Subject: [dhcwg] draft-jiang-csi-cga-config-dhcpv6-01

From: "Bernie Volz (volz)" <[email-masked]>
Date: Thu, 25 Mar 2010 12:56:17 -0500

Hi:

You should clarify the encoding of this OPTION_CGA_GR option as how does
the server (or client) know the size of the public key to understand
whether there is or is not an extension field? Perhaps there is a
particular format in which the public key is encoded which contains a
length - if this is the case, please provide a reference to the encoding
in the document.

Also, the option-len is 12 (1 for CGA_SEC, 3 for reserved, 8 for subnet
prefix) + length of public key + length of extension fields.

And, you need to provide details on how the extension field is to be
encoded (when and if it is used).

- Bernie

5.2. DHCPv6 CGA Generation Request Option

...
 
    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       OPTION_CGA_GR           |       option-len              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    CGA SEC    |                    Reserved                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     Subnet Prefix (64-bit)                    |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~                Public Key (variable length)                   ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   ~       Extension Fields (optional, variable length,)           ~
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 
       option-code     OPTION_CGA_GR (TBA).
 
       option-len      16 + Length of public key field in octets.
 
       CGA SEC        a digit between 0 and 7, the SEC level require
                       by the client.
 
       Reserved        A 24-bit field reserved for future use. The
                       value MUST be initialized to zero by the sender,
                       and MUST be ignored by the receiver.
 
       Subnet Prefix   An IPv6 prefix provided by the client, used for
                       CGA generation. If set all 0, DHCPv6 server will
                       use its own configured IPv6 subnet prefix.
 
       Public Key      This is a variable-length field contain the
                       public key of the client. This public key will
                       be used for CGA generation.

---

From: Sheng Jiang <[email-masked]>
Date: Fri, 26 Mar 2010 02:27:15 +0800

> length – if this is the case, please provide a reference to the encoding
> in the document.
>

Yes. You get it right here. We noticed that recently. We were going to 
fix it with the other comments we might receive during or after the ietf 
meeting. Thanks.

> encoded (when and if it is used).

The extension field is defined in the CGA rfc, but so far, there is no 
user case at all.

Thanks and regards,

Sheng

> …