipher.init(Cipher.DECRYPT_MODE, privateKey);
            // 返回UTF-8编码的解密信息
            int inputLen = data.length;
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int offSet = 0;
            byte[] cache;
            int i = 0;
            // 对数据分段解密
            while (inputLen - offSet > 0) {
                if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                    cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
                } else {
                    cache = cipher.doFinal(data, offSet, inputLen - offSet);
                }
                out.write(cache, 0, cache.length);
                i++;
                offSet = i * MAX_DECRYPT_BLOCK;
            }
            byte[] decryptedData = out.toByteArray();
            out.close();
            return new String(decryptedData, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }


}