[JSch-users] JSch issue with config

[CHAUMIER, R. <RAC...@bo...>]

Hi,

I'm facing an issue about ssh session with ~/.ssh/config :

I have a remote host toto.titi.fr accessible on the port 2222. Due to a limitation of the framework I'm using (which uses jsch to connect to a remote git repository), I had to define the uri like that use...@to...:path/to/my/repo<mailto:use...@to...:path/to/my/repo> and added a config file with the configuration

## redirection port
Host toto.titi.fr
     HostName toto.titi.fr
     HostKeyAlias toto.titi.fr
     Port 2222
     User username

Unfortunately when jsch try to connect (session.connect(tms) I got a NullPointerException from the method checkHost(host, port, kex) whereas it load the key list (line 801).

HostKey[] keys =
        hkr.getHostKey(chost,
                       (key_type.equals("DSA") ? "ssh-dss" : "ssh-rsa"));


Finally,  keys is null. So the line 805 (for(int j=0; j< keys.length; j++){) throws a NullPointerException.

The problem is located on the method getHostKey of HostKeyRepository. The library try to identify in the known_hosts file the remote host key. So It loops and as it finds the matched item it returns it. If no key found it returns null. In my case it returns null because the library compares the following chost  :

"[toto.titi.fr]:2222" (because of the rule (line 709 at Session.class) which modify the defaut chost value ("toto.titi.fr") when no HostKeyAlias is set and port different than 22.

to  the key in my known_hosts file which looks like :

toto.titi.fr,1.2.3.4 ssh-rsa AAAAB3Nz....C+6e/.... /9MrXset+YG/aYLMZMzG+e31PET

Why the chost is formatted like that when the port used is not the default one?


To workaround, I had to delete in my known_hosts file the key but it's not a good idea. The problem occurs if someone connect to the remote host with ssh util.

My second idea, was to used a HostKeyAlias but it not set at line 698 in the checkHost method. How can I fix the problem?

Regards

RaphC











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