[Swan] IKEv2 + PSK to Android question

[Nick Howitt]

Hi Paul,

I've trying to set up a very basic IKEv2+PSK conn from Android 5.0.1 to 
libreswan 3.20 but it is giving errors:

conn test
  type=tunnel
  authby=secret
  auto=add
  left=82.19.158.192
  leftsourceip=172.17.2.1
  leftsubnet=172.17.2.0/24
  right=%any
  rightid=@nick
  salifetime=1h
  ikelifetime=8h
  ikev2=insist
  dpdaction=clear
  dpdtimeout=120
  dpddelay=30
  rekey=no

and:

Apr 28 17:58:13 server pluto[3953]: packet from 85.255.235.101:36533: 
test IKE proposals for initial responder: 
1:IKE:ENCR=AES_GCM_C_256;PRF=HMAC_SHA2_512,HMAC_SHA2_256,HMAC_SHA1;INTEG=NONE;DH=MODP2048,MODP3072,MODP4096,MODP8192 
2:IKE:ENCR=AES_GCM_C_128;PRF=HMAC_SHA2_512,HMAC_SHA2_256,HMAC_SHA1;INTEG=NONE;DH=MODP2048,MODP3072,MODP4096,MODP8192 
3:IKE:ENCR=AES_CBC_256;PRF=HMAC_SHA2_512,HMAC_SHA2_256,HMAC_SHA1;INTEG=HMAC_SHA2_512_256,HMAC_SHA2_256_128,HMAC_SHA1_96;DH=MODP2048,MODP3072,MODP1536 
4:IKE:ENCR=AES_CBC_128;PRF=HMAC_SHA2_512,HMAC_SHA2_256,HMAC_SHA1;INTEG=HMAC_SHA2_512_256,HMAC_SHA2_256_128,HMAC_SHA1_96;DH=MODP2048,MODP3072,MODP1536 
(default)
Apr 28 17:58:13 server pluto[3953]: packet from 85.255.235.101:36533: 
proposal 2:IKE:ENCR=AES_GCM_C_256;PRF=HMAC_SHA2_512;DH=MODP2048 chosen 
from: 
1:IKE:ENCR=AES_CBC_256;ENCR=AES_CBC_128;INTEG=HMAC_SHA2_512_256;INTEG=HMAC_SHA2_384_192;INTEG=HMAC_SHA2_256_128;INTEG=HMAC_SHA1_96;PRF=HMAC_SHA2_512;PRF=HMAC_SHA2_384;PRF=HMAC_SHA2_256;PRF=HMAC_SHA1;DH=DH24;DH=ECP_384;DH=ECP_256;DH=MODP2048;DH=MODP1536[first-match] 
2:IKE:ENCR=AES_GCM_C_256;ENCR=AES_GCM_C_128;PRF=HMAC_SHA2_512;PRF=HMAC_SHA2_384;PRF=HMAC_SHA2_256;PRF=HMAC_SHA1;DH=DH24;DH=ECP_384;DH=ECP_256;DH=MODP2048;DH=MODP1536[better-match]
Apr 28 17:58:13 server pluto[3953]: packet from 85.255.235.101:36533: 
initiator guessed wrong keying material group (DH24); responding with 
INVALID_KE_PAYLOAD requesting MODP2048
Apr 28 17:58:13 server pluto[3953]: packet from 85.255.235.101:36533: 
sending unencrypted notification v2N_INVALID_KE_PAYLOAD to 
85.255.235.101:36533
Apr 28 17:58:14 server pluto[3953]: packet from 85.255.235.101:36533: 
proposal 2:IKE:ENCR=AES_GCM_C_256;PRF=HMAC_SHA2_512;DH=MODP2048 chosen 
from: 
1:IKE:ENCR=AES_CBC_256;ENCR=AES_CBC_128;INTEG=HMAC_SHA2_512_256;INTEG=HMAC_SHA2_384_192;INTEG=HMAC_SHA2_256_128;INTEG=HMAC_SHA1_96;PRF=HMAC_SHA2_512;PRF=HMAC_SHA2_384;PRF=HMAC_SHA2_256;PRF=HMAC_SHA1;DH=DH24;DH=ECP_384;DH=ECP_256;DH=MODP2048;DH=MODP1536[first-match] 
2:IKE:ENCR=AES_GCM_C_256;ENCR=AES_GCM_C_128;PRF=HMAC_SHA2_512;PRF=HMAC_SHA2_384;PRF=HMAC_SHA2_256;PRF=HMAC_SHA1;DH=DH24;DH=ECP_384;DH=ECP_256;DH=MODP2048;DH=MODP1536[better-match]
Apr 28 17:58:14 server pluto[3953]: "test"[4] 85.255.235.101 #455: 
STATE_PARENT_R1: received v2I1, sent v2R1 {auth=IKEv2 
cipher=aes_gcm_16_256 integ=n/a prf=sha2_512 group=MODP2048}
Apr 28 17:58:14 server pluto[3953]: "test"[4] 85.255.235.101 #455: new 
NAT mapping for #455, was 85.255.235.101:36533, now 85.255.235.101:54219
Apr 28 17:58:14 server pluto[3953]: "test"[4] 85.255.235.101 #455: IKEv2 
mode peer ID is ID_FQDN: '@nick'
Apr 28 17:58:14 server pluto[3953]: "test"[4] 85.255.235.101 #455: AUTH 
mismatch: Received AUTH != computed AUTH
Apr 28 17:58:14 server pluto[3953]: "test"[4] 85.255.235.101 #455: PSK 
Authentication failed: AUTH mismatch!
Apr 28 17:58:14 server pluto[3953]: "test"[4] 85.255.235.101 #455: 
sending unencrypted notification v2N_AUTHENTICATION_FAILED to 
85.255.235.101:54219
Apr 28 17:58:14 server pluto[3953]: | ikev2_parent_inI2outR2_tail 
returned STF_FATAL
Apr 28 17:58:14 server pluto[3953]: "test"[4] 85.255.235.101 #455: 
deleting state (STATE_PARENT_R1)
Apr 28 17:58:14 server pluto[3953]: "test"[4] 85.255.235.101: deleting 
connection "test"[4] 85.255.235.101 instance with peer 85.255.235.101 
{isakmp=#0/ipsec=#0}
Apr 28 17:58:15 server pluto[3953]: packet from 85.255.235.101:54219: 
sending unencrypted notification v2N_INVALID_IKE_SPI to 85.255.235.101:54219
Apr 28 17:58:17 server pluto[3953]: packet from 85.255.235.101:54219: 
sending unencrypted notification v2N_INVALID_IKE_SPI to 85.255.235.101:54219
Apr 28 17:58:20 server pluto[3953]: packet from 85.255.235.101:54219: 
sending unencrypted notification v2N_INVALID_IKE_SPI to 85.255.235.101:54219
Apr 28 17:58:27 server pluto[3953]: packet from 85.255.235.101:54219: 
sending unencrypted notification v2N_INVALID_IKE_SPI to 85.255.235.101:54219
Apr 28 17:58:37 server pluto[3953]: packet from 85.255.235.101:54219: 
sending unencrypted notification v2N_INVALID_IKE_SPI to 85.255.235.101:54219
Apr 28 17:58:56 server pluto[3953]: packet from 85.255.235.101:54219: 
sending unencrypted notification v2N_INVALID_IKE_SPI to 85.255.235.101:54219

It looks like it has agreed a proposal but I've no idea about the AUTH 
mismatch. I know I have not configured an addresspool. Is it necessary 
and causing this issue or is there something else going on?

Regards,

Nick