draft-ietf-tls-subcerts-04.txt   draft-ietf-tls-subcerts-05.txt 
Network Working Group R. Barnes Network Working Group R. Barnes
Internet-Draft Cisco Internet-Draft Cisco
Intended status: Standards Track S. Iyengar Intended status: Standards Track S. Iyengar
Expires: January 9, 2020 Facebook Expires: May 6, 2020 Facebook
N. Sullivan N. Sullivan
Cloudflare Cloudflare
E. Rescorla E. Rescorla
RTFM, Inc. Mozilla
July 08, 2019 November 03, 2019
Delegated Credentials for TLS Delegated Credentials for TLS
draft-ietf-tls-subcerts-04 draft-ietf-tls-subcerts-05
Abstract Abstract
The organizational separation between the operator of a TLS endpoint The organizational separation between the operator of a TLS endpoint
and the certification authority can create limitations. For example, and the certification authority can create limitations. For example,
the lifetime of certificates, how they may be used, and the the lifetime of certificates, how they may be used, and the
algorithms they support are ultimately determined by the algorithms they support are ultimately determined by the
certification authority. This document describes a mechanism by certification authority. This document describes a mechanism by
which operators may delegate their own credentials for use in TLS, which operators may delegate their own credentials for use in TLS,
without breaking compatibility with peers that do not support this without breaking compatibility with peers that do not support this
specification. specification.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- 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 Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 9, 2020. This Internet-Draft will expire on May 6, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Change Log . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Change Log . . . . . . . . . . . . . . . . . . . . . . . 3
2. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 4 2. Solution Overview . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Rationale . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1. Rationale . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2. Related Work . . . . . . . . . . . . . . . . . . . . . . 5 2.2. Related Work . . . . . . . . . . . . . . . . . . . . . . 6
3. Delegated Credentials . . . . . . . . . . . . . . . . . . . . 6 3. Delegated Credentials . . . . . . . . . . . . . . . . . . . . 7
3.1. Client and Server behavior . . . . . . . . . . . . . . . 8 3.1. Client and Server behavior . . . . . . . . . . . . . . . 8
3.1.1. Server authentication . . . . . . . . . . . . . . . . 8 3.1.1. Server authentication . . . . . . . . . . . . . . . . 8
3.1.2. Client authentication . . . . . . . . . . . . . . . . 9 3.1.2. Client authentication . . . . . . . . . . . . . . . . 9
3.1.3. Validating a Delegated Credential . . . . . . . . . . 9 3.1.3. Validating a Delegated Credential . . . . . . . . . . 9
3.2. Certificate Requirements . . . . . . . . . . . . . . . . 10 3.2. Certificate Requirements . . . . . . . . . . . . . . . . 10
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 5. Security Considerations . . . . . . . . . . . . . . . . . . . 11
5.1. Security of delegated private key . . . . . . . . . . . . 10 5.1. Security of delegated private key . . . . . . . . . . . . 11
5.2. Re-use of delegated credentials in multiple contexts . . 11 5.2. Re-use of delegated credentials in multiple contexts . . 11
5.3. Revocation of delegated credentials . . . . . . . . . . . 11 5.3. Revocation of delegated credentials . . . . . . . . . . . 11
5.4. Privacy considerations . . . . . . . . . . . . . . . . . 11 5.4. Interactions with session resumption . . . . . . . . . . 12
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 5.5. Privacy considerations . . . . . . . . . . . . . . . . . 12
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
7.1. Normative References . . . . . . . . . . . . . . . . . . 11 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.2. Informative References . . . . . . . . . . . . . . . . . 12 7.1. Normative References . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13 7.2. Informative References . . . . . . . . . . . . . . . . . 13
Appendix A. ASN.1 Module . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
Typically, a TLS server uses a certificate provided by some entity Typically, a TLS server uses a certificate provided by some entity
other than the operator of the server (a "Certification Authority" or other than the operator of the server (a "Certification Authority" or
CA) [RFC8446] [RFC5280]. This organizational separation makes the CA) [RFC8446] [RFC5280]. This organizational separation makes the
TLS server operator dependent on the CA for some aspects of its TLS server operator dependent on the CA for some aspects of its
operations, for example: operations, for example:
o Whenever the server operator wants to deploy a new certificate, it o Whenever the server operator wants to deploy a new certificate, it
has to interact with the CA. has to interact with the CA.
o The server operator can only use TLS authentication schemes for o The server operator can only use TLS authentication schemes for
which the CA will issue credentials. which the CA will issue credentials.
These dependencies cause problems in practice. Server operators These dependencies cause problems in practice. Server operators
often want to create short-lived certificates for servers in low- often want to create short-lived certificates for servers in low-
trust zones such as CDNs or remote data centers. This allows server trust zones such as Content Delivery Network (CDNs) or remote data
operators to limit the exposure of keys in cases that they do not centers. This allows server operators to limit the exposure of keys
realize a compromise has occurred. The risk inherent in cross- in cases that they do not realize a compromise has occurred. The
organizational transactions makes it operationally infeasible to rely risk inherent in cross-organizational transactions makes it
on an external CA for such short-lived credentials. In OCSP stapling operationally infeasible to rely on an external CA for such short-
(i.e., using the Certificate Status extension types ocsp [RFC6066] or lived credentials. In Online Certiicate Status Protocol (OCSP)
ocsp_multi [RFC6961]), if an operator chooses to talk frequently to stapling (i.e., using the Certificate Status extension types ocsp
the CA to obtain stapled responses, then failure to fetch an OCSP [RFC6066] or ocsp_multi [RFC6961]), if an operator chooses to talk
stapled response results only in degraded performance. On the other frequently to the CA to obtain stapled responses, then failure to
hand, failure to fetch a potentially large number of short lived fetch an OCSP stapled response results only in degraded performance.
certificates would result in the service not being available, which On the other hand, failure to fetch a potentially large number of
creates greater operational risk. short lived certificates would result in the service not being
available, which creates greater operational risk.
To remove these dependencies, this document proposes a limited To remove these dependencies, this document proposes a limited
delegation mechanism that allows a TLS peer to issue its own delegation mechanism that allows a TLS peer to issue its own
credentials within the scope of a certificate issued by an external credentials within the scope of a certificate issued by an external
CA. Because the above problems do not relate to the CA's inherent CA. Because the above problems do not relate to the CA's inherent
function of validating possession of names, it is safe to make such function of validating possession of names, it is safe to make such
delegations as long as they only enable the recipient of the delegations as long as they only enable the recipient of the
delegation to speak for names that the CA has authorized. For delegation to speak for names that the CA has authorized. For
clarity, we will refer to the certificate issued by the CA as a clarity, we will refer to the certificate issued by the CA as a
"certificate", or "delegation certificate", and the one issued by the "certificate", or "delegation certificate", and the one issued by the
operator as a "delegated credential" or "DC". operator as a "delegated credential" or "DC".
1.1. Change Log 1.1. Change Log
(*) indicates changes to the wire protocol. (*) indicates changes to the wire protocol.
draft-05
o Removed support for PKCS 1.5 RSA signature algorithms.
o Additional security considerations.
draft-04 draft-04
o Add support for client certificates. o Add support for client certificates.
draft-03 draft-03
o Remove protocol version from the Credential structure. (*) o Remove protocol version from the Credential structure. (*)
draft-02
o Change public key type. (*) o Change public key type. (*)
o Change DelegationUsage extension to be NULL and define its object o Change DelegationUsage extension to be NULL and define its object
identifier. identifier.
o Drop support for TLS 1.2. o Drop support for TLS 1.2.
o Add the protocol version and credential signature algorithm to the o Add the protocol version and credential signature algorithm to the
Credential structure. (*) Credential structure. (*)
skipping to change at page 4, line 21 skipping to change at page 4, line 27
sent as extensions to certificates other than the end-entity sent as extensions to certificates other than the end-entity
certificate. certificate.
2. Solution Overview 2. Solution Overview
A delegated credential is a digitally signed data structure with two A delegated credential is a digitally signed data structure with two
semantic fields: a validity interval and a public key (along with its semantic fields: a validity interval and a public key (along with its
associated signature algorithm). The signature on the credential associated signature algorithm). The signature on the credential
indicates a delegation from the certificate that is issued to the indicates a delegation from the certificate that is issued to the
peer. The secret key used to sign a credential corresponds to the peer. The secret key used to sign a credential corresponds to the
public key of the peer's X.509 end-entity certificate. public key of the peer's X.509 end-entity certificate [RFC5280].
A TLS handshake that uses delegated credentials differs from a normal A TLS handshake that uses delegated credentials differs from a normal
handshake in a few important ways: handshake in a few important ways:
o The initiating peer provides an extension in its ClientHello or o The initiating peer provides an extension in its ClientHello or
CertificateRequest that indicates support for this mechanism. CertificateRequest that indicates support for this mechanism.
o The peer sending the Certificate message provides both the o The peer sending the Certificate message provides both the
certificate chain terminating in its certificate as well as the certificate chain terminating in its certificate as well as the
delegated credential. delegated credential.
skipping to change at page 5, line 45 skipping to change at page 6, line 9
o Each delegated credential is bound to a specific signature o Each delegated credential is bound to a specific signature
algorithm that may be used to sign the TLS handshake ([RFC8446] algorithm that may be used to sign the TLS handshake ([RFC8446]
section 4.2.3). This prevents them from being used with other, section 4.2.3). This prevents them from being used with other,
perhaps unintended signature algorithms. perhaps unintended signature algorithms.
2.2. Related Work 2.2. Related Work
Many of the use cases for delegated credentials can also be addressed Many of the use cases for delegated credentials can also be addressed
using purely server-side mechanisms that do not require changes to using purely server-side mechanisms that do not require changes to
client behavior (e.g., LURK [I-D.mglt-lurk-tls-requirements]). These client behavior (e.g., a PKCS#11 interface or a remote signing
mechanisms, however, incur per-transaction latency, since the front- mechanism [KEYLESS]). These mechanisms, however, incur per-
end server has to interact with a back-end server that holds a transaction latency, since the front-end server has to interact with
private key. The mechanism proposed in this document allows the a back-end server that holds a private key. The mechanism proposed
delegation to be done off-line, with no per-transaction latency. The in this document allows the delegation to be done off-line, with no
figure below compares the message flows for these two mechanisms with per-transaction latency. The figure below compares the message flows
TLS 1.3 [I-D.ietf-tls-tls13]. for these two mechanisms with TLS 1.3 [RFC8446].
LURK: Remote key signing:
Client Front-End Back-End Client Front-End Back-End
|----ClientHello--->| | |----ClientHello--->| |
|<---ServerHello----| | |<---ServerHello----| |
|<---Certificate----| | |<---Certificate----| |
| |<-------LURK------->| | |<---remote sign---->|
|<---CertVerify-----| | |<---CertVerify-----| |
| ... | | | ... | |
Delegated credentials: Delegated credentials:
Client Front-End Back-End Client Front-End Back-End
| |<----DC minting---->| | |<--DC distribution->|
|----ClientHello--->| | |----ClientHello--->| |
|<---ServerHello----| | |<---ServerHello----| |
|<---Certificate----| | |<---Certificate----| |
|<---CertVerify-----| | |<---CertVerify-----| |
| ... | | | ... | |
These two mechanisms can be complementary. A server could use These two mechanisms can be complementary. A server could use
credentials for clients that support them, while using LURK to credentials for clients that support them, while using [KEYLESS] to
support legacy clients. support legacy clients.
It is possible to address the short-lived certificate concerns above It is possible to address the short-lived certificate concerns above
by automating certificate issuance, e.g., with ACME by automating certificate issuance, e.g., with Automated Certificate
[I-D.ietf-acme-acme]. In addition to requiring frequent Managmeent Encvironment (ACME) [RFC8555]. In addition to requiring
operationally-critical interactions with an external party, this frequent operationally-critical interactions with an external party,
makes the server operator dependent on the CA's willingness to issue this makes the server operator dependent on the CA's willingness to
certificates with sufficiently short lifetimes. It also fails to issue certificates with sufficiently short lifetimes. It also fails
address the issues with algorithm support. Nonetheless, existing to address the issues with algorithm support. Nonetheless, existing
automated issuance APIs like ACME may be useful for provisioning automated issuance APIs like ACME may be useful for provisioning
credentials within an operator network. credentials within an operator network.
3. Delegated Credentials 3. Delegated Credentials
While X.509 forbids end-entity certificates from being used as While X.509 forbids end-entity certificates from being used as
issuers for other certificates, it is perfectly fine to use them to issuers for other certificates, it is perfectly fine to use them to
issue other signed objects as long as the certificate contains the issue other signed objects as long as the certificate contains the
digitalSignature KeyUsage (RFC5280 section 4.2.1.3). We define a new digitalSignature KeyUsage ([RFC5280] section 4.2.1.3). We define a
signed object format that would encode only the semantics that are new signed object format that would encode only the semantics that
needed for this application. The credential has the following are needed for this application. The credential has the following
structure: structure:
struct { struct {
uint32 valid_time; uint32 valid_time;
SignatureScheme expected_cert_verify_algorithm; SignatureScheme expected_cert_verify_algorithm;
opaque ASN1_subjectPublicKeyInfo<1..2^24-1>; opaque ASN1_subjectPublicKeyInfo<1..2^24-1>;
} Credential; } Credential;
valid_time: Relative time in seconds from the beginning of the valid_time: Relative time in seconds from the beginning of the
delegation certificate's notBefore value after which the delegated delegation certificate's notBefore value after which the delegated
credential is no longer valid. credential is no longer valid.
expected_cert_verify_algorithm: The signature algorithm of the expected_cert_verify_algorithm: The signature algorithm of the
credential key pair, where the type SignatureScheme is as defined credential key pair, where the type SignatureScheme is as defined
in [RFC8446]. This is expected to be the same as in [RFC8446]. This is expected to be the same as
CertificateVerify.algorithm sent by the server. CertificateVerify.algorithm sent by the server. Only signature
algorithms allowed for use in CertificateVerify messages are
allowed. When using RSA, the public key MUST NOT use the
rsaEncryption OID, as a result, the following algorithms are not
allowed for use with delegated credentials: rsa_pss_rsae_sha256,
rsa_pss_rsae_sha384, rsa_pss_rsae_sha512.
ASN1_subjectPublicKeyInfo: The credential's public key, a DER- ASN1_subjectPublicKeyInfo: The credential's public key, a DER-
encoded [X690] SubjectPublicKeyInfo as defined in [RFC5280]. encoded [X690] SubjectPublicKeyInfo as defined in [RFC5280].
The delegated credential has the following structure: The delegated credential has the following structure:
struct { struct {
Credential cred; Credential cred;
SignatureScheme algorithm; SignatureScheme algorithm;
opaque signature<0..2^16-1>; opaque signature<0..2^16-1>;
skipping to change at page 8, line 21 skipping to change at page 8, line 36
this way is intended to mitigate the risk of cross protocol attacks this way is intended to mitigate the risk of cross protocol attacks
involving delegated credentials. involving delegated credentials.
The code changes required in order to create and verify delegated The code changes required in order to create and verify delegated
credentials, and the implementation complexity this entails, are credentials, and the implementation complexity this entails, are
localized to the TLS stack. This has the advantage of avoiding localized to the TLS stack. This has the advantage of avoiding
changes to security-critical and often delicate PKI code. changes to security-critical and often delicate PKI code.
3.1. Client and Server behavior 3.1. Client and Server behavior
This document defines the following extension code point. This document defines the following TLS extension code point.
enum { enum {
... ...
delegated_credential(TBD), delegated_credential(TBD),
(65535) (65535)
} ExtensionType; } ExtensionType;
3.1.1. Server authentication 3.1.1. Server authentication
A client which supports this specification SHALL send an empty A client which supports this specification SHALL send an empty
skipping to change at page 9, line 44 skipping to change at page 10, line 9
certificate to the peer's expected identity in the usual way. It certificate to the peer's expected identity in the usual way. It
also takes the following steps: also takes the following steps:
1. Verify that the current time is within the validity interval of 1. Verify that the current time is within the validity interval of
the credential and that the credential's time to live is no more the credential and that the credential's time to live is no more
than 7 days. This is done by asserting that the current time is than 7 days. This is done by asserting that the current time is
no more than the delegation certificate's notBefore value plus no more than the delegation certificate's notBefore value plus
DelegatedCredential.cred.valid_time. DelegatedCredential.cred.valid_time.
2. Verify that expected_cert_verify_algorithm matches the scheme 2. Verify that expected_cert_verify_algorithm matches the scheme
indicated in the peer's CertificateVerify message. indicated in the peer's CertificateVerify message and that the
algorithm is allowed for use with delegated credentials.
3. Verify that the end-entity certificate satisfies the conditions 3. Verify that the end-entity certificate satisfies the conditions
in Section 3.2. in Section 3.2.
4. Use the public key in the peer's end-entity certificate to verify 4. Use the public key in the peer's end-entity certificate to verify
the signature of the credential using the algorithm indicated by the signature of the credential using the algorithm indicated by
DelegatedCredential.algorithm. DelegatedCredential.algorithm.
If one or more of these checks fail, then the delegated credential is If one or more of these checks fail, then the delegated credential is
deemed invalid. Clients and servers that receive invalid delegated deemed invalid. Clients and servers that receive invalid delegated
credentials MUST terminate the connection with an "illegal_parameter" credentials MUST terminate the connection with an "illegal_parameter"
alert. If successful, the participant receiving the Certificate alert. If successful, the participant receiving the Certificate
message uses the public key in the credential to verify the signature message uses the public key in the credential to verify the signature
in the peer's CertificateVerify message. in the peer's CertificateVerify message.
3.2. Certificate Requirements 3.2. Certificate Requirements
We define a new X.509 extension, DelegationUsage, to be used in the We define a new X.509 extension, DelegationUsage, to be used in the
certificate when the certificate permits the usage of delegated certificate when the certificate permits the usage of delegated
credentials. credentials. What follows is the ASN.1 [X680] for the
DelegationUsage certificate extension.
id-ce-delegationUsage OBJECT IDENTIFIER ::= { 1.3.6.1.4.1.44363.44 } ext-delegationUsage EXTENSION ::= {
DelegationUsage ::= NULL SYNTAX DelegationUsage IDENTIFIED BY id-ce-delegationUsage
}
DelegationUsage ::= NULL
id-ce-delegationUsage OBJECT IDENTIFIER ::= { 1 3 6 1 4 1 44363 44 }
The extension MUST be marked non-critical. (See Section 4.2 of The extension MUST be marked non-critical. (See Section 4.2 of
[RFC5280].) The client MUST NOT accept a delegated credential unless [RFC5280].) The client MUST NOT accept a delegated credential unless
the server's end-entity certificate satisfies the following criteria: the server's end-entity certificate satisfies the following criteria:
o It has the DelegationUsage extension. o It has the DelegationUsage extension.
o It has the digitalSignature KeyUsage (see the KeyUsage extension o It has the digitalSignature KeyUsage (see the KeyUsage extension
defined in [RFC5280]). defined in [RFC5280]).
4. IANA Considerations 4. IANA Considerations
This document registers the "delegated_credentials" extension in the This document registers the "delegated_credentials" extension in the
"TLS ExtensionType Values" registry. The "delegated_credentials" "TLS ExtensionType Values" registry. The "delegated_credentials"
extension has been assigned a code point of TBD. The IANA registry extension has been assigned a code point of TBD. The IANA registry
lists this extension as "Recommended" (i.e., "Y") and indicates that lists this extension as "Recommended" (i.e., "Y") and indicates that
it may appear in the ClientHello (CH), CertificateRequest (CR), or it may appear in the ClientHello (CH), CertificateRequest (CR), or
Certificate (CT) messages in TLS 1.3 [RFC8446]. Certificate (CT) messages in TLS 1.3 [RFC8446].
This document also defines an ASN.1 module for the DelegationUsage
certificate extension in Appendix A. IANA is requested to register
an Object Identfiier (OID) for the ASN.1 in "SMI Security for PKIX
Module Identifier" arc. An OID for the DelegationUsage certificate
extension is not needed as it is already assigned to the extension
from Cloudflare's IANA Private Enterprise Number (PEN) arc.
5. Security Considerations 5. Security Considerations
5.1. Security of delegated private key 5.1. Security of delegated private key
Delegated credentials limit the exposure of the TLS private key by Delegated credentials limit the exposure of the TLS private key by
limiting its validity. An attacker who compromises the private key limiting its validity. An attacker who compromises the private key
of a delegated credential can act as a man-in-the-middle until the of a delegated credential can act as a man-in-the-middle until the
delegate credential expires, however they cannot create new delegated delegate credential expires, however they cannot create new delegated
credentials. Thus, delegated credentials should not be used to send credentials. Thus, delegated credentials should not be used to send
a delegation to an untrusted party, but is meant to be used between a delegation to an untrusted party, but is meant to be used between
skipping to change at page 11, line 22 skipping to change at page 12, line 5
in both contexts. in both contexts.
5.3. Revocation of delegated credentials 5.3. Revocation of delegated credentials
Delegated credentials do not provide any additional form of early Delegated credentials do not provide any additional form of early
revocation. Since it is short lived, the expiry of the delegated revocation. Since it is short lived, the expiry of the delegated
credential would revoke the credential. Revocation of the long term credential would revoke the credential. Revocation of the long term
private key that signs the delegated credential also implicitly private key that signs the delegated credential also implicitly
revokes the delegated credential. revokes the delegated credential.
5.4. Privacy considerations 5.4. Interactions with session resumption
If a client decides to cache the certificate chain an re-validate it
when resuming a connection, the client SHOULD also cache the
associated delegated credential and re-validate it.
5.5. Privacy considerations
Delegated credentials can be valid for 7 days and it is much easier Delegated credentials can be valid for 7 days and it is much easier
for a service to create delegated credential than a certificate for a service to create delegated credential than a certificate
signed by a CA. A service could determine the client time and clock signed by a CA. A service could determine the client time and clock
skew by creating several delegated credentials with different expiry skew by creating several delegated credentials with different expiry
timestamps and observing whether the client would accept it. Client timestamps and observing whether the client would accept it. Client
time could be unique and thus privacy sensitive clients, such as time could be unique and thus privacy sensitive clients, such as
browsers in incognito mode, who do not trust the service might not browsers in incognito mode, who do not trust the service might not
want to advertise support for delegated credentials or limit the want to advertise support for delegated credentials or limit the
number of probes that a server can perform. number of probes that a server can perform.
skipping to change at page 12, line 5 skipping to change at page 12, line 39
7. References 7. References
7.1. Normative References 7.1. Normative References
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008, (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<https://www.rfc-editor.org/info/rfc5280>. <https://www.rfc-editor.org/info/rfc5280>.
[RFC5912] Hoffman, P. and J. Schaad, "New ASN.1 Modules for the
Public Key Infrastructure Using X.509 (PKIX)", RFC 5912,
DOI 10.17487/RFC5912, June 2010,
<https://www.rfc-editor.org/info/rfc5912>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>. <https://www.rfc-editor.org/info/rfc8446>.
[X680] ITU-T, "Information technology - Abstract Syntax Notation
One (ASN.1): Specification of basic notation", ISO/
IEC 8824-1:2015, November 2015.
[X690] ITU-T, "Information technology - ASN.1 encoding Rules: [X690] ITU-T, "Information technology - ASN.1 encoding Rules:
Specification of Basic Encoding Rules (BER), Canonical Specification of Basic Encoding Rules (BER), Canonical
Encoding Rules (CER) and Distinguished Encoding Rules Encoding Rules (CER) and Distinguished Encoding Rules
(DER)", ISO/IEC 8825-1:2002, 2002. (DER)", ISO/IEC 8825-1:2015, November 2015.
7.2. Informative References 7.2. Informative References
[I-D.ietf-acme-acme] [KEYLESS] Sullivan, N. and D. Stebila, "An Analysis of TLS Handshake
Barnes, R., Hoffman-Andrews, J., McCarney, D., and J. Proxying", IEEE Trustcom/BigDataSE/ISPA 2015 , 2015.
Kasten, "Automatic Certificate Management Environment
(ACME)", draft-ietf-acme-acme-18 (work in progress),
December 2018.
[I-D.ietf-tls-tls13]
Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", draft-ietf-tls-tls13-28 (work in progress),
March 2018.
[I-D.mglt-lurk-tls-requirements]
Migault, D. and K. Ma, "Authentication Model and Security
Requirements for the TLS/DTLS Content Provider Edge Server
Split Use Case", draft-mglt-lurk-tls-requirements-00 (work
in progress), January 2016.
[RFC3820] Tuecke, S., Welch, V., Engert, D., Pearlman, L., and M. [RFC3820] Tuecke, S., Welch, V., Engert, D., Pearlman, L., and M.
Thompson, "Internet X.509 Public Key Infrastructure (PKI) Thompson, "Internet X.509 Public Key Infrastructure (PKI)
Proxy Certificate Profile", RFC 3820, Proxy Certificate Profile", RFC 3820,
DOI 10.17487/RFC3820, June 2004, <https://www.rfc- DOI 10.17487/RFC3820, June 2004,
editor.org/info/rfc3820>. <https://www.rfc-editor.org/info/rfc3820>.
[RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS) [RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS)
Extensions: Extension Definitions", RFC 6066, Extensions: Extension Definitions", RFC 6066,
DOI 10.17487/RFC6066, January 2011, <https://www.rfc- DOI 10.17487/RFC6066, January 2011,
editor.org/info/rfc6066>. <https://www.rfc-editor.org/info/rfc6066>.
[RFC6961] Pettersen, Y., "The Transport Layer Security (TLS) [RFC6961] Pettersen, Y., "The Transport Layer Security (TLS)
Multiple Certificate Status Request Extension", RFC 6961, Multiple Certificate Status Request Extension", RFC 6961,
DOI 10.17487/RFC6961, June 2013, <https://www.rfc- DOI 10.17487/RFC6961, June 2013,
editor.org/info/rfc6961>. <https://www.rfc-editor.org/info/rfc6961>.
[RFC8555] Barnes, R., Hoffman-Andrews, J., McCarney, D., and J.
Kasten, "Automatic Certificate Management Environment
(ACME)", RFC 8555, DOI 10.17487/RFC8555, March 2019,
<https://www.rfc-editor.org/info/rfc8555>.
[XPROT] Jager, T., Schwenk, J., and J. Somorovsky, "On the [XPROT] Jager, T., Schwenk, J., and J. Somorovsky, "On the
Security of TLS 1.3 and QUIC Against Weaknesses in PKCS#1 Security of TLS 1.3 and QUIC Against Weaknesses in PKCS#1
v1.5 Encryption", Proceedings of the 22nd ACM SIGSAC v1.5 Encryption", Proceedings of the 22nd ACM SIGSAC
Conference on Computer and Communications Security , 2015. Conference on Computer and Communications Security , 2015.
Appendix A. ASN.1 Module
The following ASN.1 module provides the complete definition of the
DelegationUsage certificate extension. The ASN.1 module makes
imports from [RFC5912].
DelegatedCredentialExtn { joint-iso-itu-t(2) country(16) us(840)
organization(1) gov(101) dod(2) infosec(1) modules(0) id-mod-
delegate-credential-extn(TBD) }
DEFINITIONS IMPLICIT TAGS ::=
BEGIN
- EXPORT ALL
IMPORTS
EXTENSION FROM PKIX-CommonTypes-2009 - From RFC 5912 { iso(1)
identified-organization(3) dod(6) internet(1) security(5)
mechanisms(5) pkix(7) id-mod(0) id-mod-pkixCommon-02(57) } ;
- OIDS
id-cloudflare OBJECT IDENTIFIER ::= { 1 3 6 1 4 1 44363 }
- EXTENSION
ext-delegationUsage EXTENSION ::= { SYNTAX DelegationUsage IDENTIFIED
BY id-ce-delegationUsage }
id-ce-delegationUsage OBJECT IDENTIFIER ::= { id-cloudflare 44 }
DelegationUsage ::= NULL
END
Authors' Addresses Authors' Addresses
Richard Barnes Richard Barnes
Mozilla Cisco
Email: rlb@ipv.sx Email: rlb@ipv.sx
Subodh Iyengar Subodh Iyengar
Facebook Facebook
Email: subodh@fb.com Email: subodh@fb.com
Nick Sullivan Nick Sullivan
Cloudflare Cloudflare
skipping to change at page 13, line 21 skipping to change at page 15, line 4
Subodh Iyengar Subodh Iyengar
Facebook Facebook
Email: subodh@fb.com Email: subodh@fb.com
Nick Sullivan Nick Sullivan
Cloudflare Cloudflare
Email: nick@cloudflare.com Email: nick@cloudflare.com
Eric Rescorla Eric Rescorla
RTFM, Inc. Mozilla
Email: ekr@rtfm.com Email: ekr@rtfm.com
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