Internet-Draft | (D)TLS IANA Registry Updates | March 2023 |
Salowey & Turner | Expires 28 September 2023 | [Page] |
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 28 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 and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
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.¶
3. Adding "Recommended" Column
The instructions in this document update the Recommended column, originally added in [RFC8447] to add a third value, "D", indicating that a value is "Discouraged". The permitted values are:¶
- Y: Indicates that the IETF has consensus that the item is RECOMMENDED. This only means that the associated mechanism is fit for the purpose for which it was defined. Careful reading of the documentation for the mechanism is necessary to understand the applicability of that mechanism. The IETF could recommend mechanisms that have limited applicability, but will provide applicability statements that describe any limitations of the mechanism or necessary constraints on its use.¶
- N: Indicates that the item has not been evaluated by the IETF and that the IETF has made no statement about the suitability of the associated mechanism. This does not necessarily mean that the mechanism is flawed, only that no consensus exists. The IETF might have consensus to leave an items marked as "N" on the basis of it having limited applicability or usage constraints.¶
- D: Indicates that the item is discouraged. This marking could be used to identify mechanisms that might result in problems if they are used, such as a weak cryptographic algorithm or a mechanism that might cause interoperability problems in deployment. Implementers SHOULD consult the linked references associated with the item to determine the conditions under which it SHOULD NOT or MUST NOT be used.¶
Setting a value to "Y" or "D" in the "Recommended" column requires IETF Standards Action [RFC8126]. Any state transition to or from a "Y" or "D" value requires IESG Approval. Not all items defined in Standards Track RFCs need to be set to "Y" or "D". Any item not otherwise specified is set to "N". The column is blank for values that are unassigned or reserved unless specifically set.¶
3.1. Recommended Note
Existing registries have a note on the meaning of the recommended column. For the registries discussed in the subsequent sections this note is updated with a sentence describing the 'D' vaue as follows:¶
- Note:
-
If "Recommended" column is set to "N", it does not necessarily mean that it is flawed; rather, it indicates that the item either has not been through the IETF consensus process, has limited applicability, or is intended only for specific use cases. If the "Recommended" column is set to "D" the item is discouraged and SHOULD NOT or MUST NOT be used.¶
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.¶
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
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.¶
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 |
- 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.¶
- Entries keep their existing Recommended column "Y" and "N" entries.¶
- 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 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:¶
- 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:¶
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 |
- Add note on the recommended column with text in Section 3.1.¶
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:¶
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 |
- Add note on the recommended column with text in Section 3.1.¶
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:¶
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 |
- Add note on the recommended column with text in Section 3.1.¶
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. 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 1.2", Work in Progress, Internet-Draft, draft-ietf-tls-deprecate-obsolete-kex-02, , <https://datatracker.ietf.org/doc/html/draft-ietf-tls-deprecate-obsolete-kex-02>.
- [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>.