SHA256withRSA证书签名，私钥签名/公钥验签（证书文件加载公私钥）

╰+攻爆jí腚メ 2021-06-11 15:14 1468阅读 0赞

[https://www.cnblogs.com/jinzhiming/p/10576385.html][https_www.cnblogs.com_jinzhiming_p_10576385.html]

证书签名

![复制代码][copycode.gif]

package test;
    
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.io.InputStream;
    import java.security.KeyStore;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.Signature;
    import java.security.cert.CertificateException;
    import java.security.cert.CertificateFactory;
    import java.security.cert.X509Certificate;
    import java.util.Base64;
    import java.util.Enumeration;
    
    /**
     * 私钥签名，公钥验签
     * @author jinzhm
     *
     */
    public class SignUtil {
        private static String CHARSET_ENCODING = "UTF-8";
        private static String ALGORITHM = "SHA256withRSA";
        
        /**
         * 签名
         * @param srcData
         * @param privateKeyPath
         * @param privateKeyPwd
         * @return
         */
        public static String sign(String srcData, String privateKeyPath, String privateKeyPwd){
            if(srcData==null || privateKeyPath==null || privateKeyPwd==null){
                return "";
            }
            try {
                // 获取证书的私钥
                PrivateKey key = readPrivate(privateKeyPath, privateKeyPwd);
                // 进行签名服务
                Signature signature = Signature.getInstance(ALGORITHM);
                signature.initSign(key);
                signature.update(srcData.getBytes(CHARSET_ENCODING));
                byte[] signedData = signature.sign();
                return Base64.getEncoder().encodeToString(signedData);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return "";
        }
        
        /**
         * 验签
         * @param srcData
         * @param signedData
         * @param publicKeyPath
         * @return
         */
        public static boolean verify(String srcData, String signedData, String publicKeyPath){
            if(srcData==null || signedData==null || publicKeyPath==null){
                return false;
            }
            try {
                PublicKey publicKey = readPublic(publicKeyPath);
                Signature sign = Signature.getInstance(ALGORITHM);
                sign.initVerify(publicKey);
                sign.update(srcData.getBytes(CHARSET_ENCODING));
                return sign.verify(Base64.getDecoder().decode(signedData));
            } catch (Exception e) {
                e.printStackTrace();
            }
            return false;
        }
        
    
        /**
         * 读取公钥
         * @param publicKeyPath
         * @return
         */
        private static PublicKey readPublic(String publicKeyPath){
            if(publicKeyPath==null){
                return null;
            }
            PublicKey pk = null;
            FileInputStream bais = null;
            try {
                CertificateFactory certificatefactory = CertificateFactory.getInstance("X.509");
                bais = new FileInputStream(publicKeyPath);
                X509Certificate cert = (X509Certificate)certificatefactory.generateCertificate(bais);
                pk = cert.getPublicKey();
            } catch (CertificateException e) {
                e.printStackTrace();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } finally{
                if(bais != null){
                    try {
                        bais.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
            return pk;
        }
        
        /**
         * 读取私钥
         * @param path
         * @return
         */
        private static PrivateKey readPrivate(String privateKeyPath, String privateKeyPwd){
            if(privateKeyPath==null || privateKeyPwd==null){
                return null;
            }
            InputStream stream = null;
            try {
                // 获取JKS 服务器私有证书的私钥，取得标准的JKS的 KeyStore实例
                KeyStore store = KeyStore.getInstance("JKS");
                stream = new FileInputStream(new File(privateKeyPath));
                // jks文件密码，根据实际情况修改
                store.load(stream, privateKeyPwd.toCharArray());
                // 获取jks证书别名
                Enumeration en = store.aliases();
                String pName = null;
                while (en.hasMoreElements()) {
                    String n = (String) en.nextElement();
                    if (store.isKeyEntry(n)) {
                        pName = n;
                    }
                }
                // 获取证书的私钥
                PrivateKey key = (PrivateKey) store.getKey(pName,
                        privateKeyPwd.toCharArray());
                return key;
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if(stream != null){
                    try {
                        stream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
            return null;
        }
    }

![复制代码][copycode.gif]

[https_www.cnblogs.com_jinzhiming_p_10576385.html]: https://www.cnblogs.com/jinzhiming/p/10576385.html
[copycode.gif]: /images/20210527/9987ea4f1406479bbebc942b38e7e543.png