net.schmizz.sshj.transport.KeyExchanger.waitForDone处超时（KeyExchanger.java:160）

我每天晚上都在用

net.schmizz.sshj

SFTP库

我怀疑我们转入的服务器发生了变化。然而，我无法准确指出确切的变化是什么。我也不能在生产服务器之外复制它。因此，我希望了解根本原因或如何重现以下错误

net.schmizz.sshj.transport.TransportException:超时已过期
net.schmizz.sshj.transport.TransportException$1.chain（TransportException.java:33）
net.schmizz.sshj.transport.TransportException$1.chain（TransportException.java:27）
位于net.schmizz.concurrent.Promise.retrieve（Promise.java:139）
net.schmizz.concurrent.Event.await（Event.java:103）
在net.schmizz.sshj.transport.KeyExchanger.waitForDone（KeyExchanger.java:160）
在net.schmizz.sshj.transport.keychanger.startKex（keychanger.java:155）
net.schmizz.sshj.transport.TransportImpl.doKex（TransportImpl.java:247）
位于net.schmizz.sshj.SSHClient.doKex（SSHClient.java:735）
位于net.schmizz.sshj.SSHClient.onConnect（SSHClient.java:723）
位于net.schmizz.sshj.SocketClient.connect（SocketClient.java:54）
位于net.schmizz.sshj.SocketClient.connect（SocketClient.java:80）

据我所知，我们正在通过

java.net.Socket

ok进行连接，然后超时，等待在此代码中完成密钥交换

package net.schmizz.sshj.transport;

/** Algorithm negotiation and key exchange. */
final class KeyExchanger
        implements SSHPacketHandler, ErrorNotifiable {

    /**
     * Starts key exchange by sending a {@code SSH_MSG_KEXINIT} packet. Key exchange needs to be done once mandatorily
     * after initializing the {@link Transport} for it to be usable and may be initiated at any later point e.g. if
     * {@link Transport#getConfig() algorithms} have changed and should be renegotiated.
     *
     * @param waitForDone whether should block till key exchange completed
     *
     * @throws TransportException if there is an error during key exchange
     * @see {@link Transport#setTimeoutMs} for setting timeout for kex
     */
    void startKex(boolean waitForDone)
            throws TransportException {
        if (!kexOngoing.getAndSet(true)) {
            done.clear();
            sendKexInit();
        }
        if (waitForDone)
            waitForDone();
    }

    /**
     * Sends SSH_MSG_KEXINIT and sets the {@link #kexInitSent} event.
     *
     * @throws TransportException
     */
    private void sendKexInit()
            throws TransportException {
        log.debug("Sending SSH_MSG_KEXINIT");
        clientProposal = new Proposal(transport.getConfig());
        transport.write(clientProposal.getPacket());
        kexInitSent.set();
    }

void waitForDone()
        throws TransportException {
    done.await(transport.getTimeoutMs(), TimeUnit.MILLISECONDS);
}

---

在发布了这个问题之后，经过多次调试，我发现问题在于，在生产环境中运行的加密库与我在本地测试中运行的加密库不同。我通过构建最小的jar来确定这一点，同时仍然保留生产中使用的所有SSHJ片段和我们自己的所有相关代码，然后在命令shell中使用调试级日志运行它，在这里我可以看到所有输出。然后，我看到了下面的内容，我意识到生产服务器日志中的超时异常是第二个异常，发生在并掩盖了未在生产中记录的根本原因之后：a

NoClassDefFoundError

Exception in thread "reader" java.lang.NoClassDefFoundError: org/bouncycastle/crypto/ec/CustomNamedCurves
    at net.schmizz.sshj.transport.kex.Curve25519DH.getCurve25519Params(Curve25519DH.java:51)
    at net.schmizz.sshj.transport.kex.Curve25519SHA256.initDH(Curve25519SHA256.java:36)
    at net.schmizz.sshj.transport.kex.AbstractDHG.init(AbstractDHG.java:55)
    at net.schmizz.sshj.transport.KeyExchanger.gotKexInit(KeyExchanger.java:239)
    at net.schmizz.sshj.transport.KeyExchanger.handle(KeyExchanger.java:359)
    at net.schmizz.sshj.transport.TransportImpl.handle(TransportImpl.java:493)
    at net.schmizz.sshj.transport.Decoder.decode(Decoder.java:107)
    at net.schmizz.sshj.transport.Decoder.received(Decoder.java:175)
    at net.schmizz.sshj.transport.Reader.run(Reader.java:60)
Caused by: java.lang.ClassNotFoundException: org.bouncycastle.crypto.ec.CustomNamedCurves
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 9 more

net.schmizz.sshj.transport.TransportException: Timeout expired
    at net.schmizz.sshj.transport.TransportException$1.chain(TransportException.java:33)
    at net.schmizz.sshj.transport.TransportException$1.chain(TransportException.java:27)
    at net.schmizz.concurrent.Promise.retrieve(Promise.java:139)
    at net.schmizz.concurrent.Event.await(Event.java:103)
    at net.schmizz.sshj.transport.KeyExchanger.waitForDone(KeyExchanger.java:160)
    at net.schmizz.sshj.transport.KeyExchanger.startKex(KeyExchanger.java:155)
    at net.schmizz.sshj.transport.TransportImpl.doKex(TransportImpl.java:247)
    at net.schmizz.sshj.SSHClient.doKex(SSHClient.java:735)
    at net.schmizz.sshj.SSHClient.onConnect(SSHClient.java:723)
    at net.schmizz.sshj.SocketClient.connect(SocketClient.java:54)
    at net.schmizz.sshj.SocketClient.connect(SocketClient.java:80)
    at kirby.App.connect(App.java:101)
    at kirby.App.execute(App.java:45)
    at kirby.App.main(App.java:31)
Caused by: java.util.concurrent.TimeoutException: Timeout expired
    ... 12 more

区别在于类路径。 我们在生产中

bcpg-jdk15on-150.jar:bcpkix-jdk15on-150.jar:bcprov-jdk15on-150.jar

但需要

bcpkix-jdk15on/1.51/bcpkix-jdk15on-1.51.jar:ecc-25519-java-1.0.1.jar:bcprov-jdk15on/1.51/bcprov-jdk15on-1.51.jar