java 获取ssl证书颁发机构的密钥标识符

你可以使用Java的KeyStore类来获取证书颁发机构的密钥标识符。以下是一些示例代码：

import java.io.FileInputStream;
import java.security.KeyStore;
import java.security.cert.X509Certificate;

public class SSLCertificateInfo {
    public static void main(String[] args) throws Exception {
        String keystorePath = "path/to/keystore";
        String keystorePassword = "keystore_password";
        String alias = "certificate_alias";

        KeyStore keystore = KeyStore.getInstance("JKS");
        keystore.load(new FileInputStream(keystorePath), keystorePassword.toCharArray());

        X509Certificate cert = (X509Certificate) keystore.getCertificate(alias);
        String issuerDN = cert.getIssuerX500Principal().getName();
        String keyId = cert.getExtensionValue("2.5.29.14"); // OID for SubjectKeyIdentifier extension
        if (keyId != null) {
            // The key identifier is a byte array, so you may want to convert it to a hex string for readability
            keyId = javax.xml.bind.DatatypeConverter.printHexBinary(keyId);
        }

        System.out.println("Issuer DN: " + issuerDN);
        System.out.println("Key ID: " + keyId);
    }
}

在上面的代码中，你需要将 `keystorePath` 替换为你的keystore文件的路径，将 `keystorePassword` 替换为你的keystore密码，将 `alias` 替换为你要查询的证书别名。这个程序会输出证书颁发机构的DN和密钥标识符。