SSH fix in headless mode

Question

So I have a brand new RasPi 3, and I'm having SSH trouble. Yes, I have enabled SSH.

My problem matches exactly what is described here:

I just bought a new Raspberry Pi 3 and was not able to connect via SSH, even after creating an empty /boot/ssh file. SSH client under linux showed the following:

$ ssh -v 192.168.0.32 OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 19: Applying options for * debug1: Connecting to 192.168.0.32 [192.168.0.32] port 22. debug1: Connection established. debug1: identity file /home/vlad/.ssh/id_rsa type -1 debug1: identity file /home/vlad/.ssh/id_rsa-cert type -1 debug1: identity file /home/vlad/.ssh/id_dsa type -1 debug1: identity file /home/vlad/.ssh/id_dsa-cert type -1 debug1: identity file /home/vlad/.ssh/id_ecdsa type -1 debug1: identity file /home/vlad/.ssh/id_ecdsa-cert type -1 debug1: identity file /home/vlad/.ssh/id_ed25519 type -1 debug1: identity file /home/vlad/.ssh/id_ed25519-cert type -1 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_6.6.1p1 Ubuntu-2ubuntu2.8 debug1: Remote protocol version 2.0, remote software version OpenSSH_6.7p1 Raspbian-5+deb8u3 debug1: match: OpenSSH_6.7p1 Raspbian-5+deb8u3 pat OpenSSH* compat 0x04000000 debug1: SSH2_MSG_KEXINIT sent Connection closed by 192.168.0.32

The proposed solution is to run the following sudo commands:

$ sudo rm -r /etc/ssh/ssh*key
$ sudo dpkg-reconfigure openssh-server`

My question is whether there is any chance to apply this fix, or another one, in headless mode, i.e. without keyboard and screen. I have neither in my home, just laptops.

Answer 1

On your other Linux system:

mount the drive, i.e:

sudo mkdir /b
sudo mount /dev/mmcblk0p2 /b

remove the old ssh host keys as in the instructions:

sudo rm /b/etc/ssh/ssh*key
sudo rm /b/etc/ssh/ssh*key.pub 

Replace the keys:

You can't run the reconfigure safely, so you could either:

• not create keys and see if the next boot detects the need to run keygen, or:

• clone your VM's keys to your RPi:

  sudo cp /etc/ssh/sshkey /b/etc/ssh/

But remember to cleanly unmount before removing the card:

sudo umount /b