SSH setup

To connect to the VPU through SSH or deploy code to the VPU with SCP, it is necessary to setup a list of authorized keys .

Generate an SSH key-pair

Note: the following instructions are tailored towards a bash (Unix shell). When deploying on a Windows based architecture, please modify the instructions sets for your shell accordingly. All user specific SSH keys are located at ~/.ssh. This is the place where the private key for the connection to the VPU should be stored.

To generate an SSH key-pair, use ssh-keygen:

$ cd ~/.ssh/
$ ssh-keygen -t rsa -b 4096 -C "<Some comment to remember what the key is for>"
Generating public/private rsa key pair.
Enter file in which to save the key (~/.ssh/id_rsa): id_o3r
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
...

A passphrase is also needed. After that command, two new keys are generated within the ~/.ssh directory. With the example above it would be id_o3r and id_o3r.pub.

Upload the public key to the VPU

Uploading the public (.pub) SSH key to the VPU is achieved via the ifm3d library. The device configuration includes a parameter for authorized keys: authorized_keys. It is empty by default.

$ ifm3d dump | jq .device.network
{
  "authorized_keys": "",
  "interfaces": {
    "eth0": {
      "ipv4": {
        "address": "192.168.0.69",
        "dns": "0.0.0.0",
        "gateway": "192.168.0.201",
        "mask": 24
      },
      "mac": "48:B0:2D:54:F9:46",
      "networkSpeed": 1000,
      "useDHCP": false
    },
    "eth1": {
      "mac": "00:02:01:42:DE:94",
      "networkSpeed": 10,
      "useDHCP": true
    }
  }
}

To add a new key, the VPU configuration needs to be changed. This can be done with several ways (see configuring the camera). The easiest way in this case is to use the jq command along with the ifm3d API CLI:

LinuxWindows

$ echo {} | jq –arg id “id’ | ifm3d config

• jq --arg id "$(< ~/.ssh/id_o3r.pub)" - This loads the public key into the variable id and provides it to the jq command

• '.device.network.authorized_keys=$id' - Here the JSON value from authorized_keys is changed for the public key within the variable id

• ifm3d config - The new JSON is now used to change the configuration of the VPU via ifm3d config

Now, the content of the authorized_keys should look something like:

$ ifm3d dump | jq .device.network.authorized_keys
"ssh-rsa AAAAB3NzaC.....wZ9l3iSUaPPWOeFVz+xwlw== Some comment"

Note that the authorized_keys is a persistent parameter: it does not require a call to save_init to be persistent over reboots.

Connect to the VPU using the passphrase

After the key is uploaded, it is possible to connect with SSH and the username oem to the VPU:

$ ssh oem@192.168.0.69
The authenticity of host '192.168.0.69 (192.168.0.69)' can't be established.
ECDSA key fingerprint is SHA256:8gjC9za45TTRZNz5JCMwaNJ27BLfsPyDtjBaBQ2vyHw.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '192.168.0.69' (ECDSA) to the list of known hosts.
o3r-vpu-c0:~$

There will be a prompt for the passphrase, configured during step 1.

You should now be able to SSH into the VPU using your customer SSH key and passphrase.