Error connecting to Debian / OpenSSH 7.4 about sshy HOT 6 OPEN

Looks like something might have gone wrong in KEX since the client is forcing a disconnection debug3: receive packet: type 1 [preauth]

Probably easier to debug if you can provide the client's side by adding:

console.log(data.toString()); to https://github.com/stuicey/SSHy/blob/master/js/parceler.js#L29
&&
console.log(r.toString()); to https://github.com/stuicey/SSHy/blob/master/js/parceler.js#L65

from sshy.

It's, erm, very binary :-)

from sshy.

I added a few console logs of my own.

function verifyKey(host_key, sig){
        var rsa = new SSHyClient.RSAKey(new SSHyClient.Message(host_key));
        console.log("Made RSAKey");
        if(!rsa.verify(SSHyClient.kex.H, new SSHyClient.Message(sig))){
            console.log("Key verify failed");
                transport.disconnect();
            throw 'RSA signature verification failed, disconnecting.';
        }
}

Result:

this.SHAVersion = SHA-256
combinedLibs.comb.js:345 Made RSAKey
combinedLibs.comb.js:345 Key verify failed

It seems that the transport.disconnect is raising an error, before throw 'RSA signature verification failed, disconnecting.' has a chance to run.

from sshy.

I can tell you off-list the hostname of the server I'm connecting to, if you want to try it for yourself. It's on the Internet.

from sshy.

Note: I am having the same issue with Ubuntu 20.04 connecting to a RHEL server... I tried connecting through the server manually and received an error saying that it was trying to request diffie-hellman-group1 algorithm. I enabled that globally in the /etc/ssh/ssh_config using KexAlgorithms=+diffie-hellman-group1-sha1 and was able to connect directly but not through SSHy.

I believe this is an error when trying to connect to an antiquated server that is not on the latest SSH version. I say this because I can connect to other servers fine but the one I am having trouble with is very old and has not been updated in a minute.

@candlerb is your distant server running the latest SSH version?

from sshy.

$ dpkg-query -l openssh-server
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                            Version              Architecture         Description
+++-===============================-====================-====================-====================================================================
ii  openssh-server                  1:7.4p1-10+deb9u7    amd64                secure shell (SSH) server, for secure access from remote machines

And when logged onto that machine:

$ ssh -Q kex
diffie-hellman-group1-sha1
diffie-hellman-group14-sha1
diffie-hellman-group14-sha256
diffie-hellman-group16-sha512
diffie-hellman-group18-sha512
diffie-hellman-group-exchange-sha1
diffie-hellman-group-exchange-sha256
ecdh-sha2-nistp256
ecdh-sha2-nistp384
ecdh-sha2-nistp521
curve25519-sha256
[email protected]

from sshy.