How to configure openssh package instaed of default dropbear ssh?

IoT Modules WP Series
1

Hello,

I am working with WP7607 module and I would like to use “openssh” instead of dropbear package.

I am tried to modify the image recipe mdm9x28-image.inc with

IMAGE_INSTALL_append = " openssh"

But this resulus in below error during build

Collected errors:
 * check_conflicts_for: The following packages conflict with dropbear:
 * check_conflicts_for:         openssh * check_conflicts_for:  openssh-sshd *
 * opkg_solver_install: Cannot install package packagegroup-swi-image-target.

I wanted to know is it safe to replace dropbear with openssh? Will there be any issues connecting via ssh later? I generally connect to the module using PuTTY with root@10.9.1.1

Thanks in advance

2

seems dropbear is used by default:

root@swi-mdm9x28-wp:~# ps aux | grep drop
root      1397  0.0  0.2   2396   384 ?        Ss   08:00   0:00 /usr/sbin/dropbear -r /etc/dropbear/dropbear_rsa_host_key -p 22 -B
root      2626  0.0  0.5   2488   936 ?        Ss   08:08   0:00 /usr/sbin/dropbear -r /etc/dropbear/dropbear_rsa_host_key -p 22 -B
root@swi-mdm9x28-wp:~# ssh -v
WARNING: Ignoring unknown option -v
Dropbear SSH client v2017.75 https://matt.ucc.asn.au/dropbear/dropbear.html
Usage: ssh [options] [user@]host[/port][,[user@]host/port],...] [command]
-p <remoteport>
-l <username>
-t    Allocate a pty
-T    Don't allocate a pty
-N    Don't run a remote command
-f    Run in background after auth
-y    Always accept remote host key if unknown
-y -y Don't perform any remote host key checking (caution)
-s    Request a subsystem (use by external sftp)
-o option     Set option in OpenSSH-like format ('-o help' to list options)
-i <identityfile>   (multiple allowed, default .ssh/id_dropbear)
-A    Enable agent auth forwarding
-L <[listenaddress:]listenport:remotehost:remoteport> Local port forwarding
-g    Allow remote hosts to connect to forwarded ports
-R <[listenaddress:]listenport:remotehost:remoteport> Remote port forwarding
-W <receive_window_buffer> (default 24576, larger may be faster, max 1MB)
-K <keepalive>  (0 is never, default 0)
-I <idle_timeout>  (0 is never, default 0)
-B <endhost:endport> Netcat-alike forwarding
-J <proxy_program> Use program pipe rather than TCP connection
-c <cipher list> Specify preferred ciphers ('-c help' to list options)
-m <MAC list> Specify preferred MACs for packet verification (or '-m help')
-V    Version

Do you want to use ssh?

3

Yes, I want to use ssh from OpenSSH package. Because dropbear has limited options. For example, openssh ssh -o supports “ConnectTimeout” , “StrictHostKeyChecking”, “ServerAliveInterval” parameters

4

Update:

I am trying around with dropbear. But no success till now:

Background:
I have a custom script which tries to connect to a remote server via ssh. This works flawlessly with openssh ssh-client. but I am having issues with dropbear ssh client.

ssh -i /home/root/.ssh/id_ecdsa -p 22 -R <remote_port>:localhost:22 device@example.com

But I end up getting

ssh: Connection to device@example.com:22 exited: No auth methods could be used.

The /home/root/.ssh/id_ecdsa private key is generated using

dropbearkey -f /home/root/.ssh/id_ecdsa -t ecdsa -b 256

Also, I have added pub key to authorized_keys in /home/root/.ssh/ with

dropbearkey -y -f id_ecdsa | grep "^ecdsa-sha2-nistp256 " >> authorized_keys

Can you please let me know what is the issue here?

5

other user does not find problem on ssh tunnel: