Support for ESNs (extended sequence numbers).
Tested with strongswan on a P2020RDB back-to-back setup.
Extracted from /etc/ipsec.conf:
esp=aes-sha1-esn-modp4096!
Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>