--- 1/draft-ietf-tokbind-https-10.txt 2017-11-15 15:13:11.837031562 -0800 +++ 2/draft-ietf-tokbind-https-11.txt 2017-11-15 15:13:11.893032897 -0800 @@ -1,24 +1,24 @@ Internet Engineering Task Force A. Popov Internet-Draft M. Nystroem Intended status: Standards Track Microsoft Corp. -Expires: January 22, 2018 D. Balfanz, Ed. +Expires: May 19, 2018 D. Balfanz, Ed. A. Langley N. Harper Google Inc. J. Hodges PayPal - July 21, 2017 + November 15, 2017 Token Binding over HTTP - draft-ietf-tokbind-https-10 + draft-ietf-tokbind-https-11 Abstract This document describes a collection of mechanisms that allow HTTP servers to cryptographically bind security tokens (such as cookies and OAuth tokens) to TLS connections. We describe both first-party and federated scenarios. In a first- party scenario, an HTTP server is able to cryptographically bind the security tokens it issues to a client, and which the client @@ -35,37 +35,37 @@ Protocol. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- - Drafts is at http://datatracker.ietf.org/drafts/current/. + Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on January 22, 2018. + This Internet-Draft will expire on May 19, 2018. Copyright Notice Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents - (http://trustee.ietf.org/license-info) in effect on the date of + (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 @@ -80,30 +80,30 @@ 5.3. HTTP Redirects . . . . . . . . . . . . . . . . . . . . . 8 5.4. Negotiated Key Parameters . . . . . . . . . . . . . . . . 10 5.5. Federation Example . . . . . . . . . . . . . . . . . . . 11 6. Implementation Considerations . . . . . . . . . . . . . . . . 13 7. Security Considerations . . . . . . . . . . . . . . . . . . . 13 7.1. Security Token Replay . . . . . . . . . . . . . . . . . . 13 7.2. Triple Handshake Vulnerability in TLS 1.2 and Older TLS Versions . . . . . . . . . . . . . . . . . . . . . . . . 14 7.3. Sensitivity of the Sec-Token-Binding Header . . . . . . . 14 7.4. Securing Federated Sign-On Protocols . . . . . . . . . . 15 - 8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 17 - 8.1. Scoping of Token Binding Key Pairs . . . . . . . . . . . 17 + 8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 18 + 8.1. Scoping of Token Binding Key Pairs . . . . . . . . . . . 18 8.2. Lifetime of Token Binding Key Pairs . . . . . . . . . . . 18 - 8.3. Correlation . . . . . . . . . . . . . . . . . . . . . . . 18 + 8.3. Correlation . . . . . . . . . . . . . . . . . . . . . . . 19 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 - 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 19 - 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 19 - 11.1. Normative References . . . . . . . . . . . . . . . . . . 19 + 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20 + 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 + 11.1. Normative References . . . . . . . . . . . . . . . . . . 20 11.2. Informative References . . . . . . . . . . . . . . . . . 21 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 1. Introduction The Token Binding Protocol [I-D.ietf-tokbind-protocol] defines a Token Binding ID for a TLS connection between a client and a server. The Token Binding ID of a TLS connection is constructed using the public key of a private-public key pair. The client proves possession of the corresponding private key. This Token Binding key pair is long-lived. I.e., subsequent TLS connections between the same client and server have the same Token Binding ID, unless @@ -781,20 +781,43 @@ referred Token Binding ID in an application-level message as part of the redirect URL) is one way to assure that the man-in-the-middle between client and Token Consumer cannot affect the communication of the referred Token Binding ID to the Token Provider. Therefore, the Sec-Token-Binding header field in the federated sign- on use case contains both: a proof of possession of the provided Token Binding key, as well as a proof of possession of the referred Token Binding key. + Note that the presence of Token Binding does not relieve the Token + Provider and Token Consumer from performing various checks to ensure + the security of clients during federated sign-on protocols. These + include the following: + + o The Token Provider should not issue tokens to Token Consumers that + have been shown to act maliciously. To aid in this, the + federation protocol should identify the Token Consumer to the + Token Provider (e.g., through OAuth client IDs or similar + mechanisms), and the Token Provider should ensure that tokens are + indeed issued to the Token Consumer identified in the token + request (e.g., by verifying that the redirect URI is associated + with the OAuth client ID.) + + o The Token Consumer should verify that the tokens were issued for + it, and not some other token consumer. To aid in this, the + federation protocol should include an audience parameter in the + token response, or apply equivalent mechanisms (the implicit OAuth + flow requires Token Consumers to identify themselves when they + exchange OAuth authorization codes for OAuth refresh tokens, + leaving it up to the Token Provider to verify that the OAuth + authorization was delivered to the correct Token Consumer). + 8. Privacy Considerations 8.1. Scoping of Token Binding Key Pairs Clients use different Token Binding key pairs for different servers, so as to not allow Token Binding to become a tracking tool across different servers. However, the scoping of the Token Binding key pairs to servers varies according to the scoping rules of the application protocol (Section 4.1 of [I-D.ietf-tokbind-protocol]). @@ -899,94 +921,94 @@ 11.1. Normative References [fetch-spec] WhatWG, "Fetch", Living Standard , . [I-D.ietf-tokbind-negotiation] Popov, A., Nystrom, M., Balfanz, D., and A. Langley, "Transport Layer Security (TLS) Extension for Token Binding Protocol Negotiation", draft-ietf-tokbind- - negotiation-09 (work in progress), July 2017. + negotiation-10 (work in progress), October 2017. [I-D.ietf-tokbind-protocol] Popov, A., Nystrom, M., Balfanz, D., Langley, A., and J. Hodges, "The Token Binding Protocol Version 1.0", draft- - ietf-tokbind-protocol-15 (work in progress), July 2017. + ietf-tokbind-protocol-16 (work in progress), October 2017. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, - . + . [RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration Procedures for Message Header Fields", BCP 90, RFC 3864, DOI 10.17487/RFC3864, September 2004, - . + . [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006, - . + . [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008, - . + . [RFC5705] Rescorla, E., "Keying Material Exporters for Transport Layer Security (TLS)", RFC 5705, DOI 10.17487/RFC5705, - March 2010, . + March 2010, . [RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265, DOI 10.17487/RFC6265, April 2011, - . + . [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing", RFC 7230, DOI 10.17487/RFC7230, June 2014, - . + . [RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content", RFC 7231, DOI 10.17487/RFC7231, June 2014, - . + . [RFC7541] Peon, R. and H. Ruellan, "HPACK: Header Compression for HTTP/2", RFC 7541, DOI 10.17487/RFC7541, May 2015, - . + . 11.2. Informative References [OpenID.Core] Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, "OpenID Connect Core 1.0", August 2015, . [RFC5746] Rescorla, E., Ray, M., Dispensa, S., and N. Oskov, "Transport Layer Security (TLS) Renegotiation Indication Extension", RFC 5746, DOI 10.17487/RFC5746, February 2010, - . + . [RFC6749] Hardt, D., Ed., "The OAuth 2.0 Authorization Framework", RFC 6749, DOI 10.17487/RFC6749, October 2012, - . + . [RFC7540] Belshe, M., Peon, R., and M. Thomson, Ed., "Hypertext Transfer Protocol Version 2 (HTTP/2)", RFC 7540, DOI 10.17487/RFC7540, May 2015, - . + . [RFC7627] Bhargavan, K., Ed., Delignat-Lavaud, A., Pironti, A., Langley, A., and M. Ray, "Transport Layer Security (TLS) Session Hash and Extended Master Secret Extension", RFC 7627, DOI 10.17487/RFC7627, September 2015, - . + . [TRIPLE-HS] Bhargavan, K., Delignat-Lavaud, A., Fournet, C., Pironti, A., and P. Strub, "Triple Handshakes and Cookie Cutters: Breaking and Fixing Authentication over TLS. IEEE Symposium on Security and Privacy", 2014. Authors' Addresses Andrei Popov