[strongSwan] swanctl -l - loses transport info?

[Kostya Vasilyev]

Some more info below

On Thu, Apr 4, 2019, at 9:32 PM, Kostya Vasilyev wrote:
> Hi,
> 
> I'm seeing something weird with the output of "swanctl -l".
> 
> Sometimes the SA's are output like this:
> 
> home_gre: #3, reqid 3, INSTALLED, TRANSPORT, ESP:AES_CTR-128/HMAC_SHA2_256_128
> 
> linode: #4, reqid 4, INSTALLED, TRANSPORT, ESP:AES_GCM_16-128
> 
> And sometimes like this:
> 
> home_gre: #6, reqid 6, INSTALLED, TRANSPORT, 
> ESP:AES_CTR-128/HMAC_SHA2_256_128/ECP_256
> 
> linode: #4, reqid 4, INSTALLED, TRANSPORT, ESP:AES_GCM_16-128/ECP_256
> 
> The variation is in the "/ECP256" at the end.
> 
> I think this varies depending on how I start strongSwan (swanctl -q vs. 
> systemctl restart) or maybe rekeying.
> 
> But my server and client configs don't change.

Found the pattern...

Initial connection:

- Client:

systemctl restart strongswan-swanctl

- Server log:

selected proposal: ESP:AES_GCM_16_128/NO_EXT_SEQ

- swanctl -l

  linode: #8, reqid 7, INSTALLED, TRANSPORT, ESP:AES_GCM_16-128
    installed 76s ago, rekeying in 3253s, expires in 3884s


Now trigger a rekey from this client

- Client

swanctl --rekey --child fra

- Server log:

selected proposal: ESP:AES_GCM_16_128/ECP_256/NO_EXT_SEQ

- swanctl -l

  linode: #9, reqid 7, INSTALLED, TRANSPORT, ESP:AES_GCM_16-128/ECP_256
    installed 23s ago, rekeying in 3312s, expires in 3937s

So ECP_256 in SA's begin to show only after a rekey.

What am I missing to be able to understand why?

-- K

> 
> My server config is like this:
> 
> connections {
> 	ec_tunnel {
> 		version = 2
> 		proposals = aes128-sha256-ecp256
> 
> 		// local, remote adds and auth omitted
> 		
> 		children {
> 			home_gre {
> 				local_ts  = dynamic[gre]
> 				remote_ts = dynamic[gre]
> 
> 				mode = transport
> 				esp_proposals = aes128ctr-sha256-ecp256
> 			}
> 
> 			linode {
> 				mode = transport
> 				esp_proposals = aes128gcm128-ecp256
> 			}
> 		}
> 	}
> }
> 
> Client config for "linode" clinets:
> 
> connections {
> 	ecdsa_tunnel {
> 		version = 2
> 		proposals = aes128-sha256-ecp256
> 
> 		// local, remote adds and auth omitted
> 		
> 		children {
> 			fra  {
> 				mode = transport
> 				esp_proposals = aes128gcm128-ecp256
> 				start_action = start
> 				close_action = start
> 				dpd_action = restart
> 			}
> 		}
> 	}
> }
> 
> Client "home_gre" (AES CTR) is a Miktotik at home and it also has 
> ECP256 in its SA encryption config.
> 
> Does this look like a bug in swanctl -l ?
> 
> Or - most likely - user error?
> 
> I got ideas for my crypto settings from here:
> 
> https://wiki.strongswan.org/projects/strongswan/wiki/IKEv2CipherSuites
> 
> Suite-B-GCM-128:
> IKEv2: aes128gcm16-prfsha256-ecp256
> ESP: aes128gcm16-ecp256
> 
> Except I can't use GCM or PRF for IKE because of the Mikrotik client.
> 
> -- 
> Kostya Vasilyev
> kman at fastmail.com
>