[
https://issues.apache.org/jira/browse/SSHD-1050?focusedWorklogId=466433&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-466433
]
ASF GitHub Bot logged work on SSHD-1050:
----------------------------------------
Author: ASF GitHub Bot
Created on: 04/Aug/20 20:16
Start Date: 04/Aug/20 20:16
Worklog Time Spent: 10m
Work Description: tomaswolf commented on pull request #156:
URL: https://github.com/apache/mina-sshd/pull/156#issuecomment-668803523
I've pushed
https://github.com/tomaswolf/mina-sshd/commit/3f15c6dbcce1dae0c88cae5b2ad0c2f07ebbc43e
in https://github.com/tomaswolf/mina-sshd/tree/SSHD-1050 . It's a follow-up
commit on this one; IMO solves the problem and I don't see any race conditions
anymore. Feel free to fetch and squash into your change here.
Ran a full build of sshd, no tests failed. JGit tests also work with this.
BTW, I like your test for this; it reproduces consistently; much better than
my original attempt.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
Issue Time Tracking
-------------------
Worklog Id: (was: 466433)
Time Spent: 40m (was: 0.5h)
> Race condition between early exceptions and AuthFuture
> ------------------------------------------------------
>
> Key: SSHD-1050
> URL: https://issues.apache.org/jira/browse/SSHD-1050
> Project: MINA SSHD
> Issue Type: Bug
> Affects Versions: 2.4.0, 2.6.0
> Reporter: Thomas Wolf
> Assignee: Lyor Goldstein
> Priority: Major
> Time Spent: 40m
> Remaining Estimate: 0h
>
> It appears that sometimes exceptions that occur early in connection setup are
> not reported on the AuthFuture. When that happens, AuthFuture.verify(timeout)
> will spend the whole timeout waiting and then report a timeout. The earlier
> exception is lost and nowhere to be seen.
> I stumbled over this when analyzing [Eclipse bug
> 565394|https://bugs.eclipse.org/bugs/show_bug.cgi?id=565394].
> It's not easy to reproduce, but with the below client test I can manage to
> make the test fail from time to time if run repeatedly. (That test uses a
> large preamble before the server identification to provoke an early
> exception. Using publickey auth instead of password auth increases the
> chances to get a failure. Running in a debugger increases the chances even
> more. It's clearly timing-related.)
> {code:java}
> private String longPreamble() {
> StringBuilder b = new StringBuilder();
> for (int i = 0; i < 250; i++) {
> b.append('a');
> }
> String line = b.toString();
> b = new StringBuilder(line);
> int limit = CoreModuleProperties.MAX_IDENTIFICATION_SIZE.get(sshd)
> .orElse(Integer.valueOf(16 * 1024)).intValue();
> limit = limit / 250 + 1;
> for (int i = 0; i < limit; i++) {
> b.append(CoreModuleProperties.SERVER_EXTRA_IDENT_LINES_SEPARATOR)
> .append(line);
> }
> return b.toString();
> }
> @Test
> public void testAuthGetsNotifiedOnLongPreamble() throws Exception {
> CoreModuleProperties.SERVER_EXTRA_IDENTIFICATION_LINES.set(sshd,
> longPreamble());
> sshd.setPasswordAuthenticator(RejectAllPasswordAuthenticator.INSTANCE);
>
> sshd.setKeyboardInteractiveAuthenticator(KeyboardInteractiveAuthenticator.NONE);
> client.setUserAuthFactories(
> Collections.singletonList(UserAuthPublicKeyFactory.INSTANCE));
> client.start();
> try (ClientSession session =
> client.connect(getCurrentTestName(), TEST_LOCALHOST, port)
> .verify(CONNECT_TIMEOUT).getSession()) {
> KeyPairProvider keys = createTestHostKeyProvider();
> session.addPublicKeyIdentity(
> keys.loadKey(session,
> CommonTestSupportUtils.DEFAULT_TEST_HOST_KEY_TYPE));
> // This auth should fail because the server sends too many lines before
> // the server identification. However, the auth must not time out!
> There's
> // an exception raised early on when the identification is read, but
> // frequently this exception gets not reported on the auth future that
> // we are waiting on here, and then we wait for the whole timeout.
> //
> // There's a race condition somewhere. The test succeeds frequently, and
> is
> // hard to make fail, but if run enough times it will usually fail.
> Running
> // this in a debugger increases the chances of it failing.
> Throwable e = assertThrows(Throwable.class,
> () -> session.auth().verify(AUTH_TIMEOUT));
> assertFalse(e.getMessage().contains("timeout"));
> assertFalse(session.isAuthenticated());
> } finally {
> client.stop();
> }
> }
> {code}
> Perhaps the connect future should be fulfilled only once the initial KEX is
> done? OpenSSH's ConnectTimeout does include the time until after the initial
> KEX.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscr...@mina.apache.org
For additional commands, e-mail: dev-h...@mina.apache.org
