SHA256WithRSA——生成公钥私钥证书Java调用方法

 生成命令备份：

生成私钥
openssl genrsa -out me_private.pem 1024

生成公钥
openssl rsa -in me_private.pem -pubout -out me_public.pem

生成证书请求文件
openssl req -new -key me_private.pem -out me_rsa_cerreq.csr

生成证书
openssl x509 -req -days 3650 -in me_rsa_cerreq.csr -signkey me_private.pem -out me_rsacert.crt

生成pkcs8格式私钥
openssl pkcs8 -topk8 -in me_private.pem -out me_private_pkcs8.pem -nocrypt

 

 

 

生成私钥
openssl genrsa -out blaze_private.pem 2048

生成公钥
openssl rsa -in blaze_private.pem -pubout -out blaze_public.pem

生成证书请求文件
openssl req -new -key blaze_private.pem -out blaze_rsa_cerreq.csr

生成证书
openssl x509 -req -days 3650 -in blaze_rsa_cerreq.csr -signkey blaze_private.pem -out blaze_cert.pem

生成pkcs8格式私钥
openssl pkcs8 -topk8 -in blaze_private.pem -out blaze_private_pkcs8.pem -nocrypt

package com.blaze.chain.util;

import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.spec.PKCS8EncodedKeySpec;

import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.util.io.pem.PemReader;
import org.slf4j.Logger;

import com.blaze.chain.common.loggers.ChainLogger;
import com.blaze.core.utils.LogUtils;

/**
 * SHA256WithRSA签名、验签工具
 * 
 * @FileName: RSASignUtils.java
 */
public class RSASignUtils {

    /** 日志 */
    private static Logger LOGGER = LogUtils.getLogger(RSASignUtils.class);

    private static final String SIGN_SHA256RSA_ALGORITHMS = "SHA256WithRSA";

    /**
     * 签名
     * 
     * @param content
     * @param privateKey
     * @return
     * @throws Exception
     */
    public static String sign(String content, PrivateKey privateKey) throws Exception {
        Signature signature = Signature.getInstance(SIGN_SHA256RSA_ALGORITHMS);
        signature.initSign(privateKey);
        signature.update(content.getBytes(StandardCharsets.UTF_8));
        // 签名使用Base64编码后得到的值即为请求数据中signature字段的值
        return Base64.encodeBase64String(signature.sign());
    }

    /**
     * 验签
     * 
     * @param content
     * @param signature
     * @param publicKey
     * @return
     */
    public static Boolean checkSign(String content, String signature, PublicKey publicKey) {
        try {
            LOGGER.info("content = " + content);
            LOGGER.info("signature = " + signature);
            Signature signatureTool = Signature.getInstance(SIGN_SHA256RSA_ALGORITHMS);
            signatureTool.initVerify(publicKey);
            signatureTool.update(content.getBytes(StandardCharsets.UTF_8));
            byte[] signbyte = Base64.decodeBase64(signature.getBytes());
            return signatureTool.verify(signbyte);
        } catch (Exception e) {
            LOGGER.error("signature error", e);
        }
        return false;
    }

    /**
     * 加载 pkcs8 格式私钥
     * 
     * @param path
     * @return
     * @throws Exception
     */
    public static PrivateKey loadPrivateKey(String path) throws Exception {
        PemReader pemReader = new PemReader(new InputStreamReader(new FileInputStream(path)));
        PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(pemReader.readPemObject().getContent());
        pemReader.close();
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        return keyFactory.generatePrivate(pkcs8EncodedKeySpec);
    }

    /**
     * 从证书加载公钥
     * 
     * @param path
     * @return
     * @throws Exception
     */
    public static PublicKey loadPublicKey(String path) throws Exception {
        CertificateFactory fact = CertificateFactory.getInstance("X.509");
        FileInputStream is = new FileInputStream(path);
        X509Certificate cer = (X509Certificate) fact.generateCertificate(is);
        return cer.getPublicKey();
    }


}

测试代码

        String configPath = System.getProperty("user.dir") + "/config/";
        PublicKey publicKey = RSASignUtils.loadPublicKey(configPath + "blaze_cert.pem");
        PrivateKey privateKey = RSASignUtils.loadPrivateKey(configPath + "blaze_private_pkcs8.pem");

        String content = "hi,man...";
        String signature = RSASignUtils.sign(content, privateKey);
        boolean rs = RSASignUtils.checkSign(content, signature, publicKey);
        LOGGER.info("content = " + content);
        LOGGER.info("signature = " + signature);
        LOGGER.info("rs = " + rs);

    

本文参考：

https://blog.csdn.net/qq_15259303/article/details/81133735