Syntax and modifying public-key users

After creating a key pair, the public key has to be input to the device in a form that it understands. A LCOS device expects the public keys in the following syntax:

<EncryptionAlgorithm> <PublicKey> <Admin1> [<Admin2> … <AdminN>]

This makes it possible to assign multiple user accounts to a single public key. It is also possible to load several keys for different users into the device. Starting with a public-key file created with PuTTYgen, the following steps describe how you modify a public key.

Open the public-key file in a text editor. It shows you the following or similar content:

---- BEGIN SSH2 PUBLIC KEY ----
Comment: "rsa-key_myuser"
AAAAB3NzaC1yc2EAAAABJQAAAgEAqQMfC3vjb1t3hctVPAnDSY1wnHGpj/yC34kq
f/UsnsDowDGHpgi98MV1OpvSgwmSHvTH5yBGh9M+uId28w3DJrdyzR+CtoqQbP5l
…
0N8V3ydp+qbx+8FNbBQCVhxxiKZwXxmMh70pTWHxixOFte4HBxGHxcRaiSoMyNdv
wCkWlx8=
---- END SSH2 PUBLIC KEY ----

Delete the header and footer and the comment line so that all that remains is the actual key. Then remove any line breaks so that the public key is on a single line.
```
AAAAB3NzaC1yc2EAAAABJQAAAgEAqQMfC3vjb1t3hctVPAnDSY1…wCkWlx8=
```
In front of the key, specify the encryption algorithm ssh-rsa and, after the key, add the name of the user account for which this key is valid (for example, root), separated with a space.
You can assign multiple users to a key or place multiple keys in a single public-key file. Examples:
```
ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAgEAqQMfC3vjb1t3hctVPAnDSY1j…wCkWlx8= root
```
```
ssh-rsa AAAAB3NzaC1yc2EAAAABJQAAAgEAqQMfC3vjb1t3hctVPAnDSY1…wCkWlx8= root admin user
ssh-rsa VLn5PpIvdubb0/eMgFH0M/xexrEVFRTdfi1iqPf1Js4wnIOtBSU…xKWNVDg/ backup
```
Important: Make sure that each each key (including the encryption algorithm and user [s]) is on a separate line. Line breaks invalidate the file and lead to an error in the subsequent authentication!
Save the file and close the text editor.