Internet-Draft (D)TLS IANA Registry Updates February 2023
Salowey & Turner Expires 6 August 2023 [Page]
Workgroup:
Transport Layer Security
Internet-Draft:
draft-ietf-tls-rfc8447bis-03
Updates:
3749, 5077, 4680, 5246, 5705, 5878, 6520, 7301, 8447 (if approved)
Published:
Intended Status:
Standards Track
Expires:
Authors:
J. Salowey
Venafi
S. Turner
sn3rd

IANA Registry Updates for TLS and DTLS

Abstract

This document updates the changes to TLS and DTLS IANA registries made in RFC 8447. It adds a new value "D" for discouraged to the recommended column of the selected TLS registries.

This document updates the following RFCs: 3749, 5077, 4680, 5246, 5705, 5878, 6520, 7301, and 8447.

About This Document

This note is to be removed before publishing as an RFC.

Status information for this document may be found at https://datatracker.ietf.org/doc/draft-ietf-tls-rfc8447bis/.

Discussion of this document takes place on the Transport Layer Security Working Group mailing list (mailto:tls@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/tls/. Subscribe at https://www.ietf.org/mailman/listinfo/tls/.

Source for this draft and an issue tracker can be found at https://github.com/tlswg/rfc8447bis.

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 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 6 August 2023.

Table of Contents

1. Introduction

This document instructs IANA to make changes to a number of the IANA registries related to Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS). These changes update the changes made in [RFC8447].

This specification updates the "Recommended" column in TLS registries to define a third value "D" for items that are discouraged.

2. 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.

4. TLS ExtensionType Values

In order to refect the changes in the Recommended column allocation, IANA SHALL update the TLS ExtensionType Values registry as follows:

    Values with the first byte in the range 0-254 (decimal) are assigned
    via Specification Required [RFC8126].  Values with the first byte
    255 (decimal) are reserved for Private Use [RFC8126].  Setting a
    "Recommended" column value to Y or D requires Standards Action {{RFC8126}}.
    Any state transition to or from a "Y" or "D" value requires
    IESG Apporval.
Table 1
Value Extension Recommended
4 truncated_hmac D
53 connection_id (deprecated) D
40 Reserved D
46 Reserved D

5. TLS Cipher Suites Registry

In order to refect the changes in the Recommended column allocation, IANA SHALL update the TLS ExtensionType Values registry as follows:

    Values with the first byte in the range 0-254 (decimal) are
    assigned via Specification Required [RFC8126].  Values with the
    first byte 255 (decimal) are reserved for Private Use [RFC8126].
    Setting a "Recommended" column value to Y or D requires Standards
    Action {{RFC8126}}. Any state transition to or from a "Y" or "D"
    value requires IESG Apporval.
Table 2
Value Cipher Suite Name Recommeded
0x00,0x01 TLS_RSA_WITH_NULL_MD5 D
0x00,0x02 TLS_RSA_WITH_NULL_SHA D
0x00,0x03 TLS_RSA_EXPORT_WITH_RC4_40_MD5 D
0x00,0x04 TLS_RSA_WITH_RC4_128_MD5 D
0x00,0x05 TLS_RSA_WITH_RC4_128_SHA D
0x00,0x06 TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5 D
0x00,0x07 TLS_RSA_WITH_IDEA_CBC_SHA D
0x00,0x08 TLS_RSA_EXPORT_WITH_DES40_CBC_SHA D
0x00,0x09 TLS_RSA_WITH_DES_CBC_SHA D
0x00,0x0B TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA D
0x00,0x0C TLS_DH_DSS_WITH_DES_CBC_SHA D
0x00,0x0D TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA D
0x00,0x0E TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA D
0x00,0x0F TLS_DH_RSA_WITH_DES_CBC_SHA D
0x00,0x11 TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA D
0x00,0x12 TLS_DHE_DSS_WITH_DES_CBC_SHA D
0x00,0x13 TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA D
0x00,0x14 TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA D
0x00,0x15 TLS_DHE_RSA_WITH_DES_CBC_SHA D
0x00,0x17 TLS_DH_anon_EXPORT_WITH_RC4_40_MD5 D
0x00,0x18 TLS_DH_anon_WITH_RC4_128_MD5 D
0x00,0x19 TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA D
0x00,0x1A TLS_DH_anon_WITH_DES_CBC_SHA D
0x00,0x1B TLS_DH_anon_WITH_3DES_EDE_CBC_SHA D
0x00,0x19 TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA D
0x00,0x1E TLS_KRB5_WITH_DES_CBC_SHA D
0x00,0x20 TLS_KRB5_WITH_RC4_128_SHA D
0x00,0x21 TLS_KRB5_WITH_IDEA_CBC_SHA D
0x00,0x22 TLS_KRB5_WITH_DES_CBC_MD5 D
0x00,0x23 TLS_KRB5_WITH_3DES_EDE_CBC_MD5 D
0x00,0x24 TLS_KRB5_WITH_RC4_128_MD5 D
0x00,0x25 TLS_KRB5_WITH_IDEA_CBC_MD5 D
0x00,0x26 TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA D
0x00,0x27 TLS_KRB5_EXPORT_WITH_RC2_CBC_40_SHA D
0x00,0x28 TLS_KRB5_EXPORT_WITH_RC4_40_SHA D
0x00,0x29 TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5 D
0x00,0x2A TLS_KRB5_EXPORT_WITH_RC2_CBC_40_MD5 D
0x00,0x2B TLS_KRB5_EXPORT_WITH_RC4_40_MD5 D
0x00,0x8A TLS_PSK_WITH_RC4_128_SHA D
0x00,0x8E TLS_DHE_PSK_WITH_RC4_128_SHA D
0x00,0x92 TLS_RSA_PSK_WITH_RC4_128_SHA D
0xC0,0x02 TLS_ECDH_ECDSA_WITH_RC4_128_SHA D
0xC0,0x07 TLS_ECDHE_ECDSA_WITH_RC4_128_SHA D
0xC0,0x0C TLS_ECDH_RSA_WITH_RC4_128_SHA D
0xC0,0x11 TLS_ECDHE_RSA_WITH_RC4_128_SHA D
0xC0,0x16 TLS_ECDH_anon_WITH_RC4_128_SHA D
0xC0,0x33 TLS_ECDHE_PSK_WITH_RC4_128_SHA D

6. TLS Supported Groups

In order to refect the changes in the Recommended column allocation, IANA SHALL update the TLS Supported Groups registry as follows:

    Setting a "Recommended" column value to Y or D requires Standards
    Action {{RFC8126}}. Any state transition to or from a "Y" or "D"
    value requires IESG Apporval.

7. TLS Exporter Labels Registry

This document updates the registration procedure for the TLS Exporter registry and updates the Recommended column allocation. IANA SHALL update the TLS Exporter Labels Registry as follows:

    Setting a "Recommended" column value to Y or D requires Standards
    Action {{RFC8126}}. Any state transition to or from a "Y" or "D"
    value requires IESG Apporval.
Note:

The role of the designated expert is described in [RFC8447]. Even though this registry does not require a specification, the designated expert [RFC8126] will highly encourage registrants to provide a link to a publicly available specification. An Internet-Draft (that is posted and never published as an RFC) or a document from another standards body, industry consortium, university site, etc. are suitable for these purposes. The expert may provide more in-depth reviews, but their approval should not be taken as an endorsement of the exporter label. The expert also verifies that the label is a string consisting of printable ASCII characters beginning with "EXPORTER". IANA MUST also verify that one label is not a prefix of any other label. For example, labels "key" or "master secretary" are forbidden.

8. TLS Certificate Types

In order to refect the changes in the Recommended column allocation, IANA SHALL update the the TLS Certificate Types registry as follows:

    Values in the range 0-223 (decimal) are assigned via Specification
    Required [RFC8126]. Values in the range 224-255 (decimal) are
    reserved for Private Use [RFC8126]. Setting a "Recommended" column
    value to Y or D requires Standards
    Action {{RFC8126}}. Any state transition to or from a "Y" or "D"
    value requires IESG Apporval.

9. TLS HashAlgorithm Registry

Though TLS 1.0 and TLS 1.1 were deprecated [RFC8996], TLS 1.2 will be in use for some time. In order to refect the changes in the Recommended column allocation, IANA SHALL update the TLS HashAlgorithm Registry registry as follows:

    Setting a "Recommended" column value to Y or D requires Standards
    Action {{RFC8126}}. Any state transition to or from a "Y" or "D"
    value requires IESG Apporval.
Table 3
Value Descsription Recommended
0 none Y
1 md5 D
2 sha1 D
3 sha224 D
4 sha256 Y
5 sha384 Y
6 sha512 Y
8 Intrinsic Y

10. TLS SignatureAlgorithm registry

Though TLS 1.0 and TLS 1.1 were deprecated [RFC8996], TLS 1.2 will be in use for some time. In order to refect the changes in the Recommended column allocation, IANA SHALL update the TLS SignatureAlgorithm registry registry as follows:

    Setting a "Recommended" column value to Y or D requires Standards
    Action {{RFC8126}}. Any state transition to or from a "Y" or "D"
    value requires IESG Apporval.
Table 4
Value Descsription Recommended
0 anonymous N
1 rsa Y
2 dsa N
3 ecdsa Y
7 ed25519 Y
8 ed448 Y
64 gostr34102012_256 N
65 gostr34102012_512 N

11. TLS ClientCertificateTypes registry

Though TLS 1.0 and TLS 1.1 were deprecated [RFC8996], TLS 1.2 will be in use for some time. In order to refect the changes in the Recommended column allocation, IANA SHALL update the TLS ClientCertificateTypes registry as follows:

    Setting a "Recommended" column value to Y or D requires Standards
    Action {{RFC8126}}. Any state transition to or from a "Y" or "D"
    value requires IESG Apporval.
Table 5
Value Descsription Recommended
1 rsa_sign Y
2 dss_sign N
3 rsa_fixed_dh N
4 dss_fixed_dh N
5 rsa_ephemeral_dh_RESERVED D
6 dss_ephemeral_dh_RESERVED D
20 fortezza_dms_RESERVED D
64 ecdsa_sign Y
65 rsa_fixed_ecdh N
66 ecdsa_fixed_ecdh N
67 gost_sign256 N
68 gost_sign512 N

12. TLS PskKeyExchangeMode registry

In order to refect the changes in the Recommended column allocation, IANA SHALL update the TLS PskKeyExchangeMode registry as follows:

    Setting a "Recommended" column value to Y or D requires Standards
    Action {{RFC8126}}. Any state transition to or from a "Y" or "D"
    value requires IESG Apporval.

13. Security Considerations

The change to Specification Required from IETF Review lowers the amount of review provided by the WG for cipher suites and supported groups. This change reflects reality in that the WG essentially provided no cryptographic review of the cipher suites or supported groups. This was especially true of national cipher suites.

Recommended algorithms are regarded as secure for general use at the time of registration; however, cryptographic algorithms and parameters will be broken or weakened over time. It is possible that the "Recommended" status in the registry lags behind the most recent advances in cryptanalysis. Implementers and users need to check that the cryptographic algorithms listed continue to provide the expected level of security.

Designated experts ensure the specification is publicly available. They may provide more in-depth reviews. Their review should not be taken as an endorsement of the cipher suite, extension, supported group, etc.

14. IANA Considerations

This document is entirely about changes to TLS-related IANA registries.

15. Normative References

[I-D.ietf-tls-deprecate-obsolete-kex]
Bartle, C. and N. Aviram, "Deprecating Obsolete Key Exchange Methods in TLS", Work in Progress, Internet-Draft, draft-ietf-tls-deprecate-obsolete-kex-01, , <https://datatracker.ietf.org/doc/html/draft-ietf-tls-deprecate-obsolete-kex-01>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8126]
Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, , <https://www.rfc-editor.org/rfc/rfc8126>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8447]
Salowey, J. and S. Turner, "IANA Registry Updates for TLS and DTLS", RFC 8447, DOI 10.17487/RFC8447, , <https://www.rfc-editor.org/rfc/rfc8447>.
[RFC8996]
Moriarty, K. and S. Farrell, "Deprecating TLS 1.0 and TLS 1.1", BCP 195, RFC 8996, DOI 10.17487/RFC8996, , <https://www.rfc-editor.org/rfc/rfc8996>.

Authors' Addresses

Joe Salowey
Venafi
Sean Turner
sn3rd