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commit b848f767cc132aa18ef42989ef979d6f7e7eb57e Author: Lyor Goldstein <[email protected]> AuthorDate: Tue Aug 4 11:01:03 2020 +0300 [SSHD-1050] Fixed race condition in AuthFuture if exception caught before authentication started --- CHANGES.md | 1 + .../sshd/client/future/InitialAuthFuture.java | 52 +++++++++++++++++++ .../sshd/client/session/ClientSessionImpl.java | 16 ++++-- .../sshd/client/session/ClientSessionTest.java | 59 +++++++++++++++++++--- 4 files changed, 119 insertions(+), 9 deletions(-) diff --git a/CHANGES.md b/CHANGES.md index 089fa2b..0dbba59 100644 --- a/CHANGES.md +++ b/CHANGES.md @@ -38,3 +38,4 @@ or `-key-file` command line option. * [SSHD-1039](https://issues.apache.org/jira/browse/SSHD-1039) Fix support for some basic options in ssh/sshd cli. * [SSHD-1047](https://issues.apache.org/jira/browse/SSHD-1047) Support for SSH jumps. * [SSHD-1048](https://issues.apache.org/jira/browse/SSHD-1048) Wrap instead of rethrow IOException in Future. +* [SSHD-1050](https://issues.apache.org/jira/browse/SSHD-1050) Fixed race condition in AuthFuture if exception caught before authentication started \ No newline at end of file diff --git a/sshd-core/src/main/java/org/apache/sshd/client/future/InitialAuthFuture.java b/sshd-core/src/main/java/org/apache/sshd/client/future/InitialAuthFuture.java new file mode 100644 index 0000000..375fdb4 --- /dev/null +++ b/sshd-core/src/main/java/org/apache/sshd/client/future/InitialAuthFuture.java @@ -0,0 +1,52 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.apache.sshd.client.future; + +import org.apache.sshd.common.future.SshFutureListener; + +/** + * A special future used until the authentication service replaces it with a "real" one. This future serves as + * a placeholder for any exceptions caught until authentication starts. It is special in one other way - it has no + * listeners attached to it and expects no authentication success or failure - only exceptions. + * + * @author <a href="mailto:[email protected]";>Apache MINA SSHD Project</a> + */ +public class InitialAuthFuture extends DefaultAuthFuture { + public InitialAuthFuture(Object id, Object lock) { + super(id, lock); + } + + @Override + public AuthFuture addListener(SshFutureListener<AuthFuture> listener) { + throw new UnsupportedOperationException("Not allowed to add listeners to this future"); + } + + @Override + protected void notifyListener(SshFutureListener<AuthFuture> l) { + if (l != null) { + throw new UnsupportedOperationException("No listeners expected for this future"); + } + } + + @Override + public void setAuthed(boolean authed) { + throw new UnsupportedOperationException("No authentication expected for this future"); + } +} diff --git a/sshd-core/src/main/java/org/apache/sshd/client/session/ClientSessionImpl.java b/sshd-core/src/main/java/org/apache/sshd/client/session/ClientSessionImpl.java index 21e0631..bc8a9bd 100644 --- a/sshd-core/src/main/java/org/apache/sshd/client/session/ClientSessionImpl.java +++ b/sshd-core/src/main/java/org/apache/sshd/client/session/ClientSessionImpl.java @@ -32,7 +32,7 @@ import java.util.concurrent.TimeUnit; import org.apache.sshd.client.ClientFactoryManager; import org.apache.sshd.client.future.AuthFuture; -import org.apache.sshd.client.future.DefaultAuthFuture; +import org.apache.sshd.client.future.InitialAuthFuture; import org.apache.sshd.common.Service; import org.apache.sshd.common.ServiceFactory; import org.apache.sshd.common.SshConstants; @@ -85,8 +85,7 @@ public class ClientSessionImpl extends AbstractClientSession { nextServiceFactory = null; } - authFuture = new DefaultAuthFuture(ioSession.getRemoteAddress(), futureLock); - authFuture.setAuthed(false); + authFuture = new InitialAuthFuture(ioSession.getRemoteAddress(), futureLock); signalSessionCreated(ioSession); @@ -124,8 +123,19 @@ public class ClientSessionImpl extends AbstractClientSession { ClientUserAuthService authService = getUserAuthService(); synchronized (sessionLock) { String serviceName = nextServiceName(); + // SSHD-1050 - check if need to propagate any previously caught exceptions + Throwable caught = (authFuture instanceof InitialAuthFuture) ? authFuture.getException() : null; authFuture = ValidateUtils.checkNotNull( authService.auth(serviceName), "No auth future generated by service=%s", serviceName); + if (caught != null) { + /* + * Safe to do under session lock despite SSHD-916 since + * the newly generated future has no associated listeners + * attached to it yet + */ + signalAuthFailure(authFuture, caught); + } + return authFuture; } } diff --git a/sshd-core/src/test/java/org/apache/sshd/client/session/ClientSessionTest.java b/sshd-core/src/test/java/org/apache/sshd/client/session/ClientSessionTest.java index ed0addf..d9e022f 100644 --- a/sshd-core/src/test/java/org/apache/sshd/client/session/ClientSessionTest.java +++ b/sshd-core/src/test/java/org/apache/sshd/client/session/ClientSessionTest.java @@ -26,15 +26,21 @@ import java.rmi.ServerException; import java.util.concurrent.atomic.AtomicInteger; import org.apache.sshd.client.SshClient; +import org.apache.sshd.client.future.AuthFuture; import org.apache.sshd.common.AttributeRepository; import org.apache.sshd.common.AttributeRepository.AttributeKey; import org.apache.sshd.common.session.Session; import org.apache.sshd.common.session.SessionListener; +import org.apache.sshd.core.CoreModuleProperties; import org.apache.sshd.server.SshServer; +import org.apache.sshd.server.auth.keyboard.KeyboardInteractiveAuthenticator; +import org.apache.sshd.server.auth.pubkey.AcceptAllPublickeyAuthenticator; import org.apache.sshd.util.test.BaseTestSupport; +import org.apache.sshd.util.test.BogusPasswordAuthenticator; import org.apache.sshd.util.test.CommandExecutionHelper; import org.apache.sshd.util.test.CoreTestSupportUtils; import org.junit.AfterClass; +import org.junit.Before; import org.junit.BeforeClass; import org.junit.FixMethodOrder; import org.junit.Test; @@ -83,10 +89,17 @@ public class ClientSessionTest extends BaseTestSupport { } } + @Before + public void setUp() { + sshd.setPasswordAuthenticator(BogusPasswordAuthenticator.INSTANCE); + sshd.setPublickeyAuthenticator(AcceptAllPublickeyAuthenticator.INSTANCE); + sshd.setKeyboardInteractiveAuthenticator(KeyboardInteractiveAuthenticator.NONE); + } + @Test public void testDefaultExecuteCommandMethod() throws Exception { - final String expectedCommand = getCurrentTestName() + "-CMD"; - final String expectedResponse = getCurrentTestName() + "-RSP"; + String expectedCommand = getCurrentTestName() + "-CMD"; + String expectedResponse = getCurrentTestName() + "-RSP"; sshd.setCommandFactory((session, command) -> new CommandExecutionHelper(command) { private boolean cmdProcessed; @@ -116,8 +129,8 @@ public class ClientSessionTest extends BaseTestSupport { @Test public void testExceptionThrownIfRemoteStderrWrittenTo() throws Exception { - final String expectedCommand = getCurrentTestName() + "-CMD"; - final String expectedErrorMessage = getCurrentTestName() + "-ERR"; + String expectedCommand = getCurrentTestName() + "-CMD"; + String expectedErrorMessage = getCurrentTestName() + "-ERR"; sshd.setCommandFactory((session, command) -> new CommandExecutionHelper(command) { private boolean cmdProcessed; @@ -161,8 +174,8 @@ public class ClientSessionTest extends BaseTestSupport { @Test public void testExceptionThrownIfNonZeroExitStatus() throws Exception { - final String expectedCommand = getCurrentTestName() + "-CMD"; - final int expectedErrorCode = 7365; + String expectedCommand = getCurrentTestName() + "-CMD"; + int expectedErrorCode = 7365; sshd.setCommandFactory((session, command) -> new CommandExecutionHelper(command) { private boolean cmdProcessed; @@ -237,4 +250,38 @@ public class ClientSessionTest extends BaseTestSupport { client.removeSessionListener(listener); } } + + @Test // SSHD-1050 + public void testAuthGetsNotifiedOnLongPreamble() throws Exception { + int limit = CoreModuleProperties.MAX_IDENTIFICATION_SIZE.getRequired(sshd); + String line = getClass().getCanonicalName() + "#" + getCurrentTestName(); + StringBuilder sb = new StringBuilder(limit + line.length()); + while (sb.length() <= limit) { + if (sb.length() > 0) { + sb.append(CoreModuleProperties.SERVER_EXTRA_IDENT_LINES_SEPARATOR); + } + sb.append(line); + } + CoreModuleProperties.SERVER_EXTRA_IDENTIFICATION_LINES.set(sshd, sb.toString()); + + try (ClientSession session = client.connect(getCurrentTestName(), TEST_LOCALHOST, port) + .verify(CONNECT_TIMEOUT) + .getSession()) { + session.addPasswordIdentity(getCurrentTestName()); + // Give time to the client to signal the overflow in server identification + Thread.sleep(AUTH_TIMEOUT.toMillis() / 2L); + + AuthFuture future = session.auth(); + assertTrue("Auth not completed on time", future.await(AUTH_TIMEOUT)); + assertTrue("No auth result", future.isDone()); + assertFalse("Unexpected auth success", future.isSuccess()); + assertTrue("Auth not marked as failed", future.isFailure()); + + Throwable exception = future.getException(); + String message = exception.getLocalizedMessage(); + assertTrue("Invalid exception message: " + message, message.contains("too many header lines")); + } finally { + CoreModuleProperties.SERVER_EXTRA_IDENTIFICATION_LINES.set(sshd, null); + } + } }
