[strongSwan] Rekey between openswan and strongswan

[Yatong Cui]

Hi all,

I've been doing a test between openswan and strongswan. And the Rekey of child_sa(setting the strongswan time counter to a smaller value,openswan time counter to a larger value) isn't successful.

Here is detailed info:
=====================================================
Network TOPO:
-------------

  OPENSWAN<========>ROUTER<===========>STRONGSWAN
  (RHEL6)                            (OPENSUSE11.3)
2001:db8:1:1::/64                   2001:db8:1:2::/64

Test Case:
----------
OPENSWAN side: configure enough long CHILD_SA lifetime (for example 300s) regardless of SA life type not to be expired before STRONGSWAN.
STRONGSWAN side: configure CHILD_SA lifetime to be expired within short period (for example 30s) regardless of SA life type.
Then STRONGSWAN initiates the connection and send continuous echo packets for more than 1 min.

Configuration
--------------
OPENSWAN side:
----------------------------------------------------------------
[root at OPENSWAN ~]# cat /etc/ipsec.conf
config setup
        crlcheckinterval="180"
        strictcrlpolicy=no
        protostack=netkey        
        plutodebug=all

conn %default
        salifetime=300s
        rekeymargin=10s
        rekeyfuzz=0%
        ike=3des-sha1;modp1024
        phase2alg=3des-sha1
        authby=secret
        ikev2=yes
        rekey=yes

conn TAHI
        connaddrfamily=ipv6
        type=transport
        left=2001:db8:1:1:20c:29ff:fe0c:3ed1
        right=2001:db8:1:2:20c:29ff:fe45:b04e
        leftid=2001:db8:1:1:20c:29ff:fe0c:3ed1
        rightid=2001:db8:1:2:20c:29ff:fe45:b04e
        auto=add
-------------------------------------------------------------------
STRONGSWAN side:
linux-9deg:~ # cat /etc/ipsec.conf 
config setup
        crlcheckinterval="180"
        strictcrlpolicy=no
        charonstart=yes

conn %default
        lifetime=30s
        margintime=10s
        rekeyfuzz=0%
        ike=aes-sha1-modp1024
        esp=3des-sha1
        authby=secret
        keyexchange=ikev2
        rekey=yes

conn TAHI
        right=2001:db8:1:1:20c:29ff:fe0c:3ed1
        left=2001:db8:1:2:20c:29ff:fe45:b04e
        rightid=2001:db8:1:1:20c:29ff:fe0c:3ed1
        leftid=2001:db8:1:2:20c:29ff:fe45:b04e
        type=transport
        compress=no
        auto=add
--------------------------------------------------------------------
Logging info:

The connection can be successful for 20s(lifetime minus margintime). And after that,because the rekey is not successful.
The connection broke down and the echo test wasn't successful.

'ipsec statusall' from strongswan:
-----------------------------------
Status of IKEv2 charon daemon (strongSwan 4.4.0):
  uptime: 29 seconds, since Oct 26 05:29:21 2010
  worker threads: 7 idle of 16, job queue load: 0, scheduled events: 3
  loaded plugins: curl ldap aes des sha1 sha2 md5 random x509 pubkey pkcs1 pgp dnskey pem openssl gcrypt fips-prf xcbc hmac agent gmp attr kernel-netlink socket-raw socket-dynamic farp stroke updown eap-identity eap-aka eap-md5 eap-gtc eap-mschapv2 dhcp resolve 
Listening IP addresses:
  192.168.2.10
  2001:db8:1:2:20c:29ff:fe45:b04e
Connections:
        TAHI:  2001:db8:1:2:20c:29ff:fe45:b04e...2001:db8:1:1:20c:29ff:fe0c:3ed1
        TAHI:   local:  [2001:db8:1:2:20c:29ff:fe45:b04e] uses pre-shared key authentication
        TAHI:   remote: [2001:db8:1:1:20c:29ff:fe0c:3ed1] uses any authentication
        TAHI:   child:  dynamic === dynamic 
Security Associations:
        TAHI[1]: ESTABLISHED 23 seconds ago, 2001:db8:1:2:20c:29ff:fe45:b04e[2001:db8:1:2:20c:29ff:fe45:b04e]...2001:db8:1:1:20c:29ff:fe0c:3ed1[2001:db8:1:1:20c:29ff:fe0c:3ed1]
        TAHI[1]: IKE SPIs: b21e1a3b193ad1a5_i* 26461e9385d874db_r, pre-shared key reauthentication in 2 hours
        TAHI[1]: IKE proposal: 3DES_CBC/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
        TAHI{1}:  REKEYING, TRANSPORT
        TAHI{1}:   2001:db8:1:2:20c:29ff:fe45:b04e/128 === 2001:db8:1:1:20c:29ff:fe0c:3ed1/128 
-----------------------------------------------------------------------------------------------
The STRONGSWAN side seems to try to rekey and the rekeying is not successful.


Additional Info:
-----------------
1 This test is successful when setting the OPENSWAN CHILD_SA lifetime to a shorter value and STRONGSWAN CHILD_SA lifetime to a larger value.
2 The rekey between 2 strongswan hosts are successful (setting one side to 30s and the other side to 300s)

Regards & Thanks
Frank