[Android5.0.2 -- Strongswan5.3.3 ] Can't create IKEv1 SA because NAT-D payloads are not recognized
I use a smartphone(Andriod 5.0.2) as a client to create a L2TPoverIPsec VPN with a server(using strongswan5.3.3)。
The ipsec.conf is like this：
config setup conn %default ikelifetime=60m keylife=20m rekeymargin=3m keyingtries=1 keyexchange=ikev1 authby=secret aggressive=yes conn net-net type=transport left=192.168.0.132 leftsubnet=0.0.0.0/0 #leftid=@sun leftid=@#313233 leftfirewall=yes right=192.168.0.124 rightsubnet=0.0.0.0/0 #rightid=@moon #rightid=192.168.0.124 rightid=@#313233 auto=add
On the phone，I created a L2tpOverIPsec VPN.The IPsec identity is "123"。
When I use dialed the VPN，I found the phone use Aggressive-Mode. Strongswan replied the second message，
and the phone never sent the third message.
phone<initiator> --------------------- strongswan<responder> first message ----> <----- second message third messge X
I checked the phone's log :
E/racoon (16015): ignore the packet, received unexpecting payload type 20.
Type 20 is NAT-D.
In the message.c，the payloads order is like this:
[ SA KE No ID NAT-D NAT-D HASH V V V]
But in RFC3947 , the order like this:
Initiator Responder ------------ ------------ UDP(500,500) HDR, SA, KE, Ni, IDii, VID --> <-- UDP(500,X) HDR, SA, KE, Nr, IDir, [CERT, ], VID, NAT-D, NAT-D, SIG_R
When I modifed the order in message.c, and dailed again,the IKE_SA was established.
The new order:
[ SA KE No ID V V V NAT-D NAT-D HASH ]
So please check the aggressive_r_order in message.c if this is a bug.
#1 Updated by Tobias Brunner almost 5 years ago
- File aggressive-nat-d-payload-order.patch aggressive-nat-d-payload-order.patch added
- Subject changed from [Android5.0.2 -- Strongswan5.3.3 ]Can't create IKE_SA to [Android5.0.2 -- Strongswan5.3.3 ] Can't create IKE_SA
- Description updated (diff)
- Category set to interoperability
- Status changed from New to Feedback
- Target version set to 5.4.0
While RFC 2409 says
Except where otherwise noted, there are no requirements for ISAKMP
payloads in any message to be in any particular order.
I guess for some simple clients it could make sense to order the Vendor ID payloads before the NAT-D payloads. Otherwise, such crappy clients might not recognize the NAT-D payloads, which are technically only defined when the appropriate Vendor ID has been received, which, of course, is the case, but clients that parse payloads only sequentially are probably not aware of that.
Patch is attached.
#2 Updated by Tobias Brunner over 4 years ago
- Subject changed from [Android5.0.2 -- Strongswan5.3.3 ] Can't create IKE_SA to [Android5.0.2 -- Strongswan5.3.3 ] Can't create IKEv1 SA because NAT-D payloads are not recognized
- Status changed from Feedback to Closed
- Assignee set to Tobias Brunner
- Resolution set to Fixed