TLS/DTLS 1.3 Profiles for the Internet of Things
draft-ietf-uta-tls13-iot-profile-06
| Document | Type | Active Internet-Draft (uta WG) | |
|---|---|---|---|
| Authors | Hannes Tschofenig , Thomas Fossati | ||
| Last updated | 2023-03-13 | ||
| Replaces | draft-tschofenig-uta-tls13-profile | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
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| Additional resources | Mailing list discussion | ||
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draft-ietf-uta-tls13-iot-profile-06
UTA H. Tschofenig
Internet-Draft
Updates: 7925 (if approved) T. Fossati
Intended status: Standards Track Arm Limited
Expires: 14 September 2023 13 March 2023
TLS/DTLS 1.3 Profiles for the Internet of Things
draft-ietf-uta-tls13-iot-profile-06
Abstract
This document is a companion to RFC 7925 and defines TLS/DTLS 1.3
profiles for Internet of Things devices. It also updates RFC 7925
with regards to the X.509 certificate profile.
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
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and may be updated, replaced, or obsoleted by other documents at any
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on 14 September 2023.
Copyright Notice
Copyright (c) 2023 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 (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
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described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conventions and Terminology . . . . . . . . . . . . . . . 3
2. Credential Types . . . . . . . . . . . . . . . . . . . . . . 3
3. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 4
4. Session Resumption . . . . . . . . . . . . . . . . . . . . . 4
5. Compression . . . . . . . . . . . . . . . . . . . . . . . . 4
6. Perfect Forward Secrecy . . . . . . . . . . . . . . . . . . 5
7. Keep-Alive . . . . . . . . . . . . . . . . . . . . . . . . . 5
8. Timeouts . . . . . . . . . . . . . . . . . . . . . . . . . . 5
9. Random Number Generation . . . . . . . . . . . . . . . . . . 5
10. Server Name Indication . . . . . . . . . . . . . . . . . . . 5
11. Maximum Fragment Length Negotiation . . . . . . . . . . . . 6
12. Crypto Agility . . . . . . . . . . . . . . . . . . . . . . . 6
13. Key Length Recommendations . . . . . . . . . . . . . . . . . 6
14. 0-RTT Data . . . . . . . . . . . . . . . . . . . . . . . . . 6
15. Certificate Profile . . . . . . . . . . . . . . . . . . . . . 6
15.1. All Certificates . . . . . . . . . . . . . . . . . . . . 6
15.1.1. Version . . . . . . . . . . . . . . . . . . . . . . 6
15.1.2. Serial Number . . . . . . . . . . . . . . . . . . . 6
15.1.3. Signature . . . . . . . . . . . . . . . . . . . . . 7
15.1.4. Issuer . . . . . . . . . . . . . . . . . . . . . . . 7
15.1.5. Validity . . . . . . . . . . . . . . . . . . . . . 7
15.1.6. subjectPublicKeyInfo . . . . . . . . . . . . . . . 7
15.2. Root CA Certificate . . . . . . . . . . . . . . . . . . 7
15.3. Subordinate CA Certificate . . . . . . . . . . . . . . . 8
15.4. End Entity Certificate . . . . . . . . . . . . . . . . . 8
15.4.1. Client Certificate Subject . . . . . . . . . . . . . 8
16. Certificate Revocation Checks . . . . . . . . . . . . . . . . 8
17. Certificate Overhead . . . . . . . . . . . . . . . . . . . . 9
18. Ciphersuites . . . . . . . . . . . . . . . . . . . . . . . . 10
19. Fault Attacks on Deterministic Signature Schemes . . . . . . 11
20. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 11
21. Security Considerations . . . . . . . . . . . . . . . . . . . 11
22. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
23. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
23.1. Normative References . . . . . . . . . . . . . . . . . . 11
23.2. Informative References . . . . . . . . . . . . . . . . . 12
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
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1. Introduction
This document defines a profile of DTLS 1.3 [DTLS13] and TLS 1.3
[RFC8446] that offers communication security services for IoT
applications and is reasonably implementable on many constrained
devices. Profile thereby means that available configuration options
and protocol extensions are utilized to best support the IoT
environment.
For IoT profiles using TLS/DTLS 1.2 please consult [RFC7925]. This
document re-uses the communication pattern defined in [RFC7925] and
makes IoT-domain specific recommendations for version 1.3 (where
necessary).
TLS 1.3 has been re-designed and several previously defined
extensions are not applicable to the new version of TLS/DTLS anymore.
This clean-up also simplifies this document. Furthermore, many
outdated ciphersuites have been omitted from the TLS/DTLS 1.3
specification.
1.1. Conventions and Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Credential Types
In accordance with the recommendations in [RFC7925], a compliant
implementation MUST implement TLS_AES_128_CCM_8_SHA256. It SHOULD
implement TLS_CHACHA20_POLY1305_SHA256.
Pre-shared key based authentication is integrated into the main TLS/
DTLS 1.3 specification and has been harmonized with session
resumption.
A compliant implementation supporting authentication based on
certificates and raw public keys MUST support digital signatures with
ecdsa_secp256r1_sha256. A compliant implementation MUST support the
key exchange with secp256r1 (NIST P-256) and SHOULD support key
exchange with X25519.
A plain PSK-based TLS/DTLS client or server MUST implement the
following extensions:
* Supported Versions,
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* Cookie,
* Server Name Indication (SNI),
* Pre-Shared Key,
* PSK Key Exchange Modes, and
* Application-Layer Protocol Negotiation (ALPN).
For use of external pre-shared keys [RFC9258] makes the following
recommendation:
Applications SHOULD provision separate PSKs for (D)TLS 1.3 and
prior versions.
Where possible, the importer interface defined in [RFC9258] MUST be
used for external PSKs. This ensures that external PSKs used in
(D)TLS 1.3 are bound to a specific key derivation function (KDF) and
hash function.
The SNI extension is discussed in this document and the justification
for implementing and using the ALPN extension can be found in
[RFC9325].
For TLS/DTLS clients and servers implementing raw public keys and/or
certificates the guidance for mandatory-to-implement extensions
described in Section 9.2 of [RFC8446] MUST be followed.
3. Error Handling
TLS 1.3 simplified the Alert protocol but the underlying challenge in
an embedded context remains unchanged, namely what should an IoT
device do when it encounters an error situation. The classical
approach used in a desktop environment where the user is prompted is
often not applicable with unattended devices. Hence, it is more
important for a developer to find out from which error cases a device
can recover from.
4. Session Resumption
TLS 1.3 has built-in support for session resumption by utilizing PSK-
based credentials established in an earlier exchange.
5. Compression
TLS 1.3 does not have support for compression of application data
traffic, as offered by previous versions of TLS. Applications are
therefore responsible for transmitting payloads that are either
compressed or use a more efficient encoding otherwise.
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With regards to the handshake itself, various strategies have been
applied to reduce the size of the exchanged payloads. TLS and DTLS
1.3 use less overhead, depending on the type of key confirmations,
when compared to previous versions of the protocol. Additionally,
the work on Compact TLS (cTLS) [I-D.ietf-tls-ctls] has taken
compression of the handshake a step further by utilizing out-of-band
knowledge between the communication parties to reduce the amount of
data to be transmitted at each individual handshake, among applying
other techniques.
6. Perfect Forward Secrecy
TLS 1.3 allows the use of PFS with all ciphersuites since the support
for it is negotiated independently.
7. Keep-Alive
The discussion in Section 10 of [RFC7925] is applicable.
8. Timeouts
The recommendation in Section 11 of [RFC7925] is applicable. In
particular this document RECOMMENDED to use an initial timer value of
9 seconds with exponential back off up to no less then 60 seconds.
9. Random Number Generation
The discussion in Section 12 of [RFC7925] is applicable with one
exception: the ClientHello and the ServerHello messages in TLS 1.3 do
not contain gmt_unix_time component anymore.
10. Server Name Indication
This specification mandates the implementation of the Server Name
Indication (SNI) extension. Where privacy requirements require it,
the Encrypted Client Hello extension [I-D.ietf-tls-esni] prevents an
on-path attacker to determine the domain name the client is trying to
connect to.
Note: To avoid leaking DNS lookups from network inspection altogether
further protocols are needed, including DoH [RFC8484] and DPRIVE
[RFC7858] [RFC8094]. Since the Encrypted Client Hello extension
requires use of Hybrid Public Key Encryption (HPKE)
[I-D.irtf-cfrg-hpke] and additional protocols require further
protocol exchanges and cryptographic operations, there is a certain
overhead associated with this privacy feature.
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11. Maximum Fragment Length Negotiation
The Maximum Fragment Length Negotiation (MFL) extension has been
superseded by the Record Size Limit (RSL) extension [RFC8449].
Implementations in compliance with this specification MUST implement
the RSL extension and SHOULD use it to indicate their RAM
limitations.
12. Crypto Agility
The recommendations in Section 19 of [RFC7925] are applicable.
13. Key Length Recommendations
The recommendations in Section 20 of [RFC7925] are applicable.
14. 0-RTT Data
Appendix E.5 of [TLS13] establishes that:
Application protocols MUST NOT use 0-RTT data without a profile
that defines its use. That profile needs to identify which
messages or interactions are safe to use with 0-RTT and how to
handle the situation when the server rejects 0-RTT and falls back
to 1-RTT.
At the time of writing, no such profile has been defined for CoAP
[CoAP]. Therefore, 0-RTT MUST NOT be used by CoAP applications.
15. Certificate Profile
This section contains updates and clarifications to the certificate
profile defined in [RFC7925]. The content of Table 1 of [RFC7925]
has been split by certificate "type" in order to clarify exactly what
requirements and recommendations apply to which entity in the PKI
hierarchy.
15.1. All Certificates
15.1.1. Version
Certificates MUST be of type X.509 v3.
15.1.2. Serial Number
CAs SHALL generate non-sequential certificate serial numbers greater
than zero (0) containing at least 64 bits of output from a CSPRNG
(cryptographically secure pseudo-random number generator).
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15.1.3. Signature
The signature MUST be ecdsa-with-SHA256 or stronger [RFC5758].
15.1.4. Issuer
Contains the DN of the issuing CA.
15.1.5. Validity
No maximum validity period is mandated. Validity values are
expressed in notBefore and notAfter fields, as described in
Section 4.1.2.5 of [RFC5280]. In particular, values MUST be
expressed in Greenwich Mean Time (Zulu) and MUST include seconds even
where the number of seconds is zero.
Note that the validity period is defined as the period of time from
notBefore through notAfter, inclusive. This means that a
hypothetical certificate with a notBefore date of 9 June 2021 at
03:42:01 and a notAfter date of 7 September 2021 at 03:42:01 becomes
valid at the beginning of the :01 second, and only becomes invalid at
the :02 second, a period that is 90 days plus 1 second. So for a
90-day, notAfter must actually be 03:42:00.
In many cases it is necessary to indicate that a certificate does not
expire. This is likely to be the case for manufacturer-provisioned
certificates. RFC 5280 provides a simple solution to convey the fact
that a certificate has no well-defined expiration date by setting the
notAfter to the GeneralizedTime value of 99991231235959Z.
Some devices might not have a reliable source of time and for those
devices it is also advisable to use certificates with no expiration
date and to let a device management solution manage the lifetime of
all the certificates used by the device. While this approach does
not utilize certificates to its widest extent, it is a solution that
extends the capabilities offered by a raw public key approach.
15.1.6. subjectPublicKeyInfo
The SubjectPublicKeyInfo structure indicates the algorithm and any
associated parameters for the ECC public key. This profile uses the
id-ecPublicKey algorithm identifier for ECDSA signature keys, as
defined and specified in [RFC5480].
15.2. Root CA Certificate
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* basicConstraints MUST be present and MUST be marked critical. The
cA field MUST be set true. The pathLenConstraint field SHOULD NOT
be present.
* keyUsage MUST be present and MUST be marked critical. Bit
position for keyCertSign MUST be set.
* extendedKeyUsage MUST NOT be present.
15.3. Subordinate CA Certificate
* basicConstraints MUST be present and MUST be marked critical. The
cA field MUST be set true. The pathLenConstraint field MAY be
present.
* keyUsage MUST be present and MUST be marked critical. Bit
position for keyCertSign MUST be set.
* extendedKeyUsage MUST NOT be present.
15.4. End Entity Certificate
* extendedKeyUsage MUST be present and contain at least one of id-
kp-serverAuth or id-kp-clientAuth.
* keyUsage MAY be present and contain one of digitalSignature or
keyAgreement.
* Domain names MUST NOT be encoded in the subject commonName,
instead they MUST be encoded in a subjectAltName of type DNS-ID.
Domain names MUST NOT contain wildcard (*) characters.
subjectAltName MUST NOT contain multiple names.
15.4.1. Client Certificate Subject
The requirement in Section 4.4.2 of [RFC7925] to only use EUI-64 for
client certificates is lifted.
If the EUI-64 format is used to identify the subject of a client
certificate, it MUST be encoded in a subjectAltName of type DNS-ID as
a string of the form HH-HH-HH-HH-HH-HH-HH-HH where 'H' is one of the
symbols '0'-'9' or 'A'-'F'.
16. Certificate Revocation Checks
The considerations in Section 4.4.3 of [RFC7925] hold.
Since the publication of RFC 7925 the need for firmware update
mechanisms has been reinforced and the work on standardizing a secure
and interoperable firmware update mechanism has made substantial
progress, see [RFC9019]. RFC 7925 recommends to use a software /
firmware update mechanism to provision devices with new trust
anchors.
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The use of device management protocols for IoT devices, which often
include an onboarding or bootstrapping mechanism, has also seen
considerable uptake in deployed devices and these protocols, some of
which are standardized, allow provision of certificates on a regular
basis. This enables a deployment model where IoT device utilize end-
entity certificates with shorter lifetime making certificate
revocation protocols, like OCSP and CRLs, less relevant.
Hence, instead of performing certificate revocation checks on the IoT
device itself this specification recommends to delegate this task to
the IoT device operator and to take the necessary action to allow IoT
devices to remain operational.
17. Certificate Overhead
In a public key-based key exchange, certificates and public keys are
a major contributor to the size of the overall handshake. For
example, in a regular TLS 1.3 handshake with minimal ECC certificates
and no subordinate CA utilizing the secp256r1 curve with mutual
authentication, around 40% of the entire handshake payload is
consumed by the two exchanged certificates.
Hence, it is not surprising that there is a strong desire to reduce
the size of certificates and certificate chains. This has lead to
various standardization efforts. Here is a brief summary of what
options an implementer has to reduce the bandwidth requirements of a
public key-based key exchange:
* Use elliptic curve cryptography (ECC) instead of RSA-based
certificate due to the smaller certificate size.
* Avoid deep and complex CA hierarchies to reduce the number of
subordinate CA certificates that need to be transmitted.
* Pay attention to the amount of information conveyed inside
certificates.
* Use session resumption to reduce the number of times a full
handshake is needed. Use Connection IDs [DTLS-CID], when
possible, to enable long-lasting connections.
* Use the TLS cached info [RFC7924] extension to avoid sending
certificates with every full handshake.
* Use client certificate URLs [RFC6066] instead of full certificates
for clients.
* Use certificate compression as defined in
[I-D.ietf-tls-certificate-compression].
* Use alternative certificate formats, where possible, such as raw
public keys [RFC7250] or CBOR-encoded certificates
[I-D.ietf-cose-cbor-encoded-cert].
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The use of certificate handles, as introduced in cTLS
[I-D.ietf-tls-ctls], is a form of caching or compressing certificates
as well.
Whether to utilize any of the above extensions or a combination of
them depends on the anticipated deployment environment, the
availability of code, and the constraints imposed by already deployed
infrastructure (e.g., CA infrastructure, tool support).
18. Ciphersuites
Section 4.5.3 of [DTLS13] flags AES-CCM with 8-octet authentication
tags (CCM_8) as unsuitable for general use with DTLS. In fact, due
to its low integrity limits (i.e., a high sensitivity to forgeries),
endpoints that negotiate ciphersuites based on such AEAD are
susceptible to a trivial DoS. (See also Section 5.3 and 5.4 of
[I-D.irtf-cfrg-aead-limits] for further discussion on this topic, as
well as references to the analysis supporting these conclusions.)
Specifically, [DTLS13] warns that:
"TLS_AES_128_CCM_8_SHA256 MUST NOT be used in DTLS without
additional safeguards against forgery. Implementations MUST set
usage limits for AEAD_AES_128_CCM_8 based on an understanding of
any additional forgery protections that are used."
Since all the ciphersuites mandated by [RFC7925] and [CoAP] are based
on CCM_8, there is no stand-by ciphersuite to use for applications
that want to avoid the security and availability risks associated
with CCM_8 while retaining interoperability with the rest of the
ecosystem.
In order to ameliorate the situation, this document RECOMMENDS that
implementations support the following two ciphersuites:
* TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
* TLS_ECDHE_ECDSA_WITH_AES_128_CCM
and offer them as their first choice. These ciphersuites provide
confidentiality and integrity limits that are considered acceptable
in the most general settings. For the details on the exact bounds of
both ciphersuites see Section 4.5.3 of [DTLS13]. Note that the GCM-
based ciphersuite offers superior interoperability with cloud
services at the cost of a slight increase in the wire and peak RAM
footprints.
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When the GCM-based ciphersuite is used with TLS 1.2, the
recommendations in Section 6.2.1 of [RFC9325] related to
deterministic nonce generation apply. In addition, the integrity
limits on key usage detailed in Section 4.4 of [RFC9325] also apply.
19. Fault Attacks on Deterministic Signature Schemes
A number of passive side-channel attacks as well as active fault-
injection attacks (e.g., [Ambrose2017]) have been demonstrated that
allow a malicious third party to gain information about the signing
key if a fully deterministic signature scheme (e.g., [RFC6979] ECDSA
or EdDSA [RFC8032]) is used.
Most of these attacks assume physical access to the device and are
therefore especially relevant to smart cards as well as IoT
deployments with poor or non-existent physical security.
In this security model, it is recommended to combine both randomness
and determinism, for example, as described in
[I-D.mattsson-cfrg-det-sigs-with-noise].
20. Open Issues
A list of open issues can be found at https://github.com/thomas-
fossati/draft-tls13-iot/issues
21. Security Considerations
This entire document is about security.
22. IANA Considerations
This document makes no requests to IANA.
23. References
23.1. Normative References
[DTLS13] Rescorla, E., Tschofenig, H., and N. Modadugu, "The
Datagram Transport Layer Security (DTLS) Protocol Version
1.3", RFC 9147, DOI 10.17487/RFC9147, April 2022,
<https://www.rfc-editor.org/rfc/rfc9147>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
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[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008,
<https://www.rfc-editor.org/rfc/rfc5280>.
[RFC5480] Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk,
"Elliptic Curve Cryptography Subject Public Key
Information", RFC 5480, DOI 10.17487/RFC5480, March 2009,
<https://www.rfc-editor.org/rfc/rfc5480>.
[RFC5758] Dang, Q., Santesson, S., Moriarty, K., Brown, D., and T.
Polk, "Internet X.509 Public Key Infrastructure:
Additional Algorithms and Identifiers for DSA and ECDSA",
RFC 5758, DOI 10.17487/RFC5758, January 2010,
<https://www.rfc-editor.org/rfc/rfc5758>.
[RFC7925] Tschofenig, H., Ed. and T. Fossati, "Transport Layer
Security (TLS) / Datagram Transport Layer Security (DTLS)
Profiles for the Internet of Things", RFC 7925,
DOI 10.17487/RFC7925, July 2016,
<https://www.rfc-editor.org/rfc/rfc7925>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/rfc/rfc8446>.
[RFC8449] Thomson, M., "Record Size Limit Extension for TLS",
RFC 8449, DOI 10.17487/RFC8449, August 2018,
<https://www.rfc-editor.org/rfc/rfc8449>.
[RFC9258] Benjamin, D. and C. A. Wood, "Importing External Pre-
Shared Keys (PSKs) for TLS 1.3", RFC 9258,
DOI 10.17487/RFC9258, July 2022,
<https://www.rfc-editor.org/rfc/rfc9258>.
[TLS13] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/rfc/rfc8446>.
23.2. Informative References
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[Ambrose2017]
Ambrose, C., Bos, J. W., Fay, B., Joye, M., Lochter, M.,
and B. Murray, "Differential Attacks on Deterministic
Signatures", 2017, <https://eprint.iacr.org/2017/975.pdf>.
[CoAP] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
Application Protocol (CoAP)", RFC 7252,
DOI 10.17487/RFC7252, June 2014,
<https://www.rfc-editor.org/rfc/rfc7252>.
[DTLS-CID] Rescorla, E., Ed., Tschofenig, H., Ed., Fossati, T., and
A. Kraus, "Connection Identifier for DTLS 1.2", RFC 9146,
DOI 10.17487/RFC9146, March 2022,
<https://www.rfc-editor.org/rfc/rfc9146>.
[I-D.ietf-cose-cbor-encoded-cert]
Mattsson, J. P., Selander, G., Raza, S., Höglund, J., and
M. Furuhed, "CBOR Encoded X.509 Certificates (C509
Certificates)", Work in Progress, Internet-Draft, draft-
ietf-cose-cbor-encoded-cert-05, 10 January 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-cose-
cbor-encoded-cert-05>.
[I-D.ietf-tls-certificate-compression]
Ghedini, A. and V. Vasiliev, "TLS Certificate
Compression", Work in Progress, Internet-Draft, draft-
ietf-tls-certificate-compression-10, 6 January 2020,
<https://datatracker.ietf.org/doc/html/draft-ietf-tls-
certificate-compression-10>.
[I-D.ietf-tls-ctls]
Rescorla, E., Barnes, R., Tschofenig, H., and B. M.
Schwartz, "Compact TLS 1.3", Work in Progress, Internet-
Draft, draft-ietf-tls-ctls-07, 3 January 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-tls-
ctls-07>.
[I-D.ietf-tls-esni]
Rescorla, E., Oku, K., Sullivan, N., and C. A. Wood, "TLS
Encrypted Client Hello", Work in Progress, Internet-Draft,
draft-ietf-tls-esni-15, 3 October 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-tls-
esni-15>.
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Internet-Draft TLS/DTLS 1.3 IoT Profiles March 2023
[I-D.irtf-cfrg-aead-limits]
Günther, F., Thomson, M., and C. A. Wood, "Usage Limits on
AEAD Algorithms", Work in Progress, Internet-Draft, draft-
irtf-cfrg-aead-limits-06, 30 January 2023,
<https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-
aead-limits-06>.
[I-D.irtf-cfrg-hpke]
Barnes, R., Bhargavan, K., Lipp, B., and C. A. Wood,
"Hybrid Public Key Encryption", Work in Progress,
Internet-Draft, draft-irtf-cfrg-hpke-12, 2 September 2021,
<https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-
hpke-12>.
[I-D.mattsson-cfrg-det-sigs-with-noise]
Mattsson, J. P., Thormarker, E., and S. Ruohomaa,
"Deterministic ECDSA and EdDSA Signatures with Additional
Randomness", Work in Progress, Internet-Draft, draft-
mattsson-cfrg-det-sigs-with-noise-04, 15 February 2022,
<https://datatracker.ietf.org/doc/html/draft-mattsson-
cfrg-det-sigs-with-noise-04>.
[RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS)
Extensions: Extension Definitions", RFC 6066,
DOI 10.17487/RFC6066, January 2011,
<https://www.rfc-editor.org/rfc/rfc6066>.
[RFC6979] Pornin, T., "Deterministic Usage of the Digital Signature
Algorithm (DSA) and Elliptic Curve Digital Signature
Algorithm (ECDSA)", RFC 6979, DOI 10.17487/RFC6979, August
2013, <https://www.rfc-editor.org/rfc/rfc6979>.
[RFC7250] Wouters, P., Ed., Tschofenig, H., Ed., Gilmore, J.,
Weiler, S., and T. Kivinen, "Using Raw Public Keys in
Transport Layer Security (TLS) and Datagram Transport
Layer Security (DTLS)", RFC 7250, DOI 10.17487/RFC7250,
June 2014, <https://www.rfc-editor.org/rfc/rfc7250>.
[RFC7858] Hu, Z., Zhu, L., Heidemann, J., Mankin, A., Wessels, D.,
and P. Hoffman, "Specification for DNS over Transport
Layer Security (TLS)", RFC 7858, DOI 10.17487/RFC7858, May
2016, <https://www.rfc-editor.org/rfc/rfc7858>.
[RFC7924] Santesson, S. and H. Tschofenig, "Transport Layer Security
(TLS) Cached Information Extension", RFC 7924,
DOI 10.17487/RFC7924, July 2016,
<https://www.rfc-editor.org/rfc/rfc7924>.
Tschofenig & Fossati Expires 14 September 2023 [Page 14]
Internet-Draft TLS/DTLS 1.3 IoT Profiles March 2023
[RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital
Signature Algorithm (EdDSA)", RFC 8032,
DOI 10.17487/RFC8032, January 2017,
<https://www.rfc-editor.org/rfc/rfc8032>.
[RFC8094] Reddy, T., Wing, D., and P. Patil, "DNS over Datagram
Transport Layer Security (DTLS)", RFC 8094,
DOI 10.17487/RFC8094, February 2017,
<https://www.rfc-editor.org/rfc/rfc8094>.
[RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS
(DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018,
<https://www.rfc-editor.org/rfc/rfc8484>.
[RFC9019] Moran, B., Tschofenig, H., Brown, D., and M. Meriac, "A
Firmware Update Architecture for Internet of Things",
RFC 9019, DOI 10.17487/RFC9019, April 2021,
<https://www.rfc-editor.org/rfc/rfc9019>.
[RFC9325] Sheffer, Y., Saint-Andre, P., and T. Fossati,
"Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 9325, DOI 10.17487/RFC9325, November
2022, <https://www.rfc-editor.org/rfc/rfc9325>.
Acknowledgments
We would like to thank Ben Kaduk and John Mattsson.
Authors' Addresses
Hannes Tschofenig
Email: Hannes.Tschofenig@gmx.net
Thomas Fossati
Arm Limited
Email: Thomas.Fossati@arm.com
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