Hello,
we would like to use bitvise and kitty as ssh-clients to connect to OpenWrt. However, it does not work.
Bitvise shows the error
The SSH connection has terminated with error. Reason: Error in component session/transport/kexHandler. Error class: Flow, code: ComponentException, message: Exception in component: Windows CNG (x86) with additions: CiPkPubInit: Unrecognized algorithm.
Kitty just stalls.
I alredy tried differnet encryptions methodds ... no success.
Connection with putty works. However, we should use Bitvise in the first place.
As description of Dropbear ist very limited. Has anybody a simular problem and even better 
a solution?!
Thanks already!
Mark
Newer ssh clients might require an additional option to be able to connect, could be the same case here.
As in
ssh -oHostKeyAlgorithms=+ssh-rsa root@mir4a
Same issue here, works with putty but not with bitvise on a OpenWRT teltonika router RUT240.
BitVise
11:56:56.068 Current date: 2024-04-20
11:56:56.068 Bitvise SSH Client 9.35, a fully featured SSH client for Windows.
Copyright (C) 2000-2024 by Bitvise Limited.
11:56:56.068 Visit www.bitvise.com for latest information about our SSH software.
11:56:56.068 Run 'BvSsh -help' to learn about supported command-line parameters.
11:56:56.068 Cryptographic provider: Windows CNG (x86) with additions
11:56:56.652 Version status: Current
This is the latest release.
11:56:56.716 Loading last used profile 'C:\Users\xxxxxxxxxx'.
11:56:56.718 Last used profile loaded successfully.
11:56:59.059 Started a new SSH connection.
11:56:59.060 Connecting to SSH server 192.168.18.1:22.
11:56:59.202 Connection established.
11:56:59.296 Server version: SSH-2.0-dropbear
11:56:59.296 First key exchange started. Cryptographic provider: Windows CNG (x86) with additions
11:56:59.676 The SSH connection has terminated with error. Reason: Error in component session/transport/kexHandler. Error class: Flow, code: ComponentException, message: Exception in component: Windows CNG (x86) with additions: CiPkPubInit: Unrecognized algorithm.
Putty
2024-04-20 11:22:41 Looking up host "192.168.18.1" for SSH connection
2024-04-20 11:22:41 Connecting to 192.168.18.1 port 22
2024-04-20 11:22:41 We claim version: SSH-2.0-PuTTY_Release_0.79
2024-04-20 11:22:41 Connected to 192.168.18.1
2024-04-20 11:22:41 Remote version: SSH-2.0-dropbear
2024-04-20 11:22:41 Using SSH protocol version 2
2024-04-20 11:22:41 No GSSAPI security context available
2024-04-20 11:22:41 Doing ECDH key exchange with curve Curve25519, using hash SHA-256 (SHA-NI accelerated)
2024-04-20 11:22:41 Server also has ecdsa-sha2-nistp256/rsa-sha2-256/ssh-rsa host keys, but we don't know any of them
2024-04-20 11:22:41 Host key fingerprint is:
2024-04-20 11:22:41 ssh-ed25519 255 SHA256:************************************************************
2024-04-20 11:22:41 Initialised AES-256 SDCTR (AES-NI accelerated) outbound encryption
2024-04-20 11:22:41 Initialised HMAC-SHA-256 (SHA-NI accelerated) outbound MAC algorithm
2024-04-20 11:22:41 Initialised AES-256 SDCTR (AES-NI accelerated) inbound encryption
2024-04-20 11:22:41 Initialised HMAC-SHA-256 (SHA-NI accelerated) inbound MAC algorithm
2024-04-20 11:22:49 Sent password
2024-04-20 11:22:50 Access granted
2024-04-20 11:22:50 Opening main session channel
2024-04-20 11:22:50 Opened main channel
2024-04-20 11:22:50 Allocated pty
2024-04-20 11:22:50 Started a shell/command
AFAIK the RUT240 isn't supported here, my guess is you're using some vendor OS claiming to be Openwrt.
Hi there,
found a solution that works:
the supported Host key algorithms for the teltonika routers are Ed25519 and ECDSA/nistp256. To get bitvise client to work you must disable RSA/* algorithms in the SSH Host key configuration.
It worked for me! Hope vor you too
Mark
1 Like
THX! 
It works with RUT240 & RUTX50.