package com.nuvole.four.config;


import javax.crypto.Cipher;
import java.security.KeyFactory;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.util.Base64;

public class RsaDecryptor {
    /**
     * 读取私钥文件，生成RSA私钥
     *
     * @return RSA私钥
     * @throws NoSuchAlgorithmException
     * @throws InvalidKeySpecException
     */
    private static PrivateKey getRsaPrivateKey() throws NoSuchAlgorithmException, InvalidKeySpecException {
        String privateKeyContent = "-----BEGIN PRIVATE KEY-----\n" +
                "MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCDpJ23UWIqAMiv\n" +
                "JwdrzEOS5WbbUvFlFxiW0Q4MDzwT4zg63gq6bk1BIi3v/mVchoDEhrr4bgSDqVjN\n" +
                "wfI4gfVZQ0tVlrfMayGi5MvjCdjbPRmeGBkBqKmB3WMkzXxVR0dHz1KFgc3Tt8Av\n" +
                "tpwK8GDzTavBXF/NSm2k9PL0BKcJuWmQS5Id+MGHxQMjmKJOXERBqDsFF2ghMaRk\n" +
                "lj5hvHCRcJXLehTzbWERfOV2t+teSs6K8CmCxoJjLdhNna3CEXS1fhfQ7UKBNydD\n" +
                "EqTDgG5ws2KrazhiE6QUcHSPUuuTXMVQuMusG63cyKRJazf0qqAQM3WjMInI56ui\n" +
                "rn1yvdUbAgMBAAECggEANZJSFH3sAsfa41xwqq+veCIe33Y7gjYJ7aYZn1K70iQP\n" +
                "h/VATGoCylTMePP/781UraVehSbQc3wBBYq9tb09SRwXljcFiQy33YBacIRbWazd\n" +
                "tfZ8hq5KfOzJIfr1dAbTvSdjn60ZQ+VtMn2PtuvnqFudX8zlt7doM07zZ9ZU26Gg\n" +
                "9W67OlGpxDxfWryUWI//tkCrguORceurhydByhYdRqJlDwc3xAgctyGXBfY9Plp0\n" +
                "m3VWaWvgDBJ54d0MpVleQVOufWRH85Jyj+7ZIxmn53oh3iPx6samq26FPiwbl4se\n" +
                "q82waM4wOeunJDHSLNjuJJSWwR3MovHrzwnc4XmaoQKBgQDBQRDIODW6MYPXklin\n" +
                "+sotoDe1raZRZCenAhpNO5pMcpS955SKkhi/NU/8mSEGpxw+fZPL0/gtnn2aHoXU\n" +
                "/z5pjhSBbYPJXrt3PeuOqKfNEdBXQx56JNyZw7UF3po/SkO2hJAwlQy2WYanhx4b\n" +
                "+5sYLVtHKWAmIRDmb+EtQ225EwKBgQCuYoufmFk62FYPpLeHtLAhSGqmDvrKPavj\n" +
                "cNsJsJZeltjQI9Juap+Xez5qlovS87vnyTqjEysUcAqMgcSthjK/VgFxNiL8Y93J\n" +
                "ORGTI6tkI306DhKmj8Jc02sB1VF4DV4IYGsQ3NOPP+AWrV3YlTj4Cw5wusX8jq9K\n" +
                "9Ubfiia82QKBgBGi+4IaRyT38d1RmM+zvpHNZmgpMd2Js2i1c2sK/njtmA+Au/it\n" +
                "fp6soeEepHnz9ErrsPpQHP0k0renA3W92ZdOhSaOtRFCmP834nCBidbYQlhEYtqo\n" +
                "1I0f5Dxl5VPTVjyo+nPEloVpxDUzypapLq1VLlhfOUwhhmZRXY6A8dmLAoGBAKtP\n" +
                "yBZq1g3HBRStHldEnFq2B39G6/zOBRSUg7nLLo2R50DiUBGE0W9A9ZpEduwv4QLd\n" +
                "XqthY0ranqJVwV8unJ/238fWBRypBvJtC+Tef7sKWjU0KgJS6//A+jh81WH4z82u\n" +
                "2r9gEL2DZKMigTUJs0OJqQ/5jBKGIZKjzpI/57pRAoGAGoaweJrzbYuFp7JSJw/W\n" +
                "nKsnDUAI14AN5DI4UlVt78ZESj/D7ArKtDLMkIDrLRk/NofDRQy9YdEwmw7Jjxa9\n" +
                "j8NF0ll01dV3Sr7SXqmkVtqfAvt58tdXwxXdsUvLV7+otZfAzinY7959MUoPc8gb\n" +
                "4kmHYWNzm1vJyr/QIapo94g=\n" +
                "-----END PRIVATE KEY-----\n";

        privateKeyContent = privateKeyContent.replaceAll("\\n", "").replace("-----BEGIN PRIVATE KEY-----", "").replace("-----END PRIVATE KEY-----", "");
        KeyFactory kf = KeyFactory.getInstance("RSA");
        PKCS8EncodedKeySpec keySpecPKCS8 = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(privateKeyContent));
        return kf.generatePrivate(keySpecPKCS8);
    }

    public static String doDecrypt(String encrypted) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, getRsaPrivateKey());
        return new String(cipher.doFinal(Base64.getDecoder().decode(encrypted.getBytes())));
    }

}