draft-ietf-dnsop-algorithm-update-07.txt   draft-ietf-dnsop-algorithm-update-08.txt 
dnsop P. Wouters dnsop P. Wouters
Internet-Draft Red Hat Internet-Draft Red Hat
Obsoletes: 6944 (if approved) O. Sury Obsoletes: 6944 (if approved) O. Sury
Intended status: Standards Track Internet Systems Consortium Intended status: Standards Track Internet Systems Consortium
Expires: September 13, 2019 March 12, 2019 Expires: October 11, 2019 April 9, 2019
Algorithm Implementation Requirements and Usage Guidance for DNSSEC Algorithm Implementation Requirements and Usage Guidance for DNSSEC
draft-ietf-dnsop-algorithm-update-07 draft-ietf-dnsop-algorithm-update-08
Abstract Abstract
The DNSSEC protocol makes use of various cryptographic algorithms in The DNSSEC protocol makes use of various cryptographic algorithms in
order to provide authentication of DNS data and proof of non- order to provide authentication of DNS data and proof of non-
existence. To ensure interoperability between DNS resolvers and DNS existence. To ensure interoperability between DNS resolvers and DNS
authoritative servers, it is necessary to specify a set of algorithm authoritative servers, it is necessary to specify a set of algorithm
implementation requirements and usage guidelines to ensure that there implementation requirements and usage guidelines to ensure that there
is at least one algorithm that all implementations support. This is at least one algorithm that all implementations support. This
document defines the current algorithm implementation requirements document defines the current algorithm implementation requirements
and usage guidance for DNSSEC. This document obsoletes [RFC6944]. and usage guidance for DNSSEC. This document obsoletes [RFC6944].
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 September 13, 2019. This Internet-Draft will expire on October 11, 2019.
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.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
skipping to change at page 2, line 43 skipping to change at page 2, line 43
1. Introduction 1. Introduction
The DNSSEC signing algorithms are defined by various RFCs, including The DNSSEC signing algorithms are defined by various RFCs, including
[RFC4034], [RFC5155], [RFC5702], [RFC5933], [RFC6605], [RFC8080]. [RFC4034], [RFC5155], [RFC5702], [RFC5933], [RFC6605], [RFC8080].
DNSSEC is used to provide authentication of data. To ensure DNSSEC is used to provide authentication of data. To ensure
interoperability, a set of "mandatory-to-implement" DNSKEY algorithms interoperability, a set of "mandatory-to-implement" DNSKEY algorithms
are defined. This document obsoletes [RFC6944]. are defined. This document obsoletes [RFC6944].
1.1. Updating Algorithm Implementation Requirements and Usage Guidance 1.1. Updating Algorithm Implementation Requirements and Usage Guidance
The field of cryptography evolves continuously. New stronger The field of cryptography evolves continuously. New, stronger
algorithms appear and existing algorithms are found to be less secure algorithms appear and existing algorithms are found to be less secure
then originally thought. Therefore, algorithm implementation then originally thought. Attacks previously thought to be
requirements and usage guidance need to be updated from time to time computationally infeasible become more accessible as the available
to reflect the new reality. The choices for algorithms must be computational resources increase. Therefore, algorithm
conservative to minimize the risk of algorithm compromise. implementation requirements and usage guidance need to be updated
from time to time to reflect the new reality. The choices for
algorithms must be conservative to minimize the risk of algorithm
compromise.
1.2. Updating Algorithm Requirement Levels 1.2. Updating Algorithm Requirement Levels
The mandatory-to-implement algorithm of tomorrow should already be The mandatory-to-implement algorithm of tomorrow should already be
available in most implementations of DNSSEC by the time it is made available in most implementations of DNSSEC by the time it is made
mandatory. This document attempts to identify and introduce those mandatory. This document attempts to identify and introduce those
algorithms for future mandatory-to-implement status. There is no algorithms for future mandatory-to-implement status. There is no
guarantee that algorithms in use today will become mandatory in the guarantee that algorithms in use today will become mandatory in the
future. Published algorithms are continuously subjected to future. Published algorithms are continuously subjected to
cryptographic attack and may become too weak, or even be completely cryptographic attack and may become too weak, or even be completely
broken, before this document is updated. broken, before this document is updated.
This document only provides recommendations with respect to This document only provides recommendations with respect to
mandatory-to-implement algorithms or algorithms so weak that mandatory-to-implement algorithms or algorithms so weak that these
recommendation cannot be recommended. Any algorithm listed in the cannot be recommended. Any algorithm listed in the [DNSKEY-IANA] and
[DNSKEY-IANA] and [DS-IANA] registries, but not mentioned in this [DS-IANA] registries, but not mentioned in this document, MAY be
document, MAY be implemented. For clarification and consistency, an implemented. For clarification and consistency, an algorithm will be
algorithm will be specified as MAY in this document only when it has specified as MAY in this document only when it has been downgraded
been downgraded. from a MUST or a RECOMMENDED to a MAY.
Although this document's primary purpose is to update algorithm Although this document's primary purpose is to update algorithm
recommendations to keep DNSSEC authentication secure over time, it recommendations to keep DNSSEC authentication secure over time, it
also aims to do so in such a way that DNSSEC implementations remain also aims to do so in such a way that DNSSEC implementations remain
interoperable. DNSSEC interoperability is addressed by an interoperable. DNSSEC interoperability is addressed by an
incremental introduction or deprecation of algorithms. incremental introduction or deprecation of algorithms.
[RFC2119] considers the term SHOULD equivalent to RECOMMENDED, and [RFC2119] considers the term SHOULD equivalent to RECOMMENDED, and
SHOULD NOT equivalent to NOT RECOMMENDED. The authors of this SHOULD NOT equivalent to NOT RECOMMENDED. The authors of this
document have chosen to use the terms RECOMMENDED and NOT document have chosen to use the terms RECOMMENDED and NOT
RECOMMENDED, as this more clearly expresses the recommendations to RECOMMENDED, as this more clearly expresses the intent to
implementers. implementers.
It is expected that deprecation of an algorithm will be performed It is expected that deprecation of an algorithm will be performed
gradually. This provides time for various implementations to update gradually in a series of updates to this document. This provides
their implemented algorithms while remaining interoperable. Unless time for various implementations to update their implemented
there are strong security reasons, an algorithm is expected to be algorithms while remaining interoperable. Unless there are strong
downgraded from MUST to NOT RECOMMENDED or MAY, instead of to MUST security reasons, an algorithm is expected to be downgraded from MUST
NOT. Similarly, an algorithm that has not been mentioned as to NOT RECOMMENDED or MAY, instead of to MUST NOT. Similarly, an
mandatory-to-implement is expected to be introduced with a algorithm that has not been mentioned as mandatory-to-implement is
RECOMMENDED instead of a MUST. expected to be introduced with a RECOMMENDED instead of a MUST.
Since the effect of using an unknown DNSKEY algorithm is that the Since the effect of using an unknown DNSKEY algorithm is that the
zone is treated as insecure, it is recommended that algorithms zone is treated as insecure, it is recommended that algorithms
downgraded to NOT RECOMMENDED or lower not be used by authoritative downgraded to NOT RECOMMENDED or lower not be used by authoritative
nameservers and DNSSEC signers to create new DNSKEY's. This will nameservers and DNSSEC signers to create new DNSKEYs. This will
allow for deprecated algorithms to become less and less common over allow for deprecated algorithms to become less and less common over
time. Once an algorithm has reached a sufficiently low level of time. Once an algorithm has reached a sufficiently low level of
deployment, it can be marked as MUST NOT, so that recursive resolvers deployment, it can be marked as MUST NOT, so that recursive resolvers
can remove support for validating it. can remove support for validating it.
Recursive nameservers are encouraged to retain support for all Recursive nameservers are encouraged to retain support for all
algorithms not marked as MUST NOT. algorithms not marked as MUST NOT.
1.3. Document Audience 1.3. Document Audience
The recommendations of this document mostly target DNSSEC The recommendations of this document mostly target DNSSEC
implementers, as implementations need to meet both high security implementers, as implementations need to meet both high security
expectations as well as high interoperability between various vendors expectations as well as high interoperability between various vendors
and with different versions. Interoperability requires a smooth and with different versions. Interoperability requires a smooth
transition to more secure algorithms. This perspective may differ transition to more secure algorithms. This perspective may differ
from from that of a user who wishes to deploy and configure DNSSEC from that of a user who wishes to deploy and configure DNSSEC with
with only the safest algorithm. On the other hand, the comments and only the safest algorithm. On the other hand, the comments and
recommendations in this document are also expected to be useful for recommendations in this document are also expected to be useful for
such users. such users.
2. Conventions Used in This Document 2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
skipping to change at page 5, line 20 skipping to change at page 5, line 20
DSA and DSA-NSEC3-SHA1 are not widely deployed and vulnerable to DSA and DSA-NSEC3-SHA1 are not widely deployed and vulnerable to
private key compromise when generating signatures using a weak or private key compromise when generating signatures using a weak or
compromised random number generator. compromised random number generator.
RSASHA256 is in wide use and considered strong. RSASHA256 is in wide use and considered strong.
RSASHA512 is NOT RECOMMENDED for DNSSEC Signing because it has not RSASHA512 is NOT RECOMMENDED for DNSSEC Signing because it has not
seen wide deployment, but there are some deployments hence DNSSEC seen wide deployment, but there are some deployments hence DNSSEC
Validation MUST implement RSASHA512 to ensure interoperability. Validation MUST implement RSASHA512 to ensure interoperability.
There is no significant difference in cryptographics strength between There is no significant difference in cryptographic strength between
RSASHA512 and RSASHA256, therefore it is discouraged to use RSASHA512 and RSASHA256, therefore it is discouraged to use
RSASHA512, as it will only make deprecation of older algorithms RSASHA512, as it will only make deprecation of older algorithms
harder. People that wish to use a cryptographically stronger harder. People who wish to use a cryptographically stronger
algorithm should switch to elliptic curve cryptography algorithms. algorithm should switch to elliptic curve cryptography algorithms.
ECC-GOST (GOST R 34.10-2001) has been superseded by GOST R 34.10-2012 ECC-GOST (GOST R 34.10-2001) has been superseded by GOST R 34.10-2012
in [RFC7091]. The GOST R 34.10-2012 hasn't been standardized for use in [RFC7091]. GOST R 34.10-2012 hasn't been standardized for use in
in DNSSEC. DNSSEC.
ECDSAP256SHA256 provides more cryptographic strength with a shorter ECDSAP256SHA256 provides more cryptographic strength with a shorter
signature length than either RSASHA256 or RSASHA512. ECDSAP256SHA256 signature length than either RSASHA256 or RSASHA512. ECDSAP256SHA256
has been widely deployed and therefore it is now at MUST level for has been widely deployed and therefore it is now at MUST level for
both validation and signing. It is RECOMMENDED to use deterministic both validation and signing. It is RECOMMENDED to use the
digital signature generation procedure of the ECDSA ([RFC6979]) when deterministic digital signature generation procedure of the ECDSA
implementing ECDSAP256SHA256 (and ECDSAP384SHA384). ([RFC6979]) when implementing ECDSAP256SHA256 (and ECDSAP384SHA384).
ECDSAP384SHA384 shares the same properties as ECDSAP256SHA256, but ECDSAP384SHA384 shares the same properties as ECDSAP256SHA256, but
offers a modest security advantage over ECDSAP256SHA256 (192 bits of offers a modest security advantage over ECDSAP256SHA256 (192 bits of
strength versus 128 bits). For most DNSSEC applications, strength versus 128 bits). For most DNSSEC applications,
ECDSAP256SHA256 should be satisfactory and robust for the foreseeable ECDSAP256SHA256 should be satisfactory and robust for the foreseeable
future, and is therefore recommended for signing. While it is future, and is therefore recommended for signing. While it is
unlikely for a DNSSEC use case requiring 192-bit security strength to unlikely for a DNSSEC use case requiring 192-bit security strength to
arise, ECDSA384SHA384 is provided for such applications and it MAY be arise, ECDSA384SHA384 is provided for such applications and it MAY be
used for signing in these cases. used for signing in these cases.
ED25519 and ED448 use Edwards-curve Digital Security Algorithm ED25519 and ED448 use the Edwards-curve Digital Security Algorithm
(EdDSA). There are three main advantages of the EdDSA algorithm: It (EdDSA). There are three main advantages of EdDSA: It does not
does not require the use of a unique random number for each require the use of a unique random number for each signature, there
signature, there are no padding or truncation issues as with ECDSA, are no padding or truncation issues as with ECDSA, and it is more
and it is more resilient to side-channel attacks. Furthermore, EdDSA resilient to side-channel attacks. Furthermore, EdDSA cryptography
cryptography is less prone to implementation errors ([RFC8032], is less prone to implementation errors ([RFC8032], [RFC8080]). It is
[RFC8080]). It is expected that ED25519 will become the future expected that ED25519 will become the future RECOMMENDED default
RECOMMENDED default algorithm once there's enough support for this algorithm once there's enough support for this algorithm in the
algorithm in the deployed DNSSEC validators. deployed DNSSEC validators.
3.2. DNSKEY Algorithm Recommendation 3.2. DNSKEY Algorithm Recommendation
Operation recommendation for new and existing deployments. Operational recommendation for new and existing deployments.
Due to industry-wide trend to move to elliptic curve cryptography, Due to the industry-wide trend towards elliptic curve cryptography,
the ECDSAP256SHA256 is RECOMMENDED DNSKEY algorithm for use by new ECDSAP256SHA256 is the RECOMMENDED DNSKEY algorithm for use by new
DNSSEC deployments, and users of RSA based algorithms SHOULD upgrade DNSSEC deployments, and users of RSA-based algorithms SHOULD upgrade
to ECDSAP256SHA256. to ECDSAP256SHA256.
3.3. DS and CDS Algorithms 3.3. DS and CDS Algorithms
Recommendations for Delegation Signer Digest Algorithms [DNSKEY-IANA] Recommendations for Delegation Signer Digest Algorithms [DNSKEY-IANA]
These also apply to the CDS RRTYPE as specified in [RFC7344] These recommendations also apply to the CDS RRTYPE as specified in
[RFC7344]
+--------+-----------------+-------------------+-------------------+ +--------+-----------------+-------------------+-------------------+
| Number | Mnemonics | DNSSEC Delegation | DNSSEC Validation | | Number | Mnemonics | DNSSEC Delegation | DNSSEC Validation |
+--------+-----------------+-------------------+-------------------+ +--------+-----------------+-------------------+-------------------+
| 0 | NULL (CDS only) | MUST NOT [*] | MUST NOT [*] | | 0 | NULL (CDS only) | MUST NOT [*] | MUST NOT [*] |
| 1 | SHA-1 | MUST NOT | MUST | | 1 | SHA-1 | MUST NOT | MUST |
| 2 | SHA-256 | MUST | MUST | | 2 | SHA-256 | MUST | MUST |
| 3 | GOST R 34.11-94 | MUST NOT | MAY | | 3 | GOST R 34.11-94 | MUST NOT | MAY |
| 4 | SHA-384 | MAY | RECOMMENDED | | 4 | SHA-384 | MAY | RECOMMENDED |
+--------+-----------------+-------------------+-------------------+ +--------+-----------------+-------------------+-------------------+
[*] - This is a special type of CDS record signaling removal of DS at [*] - This is a special type of CDS record signaling removal of DS at
the parent in [RFC8078] the parent in [RFC8078].
NULL is a special case, see [RFC8078] NULL is a special case, see [RFC8078].
SHA-1 is still in wide use for DS records, so validators MUST SHA-1 is still in wide use for DS records, so validators MUST
implement validation, but it MUST NOT be used to generate new DS and implement validation, but it MUST NOT be used to generate new DS and
CDS records. (See Operational Considerations for caveats when CDS records. (See Operational Considerations for caveats when
upgrading from SHA-1 to SHA-256 DS Algorithm.) upgrading from SHA-1 to SHA-256 DS Algorithm.)
SHA-256 is in wide use and considered strong. SHA-256 is in wide use and considered strong.
GOST R 34.11-94 has been superseded by GOST R 34.11-2012 in GOST R 34.11-94 has been superseded by GOST R 34.11-2012 in
[RFC6986]. The GOST R 34.11-2012 hasn't been standardized for use in [RFC6986]. GOST R 34.11-2012 has not been standardized for use in
DNSSEC. DNSSEC.
SHA-384 shares the same properties as SHA-256, but offers a modest SHA-384 shares the same properties as SHA-256, but offers a modest
security advantage over SHA-384 (384-bits of strength versus security advantage over SHA-256 (384-bits of strength versus
256-bits). For most applications of DNSSEC, SHA-256 should be 256-bits). For most applications of DNSSEC, SHA-256 should be
satisfactory and robust for the foreseeable future, and is therefore satisfactory and robust for the foreseeable future, and is therefore
recommended for DS and CDS records. While it is unlikely for a recommended for DS and CDS records. While it is unlikely for a
DNSSEC use case requiring 384-bit security strength to arise, SHA-384 DNSSEC use case requiring 384-bit security strength to arise, SHA-384
is provided for such applications and it MAY be used for generating is provided for such applications and it MAY be used for generating
DS and CDS records in these cases. DS and CDS records in these cases.
3.4. DS and CDS Algorithm Recommendation 3.4. DS and CDS Algorithm Recommendation
Operation recommendation for new and existing deployments. Operation recommendation for new and existing deployments: SHA-256 is
the RECOMMENDED DS and CDS algorithm.
The SHA-256 is RECOMMENDED DS and CDS algorithm.
4. Implementation Status 4. Implementation Status
[RFC Editor Note: Please remove this entire seciton plus all [RFC Editor Note: Please remove this entire seciton plus all
references to [RFC7942] prior to publication as an RFC.] references to [RFC7942] prior to publication as an RFC.]
This section records the status of known implementations of the This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942]. Internet-Draft, and is based on a proposal described in [RFC7942].
The description of implementations in this section is intended to The description of implementations in this section is intended to
skipping to change at page 8, line 35 skipping to change at page 8, line 35
The security of cryptographic systems depends on both the strength of The security of cryptographic systems depends on both the strength of
the cryptographic algorithms chosen and the strength of the keys used the cryptographic algorithms chosen and the strength of the keys used
with those algorithms. The security also depends on the engineering with those algorithms. The security also depends on the engineering
of the protocol used by the system to ensure that there are no non- of the protocol used by the system to ensure that there are no non-
cryptographic ways to bypass the security of the overall system. cryptographic ways to bypass the security of the overall system.
This document concerns itself with the selection of cryptographic This document concerns itself with the selection of cryptographic
algorithms for the use of DNSSEC, specifically with the selection of algorithms for the use of DNSSEC, specifically with the selection of
"mandatory-to-implement" algorithms. The algorithms identified in "mandatory-to-implement" algorithms. The algorithms identified in
this document as MUST or RECOMMENDED to implement are not known to be this document as MUST or RECOMMENDED to implement are not known to be
broken at the current time, and cryptographic research so far leads broken (in the cryptographic sense) at the current time, and
us to believe that they are likely to remain secure into the cryptographic research so far leads us to believe that they are
foreseeable future. However, this isn't necessarily forever, and it likely to remain secure into the foreseeable future. However, this
is expected that new revisions of this document will be issued from isn't necessarily forever, and it is expected that new revisions of
time to time to reflect the current best practices in this area. this document will be issued from time to time to reflect the current
best practices in this area.
Retiring an algorithm too soon would result in a zone signed with the Retiring an algorithm too soon would result in a zone signed with the
retired algorithm being downgraded to the equivalent of an unsigned retired algorithm being downgraded to the equivalent of an unsigned
zone. Therefore, algorithm deprecation must be done very slowly and zone. Therefore, algorithm deprecation must be done very slowly and
only after careful consideration and measurement of its use. only after careful consideration and measurement of its use.
6. Operational Considerations 6. Operational Considerations
DNSKEY algorithm rollover in a live zone is a complex process. See DNSKEY algorithm rollover in a live zone is a complex process. See
[RFC6781] and [RFC7583] for guidelines on how to perform algorithm [RFC6781] and [RFC7583] for guidelines on how to perform algorithm
skipping to change at page 9, line 18 skipping to change at page 9, line 18
algorithm first before rolling the Key Signing Key. algorithm first before rolling the Key Signing Key.
7. IANA Considerations 7. IANA Considerations
This document makes no requests of IANA. This document makes no requests of IANA.
8. Acknowledgements 8. Acknowledgements
This document borrows text from RFC 4307 by Jeffrey I. Schiller of This document borrows text from RFC 4307 by Jeffrey I. Schiller of
the Massachusetts Institute of Technology (MIT) and the 4307bis the Massachusetts Institute of Technology (MIT) and the 4307bis
document by Yoav Nir, Tero Kivinen, Paul Wouters and Daniel Migault. document by Yoav Nir, Tero Kivinen, Paul Wouters, and Daniel Migault.
Much of the original text has been copied verbatim. Much of the original text has been copied verbatim.
We wish to thank Michael Sinatra, Roland van Rijswijk-Deij, Olafur We wish to thank Michael Sinatra, Roland van Rijswijk-Deij, Olafur
Gudmundsson, Paul Hoffman and Evan Hunt for their imminent feedback. Gudmundsson, Paul Hoffman, Evan Hunt, and Peter Yee for their
feedback.
Kudos to Roy Arends for bringing the DS rollover issue to the Kudos to Roy Arends for bringing the DS rollover issue to light.
daylight.
9. References 9. References
9.1. Normative References 9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, <https://www.rfc- DOI 10.17487/RFC2119, March 1997,
editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
9.2. Informative References 9.2. Informative References
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S. [RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security Extensions", Rose, "Resource Records for the DNS Security Extensions",
RFC 4034, DOI 10.17487/RFC4034, March 2005, RFC 4034, DOI 10.17487/RFC4034, March 2005,
<https://www.rfc-editor.org/info/rfc4034>. <https://www.rfc-editor.org/info/rfc4034>.
[RFC5155] Laurie, B., Sisson, G., Arends, R., and D. Blacka, "DNS [RFC5155] Laurie, B., Sisson, G., Arends, R., and D. Blacka, "DNS
Security (DNSSEC) Hashed Authenticated Denial of Security (DNSSEC) Hashed Authenticated Denial of
Existence", RFC 5155, DOI 10.17487/RFC5155, March 2008, Existence", RFC 5155, DOI 10.17487/RFC5155, March 2008,
<https://www.rfc-editor.org/info/rfc5155>. <https://www.rfc-editor.org/info/rfc5155>.
[RFC5702] Jansen, J., "Use of SHA-2 Algorithms with RSA in DNSKEY [RFC5702] Jansen, J., "Use of SHA-2 Algorithms with RSA in DNSKEY
and RRSIG Resource Records for DNSSEC", RFC 5702, and RRSIG Resource Records for DNSSEC", RFC 5702,
DOI 10.17487/RFC5702, October 2009, <https://www.rfc- DOI 10.17487/RFC5702, October 2009,
editor.org/info/rfc5702>. <https://www.rfc-editor.org/info/rfc5702>.
[RFC5933] Dolmatov, V., Ed., Chuprina, A., and I. Ustinov, "Use of [RFC5933] Dolmatov, V., Ed., Chuprina, A., and I. Ustinov, "Use of
GOST Signature Algorithms in DNSKEY and RRSIG Resource GOST Signature Algorithms in DNSKEY and RRSIG Resource
Records for DNSSEC", RFC 5933, DOI 10.17487/RFC5933, July Records for DNSSEC", RFC 5933, DOI 10.17487/RFC5933, July
2010, <https://www.rfc-editor.org/info/rfc5933>. 2010, <https://www.rfc-editor.org/info/rfc5933>.
[RFC6605] Hoffman, P. and W. Wijngaards, "Elliptic Curve Digital [RFC6605] Hoffman, P. and W. Wijngaards, "Elliptic Curve Digital
Signature Algorithm (DSA) for DNSSEC", RFC 6605, Signature Algorithm (DSA) for DNSSEC", RFC 6605,
DOI 10.17487/RFC6605, April 2012, <https://www.rfc- DOI 10.17487/RFC6605, April 2012,
editor.org/info/rfc6605>. <https://www.rfc-editor.org/info/rfc6605>.
[RFC6781] Kolkman, O., Mekking, W., and R. Gieben, "DNSSEC [RFC6781] Kolkman, O., Mekking, W., and R. Gieben, "DNSSEC
Operational Practices, Version 2", RFC 6781, Operational Practices, Version 2", RFC 6781,
DOI 10.17487/RFC6781, December 2012, <https://www.rfc- DOI 10.17487/RFC6781, December 2012,
editor.org/info/rfc6781>. <https://www.rfc-editor.org/info/rfc6781>.
[RFC6944] Rose, S., "Applicability Statement: DNS Security (DNSSEC) [RFC6944] Rose, S., "Applicability Statement: DNS Security (DNSSEC)
DNSKEY Algorithm Implementation Status", RFC 6944, DNSKEY Algorithm Implementation Status", RFC 6944,
DOI 10.17487/RFC6944, April 2013, <https://www.rfc- DOI 10.17487/RFC6944, April 2013,
editor.org/info/rfc6944>. <https://www.rfc-editor.org/info/rfc6944>.
[RFC6979] Pornin, T., "Deterministic Usage of the Digital Signature [RFC6979] Pornin, T., "Deterministic Usage of the Digital Signature
Algorithm (DSA) and Elliptic Curve Digital Signature Algorithm (DSA) and Elliptic Curve Digital Signature
Algorithm (ECDSA)", RFC 6979, DOI 10.17487/RFC6979, August Algorithm (ECDSA)", RFC 6979, DOI 10.17487/RFC6979, August
2013, <https://www.rfc-editor.org/info/rfc6979>. 2013, <https://www.rfc-editor.org/info/rfc6979>.
[RFC6986] Dolmatov, V., Ed. and A. Degtyarev, "GOST R 34.11-2012: [RFC6986] Dolmatov, V., Ed. and A. Degtyarev, "GOST R 34.11-2012:
Hash Function", RFC 6986, DOI 10.17487/RFC6986, August Hash Function", RFC 6986, DOI 10.17487/RFC6986, August
2013, <https://www.rfc-editor.org/info/rfc6986>. 2013, <https://www.rfc-editor.org/info/rfc6986>.
[RFC7091] Dolmatov, V., Ed. and A. Degtyarev, "GOST R 34.10-2012: [RFC7091] Dolmatov, V., Ed. and A. Degtyarev, "GOST R 34.10-2012:
Digital Signature Algorithm", RFC 7091, Digital Signature Algorithm", RFC 7091,
DOI 10.17487/RFC7091, December 2013, <https://www.rfc- DOI 10.17487/RFC7091, December 2013,
editor.org/info/rfc7091>. <https://www.rfc-editor.org/info/rfc7091>.
[RFC7344] Kumari, W., Gudmundsson, O., and G. Barwood, "Automating [RFC7344] Kumari, W., Gudmundsson, O., and G. Barwood, "Automating
DNSSEC Delegation Trust Maintenance", RFC 7344, DNSSEC Delegation Trust Maintenance", RFC 7344,
DOI 10.17487/RFC7344, September 2014, <https://www.rfc- DOI 10.17487/RFC7344, September 2014,
editor.org/info/rfc7344>. <https://www.rfc-editor.org/info/rfc7344>.
[RFC7583] Morris, S., Ihren, J., Dickinson, J., and W. Mekking, [RFC7583] Morris, S., Ihren, J., Dickinson, J., and W. Mekking,
"DNSSEC Key Rollover Timing Considerations", RFC 7583, "DNSSEC Key Rollover Timing Considerations", RFC 7583,
DOI 10.17487/RFC7583, October 2015, <https://www.rfc- DOI 10.17487/RFC7583, October 2015,
editor.org/info/rfc7583>. <https://www.rfc-editor.org/info/rfc7583>.
[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running [RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", BCP 205, Code: The Implementation Status Section", BCP 205,
RFC 7942, DOI 10.17487/RFC7942, July 2016, RFC 7942, DOI 10.17487/RFC7942, July 2016,
<https://www.rfc-editor.org/info/rfc7942>. <https://www.rfc-editor.org/info/rfc7942>.
[RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital [RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital
Signature Algorithm (EdDSA)", RFC 8032, Signature Algorithm (EdDSA)", RFC 8032,
DOI 10.17487/RFC8032, January 2017, <https://www.rfc- DOI 10.17487/RFC8032, January 2017,
editor.org/info/rfc8032>. <https://www.rfc-editor.org/info/rfc8032>.
[RFC8078] Gudmundsson, O. and P. Wouters, "Managing DS Records from [RFC8078] Gudmundsson, O. and P. Wouters, "Managing DS Records from
the Parent via CDS/CDNSKEY", RFC 8078, the Parent via CDS/CDNSKEY", RFC 8078,
DOI 10.17487/RFC8078, March 2017, <https://www.rfc- DOI 10.17487/RFC8078, March 2017,
editor.org/info/rfc8078>. <https://www.rfc-editor.org/info/rfc8078>.
[RFC8080] Sury, O. and R. Edmonds, "Edwards-Curve Digital Security [RFC8080] Sury, O. and R. Edmonds, "Edwards-Curve Digital Security
Algorithm (EdDSA) for DNSSEC", RFC 8080, Algorithm (EdDSA) for DNSSEC", RFC 8080,
DOI 10.17487/RFC8080, February 2017, <https://www.rfc- DOI 10.17487/RFC8080, February 2017,
editor.org/info/rfc8080>. <https://www.rfc-editor.org/info/rfc8080>.
[DNSKEY-IANA] [DNSKEY-IANA]
"DNSKEY Algorithms", <http://www.iana.org/assignments/ "DNSKEY Algorithms", <http://www.iana.org/assignments/
dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml>. dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml>.
[DS-IANA] "Delegation Signer Digest Algorithms", [DS-IANA] "Delegation Signer Digest Algorithms",
<http://www.iana.org/assignments/ds-rr-types/ <http://www.iana.org/assignments/ds-rr-types/
ds-rr-types.xhtml>. ds-rr-types.xhtml>.
Authors' Addresses Authors' Addresses
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