如何使用 javax.mail 遵守 RHEL8 加密策略？

如何解决如何使用 javax.mail 遵守 RHEL8 加密策略？

我正在尝试使用 javax.mail 制作一个发送邮件的应用程序。

我一直在想如何解决错误 No appropriate protocol (protocol is disabled or cipher suites are inappropriate)

我将在不控制操作系统的系统上使用它，因此我需要遵守默认的 rhel8 策略。

这适用于 Windows 10 机器。
只有在我使用以下命令时，它才能在我的 rhel8 测试系统中工作：update-crypto-policies --set LEGACY

我需要在代码中解决这个问题，而不是在操作系统中。

我在rhel8上遇到的错误：

DEBUG SMTP: Found extension "CHUNKING",arg ""
DEBUG SMTP: Found extension "SMTPUTF8",arg ""
STARTTLS
220 2.0.0 SMTP server ready
EHLO localhost.localdomain
javax.mail.MessagingException: Can't send command to SMTP host;
  nested exception is:
    javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
    at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:1420)
    at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:1408)
    at com.sun.mail.smtp.SMTPTransport.ehlo(SMTPTransport.java:847)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:384)
    at javax.mail.Service.connect(Service.java:297)
    at javax.mail.Service.connect(Service.java:156)
    at javax.mail.Service.connect(Service.java:105)
    at javax.mail.Transport.send0(Transport.java:168)
    at javax.mail.Transport.send(Transport.java:98)
    at MailTest.sendMail(MailTest.java:59)
    at MailTest.main(MailTest.java:103)
Caused by: javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
    at sun.security.ssl.HandshakeContext.<init>(HandshakeContext.java:171)
    at sun.security.ssl.ClientHandshakeContext.<init>(ClientHandshakeContext.java:98)
    at sun.security.ssl.TransportContext.kickstart(TransportContext.java:220)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:428)
    at sun.security.ssl.SSLSocketImpl.ensureNegotiated(SSLSocketImpl.java:804)
    at sun.security.ssl.SSLSocketImpl.access$200(SSLSocketImpl.java:73)
    at sun.security.ssl.SSLSocketImpl$AppOutputStream.write(SSLSocketImpl.java:1166)
    at com.sun.mail.util.TraceOutputStream.write(TraceOutputStream.java:101)
    at java.io.bufferedoutputstream.flushBuffer(bufferedoutputstream.java:82)
    at java.io.bufferedoutputstream.flush(bufferedoutputstream.java:140)
    at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:1418)
    ... 10 more

我尝试过：

props.put("mail.smtp.ssl.protocols","TLSv1.2");
props.put("mail.smtp.ssl.protocols","TLSv1.3");
没有 mail.smtp.ssl.protocols 条目

我的代码：

import com.sun.mail.smtp.SMTPSendFailedException;
import java.io.IOException;
import java.util.Date;
import java.util.Properties;
import javax.mail.AuthenticationFailedException;
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

/**
 * Standalone mail client.
 */
public class MailTest {
    
    private final Properties props;
    
    public MailTest(Properties props) {
        this.props = props;
    }
    
    public void sendMail() {
        try {
            Authenticator auth = null;
            final String username = props.getProperty("mail.username");
            final String password = props.getProperty("mail.password");
            if (username != null && username.length() > 0) {
                auth = new Authenticator() {
                    @Override
                    protected PasswordAuthentication getpasswordAuthentication() {
                        System.out.println("Providing authentication for: " + username);
                        return new PasswordAuthentication(username,password);
                    }
                };
            }
            
            Session session = Session.getInstance(props,auth);
            session.setDebug(true);
            
            MimeMessage msg = new MimeMessage(session);
            msg.addHeader("Content-type","text/HTML; charset=UTF-8");
            msg.addHeader("format","flowed");
            msg.addHeader("Content-transfer-encoding","8bit");

            msg.setFrom(new InternetAddress(props.getProperty("test.from"),"test"));
            msg.setReplyTo(InternetAddress.parse(props.getProperty("test.from"),false));
            msg.setSubject("Test","UTF-8");
            msg.setText("This is a test.","UTF-8");
            msg.setSentDate(new Date());

            msg.setRecipients(Message.RecipientType.TO,InternetAddress.parse(props.getProperty("test.to"),false));
            
            System.out.println("Sending message...");
            Transport.send(msg); 
            System.out.println("Message was sent.");
            
        } catch (AuthenticationFailedException ex) {
            System.err.println("Authentication Failed - please check the username and password.");
            ex.printstacktrace();
        } catch (SMTPSendFailedException ex) {
            System.err.println("SMTP error - please check your SMTP settings.");
            ex.printstacktrace();            
        } catch (MessagingException ex) {
            ex.printstacktrace();
        } catch (IOException ex) {
            ex.printstacktrace();
        }        
    }
    
    public static void main(String[] args) {
        System.out.println("Performing mail test.");

        Properties props = new Properties();

        // SMTP server and port
        props.put("mail.smtp.host","smtp.office365.com");
        props.put("mail.smtp.port","587");        

        // If set to false,username + password will not be used
        props.put("mail.smtp.auth","true");
        props.put("mail.username","test@example.com");
        props.put("mail.password","yourpassword");

        // If true,enables the use of the STARTTLS command (if supported by the server) 
        // to switch the connection to a TLS-protected connection before issuing any login commands. 
        // Defaults to false.
        props.put("mail.smtp.starttls.enable","true");
        props.put("mail.smtp.ssl.protocols","TLSv1.3");
        // If true,requires the use of the STARTTLS command. If the server doesn't support the STARTTLS command,// or the command fails,the connect method will fail. Defaults to false.
        props.put("mail.smtp.starttls.required","true");

        // FROM / TO address
        props.put("test.from","test@example.com");
        props.put("test.to","test@example.com");
        
        MailTest test = new MailTest(props);
        test.sendMail();
    }    
}