strongSwan

I am trying the following scenario:

server: Centos 6.3 with strongswan 5.0.1
client: Mac OSX Mountain Lion with built-in racoon VPN client
auth: PSK + Xauth

ipsec.conf:

<pre>
config setup

conn %default
ikelifetime=24h
keylife=20m
rekeymargin=3m

keyingtries=1

keyexchange=ikev1
rekey = no

left=109.168.103.185

leftsubnet=192.168.8.0/24

auto=add



conn rw
leftid=@my.gateway.hostname
leftauth=psk
leftprotoport=%any
right=%any
rightsourceip=%vpnclients
rightauth=psk
rightauth2=xauth
rightprotoport=%any
auto=add
dpddelay=40

dpdtimeout=130

dpdaction=clear
</pre>



strongswan.conf:

<pre>
charon {
threads = 16
cisco_unity = yes
interfaces_use = eth0
plugins {
sql {
database = sqlite:///usr/local/etc/ipsec.d/ipsec.db
}
attr-sql {
database = sqlite:///usr/local/etc/ipsec.d/ipsec.db
}
}
}

pluto {
dns1 = 192.168.8.41
load = sha1 sha2 md5 aes des hmac gmp random nonce xauth-generic attr kernel-netlink socket-default stroke updown attr-sql
}

libhydra {
plugins {
attr-sql {
database = sqlite:///usr/local/etc/ipsec.d/ipsec.db
}
}
}
</pre>



Everything works fine when initially negotiating connection. The mac prompts for xauth password, gets an IP address from the pool, and also the route, everything works like a charm, until racoon on the mac tries to renegotiate the SA.
Child SA negotiation works fine, but when racoon wants to renegotiate the main SA weird things happen.
In theory I could avoid this hassle by setting the SA lifetime to 24 hours or something like that, but unfortunately
the lifetime in Apple's racoon client is hardcoded to 1 hour. Someone published an hack to convince racoon to use a longer
lifetime but for some reason it is just ignored on my macbook... so I am stuck with a lifetime of 1 hour and every 50 minutes
the phase 1 negotiation is restarted on client side, and this breaks the VPN.
When racoon restarts the phase 1 negotiation it also repeats the xauth authentication and I am prompted with the xauth
password request again. Even if I input the password again, however, no more traffic goes through the VPN.

Some more info.

racoon.conf on macosx:

<pre>
path include "/etc/racoon" ;

log debug;

# "padding" defines some parameter of padding. You should not touch these.
padding
{
maximum_length 20; # maximum padding length.
randomize off; # enable randomize length.
strict_check off; # enable strict check.
exclusive_tail off; # extract last one octet.
}

# Specification of default various timer.
timer
{
# These value can be changed per remote node.
counter 10; # maximum trying count to send.
interval 3 sec; # interval to resend (retransmit)
persend 1; # the number of packets per a send.

# timer for waiting to complete each phase.
phase1 30 sec;
phase2 30 sec;

# Auto exit delay timer - for use when controlled by VPN socket
auto_exit_delay 3 sec;
}

remote ::1 [8000]
{
#exchange_mode main,aggressive;
exchange_mode aggressive,main;
doi ipsec_doi;
situation identity_only;

my_identifier user_fqdn "macuser@localhost";
peers_identifier user_fqdn "macuser@localhost";
#certificate_type x509 "mycert" "mypriv";

nonce_size 16;
lifetime time 1 min; # sec,min,hour

proposal {
encryption_algorithm aes;
hash_algorithm sha1;
authentication_method pre_shared_key ;
dh_group 2 ;
}
}

sainfo address ::1 icmp6 address ::1 icmp6
{
pfs_group 1;
lifetime time 60 sec;
encryption_algorithm 3des, aes ;
authentication_algorithm hmac_sha1, hmac_md5 ;
compression_algorithm deflate ;
}



include "/var/run/racoon/*.conf" ;
</pre>

the generated file in the above folder for my gateway:

<pre>
remote x.x.x.x {
doi ipsec_doi;
situation identity_only;
exchange_mode main;
verify_identifier off;
shared_secret keychain "FC6D8EA9-5021-4041-9DC8-FB5C6B0B634A.SS";
nonce_size 16;
dpd_delay 20;
dpd_retry 5;
dpd_maxfail 5;
dpd_algorithm dpd_blackhole_detect;
initial_contact on;
support_proxy on;
proposal_check obey;
xauth_login "mylogin";
mode_cfg on;

proposal {
authentication_method xauth_psk_client;
hash_algorithm sha1;
encryption_algorithm aes 256;
lifetime time 3600 sec;
dh_group 2;
}

proposal {
authentication_method xauth_psk_client;
hash_algorithm sha1;
encryption_algorithm aes;
lifetime time 3600 sec;
dh_group 2;
}

proposal {
authentication_method xauth_psk_client;
hash_algorithm md5;
encryption_algorithm aes 256;
lifetime time 3600 sec;
dh_group 2;
}

proposal {
authentication_method xauth_psk_client;
hash_algorithm md5;
encryption_algorithm aes;
lifetime time 3600 sec;
dh_group 2;
}

proposal {
authentication_method xauth_psk_client;
hash_algorithm sha1;
encryption_algorithm 3des;
lifetime time 3600 sec;
dh_group 2;
}

proposal {
authentication_method xauth_psk_client;
hash_algorithm md5;
encryption_algorithm 3des;
lifetime time 3600 sec;
dh_group 2;
}

proposal {
authentication_method xauth_psk_client;
hash_algorithm sha1;
encryption_algorithm des;
lifetime time 3600 sec;
dh_group 2;
}

proposal {
authentication_method xauth_psk_client;
hash_algorithm md5;
encryption_algorithm des;
lifetime time 3600 sec;
dh_group 2;
}
}
</pre>

When the connection is up and working, strongswan statusall:

<pre>
Status of IKE charon daemon (strongSwan 5.0.1, Linux 2.6.32-279.14.1.el6.x86_64, x86_64):
uptime: 75 minutes, since Dec 07 09:28:11 2012
malloc: sbrk 450560, mmap 0, used 367744, free 82816
worker threads: 8 of 16 idle, 7/1/0/0 working, job queue: 0/0/0/0, scheduled: 4
loaded plugins: charon sqlite aes des sha1 sha2 md5 random nonce x509 revocation constraints pubkey pkcs1 pkcs8 pgp dnskey pem fips-prf gmp xcbc cmac hmac attr attr-sql kernel-netlink resolve socket-default stroke sql updown xauth-generic unity
Listening IP addresses:
x.x.x.x
Connections:
rw: x.x.x.x5...%any IKEv1, dpddelay=40s
rw: local: [my.gateway.fqdn] uses pre-shared key authentication
rw: remote: uses pre-shared key authentication
rw: remote: uses XAuth authentication: any
rw: child: 192.168.8.0/24 === dynamic TUNNEL, dpdaction=clear
Security Associations (1 up, 0 connecting):
rw[3]: ESTABLISHED 2 minutes ago, x.x.x.x[my.gateway.fqdn]...2.225.141.140[192.168.2.105]
rw[3]: Remote XAuth identity: myid
rw[3]: IKEv1 SPIs: 4be963d5fcc1f25f_i 703fcb9599724566_r*, rekeying disabled
rw[3]: IKE proposal: AES_CBC_256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
rw{2}: INSTALLED, TUNNEL, ESP in UDP SPIs: c86fbcb6_i 0a6424b3_o
rw{2}: AES_CBC_256/HMAC_SHA1_96, 0 bytes_i, 0 bytes_o, rekeying disabled
rw{2}: 192.168.8.0/24 === 192.168.100.2/32
</pre>



when VPN is working, racoon side:

<pre>
192.168.2.105 x.x.x.x
esp mode=tunnel spi=3362766006(0xc86fbcb6) reqid=16471(0x00004057)
E: aes-cbc 7e25f168 aaab7ef1 97cdfc9e e3236ee6 226ccfc8 65541b18 f83632ba d0c795d1
A: hmac-sha1 8464d3df 84ba2218 4262a601 0aac0905 0bb1073d
seq=0x00000000 replay=4 flags=0x00000006 state=mature
created: Dec 7 10:41:08 2012 current: Dec 7 11:01:44 2012
diff: 1236(s) hard: 3600(s) soft: 2880(s)
last: hard: 0(s) soft: 0(s)
current: 0(bytes) hard: 0(bytes) soft: 0(bytes)
allocated: 0 hard: 0 soft: 0
sadb_seq=1 pid=7850 refcnt=2
x.x.x.x 192.168.2.105
esp mode=tunnel spi=174335155(0x0a6424b3) reqid=16472(0x00004058)
E: aes-cbc 38101561 83e27ddc d7690dc7 4765744d 19d56957 cdbfca39 fdd0d3bf eb5cc824
A: hmac-sha1 0bc6c89b 9a0fa690 8fe91a36 2bf55985 f339c674
seq=0x00000000 replay=4 flags=0x00000006 state=mature
created: Dec 7 10:41:08 2012 current: Dec 7 11:01:44 2012
diff: 1236(s) hard: 3600(s) soft: 2880(s)
last: hard: 0(s) soft: 0(s)
current: 0(bytes) hard: 0(bytes) soft: 0(bytes)
allocated: 0 hard: 0 soft: 0
sadb_seq=0 pid=7850 refcnt=2
</pre>



logs on strongswan side, about 50 minutes after successful VPN establishment:

<pre>
Dec 6 21:26:23 it charon: 11[IKE] sending DPD request
Dec 6 21:26:23 it charon: 11[ENC] generating INFORMATIONAL_V1 request 3267501863 [ HASH N(DPD) ]
Dec 6 21:26:23 it charon: 11[NET] sending packet: from x.x.x.x[4500] to 2.225.141.140[4500]
Dec 6 21:26:23 it charon: 13[NET] received packet: from 2.225.141.140[4500] to x.x.x.x[4500]
Dec 6 21:26:23 it charon: 13[ENC] parsed INFORMATIONAL_V1 request 4064578958 [ HASH N(DPD_ACK) ]
Dec 6 21:26:46 it charon: 15[NET] received packet: from 2.225.141.140[4500] to x.x.x.x[4500]
Dec 6 21:26:46 it charon: 15[ENC] parsed ID_PROT request 0 [ SA V V V V V V V V V V V V V V ]
Dec 6 21:26:46 it charon: 15[IKE] received NAT-T (RFC 3947) vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received draft-ietf-ipsec-nat-t-ike vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received draft-ietf-ipsec-nat-t-ike-08 vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received draft-ietf-ipsec-nat-t-ike-07 vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received draft-ietf-ipsec-nat-t-ike-06 vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received draft-ietf-ipsec-nat-t-ike-05 vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received draft-ietf-ipsec-nat-t-ike-04 vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received draft-ietf-ipsec-nat-t-ike-03 vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received draft-ietf-ipsec-nat-t-ike-02 vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received draft-ietf-ipsec-nat-t-ike-02\n vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received XAuth vendor ID
Dec 6 21:26:46 it charon: 15[IKE] received Cisco Unity vendor ID
Dec 6 21:26:46 it charon: 15[ENC] received unknown vendor ID: 40:48:b7:d5:6e:bc:e8:85:25:e7:de:7f:00:d6:c2:d3:80:00:00:00
Dec 6 21:26:46 it charon: 15[IKE] received DPD vendor ID
Dec 6 21:26:46 it charon: 15[IKE] 2.225.141.140 is initiating a Main Mode IKE_SA
Dec 6 21:26:46 it charon: 15[ENC] generating ID_PROT response 0 [ SA V V V V ]
Dec 6 21:26:46 it charon: 15[NET] sending packet: from x.x.x.x[4500] to 2.225.141.140[4500]
Dec 6 21:26:46 it charon: 16[NET] received packet: from 2.225.141.140[4500] to x.x.x.x[4500]
Dec 6 21:26:46 it charon: 16[ENC] parsed ID_PROT request 0 [ KE No NAT-D NAT-D ]
Dec 6 21:26:46 it charon: 16[IKE] remote host is behind NAT
Dec 6 21:26:46 it charon: 16[ENC] generating ID_PROT response 0 [ KE No NAT-D NAT-D ]
Dec 6 21:26:46 it charon: 16[NET] sending packet: from x.x.x.x[4500] to 2.225.141.140[4500]
Dec 6 21:26:46 it charon: 03[NET] received packet: from 2.225.141.140[4500] to x.x.x.x[4500]
Dec 6 21:26:46 it charon: 03[ENC] parsed ID_PROT request 0 [ ID HASH ]
Dec 6 21:26:46 it charon: 03[CFG] looking for XAuthInitPSK peer configs matching x.x.x.x...2.225.141.140[192.168.2.105]
Dec 6 21:26:46 it charon: 03[CFG] selected peer config "rw"
Dec 6 21:26:46 it charon: 03[ENC] generating ID_PROT response 0 [ ID HASH ]
Dec 6 21:26:46 it charon: 03[NET] sending packet: from x.x.x.x[4500] to 2.225.141.140[4500]
Dec 6 21:26:46 it charon: 03[ENC] generating TRANSACTION request 44664428 [ HASH CP ]
Dec 6 21:26:46 it charon: 03[NET] sending packet: from x.x.x.x[4500] to 2.225.141.140[4500]
Dec 6 21:26:50 it charon: 02[IKE] sending retransmit 1 of request message ID 44664428, seq 1
Dec 6 21:26:50 it charon: 02[NET] sending packet: from x.x.x.x[4500] to 2.225.141.140[4500]
Dec 6 21:26:51 it charon: 01[NET] received packet: from 2.225.141.140[4500] to x.x.x.x[4500]
Dec 6 21:26:51 it charon: 01[ENC] parsed INFORMATIONAL_V1 request 3116209513 [ HASH D ]
Dec 6 21:26:51 it charon: 01[IKE] received DELETE for IKE_SA rw[1]
Dec 6 21:26:51 it charon: 01[IKE] deleting IKE_SA rw[1] between x.x.x.x[my.gateway.fqdn]...2.225.141.140[192.168.2.105]
Dec 6 21:26:54 it charon: 12[NET] received packet: from 2.225.141.140[4500] to x.x.x.x[4500]
Dec 6 21:26:54 it charon: 12[ENC] parsed TRANSACTION response 44664428 [ HASH CP ]
Dec 6 21:26:54 it charon: 12[IKE] XAuth authentication of 'myid' successful
Dec 6 21:26:54 it charon: 12[ENC] generating TRANSACTION request 3158087928 [ HASH CP ]
Dec 6 21:26:54 it charon: 12[NET] sending packet: from x.x.x.x[4500] to 2.225.141.140[4500]
Dec 6 21:26:54 it charon: 11[NET] received packet: from 2.225.141.140[4500] to x.x.x.x[4500]
Dec 6 21:26:54 it charon: 11[ENC] parsed TRANSACTION response 3158087928 [ HASH CP ]
Dec 6 21:26:54 it charon: 11[IKE] IKE_SA rw[2] established between x.x.x.x[my.gateway.fqdn]...2.225.141.140[192.168.2.105]
Dec 6 21:27:26 it charon: 01[NET] received packet: from 2.225.141.140[4500] to x.x.x.x[4500]
Dec 6 21:27:26 it charon: 01[ENC] parsed INFORMATIONAL_V1 request 2293057995 [ HASH N(DPD) ]
Dec 6 21:27:26 it charon: 01[ENC] generating INFORMATIONAL_V1 request 3253914055 [ HASH N(DPD_ACK) ]
Dec 6 21:27:26 it charon: 01[NET] sending packet: from x.x.x.x[4500] to 2.225.141.140[4500]
</pre>



logs on racoon side at the same time:

<pre>
Dec 6 21:26:23 myid.local racoon[4261]: IKE Packet: transmit success. (Information message).
Dec 6 21:26:23 myid.local racoon[4261]: IKEv1 Information-Notice: transmit success. (R-U-THERE? ACK).
Dec 6 21:26:23 myid.local racoon[4261]: IKE Packet: receive success. (Information message).
Dec 6 21:26:46 myid.local racoon[4261]: IPSec Phase1 started (Initiated by me).
Dec 6 21:26:46 myid.local racoon[4261]: IKE Packet: transmit success. (Initiator, Main-Mode message 1).
Dec 6 21:26:46 myid.local racoon[4261]: IKE Packet: receive success. (Initiator, Main-Mode message 2).
Dec 6 21:26:46 myid.local racoon[4261]: IKE Packet: transmit success. (Initiator, Main-Mode message 3).
Dec 6 21:26:46 myid.local racoon[4261]: IKE Packet: receive success. (Initiator, Main-Mode message 4).
Dec 6 21:26:46 myid.local racoon[4261]: IKE Packet: transmit success. (Initiator, Main-Mode message 5).
Dec 6 21:26:46 myid.local racoon[4261]: IKEv1 Phase1 AUTH: success. (Initiator, Main-Mode Message 6).
Dec 6 21:26:46 myid.local racoon[4261]: IKE Packet: receive success. (Initiator, Main-Mode message 6).
Dec 6 21:26:46 myid.local racoon[4261]: IKEv1 Phase1 Initiator: success. (Initiator, Main-Mode).
Dec 6 21:26:46 myid.local racoon[4261]: IPSec Phase1 established (Initiated by me).
Dec 6 21:26:46 myid.local racoon[4261]: IPSec Extended Authentication requested.
Dec 6 21:26:51 myid.local racoon[4261]: IKE Packet: transmit success. (Information message).
Dec 6 21:26:51 myid.local racoon[4261]: IKEv1 Information-Notice: transmit success. (Delete ISAKMP-SA).
Dec 6 21:26:54 myid.local racoon[4261]: IKE Packet: transmit success. (Mode-Config message).
Dec 6 21:26:54 myid.local racoon[4261]: IPSec Extended Authentication sent.
Dec 6 21:26:54 myid.local racoon[4261]: IKEv1 XAUTH: success. (XAUTH Status is OK).
Dec 6 21:26:54 myid.local racoon[4261]: IPSec Extended Authentication Passed.
Dec 6 21:26:54 myid.local racoon[4261]: IKE Packet: transmit success. (Mode-Config message).
Dec 6 21:27:26 myid.local racoon[4261]: IKE Packet: transmit success. (Information message).
Dec 6 21:27:26 myid.local racoon[4261]: IKEv1 Information-Notice: transmit success. (R-U-THERE?).
Dec 6 21:27:26 myid.local racoon[4261]: IKEv1 Dead-Peer-Detection: request transmitted. (Initiator DPD Request).
Dec 6 21:27:26 myid.local racoon[4261]: IKEv1 Dead-Peer-Detection: response received. (Initiator DPD Response).
Dec 6 21:27:26 myid.local racoon[4261]: IKE Packet: receive success. (Information message).
</pre>



After phase 1 renegotiation (VPN still up but no traffic flowing:

strongswan statusall

<pre>
Status of IKE charon daemon (strongSwan 5.0.1, Linux 2.6.32-279.14.1.el6.x86_64, x86_64):
uptime: 2 hours, since Dec 07 09:28:11 2012
malloc: sbrk 450560, mmap 0, used 367200, free 83360
worker threads: 8 of 16 idle, 7/1/0/0 working, job queue: 0/0/0/0, scheduled: 6
loaded plugins: charon sqlite aes des sha1 sha2 md5 random nonce x509 revocation constraints pubkey pkcs1 pkcs8 pgp dnskey pem fips-prf gmp xcbc cmac hmac attr attr-sql kernel-netlink resolve socket-default stroke sql updown xauth-generic unity
Listening IP addresses:
x.x.x.x
Connections:
rw: x.x.x.x...%any IKEv1, dpddelay=40s
rw: local: [my.gateway.fqdn] uses pre-shared key authentication
rw: remote: uses pre-shared key authentication
rw: remote: uses XAuth authentication: any
rw: child: 192.168.8.0/24 === dynamic TUNNEL, dpdaction=clear
Security Associations (1 up, 0 connecting):
rw[4]: ESTABLISHED 21 seconds ago, 109.168.103.185[it.leopardus.com]...2.225.141.140[192.168.2.105]
rw[4]: Remote XAuth identity: myid
rw[4]: IKEv1 SPIs: 6a141bc46e3209be_i 15a6214f140cfbc9_r*, rekeying disabled
rw[4]: IKE proposal: AES_CBC_256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
</pre>

racoon ss ipsec returns: @no no SAD entries@. entries.

One issue I see here is the fact xauth is requested again, also password is stored and not asked
when first establishing the VPN but after renegotiation it is asked again (weird but maybe a client problem)...

I am no IPSEC expert so it could be that I am missing something obvious here, but for the life of me I cannot
see what's wrong with this setup...

Thanks in advance for your help on this matter!

Rick