GOST DNSSEC: Use of GOST 2012 Signature Algorithms in DNSKEY and RRSIG Resource Records for DNSSEC
Securing the Domain Name System with Russian cryptographic standards
Makarenko, B. and V. Dolmatov, Ed., "Use of GOST 2012 Signature Algorithms in DNSKEY and RRSIG Resource Records for DNSSEC", RFC 9558, DOI 10.17487/RFC9558, April 2024, <https://www.rfc-editor.org/info/rfc9558>.
@misc{rfc9558,
series = {Request for Comments},
number = 9558,
howpublished = {RFC 9558},
publisher = {RFC Editor},
doi = {10.17487/RFC9558},
url = {https://www.rfc-editor.org/info/rfc9558},
author = {B. Makarenko and V. Dolmatov},
title = {{Use of GOST 2012 Signature Algorithms in DNSKEY and RRSIG Resource Records for DNSSEC}},
pagetotal = 9,
year = 2024,
month = apr,
} RFC text
Contents
Independent Submission B. Makarenko
Request for Comments: 9558 The Technical center of Internet, LLC
Category: Informational V. Dolmatov, Ed.
ISSN: 2070-1721 JSC "NPK Kryptonite"
April 2024
Use of GOST 2012 Signature Algorithms in DNSKEY and RRSIG Resource
Records for DNSSEC
Abstract
This document describes how to produce digital signatures and hash
functions using the GOST R 34.10-2012 and GOST R 34.11-2012
algorithms for DNSKEY, RRSIG, and DS resource records, for use in the
Domain Name System Security Extensions (DNSSEC).
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This is a contribution to the RFC Series, independently of any other
RFC stream. The RFC Editor has chosen to publish this document at
its discretion and makes no statement about its value for
implementation or deployment. Documents approved for publication by
the RFC Editor are not candidates for any level of Internet Standard;
see Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9558.
Copyright Notice
Copyright (c) 2024 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.
Table of Contents
1. Introduction
1.1. Terminology
2. DNSKEY Resource Records
2.1. Using a Public Key with Existing Cryptographic Libraries
2.2. GOST DNSKEY RR Example
3. RRSIG Resource Records
3.1. RRSIG RR Example
4. DS Resource Records
4.1. DS RR Example
5. Operational Considerations
5.1. Key Sizes
5.2. Signature Sizes
5.3. Digest Sizes
6. Implementation Considerations
7. IANA Considerations
8. Security Considerations
9. References
9.1. Normative References
9.2. Informative References
Acknowledgments
Authors' Addresses
1. Introduction
The Domain Name System (DNS) is the global, hierarchically
distributed database for Internet Naming. The DNS has been extended
to use cryptographic keys and digital signatures for the verification
of the authenticity and integrity of its data. RFC 4033 [RFC4033],
RFC 4034 [RFC4034], and RFC 4035 [RFC4035] describe these DNS
Security Extensions, called DNSSEC.
RFC 4034 describes how to store DNSKEY and RRSIG resource records and
specifies a list of cryptographic algorithms to use. This document
extends that list with the signature and hash algorithms GOST R
34.10-2012 ([RFC7091]) and GOST R 34.11-2012 ([RFC6986]), and it
specifies how to store DNSKEY data and how to produce RRSIG resource
records with these algorithms.
GOST R 34.10-2012 and GOST R 34.11-2012 are Russian national
standards. Their cryptographic properties haven't been independently
verified.
Familiarity with DNSSEC and with GOST signature and hash algorithms
is assumed in this document.
Caution:
This specification is not a standard and does not have IETF community
consensus. It makes use of a cryptographic algorithm that is a
national standard for Russia. Neither the IETF nor the IRTF has
analyzed that algorithm for suitability for any given application,
and it may contain either intended or unintended weaknesses.
1.1. 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. DNSKEY Resource Records
The format of the DNSKEY RR can be found in RFC 4034 [RFC4034].
GOST R 34.10-2012 public keys are stored with the algorithm number
23.
According to RFC 7091 [RFC7091], a GOST R 34.10-2012 public key is a
point on the elliptic curve Q = (x, y). The wire representation of a
public key MUST contain 64 octets, where the first 32 octets contain
the little-endian representation of x and the second 32 octets
contain the little-endian representation of y.
As RFC 6986 and RFC 7091 allow two variants of the length of the
output hash and the signature and many variants of parameters of the
digital signature, for the purpose of this document we use the
256-bit variant of the digital signature algorithm, corresponding
with the 256-bit variant of the digest algorithm. We select the
parameters for the digital signature algorithm to be id-tc26-gost-
3410-2012-256-paramSetA as specified in RFC 7836 [RFC7836]; this
document refers to it as "parameter set A".
2.1. Using a Public Key with Existing Cryptographic Libraries
At the time of this writing, existing GOST-aware cryptographic
libraries are capable of reading GOST R 34.10-2012 public keys via a
generic X.509 API if the key is encoded according to RFC 9215
[RFC9215], Section 4.
To make this encoding from the wire format of a GOST R 34.10-2012
public key with the parameters used in this document, prepend the 64
octets of key data with the following 30-byte sequence:
0x30 0x5c 0x30 0x17 0x06 0x08 0x2a 0x85
0x03 0x07 0x01 0x01 0x01 0x01 0x30 0x0b
0x06 0x09 0x2a 0x85 0x03 0x07 0x01 0x02
0x01 0x01 0x01 0x03 0x41 0x00
These bytes provide the following ASN.1 structure suitable for
parsing by cryptographic toolkits:
0 92: SEQUENCE {
2 23: SEQUENCE {
4 8: OBJECT IDENTIFIER '1 2 643 7 1 1 1 1'
14 11: SEQUENCE {
16 9: OBJECT IDENTIFIER '1 2 643 7 1 2 1 1 1'
: }
: }
27 65: BIT STRING
The OIDs in the structure above represent a GOST R 34.10-2012 public
key with a 256-bit private key length and parameter set A. The
structure itself represents SubjectPublicKeyInfo field of an X.509
certificate as defined in RFC 5280 [RFC5280], Section 4.1
2.2. GOST DNSKEY RR Example
Given a private key with the following value:
Private-key-format: v1.2
Algorithm: 23 (ECC-GOST12)
Gost12Asn1: MD4CAQAwFwYIKoUDBwEBAQEwCwYJKoUDBwECAQEBBCD/Mw9o6R5lQHJ13
jz0W+C1tdsS4W7RJn04rk9MGJq3Hg==
The following DNSKEY RR stores a DNS zone key for example:
example. 600 IN DNSKEY 256 3 23 (
XGiiHlKUJd5fSeAK5O3L4tUNCPxs4pGqum6wKbqjdkqu
IQ8nOXrilXZ9HcY8b2AETkWrtWHfwvJD4twPPJFQSA==
) ;{id = 47355 (zsk), size = 512b}
The private key here is presented in PrivateKeyInfo ASN.1 structure,
as described in RFC 5958 [RFC5958], Section 2.
The public key can be calculated from the private key using algorithm
described in RFC 7091 [RFC7091].
3. RRSIG Resource Records
The value of the signature field in the RRSIG RR follows RFC 7091
[RFC7091] and is calculated as follows. The values for the RDATA
fields that precede the signature data are specified in RFC 4034
[RFC4034].
hash = GOSTR3411-2012(data)
where "data" is the wire format data of the resource record set that
is signed, as specified in RFC 4034 [RFC4034].
The signature is calculated from the hash according to GOST R
34.10-2012, and its wire format is compatible with RFC 7091
[RFC7091].
3.1. RRSIG RR Example
Consider a given RRset consisting of one MX RR to be signed with the
private key described in Section 2.2 of this document:
example. 600 IN MX 10 mail.example.
Setting the inception date to 2022-10-06 12:32:30 UTC and the
expiration date to 2022-11-03 12:32:30 UTC, the following signature
RR will be valid:
example. 600 IN RRSIG MX 23 1 600 20221103123230 (
20221006123230 47355 example.
EuLO0Qpn6zT1pzj9T2H5AWjcgzfmjNiK/vj811bExa0V
HMOVD9ma8rpf0B+D+V4Q0CWu1Ayzu+H/SyndnOWGxw==
)
The GOST R 34.10-2012 signature algorithm uses random (pseudorandom)
integer k as described in Section 6.1 of RFC 7091 [RFC7091]. The
following value for k was used to produce the signature example.
k = 8BBD0CE7CAF3FC1C2503DF30D13ED5DB75EEC44060FA22FB7E29628407C1E34
This value for k MUST NOT be used when computing GOST R 34.10-2012
signatures. It is provided only so the above signature example can
be reproduced. The actual signature value will differ between
signature calculations.
4. DS Resource Records
The GOST R 34.11-2012 digest algorithm is denoted in DS RRs by the
digest type 5. The wire format of a digest value is compatible with
RFC 6986 [RFC6986].
4.1. DS RR Example
For Key Signing Key (KSK):
example. IN DNSKEY 257 3 23 (
p8Req8DLJOfPymO5vExuK4gCcihF5N1YL7veCJ47av+w
h/qs9yJpD064k02rYUHfWnr7IjvJlbn3Z0sTZe9GRQ==
) ;{id = 29468 (ksk), size = 512b}
The DS RR will be:
example. IN DS 29468 23 5 (
6033725b0ccfc05d1e9d844d49c6cf89
0b13d5eac9439189947d5db6c8d1c1ec
)
5. Operational Considerations
5.1. Key Sizes
The key size of GOST R 34.10-2012 public keys conforming to this
specification MUST be 512 bits according to RFC 7091 [RFC7091].
5.2. Signature Sizes
The size of a GOST R 34.10-2012 signature conforming to this
specification MUST be 512 bits according to RFC 7091 [RFC7091].
5.3. Digest Sizes
The size of a GOST R 34.11-2012 digest conforming to this
specification MUST be 256 bits according to RFC 6986 [RFC6986].
6. Implementation Considerations
The support of this cryptographic suite in DNSSEC-aware systems is
OPTIONAL. According to RFC 6840 [RFC6840], Section 5.2, systems that
do not support these algorithms MUST ignore the RRSIG, DNSKEY, and DS
resource records associated with the GOST R 34.10-2012 digital
signature algorithm.
7. IANA Considerations
The following entry has been added to the IANA registry for "DNS
Security Algorithm Numbers":
+========+=============+============+=========+========+===========+
| Number | Description | Mnemonic | Zone | Trans. | Reference |
| | | | Signing | Sec. | |
+========+=============+============+=========+========+===========+
| 23 | GOST R | ECC-GOST12 | Y | * | RFC 9558 |
| | 34.10-2012 | | | | |
+--------+-------------+------------+---------+--------+-----------+
Table 1
The following entry has been added to the IANA registry for "Digest
Algorithms" in the "Delegation Signer (DS) Resource Record (RR) Type
Digest Algorithms" registry group:
+=======+===================+==========+===========+
| Value | Description | Status | Reference |
+=======+===================+==========+===========+
| 5 | GOST R 34.11-2012 | OPTIONAL | RFC 9558 |
+-------+-------------------+----------+-----------+
Table 2
8. Security Considerations
It is recommended to use a dual KSK algorithm signed zone until GOST-
aware DNSSEC software becomes more widespread, unless GOST-only
cryptography is to be used. Otherwise, GOST-signed zones may be
considered unsigned by the DNSSEC software currently in use.
Like all algorithms, it is possible that a significant flaw could be
discovered with GOST R 34.11-2012. In that case, deployments should
roll over to another algorithm. See RFC 7583 [RFC7583] on the timing
of such changes.
9. References
9.1. Normative References
[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/info/rfc2119>.
[RFC3110] Eastlake 3rd, D., "RSA/SHA-1 SIGs and RSA KEYs in the
Domain Name System (DNS)", RFC 3110, DOI 10.17487/RFC3110,
May 2001, <https://www.rfc-editor.org/info/rfc3110>.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements",
RFC 4033, DOI 10.17487/RFC4033, March 2005,
<https://www.rfc-editor.org/info/rfc4033>.
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security Extensions",
RFC 4034, DOI 10.17487/RFC4034, March 2005,
<https://www.rfc-editor.org/info/rfc4034>.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
<https://www.rfc-editor.org/info/rfc4035>.
[RFC6840] Weiler, S., Ed. and D. Blacka, Ed., "Clarifications and
Implementation Notes for DNS Security (DNSSEC)", RFC 6840,
DOI 10.17487/RFC6840, February 2013,
<https://www.rfc-editor.org/info/rfc6840>.
[RFC6986] Dolmatov, V., Ed. and A. Degtyarev, "GOST R 34.11-2012:
Hash Function", RFC 6986, DOI 10.17487/RFC6986, August
2013, <https://www.rfc-editor.org/info/rfc6986>.
[RFC7091] Dolmatov, V., Ed. and A. Degtyarev, "GOST R 34.10-2012:
Digital Signature Algorithm", RFC 7091,
DOI 10.17487/RFC7091, December 2013,
<https://www.rfc-editor.org/info/rfc7091>.
[RFC7583] Morris, S., Ihren, J., Dickinson, J., and W. Mekking,
"DNSSEC Key Rollover Timing Considerations", RFC 7583,
DOI 10.17487/RFC7583, October 2015,
<https://www.rfc-editor.org/info/rfc7583>.
[RFC7836] Smyshlyaev, S., Ed., Alekseev, E., Oshkin, I., Popov, V.,
Leontiev, S., Podobaev, V., and D. Belyavsky, "Guidelines
on the Cryptographic Algorithms to Accompany the Usage of
Standards GOST R 34.10-2012 and GOST R 34.11-2012",
RFC 7836, DOI 10.17487/RFC7836, March 2016,
<https://www.rfc-editor.org/info/rfc7836>.
[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/info/rfc8174>.
9.2. Informative References
[RFC4509] Hardaker, W., "Use of SHA-256 in DNSSEC Delegation Signer
(DS) Resource Records (RRs)", RFC 4509,
DOI 10.17487/RFC4509, May 2006,
<https://www.rfc-editor.org/info/rfc4509>.
[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/info/rfc5280>.
[RFC5933] Dolmatov, V., Ed., Chuprina, A., and I. Ustinov, "Use of
GOST Signature Algorithms in DNSKEY and RRSIG Resource
Records for DNSSEC", RFC 5933, DOI 10.17487/RFC5933, July
2010, <https://www.rfc-editor.org/info/rfc5933>.
[RFC5958] Turner, S., "Asymmetric Key Packages", RFC 5958,
DOI 10.17487/RFC5958, August 2010,
<https://www.rfc-editor.org/info/rfc5958>.
[RFC9215] Baryshkov, D., Ed., Nikolaev, V., and A. Chelpanov, "Using
GOST R 34.10-2012 and GOST R 34.11-2012 Algorithms with
the Internet X.509 Public Key Infrastructure", RFC 9215,
DOI 10.17487/RFC9215, March 2022,
<https://www.rfc-editor.org/info/rfc9215>.
Acknowledgments
This document is a minor extension to RFC 4034 [RFC4034]. Also, we
tried to follow the documents RFC 3110 [RFC3110], RFC 4509 [RFC4509],
and RFC 5933 [RFC5933] for consistency. The authors of and
contributors to these documents are gratefully acknowledged for their
hard work.
The following people provided additional feedback, text, and valuable
assistance: Alexander Venedyukhin, Michael StJohns, Valery Smyslov,
Tim Wicinski, and Stéphane Bortzmeyer.
Authors' Addresses
Boris Makarenko
The Technical center of Internet, LLC
8 marta St., 1, Bldg. 12
Moscow
127083
Russian Federation
Email: bmakarenko@tcinet.ru
Vasily Dolmatov (editor)
JSC "NPK Kryptonite"
Spartakovskaya Sq., 14, Bldg. 2
Moscow
105082
Russian Federation
Email: vdolmatov@gmail.com
AI ELI5
On this page
§1Introduction
The Domain Name System (DNS) is the global address book for the Internet. DNSSEC adds cryptographic signatures to DNS records, proving that they are authentic and have not been tampered with. RFC 4033, RFC 4034, and RFC 4035 describe the DNSSEC system and the algorithms that can be used to sign records.
This document extends the list of algorithms with Russian national standards: GOST R 34.10-2012 for digital signatures and GOST R 34.11-2012 for hashing. These are Russian government standards. The document specifies how to store GOST public keys in DNSKEY records, how to create RRSIG (signature) records, and how to use GOST digests in DS (Delegation Signer) records for DNSSEC.
Important caution: This RFC is informational, not a standard. It does not have IETF community consensus. The cryptographic properties of GOST have not been independently verified by the IETF or IRTF. The algorithms may contain weaknesses, either intentional or unintended. Support for GOST in DNSSEC-aware systems is optional.
A recipe for making stamps exists. This document says how to use a different recipe—Russia's official recipe—to make DNS stamps that work the same way.
§2GOST Keys and Signatures in DNSSEC
DNSSEC protects DNS by using pairs of cryptographic keys. A zone has two keys: a Key Signing Key (KSK) for signing other keys, and a Zone Signing Key (ZSK) for signing records in the zone. Public keys are stored in DNSKEY resource records. Signatures are stored in RRSIG (Resource Record Signature) records.
When you sign a zone with GOST, the process works the same as with other algorithms. A GOST public key is a point on an elliptic curve, represented as two 32-byte coordinates (x and y). The GOST signature algorithm takes the hash of the record to sign and produces a 512-bit (64-byte) signature using the GOST R 34.10-2012 algorithm. The hash is computed using GOST R 34.11-2012.
The main challenge is compatibility. Most DNS resolvers worldwide understand RSA and ECDSA signatures but not GOST. If you sign a zone with GOST alone, many resolvers will treat it as unsigned. Therefore, deployments should consider using dual algorithms: signing with both GOST and a widely-supported algorithm (like RSA or ECDSA) until GOST-aware DNSSEC software becomes more common.
Two keys protect a zone: a master key and a working key. GOST lets you use a Russian recipe for both. But most people still use other recipes, so your zone should use both until everyone learns the Russian recipe.
§3DNSKEY and RRSIG Records
GOST public keys in DNSKEY records use algorithm number 23. A GOST key is exactly 64 octets: the first 32 bytes are the x-coordinate of the elliptic curve point (in little-endian format), and the next 32 bytes are the y-coordinate (also little-endian). The document specifies which parameter set to use: parameter set A from RFC 7836, which defines a 256-bit variant of GOST for both signature and hash.
When signing an RRset (a group of records with the same name and type), the signer first computes the GOST R 34.11-2012 hash of the record data. Then it signs this hash using the GOST R 34.10-2012 algorithm. The resulting signature (64 bytes) is placed in the RRSIG record. The format is compatible with RFC 7091, which defines the wire format for GOST signatures.
To use GOST keys with standard cryptographic libraries, you may need to prepend 30 bytes of ASN.1 structure to the 64-byte key data. These bytes encode the parameter set and algorithm identifiers in X.509 format, allowing existing cryptographic toolkits to parse GOST keys correctly.
A GOST key is 64 bytes: the secret lock shape written down. A signature is also 64 bytes: the result of signing with the secret. Some tools need you to add 30 bytes of instructions before the key so they know which recipe was used.
| Field | Name | Size | Value | Description |
|---|---|---|---|---|
X-COORD | X Coordinate | 32 bytes | Little-endian representation of the x-coordinate of the elliptic curve point. | |
Y-COORD | Y Coordinate | 32 bytes | Little-endian representation of the y-coordinate of the elliptic curve point. |
§4Sizes and Specifications
This specification requires specific key and signature sizes. GOST R 34.10-2012 keys MUST be 512 bits (64 bytes) as defined in RFC 7091. Signatures produced by this algorithm MUST also be 512 bits. Hash digests produced by GOST R 34.11-2012 MUST be 256 bits (32 bytes) as defined in RFC 6986. These sizes are fixed and non-negotiable for this RFC.
In DS records, which contain a digest of the DNSKEY record for secure delegation, GOST R 34.11-2012 is registered as digest type 5. The 256-bit digest is placed in the DS record. This allows a parent zone to securely reference a child zone that uses GOST signatures by publishing a GOST digest of the child's DNSKEY record.
The RFC specifies that the 256-bit variants of both GOST algorithms be used. While RFC 6986 and RFC 7091 define longer variants (512-bit), this specification deliberately constrains implementations to the 256-bit versions for consistency and compatibility.
The lock is 64 bytes. The key is 64 bytes. The digest is 32 bytes. These numbers are fixed so everyone's recipe gives the same result.
- 23GOST R 34.10-2012 (ECC-GOST12) — Signature algorithm for DNSKEY and RRSIG records.
- 5GOST R 34.11-2012 — Hash digest algorithm for DS records.
§5Security and Deployment Concerns
The RFC carries a significant security note: GOST R 34.10-2012 and GOST R 34.11-2012 are Russian national standards whose cryptographic properties have not been independently verified by the IETF or IRTF. The algorithms may contain either intentional or unintended weaknesses. Implementers must be aware of this risk.
Like any cryptographic algorithm, GOST could be found to have a significant flaw in the future. If that happens, deployments should migrate to another algorithm. RFC 7583 provides guidance on the timing of such key rollovers. In the interim, it is recommended to use a dual-algorithm setup, signing zones with both GOST and a widely-supported algorithm (such as RSA or ECDSA), until GOST-aware DNSSEC software becomes more widespread.
RFC 6840 specifies that systems which do not support GOST algorithms MUST ignore associated RRSIG, DNSKEY, and DS records. This means zones signed only with GOST may appear unsigned to resolvers that do not support it, creating operational risks in mixed deployments.
Nobody outside Russia has checked this recipe carefully. It could have a hidden flaw. Until many people use it, do not rely on it alone—use another recipe too.
§6Practical Use and Limitations
This RFC documents how to use GOST algorithms in DNSSEC, but it is informational rather than a standard. Support for GOST in DNSSEC software is optional, not required. Implementers are not obligated to support it, and most DNS resolvers do not currently do so.
The RFC is useful for organizations required to use GOST by Russian law or regulation, or for zones operated in Russia where national cryptographic standards are mandated. For other organizations, GOST support in DNSSEC is not necessary. The document acknowledges this by noting that it is an independent submission, not a work of the IETF, and does not have the IETF's consensus or verification.
For anyone implementing GOST DNSSEC support, the RFC provides clear specifications: key format (64 octets), signature format (64 octets), digest type (5), and algorithm number (23). It also provides example DNSKEY, RRSIG, and DS records showing how GOST records look in practice.
This is optional. Most of the world does not need it. If you are required to use Russia's recipe by law, here is how. Otherwise, the other recipes work fine.