Subject: Re: [Netconf] zerotouch/17: How to verify boot-image integrity?

From: Kent Watsen <[email-masked]>
Date: Tue, 16 Aug 2016 00:01:49 +0000

This issue was discussed in Berlin.  The minutes capture the following:

    Issue #17:
    RW: My preference is NOT to do nothing. I support option #3 - encode both.
    KW: it is good not to have to worry about outdated security methods, hence option 1 is not a good idea.

Listening to the audio recording, it seems that we were leaning towards option #3  - that is, a format that allows us to use SHA256 now, and gracefully add support for additional algorithms in the future if needed.

During the meeting, we discussed an option for the Security Area to quickly publish a new draft defining a generic hashing format, but I’m not sure if it’s needed, as it seems that we could more easily do it using a ‘choice’ statement as follows:

     container boot-image {
        leaf name {
           type string;
        }
        choice name {
           leaf sha256 {      <--- this would be the only choice for now
              type string;
           }
           mandatory true;
        }
        <snip/>
     }

In this way, future revisions of the module can add new ‘case’ statements.  This solution results in a simple instance encoding, for example:

  <boot-image>
     <name>boot-image-v3.2R1.6.img</name>
    <sha256>9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08</sha256>
    ...
  </boot-image>

What do you think?  I’ll assume this is okay If no objections are raised by the end of this week.

Thanks,
Kent