[Hipsec] rfc5201-bis issue 35: limiting ECC cofactor to 1

["Henderson, Thomas R" <[e-mail]>]

This was already proposed to the list a while back:
http://www.ietf.org/mail-archive/web/hipsec/current/msg03462.html

so I'd like to close this issue by adopting the proposed text; specifically:

1) Section 5.2.7 (Diffie Hellman)

OLD TEXT:

   The MODP Diffie-Hellman groups are defined in [RFC3526].  The ECDH
   groups 8 - 10 are defined in [RFC5903] and [RFC6090].  ECDH group 7
   is covered in Appendix D.

NEW TEXT:

   The MODP Diffie-Hellman groups are defined in [RFC3526]. The ECDH
   groups 7 - 9 are defined in [RFC5903] and [RFC6090]. ECDH group 10 
   is covered in Appendix D.  Any ECDH used with HIP MUST have a 
   co-factor of 1.

2) Section 5.2.9 (HOST ID)

OLD TEXT:

   ...  For ECC we distinguish two different profiles:
   ECDSA and ECDSA_LOW.  ECC contains curves approved by NIST and
   defined in RFC 4754 [RFC4754].  ECDSA_LOW is defined for devices with
   low computational capabilities and uses shorter curves from SECG
   [SECG].

   ...  For ECC we distinguish two different profiles:
   ECDSA and ECDSA_LOW. ECC contains curves approved by NIST and
   defined in RFC 4754 [RFC4754]. ECDSA_LOW is defined for devices with
   low computational capabilities and uses shorter curves from SECG
   [SECG].  Any ECDSA used with HIP MUST have a co-factor of 1.