问题
I'm extending the following question/solution to be re-entrant for connecting/submitting subsequent emails to an SMTP email server (e.g., Comcast), with TLS encryption.
Unsupported or unrecognized ssl-message exception at startHandshake after issuing STARTTLS command in a java program
I've been successful in studying and prototyping user9191556's algorithm and adapting it for subsequent emails. After much trial-n-error, I was successful in applying his/her TLS encryption capability to my prior algorithm and my code works, consistently ... although, I don't think it's correct. (yes, I lack the fundamentals of email server connectivity protocol and could also use a reference) I'm not satisfied with a non-dependent sleep before handshaking (i.e., 100ms) Works for my environment, but doubt it's guaranteed for general. I tried looping on the TLS input stream (sslIn) to see when it's 'ready', but it always times out. Hence, the 100ms sleep.
Is there a more formal/correct method for managing the inputStreams - both Socket and SSLSocket verions?
Thanks Bob Buckley Castle Rock, CO ... yep, it's snowing.
//------------------------------------------------------------------------------
public class SSLComcastTLSPrototype
{
//----------------------------------------------------------------------------
public static void main(String[] args) throws InterruptedException
{
for (int i=0; i<5; ++i)
{
System.out.println("----------------------------------------------");
System.out.println("sendMessage #" + i);
System.out.flush();
sendMessage(i);
}
}
//----------------------------------------------------------------------------
public static void sendMessage(int msgNum)
{
Date dDate = new Date();
DateFormat dFormat = DateFormat.getDateInstance(DateFormat.FULL, Locale.US);
int SMTPPort = 587;
String SMTPServer = "smtp.comcast.net";
try (Socket smtpSocket = new Socket(SMTPServer, SMTPPort);
DataOutputStream os = new DataOutputStream(smtpSocket.getOutputStream());
BufferedReader is = new BufferedReader(new nputStreamReader(smtpSocket.getInputStream ())))
{
int i = 0;
while (! is.ready() && ++i < 10)
Thread.sleep(100);
if (! is.ready())
{
System.err.println("BufferedReader InputStream Timed Out - Email failed");
System.err.flush();
return;
}
new Thread(new ReadInput(is)).start();
os.writeBytes("EHLO WOPR\r\n");
os.writeBytes("STARTTLS\r\n");
SSLContext ctx = SSLContext.getInstance("TLSv1.2");
ctx.init(null, null, null);
SSLSocketFactory factory = ctx.getSocketFactory();
try (SSLSocket sslSocket = (SSLSocket) factory.createSocket(
smtpSocket,
smtpSocket.getInetAddress().getHostAddress(),
smtpSocket.getPort(),
true))
{
String[] suites = sslSocket.getSupportedCipherSuites();
sslSocket.setEnabledCipherSuites(suites);
try (DataOutputStream sslOut = new DataOutputStream(sslSocket.getOutputStream());
BufferedReader sslIn = new BufferedReader(new InputStreamReader(sslSocket.getInputStream())))
{
Thread.sleep(100);
sslSocket.startHandshake();
sslOut.writeBytes("EHLO WOPR\r\n");
sslOut.writeBytes("AUTH LOGIN\r\n");
sslOut.writeBytes("<encoded username>=\r\n"); // Username, BASE64 encoded
sslOut.writeBytes("<encoded password>\r\n"); // Password, BASE64 encoded
sslOut.writeBytes("MAIL From: Joe@Comcast.net\r\n");
sslOut.writeBytes("RCPT To: JoeCool@Comcast.net\r\n");
//sslOut.writeBytes("RCPT Cc: <Jim@AnyCompany.com>\r\n");
sslOut.writeBytes("DATA\r\n");
sslOut.writeBytes("X-Mailer: Via Java\r\n");
sslOut.writeBytes("DATE: " + dFormat.format(dDate) + "\r\n");
sslOut.writeBytes("From: Runway <Runway@Airfield.com>\r\n");
sslOut.writeBytes("To: Joe Pilot\r\n");
//sslOut.writeBytes("Cc: CCDUDE <CCPerson@TheirCompany.com>\r\n");
//sslOut.writeBytes("RCPT Bcc: BCCDude<BCC@InvisibleCompany.com>\r\n");
sslOut.writeBytes("Subject: Foo Foo\r\n");
sslOut.writeBytes("MIME-VERSION: 1.0\r\n");
sslOut.writeBytes("CONTENT-TYPE: TEXT/HTML; charset=\"ISO-8859-1\"\r\n");
sslOut.writeBytes("CONTENT-TRANSFER-ENCODING: 7bit\r\n");
sslOut.writeBytes("\r\n");
sslOut.writeBytes("<html>\r\n");
//sslOut.writeBytes("<head>\r\n");
sslOut.writeBytes("<title>G'day, mate!</title>\r\n");
//sslOut.writeBytes("</head>\r\n");
sslOut.writeBytes("Message #" + msgNum + "\r\n\r\n\r\n");
DateFormat df = DateFormat.getDateTimeInstance(DateFormat.FULL, DateFormat.SHORT);
sslOut.writeBytes("\r\n");
sslOut.writeBytes("This is the introduction of my email<br>\r\n");
sslOut.writeBytes("Heading of the Date<br>\r\n");
sslOut.writeBytes(df.format(new Date()) + "<br><br>\r\n");
sslOut.writeBytes("</html>\r\n");
sslOut.writeBytes("\r\n.\r\n");
sslOut.writeBytes("QUIT\r\n");
//System.out.println("EMail Message Submitted Successfully");
//System.out.flush();
String response;
while ((response = sslIn.readLine()) != null)
{
//System.out.println("response: " + response);
//System.out.flush();
if (response.contains("recipient invalid domain"))
{
System.err.println("***** Invalid Email Address *****");
System.err.flush();
}
}
}
}
}
catch (NoSuchAlgorithmException | KeyManagementException | IOException | InterruptedException ex)
{
Logger.getLogger(SSLComcastTLSPrototype.class.getName()).log(Level.SEVERE, null, ex);
}
}
//----------------------------------------------------------------------------
static class ReadInput implements Runnable
{
//--------------------------------------------------------------------------
private final BufferedReader br;
//--------------------------------------------------------------------------
public ReadInput(BufferedReader br)
{
this.br = br;
}
//--------------------------------------------------------------------------
@Override
public void run()
{
try
{
int input;
String allInput = "";
while ((input = br.read()) >= 0)
{
allInput += (char) input;
if (allInput.toLowerCase().endsWith("start tls\r\n"))
break;
}
}
catch (IOException e)
{
System.err.println("***** Exception: readInput *****");
System.err.flush();
e.printStackTrace();
}
}
}
}
来源：https://stackoverflow.com/questions/65362799/extending-ssl-tls-message-to-be-re-entrant-in-a-java-program