MUD processing and extensions for Secure Home Gateway Project
draft-richardson-opsawg-securehomegateway-mud-00

Abstract

This document details the mechanism used by the CIRA Secure Home Gateway and CIRA MUD integration server to return MUD artifacts to participating gateway systems.

The work in [I-D.ietf-opsawg-mud] creates a relationship between a device's manufacturer and a border gateway that may need to enforce policy. This document ads an additional relationship to a service provider, trusted by the border gateway to enhance or modify the stated security policy.

Status of This Memo

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This Internet-Draft will expire on March 21, 2019.

Copyright Notice

Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved.

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Table of Contents

• 1. Introduction
• 2. Terminology
• 3. Requirements Language
• 4. MUD file extensions
• 4.1. Tree Diagram
• 4.2. YANG FILE
• 5. Security Considerations
• 6. IANA Considerations
• 7. Acknowledgements
• 8. Normative References
• Authors' Addresses

1. Introduction

The initial extension from this document is to provide for a way to mark a set of ACLs as being enabled even though the device has quaranteed. {EDNOTE: more motivational text here}

The second issue addressed by the document is the question of whether and when the MUD file should be specific to a specific version of the device firmware.

The third issue is that an intermediary (ISP, or third-party security service) may want to extend or amend a MUD file received from a manufacturer. In order to maintain an audit trail of changes, a way to encode the previous MUD URL and signature file (and status) is provided.

2. Terminology

The major new term, compared to the MUD document is the term

quaranteed:

a device which has shown behaviour forbidden by a MUD file ACL, and has subsequently been denied further access to the network.

3. Requirements Language

In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in BCP 14, RFC 2119 [RFC2119] and indicate requirement levels for compliant STuPiD implementations.

4. MUD file extensions

4.1. Tree Diagram

module: cira-shg-mud
  augment /m:mud:
    +--rw quaranteed-device-policy
       +--rw access-lists
          +--rw access-list* [name]
             +--rw name    -> /acl:acls/acl/name

4.2. YANG FILE

<CODE BEGINS> file "cira-shg-mud@2017-12-11.yang"
module cira-shg-mud {
  yang-version 1.1;

  namespace
    "urn:ietf:params:xml:ns:yang:ietf-shg-mud";
  prefix "shg";

  import ietf-mud {
    prefix m;
    description "This module defines the format for a MUD description";
    reference "RFC YYYY: MUD YANG";
  }

  organization "CIRALabs Secure Home Gateway project.";

  contact
   "WG Web:   <http://securehomegateway.ca/>
    WG List:  <mailto:securehomegateway@cira.ca>
    Author:   Michael Richardson
              <mailto:mcr+ietf@sandelman.ca>";

  description
   "This module extends the RFCXXXX MUD format to include two
   facilities: definition of an Access Control List appropriate
   to enable device upgrade only, and provide for a history of
   modifications by third-parties to the MUD file";

  revision "2017-12-11" {
    description
     "Initial version";
    reference
     "RFC XXXX: MUD profile for Secure Home Gateway Project";
  }

  augment "/m:mud" {
    description
      "Adds leaf nodes appropriate MUD usage in the
       Secure Home Gateway";

    container quaranteed-device-policy {
      description
        "The policies that should be enforced on traffic
         coming from the device when it is under quaranteen.
         These policies are usually a subset of operational policies
         and are intended to permit firmware updates only.
         They are intended to keep the device safe (and the network safe
         from the device) when the device is suspected of being
         out-of-date, but still considered sufficiently intact to be
         able to do a firmware update";
      uses m:access-lists;
    }
  }

}

<CODE ENDS>

5. Security Considerations

TBD.

6. IANA Considerations

TBD.

7. Acknowledgements

This work was supported by the Canadian Internet Registration Authority (cira.ca).

8. Normative References

Authors' Addresses