STIR Out-of-Band Architecture and Use Cases
draft-ietf-stir-oob-01
Network Working Group E. Rescorla
Internet-Draft Mozilla
Intended status: Standards Track J. Peterson
Expires: May 2, 2018 Neustar
October 29, 2017
STIR Out-of-Band Architecture and Use Cases
draft-ietf-stir-oob-01.txt
Abstract
The PASSporT format defines a token that can be carried by signaling
protocols, including SIP, to cryptographically attest the identify of
callers. Not all telephone calls use Internet signaling protocols,
however, and some calls use them for only part of their signaling
path. This document describes use cases that require the delivery of
PASSporT objects outside of the signaling path, and defines
architectures and semantics to provide this functionality.
Status of This Memo
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This Internet-Draft will expire on May 2, 2018.
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Copyright (c) 2017 IETF Trust and the persons identified as the
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Rescorla & Peterson Expires May 2, 2018 [Page 1]
Internet-Draft STIR Fallback October 2017
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Operating Environments . . . . . . . . . . . . . . . . . . . 4
4. Dataflows . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Case 1: VoIP to PSTN Call . . . . . . . . . . . . . . . . 6
5.2. Case 2: Two Smart PSTN endpoints . . . . . . . . . . . . 6
5.3. Case 3: PSTN to VoIP Call . . . . . . . . . . . . . . . . 7
5.4. Case 4: Gateway Out-of-band . . . . . . . . . . . . . . . 7
6. Storing and Retrieving PASSporTs . . . . . . . . . . . . . . 8
6.1. Storage . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.2. Retrieval . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Solution Architecture . . . . . . . . . . . . . . . . . . . . 11
7.1. Credentials and Phone Numbers . . . . . . . . . . . . . . 12
7.2. Call Flow . . . . . . . . . . . . . . . . . . . . . . . . 12
7.3. Security Analysis . . . . . . . . . . . . . . . . . . . . 13
7.4. Substitution Attacks . . . . . . . . . . . . . . . . . . 13
8. Call Placement Service Discovery . . . . . . . . . . . . . . 14
9. Credential Lookup . . . . . . . . . . . . . . . . . . . . . . 15
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
12. Security Considerations . . . . . . . . . . . . . . . . . . . 16
13. Informative References . . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction
The STIR problem statement [RFC7340] describes widespread problems
enabled by impersonation in the telephone network, including illegal
robocalling, voicemail hacking, and swatting. As telephone services
are increasingly migrating onto the Internet, and using Voice over IP
(VoIP) protocols such as SIP [RFC3261], it is necessary for these
protocols to support stronger identity mechanisms to prevent
impersonation. For example, [I-D.ietf-stir-rfc4474bis] defines an
Identity header of SIP requests capable of carrying a PASSporT
[I-D.ietf-stir-passport] object in SIP as a means to
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