Exception in thread "reader" java.lang.NoClassDefFoundError: org/bouncycastle/crypto/ec/CustomNamedCurves

Question

I've used 'net.schmizz.sshj.SSHClient' package to connect to a server. Below is my code:

public class ConnectToServer {
    String hostName = "10.250.176.6";
    int port = 22;
    public ConnectToServer(String hostName, int port) {
        this.hostName = hostName;
        this.port = port;
    }

    public void ssh() {
      SSHClient ssh = new SSHClient();
      String cmd = "ipconfig";
      try {
            ssh.connect(this.hostName, this.port);
            ssh.isConnected();
            final Process process = Runtime.getRuntime().exec(cmd);
            ssh.disconnect();
      } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
      }

    }

However, I faced to an error: "Exception in thread "reader" java.lang.NoClassDefFoundError: org/bouncycastle/crypto/ec/CustomNamedCurves". I added bcprov-jdk15on-1.49 and bouncycastle.jar into my classpath. Please help me to resolve this error.

Complete exception:

    08:46:05.526 [main] DEBUG net.schmizz.concurrent.Promise - Awaiting  <<kex done>> 
    08:46:05.528 [reader] DEBUG    n.s.sshj.transport.KeyExchanger - Received SSH_MSG_KEXINIT   
    08:46:05.528 [reader] DEBUG n.s.sshj.transport.KeyExchanger -    Negotiated algorithms: [ [email protected];    sig=ecdsa-sha2-nistp256; c2sCipher=aes128-ctr; s2cCipher=aes128-ctr; c2sMAC=hmac-sha1; s2cMAC=hmac-sha1; c2sComp=none; s2cComp=none ]    
    **Exception in thread "reader" java.lang.NoClassDefFoundError:    org/bouncycastle/crypto/ec/CustomNamedCurves**    
    at    net.schmizz.sshj.transport.kex.Curve25519DH.getCurve25519Params(Curve25519DH.java:60)
        at    net.schmizz.sshj.transport.kex.Curve25519SHA256.initDH(Curve25519SHA256.java:44)
        at    net.schmizz.sshj.transport.kex.AbstractDHG.init(AbstractDHG.java:46)
        at    net.schmizz.sshj.transport.KeyExchanger.gotKexInit(KeyExchanger.java:236)
        at    net.schmizz.sshj.transport.KeyExchanger.handle(KeyExchanger.java:356)
        at    net.schmizz.sshj.transport.TransportImpl.handle(TransportImpl.java:503)
        at net.schmizz.sshj.transport.Decoder.decode(Decoder.java:102)  
    at       net.schmizz.sshj.transport.Decoder.received(Decoder.java:170)      at  net.schmizz.sshj.transport.Reader.run(Reader.java:59) 
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)

Answer 1

Clean your project or rebuild it again. If the problem is not solved, please post complete exception so that we will get more clarity.

Answer 2

Your jar is probably missing its dependencies (or some of it.) If its a maven project i suggest you rather switch to Maven.

A nice tutorial can be found here: Maven in 5 Minutes

I think, the SSH Client is missing org.Bouncycastle.crypto as libary (dependency). Quick way to fix this is to get the jar for it too.

Answer 3

This issue might be occurred due to use of different versions of bouncycastle jars in the project. the solution is ,

1. to find the different versions of bouncycastle jars getting used directly or indirectly in the project.
2. try to use one version of bouncycastle jars in whole project.
3. make changes according to version which you have chosen to use across project as code written with one version of bouncycastle jar may not work for other version of bouncycastle.