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apache
NullPointerException in org.apache.sshd.common.kex.MontgomeryCurve.generateKeyPair()
Version
2.9.2
Bug description
Download the Gerrit code review source code and run all unit tests several times.
Actual behavior
In every full unit test run multiple random tests will fail with NullPointerException:
Caused by: java.lang.NullPointerException
at org.bouncycastle.math.ec.rfc7748.X25519.generatePrivateKey(X25519.java:54)
at org.bouncycastle.crypto.params.X25519PrivateKeyParameters.
Expected behavior
There should not be random test fails caused by NullPointerException at org.apache.sshd.common.kex.MontgomeryCurve.generateKeyPair(MontgomeryCurve.java:156). All tests should complete successfully every time.
Relevant log output
There was 1 failure:
1) sshKeyEndpoints(com.google.gerrit.acceptance.rest.binding.AccountsRestApiBindingsIT)
org.eclipse.jgit.errors.TransportException: ssh://[email protected]:43749: DefaultAuthFuture[ssh-connection]: Failed (NullPointerException) to execute: null
at org.eclipse.jgit.transport.sshd.SshdSessionFactory.getSession(SshdSessionFactory.java:263)
at com.google.gerrit.acceptance.SshSessionMina.getMinaSession(SshSessionMina.java:164)
at com.google.gerrit.acceptance.SshSessionMina.open(SshSessionMina.java:82)
at com.google.gerrit.acceptance.AbstractDaemonTest.initSsh(AbstractDaemonTest.java:573)
at com.google.gerrit.acceptance.AbstractDaemonTest.beforeTest(AbstractDaemonTest.java:479)
at com.google.gerrit.acceptance.AbstractDaemonTest$1$1.evaluate(AbstractDaemonTest.java:231)
at org.junit.rules.RunRules.evaluate(RunRules.java:20)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:27)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
at org.junit.rules.RunRules.evaluate(RunRules.java:20)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:27)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at com.google.testing.junit.runner.internal.junit4.CancellableRequestFactory$CancellableRunner.run(CancellableRequestFactory.java:108)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at com.google.testing.junit.runner.junit4.JUnit4Runner.run(JUnit4Runner.java:116)
at com.google.testing.junit.runner.BazelTestRunner.runTestsInSuite(BazelTestRunner.java:148)
at com.google.testing.junit.runner.BazelTestRunner.main(BazelTestRunner.java:75)
Caused by: org.apache.sshd.common.SshException: DefaultAuthFuture[ssh-connection]: Failed (NullPointerException) to execute: null
at org.apache.sshd.common.future.AbstractSshFuture.lambda$verifyResult$1(AbstractSshFuture.java:132)
at org.apache.sshd.common.future.AbstractSshFuture.formatExceptionMessage(AbstractSshFuture.java:190)
at org.apache.sshd.common.future.AbstractSshFuture.verifyResult(AbstractSshFuture.java:131)
at org.apache.sshd.client.future.DefaultAuthFuture.verify(DefaultAuthFuture.java:39)
at org.apache.sshd.client.future.DefaultAuthFuture.verify(DefaultAuthFuture.java:32)
at org.apache.sshd.common.future.VerifiableFuture.verify(VerifiableFuture.java:68)
at org.eclipse.jgit.transport.sshd.SshdSession.connect(SshdSession.java:172)
at org.eclipse.jgit.transport.sshd.SshdSession.connect(SshdSession.java:101)
at org.eclipse.jgit.transport.sshd.SshdSessionFactory.getSession(SshdSessionFactory.java:256)
... 40 more
Caused by: java.lang.NullPointerException
at org.bouncycastle.math.ec.rfc7748.X25519.generatePrivateKey(X25519.java:54)
at org.bouncycastle.crypto.params.X25519PrivateKeyParameters.<init>(X25519PrivateKeyParameters.java:24)
at org.bouncycastle.crypto.generators.X25519KeyPairGenerator.generateKeyPair(X25519KeyPairGenerator.java:23)
at org.bouncycastle.jcajce.provider.asymmetric.edec.KeyPairGeneratorSpi.generateKeyPair(KeyPairGeneratorSpi.java:193)
at java.base/java.security.KeyPairGenerator$Delegate.generateKeyPair(KeyPairGenerator.java:722)
at org.apache.sshd.common.kex.MontgomeryCurve.generateKeyPair(MontgomeryCurve.java:156)
at org.apache.sshd.common.kex.XDH.calculateE(XDH.java:45)
at org.apache.sshd.common.kex.AbstractDH.getE(AbstractDH.java:60)
at org.apache.sshd.client.kex.DHGClient.init(DHGClient.java:98)
at org.apache.sshd.common.session.helpers.AbstractSession.doKexNegotiation(AbstractSession.java:888)
at org.apache.sshd.common.session.helpers.AbstractSession.handleKexInit(AbstractSession.java:827)
at org.apache.sshd.common.session.helpers.AbstractSession.doHandleMessage(AbstractSession.java:567)
at org.apache.sshd.common.session.helpers.AbstractSession.lambda$handleMessage$0(AbstractSession.java:522)
at org.apache.sshd.common.util.threads.ThreadUtils.runAsInternal(ThreadUtils.java:68)
at org.apache.sshd.common.session.helpers.AbstractSession.handleMessage(AbstractSession.java:521)
at org.apache.sshd.common.session.helpers.AbstractSession.decode(AbstractSession.java:1639)
at org.apache.sshd.common.session.helpers.AbstractSession.messageReceived(AbstractSession.java:482)
at org.eclipse.jgit.internal.transport.sshd.JGitClientSession.messageReceived(JGitClientSession.java:197)
at org.apache.sshd.common.session.helpers.AbstractSessionIoHandler.messageReceived(AbstractSessionIoHandler.java:64)
at org.apache.sshd.common.io.nio2.Nio2Session.handleReadCycleCompletion(Nio2Session.java:407)
at org.apache.sshd.common.io.nio2.Nio2Session$1.onCompleted(Nio2Session.java:380)
at org.apache.sshd.common.io.nio2.Nio2Session$1.onCompleted(Nio2Session.java:375)
at org.apache.sshd.common.io.nio2.Nio2CompletionHandler.lambda$completed$0(Nio2CompletionHandler.java:38)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at org.apache.sshd.common.io.nio2.Nio2CompletionHandler.completed(Nio2CompletionHandler.java:37)
at java.base/sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:127)
at java.base/sun.nio.ch.Invoker.invokeDirect(Invoker.java:158)
at java.base/sun.nio.ch.UnixAsynchronousSocketChannelImpl.implRead(UnixAsynchronousSocketChannelImpl.java:562)
at java.base/sun.nio.ch.AsynchronousSocketChannelImpl.read(AsynchronousSocketChannelImpl.java:277)
at java.base/sun.nio.ch.AsynchronousSocketChannelImpl.read(AsynchronousSocketChannelImpl.java:298)
at org.apache.sshd.common.io.nio2.Nio2Session.doReadCycle(Nio2Session.java:492)
at org.apache.sshd.common.io.nio2.Nio2Session.doReadCycle(Nio2Session.java:370)
at org.apache.sshd.common.io.nio2.Nio2Session.startReading(Nio2Session.java:363)
at org.apache.sshd.common.io.nio2.Nio2Session.startReading(Nio2Session.java:359)
at org.apache.sshd.common.io.nio2.Nio2Session.startReading(Nio2Session.java:355)
at org.apache.sshd.common.io.nio2.Nio2Session.startReading(Nio2Session.java:351)
at org.apache.sshd.common.io.nio2.Nio2Session.startReading(Nio2Session.java:347)
at org.apache.sshd.common.io.nio2.Nio2Connector$ConnectionCompletionHandler.onCompleted(Nio2Connector.java:163)
at org.apache.sshd.common.io.nio2.Nio2Connector$ConnectionCompletionHandler.onCompleted(Nio2Connector.java:118)
at org.apache.sshd.common.io.nio2.Nio2CompletionHandler.lambda$completed$0(Nio2CompletionHandler.java:38)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at org.apache.sshd.common.io.nio2.Nio2CompletionHandler.completed(Nio2CompletionHandler.java:37)
at java.base/sun.nio.ch.Invoker.invokeUnchecked(Invoker.java:127)
at java.base/sun.nio.ch.Invoker$2.run(Invoker.java:219)
at java.base/sun.nio.ch.AsynchronousChannelGroupImpl$1.run(AsynchronousChannelGroupImpl.java:112)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:829)
Other information
The keyPairGenerator object in the MontgomeryCurve is a bouncycastle implementation of the java.security.KeyPairGenerator class. The generateKeyPair method in class org.bouncycastle.jcajce.provider.asymmetric.edec.KeyPairGeneratorSpi is not thread safe and calling the generateKeyPair method in org.apache.sshd.common.kex.MontgomeryCurve.generateKeyPair() is not synchronized. Therefore calling method org.apache.sshd.common.kex.MontgomeryCurve.generateKeyPair() by multiple threads will often cause a NullPointerException due to a race conditions.
Consider the following scenario: two threads simultaneously reach the generateKeyPair() method in class org.bouncycastle.jcajce.provider.asymmetric.edec.KeyPairGeneratorSpi. Thread one performs the if (!initialised) check. The "initialised" variable is false. Therefore, the setupGenerator(algorithm) method is executed. In the setupGenerator method, the "initialised" variable is assigned true at the very beginning. And at this moment, execution of the thread one is suspended and execution of the thread two continues. Thread two evaluates the "initialised" variable. The variable is true therefore thread two executes the further command AsymmetricCipherKeyPair kp = generator.generateKeyPair(); the generator is not yet correctly initialized. Thread two continues its execution and eventually throws a NullPointerException, which is the result of the generator not being initialized correctly because the setupGenerator method was not executed to completion even though the "initialised" variable was already set to true. The callstack looks like this:
Caused by: java.lang.NullPointerException
at org.bouncycastle.math.ec.rfc7748.X25519.generatePrivateKey(X25519.java:54)
at org.bouncycastle.crypto.params.X25519PrivateKeyParameters.
