Internet-Draft (D)TLS IANA Registry Updates January 2024
Salowey & Turner Expires 26 July 2024 [Page]
Workgroup:
Transport Layer Security
Internet-Draft:
draft-ietf-tls-rfc8447bis-08
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 26 July 2024.

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:

  • Change the registration procedure to:

    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 Approval.
  • Add a reference to this document under the reference heading.

  • Update the "Recommended" column with the changes as listed below. Entries keep their existing "Y" and "N" entries except for the entries in following table. A reference to this document SHALL be added to these entries.

Table 1
Value Extension Recommended
4 truncated_hmac D
53 connection_id (deprecated) D
40 Reserved D
46 Reserved D
  • Update note on the recommended column with text in Section 3.1.

5. TLS Cipher Suites Registry

Several categories of ciphersuites are discouraged for general use and are maked as "D".

Ciphersuites that use NULL encryption do not provide the confidentiality normally expected of TLS. Protocols and applications are often designed to require confidentialy as a security property. These ciphersuites MUST NOT be used in those cases.

Ciphersuites marked as EXPORT use weak ciphers and were deprecated in TLS 1.1 [RFC4346].

Cipher suites maked as anon do not provide any authentication and are vulnerable to man-in-the-middle attacks and are deprecated in TLS 1.1 [RFC4346].

RC4 is a weak cipher and is deprecated in [RFC7465].

DES and IDEA are not considered secure for general use and are deprecated in [RFC5469].

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

  • Change the registration procedure to:

    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 Approval.
  • Add a reference to this document under the reference heading.

  • Update the "Recommended" column with the changes as listed below. Entries keep their existing "Y" and "N" entries except for the entries in following table. A reference to this document SHALL be added to these entries. This document does not make any changes to the DTLS-OK column.

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
0x00,0x0E 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
0x00,0x14 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
0x00,0x1E 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
0x00,0x24 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
0x00,0x2C TLS_PSK_WITH_NULL_SHA D
0x00,0x2D TLS_DHE_PSK_WITH_NULL_SHA D
0x00,0x2E TLS_RSA_PSK_WITH_NULL_SHA D
0x00,0x34 TLS_DH_anon_WITH_AES_128_CBC_SHA D
0x00,0x3A TLS_DH_anon_WITH_AES_256_CBC_SHA D
0x00,0x3B TLS_RSA_WITH_NULL_SHA256 D
0x00,0x46 TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA D
0x00,0x6C TLS_DH_anon_WITH_AES_128_CBC_SHA256 D
0x00,0x6D TLS_DH_anon_WITH_AES_256_CBC_SHA256 D
0x00,0x89 TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA 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
0x00,0x9B TLS_DH_anon_WITH_SEED_CBC_SHA D
0x00,0xA6 TLS_DH_anon_WITH_AES_128_GCM_SHA256 D
0x00,0xA7 TLS_DH_anon_WITH_AES_256_GCM_SHA384 D
0x00,0xB0 TLS_PSK_WITH_NULL_SHA256 D
0x00,0xB1 TLS_PSK_WITH_NULL_SHA384 D
0x00,0xB4 TLS_DHE_PSK_WITH_NULL_SHA256 D
0x00,0xB5 TLS_DHE_PSK_WITH_NULL_SHA384 D
0x00,0xB8 TLS_RSA_PSK_WITH_NULL_SHA256 D
0x00,0xB9 TLS_RSA_PSK_WITH_NULL_SHA384 D
0x00,0xBF TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA256 D
0x00,0xC5 TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA256 D
0xC0,0x01 TLS_ECDH_ECDSA_WITH_NULL_SHA D
0xC0,0x02 TLS_ECDH_ECDSA_WITH_RC4_128_SHA D
0xC0,0x06 TLS_ECDHE_ECDSA_WITH_NULL_SHA D
0xC0,0x07 TLS_ECDHE_ECDSA_WITH_RC4_128_SHA D
0xC0,0x0B TLS_ECDH_RSA_WITH_NULL_SHA D
0xC0,0x0C TLS_ECDH_RSA_WITH_RC4_128_SHA D
0xC0,0x10 TLS_ECDHE_RSA_WITH_NULL_SHA D
0xC0,0x11 TLS_ECDHE_RSA_WITH_RC4_128_SHA D
0xC0,0x15 TLS_ECDH_anon_WITH_NULL_SHA D
0xC0,0x16 TLS_ECDH_anon_WITH_RC4_128_SHA D
0xC0,0x17 TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA D
0xC0,0x18 TLS_ECDH_anon_WITH_AES_128_CBC_SHA D
0xC0,0x19 TLS_ECDH_anon_WITH_AES_256_CBC_SHA D
0xC0,0x33 TLS_ECDHE_PSK_WITH_RC4_128_SHA D
0xC0,0x39 TLS_ECDHE_PSK_WITH_NULL_SHA D
0xC0,0x3A TLS_ECDHE_PSK_WITH_NULL_SHA256 D
0xC0,0x3B TLS_ECDHE_PSK_WITH_NULL_SHA384 D
0xC0,0x46 TLS_DH_anon_WITH_ARIA_128_CBC_SHA256 D
0xC0,0x47 TLS_DH_anon_WITH_ARIA_256_CBC_SHA384 D
0xC0,0x5A TLS_DH_anon_WITH_ARIA_128_GCM_SHA256 D
0xC0,0x5B TLS_DH_anon_WITH_ARIA_256_GCM_SHA384 D
0xC0,0x84 TLS_DH_anon_WITH_CAMELLIA_128_GCM_SHA256 D
0xC0,0x85 TLS_DH_anon_WITH_CAMELLIA_256_GCM_SHA384 D
0xC0,0xB4 TLS_SHA256_SHA256 D
0xC0,0xB5 TLS_SHA384_SHA384 D
  • Update note on the recommended column with text in Section 3.1.

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:

  • Update the registration policy to include:

    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 Approval.
  • Add a reference to this document under the reference heading.

  • Update the "Recommended" column with the changes as listed below. Entries keep their existing "Y" and "N" entries except for the entries in following table. A reference to this document SHALL be added to these entries.

Table 3
Value Curve Recommended
1 sect163k1 D
2 sect163r1 D
3 sect163r2 D
4 sect193r1 D
5 sect193r2 D
6 sect233k1 D
7 sect233r1 D
8 sect239k1 D
15 secp160k1 D
16 secp160r1 D
17 secp160r2 D
18 secp192k1 D
19 secp192r1 D
20 secp224k1 D
21 secp224r1 D
  • Update note on the recommended column with text in Section 3.1.

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:

  • Change the registration procedure from Specification Required to Expert Review and update it to include:

    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 Approval.
  • Add a reference to this document under the reference heading.

  • Entries keep their existing Recommended column "Y" and "N" entries

  • Update note on the recommended column with text in Section 3.1.

  • update the note on the role of the expert reviewer as follows.

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 strongly 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:

  • Change the registration procedure to:

    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 Approval.
  • Add a reference to this document under the reference heading.

  • Entries keep their existing Recommended column "Y" and "N" entries.

  • Update note on the recommended column with text in Section 3.1.

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:

  • Update the registration procedure to include:

    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 Approval.
  • Add a reference to this document under the reference heading.

  • Update the TLS HashAlgorithm registry to add a "Recommended" column as follows:

Table 4
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:

  • Update the registration procedure to include:

    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 Approval.
  • Add a reference to this document under the reference heading.

  • Update the TLS SignatureAlgorithm registry to add a "Recommended" column as follows:

Table 5
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:

  • Update the registration procedure to include:

    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 Approval.
  • Add a reference to this document under the reference heading.

  • Update the TLS ClientCertificateTypes registry to add a "Recommended" column as follows:

Table 6
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:

  • Update the registration procedure to include:

    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 Approval.
  • Add a reference to this document under the reference heading.

  • Entries keep their existing recommended column "Y" and "N" entries.

  • Update note on the recommended column with text in Section 3.1.

13. TLS SignatureScheme registry

IANA is requested to add a reference to this document under the reference heading.

14. Adding "Comment" Column

IANA is requested to add a "Comment" column to the following registries:

  • TLS ExtensionType Values

  • TLS Application-Layer Protocol Negotiation (ALPN) Protocol IDs

  • TLS CachedInformationType Values

  • TLS Certificate Compression Algorithm IDs

  • TLS Cipher Suites

  • TLS ContentType

  • TLS EC Point Formats

  • TLS EC Curve Types

  • TLS Supplemental Data Formats (SupplementalDataType)

  • TLS UserMappingType Values

  • TLS Authorization Data Formats

  • TLS Heartbeat Message Types

  • TLS Heartbeat Modes

  • TLS SignatureScheme

  • TLS PskKeyExchangeMode

  • TLS KDF Identifiers

This list of registries is all registries that do not already have a "Comment" or "Notes" column or that were not orphaned by TLS 1.3.

15. Expert Review of Current and Potential IETF and IRTF Documents

The intent of the Specification Required standard for TLS code points is to allow for easy registration for code points associated with protocols and algorithms that are not being actively developed inside IETF or IRTF. When TLS-based technologies are being developed inside the IRTF/IETF they should be done in coordination with the TLS WG in order to provide appropriate review. For this reason, designated experts should decline code point registrations for documents which have already been adopted or are being proposed for adoption by IETF working groups or IRTF research groups.

16. 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.

17. IANA Considerations

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

18. Normative References

[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>.
[RFC4346]
Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.1", RFC 4346, DOI 10.17487/RFC4346, , <https://www.rfc-editor.org/rfc/rfc4346>.
[RFC5469]
Eronen, P., Ed., "DES and IDEA Cipher Suites for Transport Layer Security (TLS)", RFC 5469, DOI 10.17487/RFC5469, , <https://www.rfc-editor.org/rfc/rfc5469>.
[RFC7465]
Popov, A., "Prohibiting RC4 Cipher Suites", RFC 7465, DOI 10.17487/RFC7465, , <https://www.rfc-editor.org/rfc/rfc7465>.
[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