Problem with storing multiple OpenSSH keys in ECC slots

[schlomie]

Environment

Firmware: 2.1.1
OnlyKey App: 5.3.3
onlykey-cli: 1.2.6
onlykey-agent: 1.1.12

Issue

I don't know if this issue is related to

• The OnlyKey app (not updating/writing to slots)
• The firmware
• onlykey-agent not reading the right slot

... but I am happy to move this issue to the correct repo.

But this is the issue:

I've generated two different OpenSSH keys:

$ ssh-keygen -t ed25519 -f 101.key -C "ECC101"
Generating public/private ed25519 key pair.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in 101.key
Your public key has been saved in 101.key.pub
The key fingerprint is:
SHA256:HNvgWIJ/egc4xOSWG/7Jrrab0Sekh8KhQJWAcjqIsK0 ECC101
The key's randomart image is:
+--[ED25519 256]--+
|..... .          |
|+ o. = .         |
|=*  . O +        |
|B .  = X =       |
|.o  . B S .      |
|E. o . @ o       |
|  . o = O o      |
|     ..* +       |
|     .=+.        |
+----[SHA256]-----+

and

$ ssh-keygen -t ed25519 -f 102.key -C "ECC102"
Generating public/private ed25519 key pair.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in 102.key
Your public key has been saved in 102.key.pub
The key fingerprint is:
SHA256:ePt+xoe+XZlNtJUAAOXPPbD/lYOc6cMLBpnPR27j21k ECC102
The key's randomart image is:
+--[ED25519 256]--+
|       .oo....   |
|        .     . .|
|         . .   .o|
|       .  = +  .o|
|      . S+ + + ..|
|       . .+ = =.=|
|        .  *.% =E|
|         .. @+=.=|
|         .o+oB=+ |
+----[SHA256]-----+

While in config mode, I "successfully" loaded 101.key and 102.key into their respected ECC slots. But when I go to use the keys stored in the slots, only 101.key is usable. In fact, it appears ALL slots return the same 101.key

$ cat 101.key.pub 102.key.pub 
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIXjkzBVWpexS1Ro9OC4MOj5ekAh2Veh+TpIkp371w79 ECC101
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIETGE/eiAhPohk8KbJ/Go1MXZ74e6XSO5G7OI/CDqbH+ ECC102
$
$ onlykey-agent -sk ECC101 user@host
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIXjkzBVWpexS1Ro9OC4MOj5ekAh2Veh+TpIkp371w79 <ssh://user@host|ed25519>
$
$ onlykey-agent -sk ECC102 user@host
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIXjkzBVWpexS1Ro9OC4MOj5ekAh2Veh+TpIkp371w79 <ssh://user@host|ed25519>
$
$ onlykey-agent -sk ECC103 user@host
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIXjkzBVWpexS1Ro9OC4MOj5ekAh2Veh+TpIkp371w79 <ssh://user@host|ed25519>
$ onlykey-agent -sk ECC104 user@host
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIXjkzBVWpexS1Ro9OC4MOj5ekAh2Veh+TpIkp371w79 <ssh://user@host|ed25519>
$ onlykey-agent -sk ECC105 user@host
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIXjkzBVWpexS1Ro9OC4MOj5ekAh2Veh+TpIkp371w79 <ssh://user@host|ed25519>
... 
$ onlykey-agent -sk ECC115 user@host
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIXjkzBVWpexS1Ro9OC4MOj5ekAh2Veh+TpIkp371w79 <ssh://user@host|ed25519>
$ onlykey-agent -sk ECC116 user@host
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIXjkzBVWpexS1Ro9OC4MOj5ekAh2Veh+TpIkp371w79 <ssh://user@host|ed25519>

---

Or, maybe I have entirely the wrong idea about storing multiple keys in select ECC slots?

[onlykey]

@schlomie We used to use 101 - 116 for ECC keys but for simplicity this was changed to ECC1 - ECC16 so that both the OnlyKey Agent and App have the same naming:
https://docs.crp.to/onlykey-agent.html#stored-keys

onlykey-agent -sk ECC102 user@host
should be:
onlykey-agent -sk ECC2 user@host

onlykey-agent -sk ECC102 user@host
is actually read by the agent as onlykey-agent -sk ECC1 user@host because ECC102 is not a valid option. We should have an error thrown here though I will make a note to add an error when incorrect slot is selected.

[schlomie]

Oh geez. I skipped right over that and certainly didn't grok it. Yeah, this makes so much more sense.

Thanks and apologies!