Internet DRAFT - draft-cuiling-dnsop-sm2-alg
draft-cuiling-dnsop-sm2-alg
Workgroup: Network Working Group C. Zhang
Internet-Draft: draft-cuiling-dnsop-sm2-alg-05 Y. Liu
Updates: 8624 (if approved) F. Leng
Published: 2023-03-08 Q. Zhao
Intended Status: Informational Z. He
Expires: 2023-09-08 CNNIC
SM2 Digital Signature Algorithm for DNSSEC
Abstract
This document describes how to specify SM2 Digital Signature
Algorithm keys and signatures in DNS Security (DNSSEC). It lists
the curve and uses SM3 as hash algorithm for signatures.
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1. Introduction
DNSSEC is broadly defined in RFCs 4033, 4034, and 4035 ([RFC4033],
[RFC4034], and [RFC4035]). It uses cryptographic keys and digital
signatures to provide authentication of DNS data. Currently, there
are several signature algorithms, such as RSA with SHA-256,ECDSA
with curve P-256 and SHA-256, etc.
This document defines the DNSKEY and RRSIG resource records (RRs)
of a new signing algorithms: SM2 uses elliptic curves over 256-bit
prime fields with SM3 hash algorithm. (A description of SM2 and SM3
can be found in GB/T 32918.2-2016 [GB/T 32918.2-2016] or ISO/IEC14888-3:2018
[ISO/IEC14888-3:2018], and GB/T 32905-2016 [GB/T 32905-2016] or
ISO/IEC10118-3:2018 [ISO/IEC10118-3:2018].) This document also
defines the DS RR for the SM3 one-way hash algorithm. In the signing
algorithm defined in this document, the size of the key for the
elliptic curve is matched with the size of the output of the hash
algorithm. Both are 256 bits.
Like all ECC-based algorithms, signing with SM2 is significantly
faster than RSA based algorithms, while the validating is slower.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
2. SM3 DS Records
SM3 is included in ISO/IEC 10118-3:2018 and is similar to SHA-256
in many ways. The implementation of SM3 in DNSSEC follows the
implementation of SHA-256 as specified in RFC 4509[RFC4509] except
that the underlying algorithm is SM3 with digest type code [TBD1].
3. SM2 Parameters
Verifying SM2 signatures requires agreement between the signer and
the verifier of the parameters used. SM2 digital signature algorithm
has been added to ISO/IEC 14888-3:2018. And the parameters of the
curve used in this document are as follows:
p = FFFFFFFE FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF 00000000 FFFFFFFF FFFFFFFF
a = FFFFFFFE FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF 00000000 FFFFFFFF FFFFFFFC
b = 28E9FA9E 9D9F5E34 4D5A9E4B CF6509A7 F39789F5 15AB8F92 DDBCBD41 4D940E93
xG = 32C4AE2C 1F198119 5F990446 6A39C994 8FE30BBF F2660BE1 715A4589 334C74C7
yG = BC3736A2 F4F6779C 59BDCEE3 6B692153 D0A9877C C62A4740 02DF32E5 2139F0A0
n = FFFFFFFE FFFFFFFF FFFFFFFF FFFFFFFF 7203DF6B 21C6052B 53BBF409 39D54123
4. DNSKEY and RRSIG Resource Records for SM2
SM2 public keys consist of a single value, called "P". In DNSSEC keys,
P is a string of 32 octets that represents the uncompressed form of a
curve point, "x | y".
The SM2 signature is the combination of two non-negative integers,
called "r" and "s". The two integers, each of which is formatted as
a simple octet string, are combined into a single longer octet string
for DNSSEC as the concatenation "r | s". (Conversion of the integers
to bit strings is the same as ECDSA signature.) Each integer MUST be
encoded as 32 octets.
Although SM2 uses elliptic curves, the process of digest and signature
generation is different from ECDSA.
The algorithm number associated with the DNSKEY and RRSIG resource records
is [TBD2], which is described in the IANA Considerations section.
Conformant implementations that create records to be put into the DNS MAY
implement signing and verification for the above algorithm. Conformant
DNSSEC verifiers MAY implement verification for the above algorithm.
5. Support for NSEC3 Denial of Existence
This document does not define algorithm aliases mentioned in RFC 5155
[RFC5155].
A DNSSEC validator that implements the signing algorithms defined in this
document MUST be able to validate negative answers in the form of both NSEC
and NSEC3 with hash algorithm 1, as defined in RFC 5155. An authoritative
server that does not implement NSEC3 MAY still serve zones that use the
signing algorithms defined in this document with NSEC denial of existence.
6. Example
The following is an example of SM2 keys and signatures in DNS format.
6.1. SM2 Example
Private-key-format: v1.3
Algorithm: [TBD2] (SM2SM3)
PrivateKey: V24tjJgXxp2ykscKRZdT+iuR5J1xRQN+FKoQACmo9fA=
example.net. 3600 IN DNSKEY 257 3 TBD2 (
jZbZMBImG9dtGWSVEwnv2l32OVKcX7MMJv+83/+A41ia
ZuO0ajXMcuyJbTr8Ud+kae6UlfqrnsG6tgADIPHxXA== )
example.net. 3600 IN DS 27215 TBD2 TBD1 (
86671f82dd872e4ee73647a95dff7fd0af599ff8a43f
fa26c9a2593091653c0e )
www.example.net. 3600 IN A 192.0.2.1
www.example.net. 3600 IN RRSIG A TBD2 6 3600 (
20220428075649 20220331075649 27215 example.net.
tz295lkfu2InRnLdLhKWDm354I6ZGSmYeOSDswKiQMU7
/Va0QrH7bD7ZnHB4wWsEjfy1XscwM4P86sVxkMJE7w== )
7. IANA Considerations
This document will update the IANA registry for digest types in DS records,
currently called "Delegation Signer (DS) Resource Record (RR) Type Digest
Algorithms".
Value TBD1
Digest Type SM3
Status OPTIONAL
This document will update the IANA registry "Domain Name System Security
(DNSSEC) Algorithm Numbers".
Number TBD2
Description SM2 signing algorithm with SM3 hashing algorithm
Mnemonic SM2SM3
Zone Signing Y
Trans. Sec. *
Reference This document
* There has been no determination of standardization of the use of this
algorithm with Transaction Security.
8. Security Considerations
The cryptographic work factor of SM2 is generally considered to be
equivalent to half the size of the key, which is 128 bits. Such an
assessment could, of course, change in the future if new attacks that
work better than the ones known today are found.
SM2 digital signature algorithm has come into use for less than a score
of years. So SM2SM3 algorithm is mainly used for research and experiment
purpose currently. The security of ECC-based algorithms is influenced by
the curve it uses. SM2 uses a different curve and has different process with
the signature generation and validation, so SM2 could be considered as an
alternative to ECDSA.
The security considerations listed in RFC 4509 apply here as well.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements",
RFC 4033, March 2005.
[RFC4034] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Resource Records for the DNS Security
Extensions", RFC 4034, March 2005.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, March 2005.
[RFC4509] Hardaker, W., "Use of SHA-256 in DNSSEC Delegation
Signer (DS) Resource Records (RRs)", RFC 4509,
May 2006.
[RFC5155] Laurie, B., Sisson, G., Arends, R., and D. Blacka, "DNS
Security (DNSSEC) Hashed Authenticated Denial of
Existence", RFC 5155, March 2008.
[RFC6605] Hoffman, P., and Wouter C.A. Wijngaards, "Elliptic Curve
Digital Signature Algorithm (DSA) for DNSSEC", RFC 6605,
April 2012.
9.2. Informative References
[GB/T 32918.2-2016] Standardization Administration of the People's Republic of
China, "Information security technology --- Public key
cryptographic algorithm SM2 based on elliptic curves ---
Part 2: Digital signature algorithm", GB/T 32918.2-2016,
March 2017, <https://github.com/alipay/tls13-sm-spec/blob/
master/sm-en-pdfs/sm2/GBT.32918.2-2016.SM2-en.pdf>.
[ISO/IEC14888-3:2018] International Organization for Standardization,
"IT Security techniques — Digital signatures with appendix —
Part 3: Discrete logarithm based mechanisms",
ISO ISO/IEC 14888-3:2018, November 2018.
[GB/T 32905-2016] Standardization Administration of the People's Republic of
China, "SM3 Cryptographic Hash Algorithm", GB/T 32905-2016,
March 2017, <https://github.com/alipay/tls13-sm-spec/blob/
master/sm-en-pdfs/sm3/GBT.32905-2016.SM3-en.pdf>.
[ISO/IEC10118-3:2018] International Organization for Standardization,
"IT Security techniques -- Hash-functions -- Part 3: Dedicated
hash-functions", ISO ISO/IEC 10118-3:2018, October 2018.
Appendix A. Example Zone
This is a zone showing its RRSIG RRs generated with SM3 hash algorithm
and SM2 signature algorithm.
example. 3600 IN SOA ns1.example. root.example. (
1 ; serial
3600 ; refresh (1 hour)
300 ; retry (5 minutes)
3600000 ; expire (5 weeks 6 days 16 hours)
3600 ; minimum (1 hour)
)
RRSIG SOA TBD2 1 3600 (
20230901000000 20220901000000 65042 example.
vXGQ/M+QJbEzdF9MW8rqJVN+QC5LdpK7k7vt
nupu/SrZhiKDGcXpORMpprlljlQ6w4YqytdA
ZHfbu25HfIyEgw== )
NS ns1.example.
NS ns2.example.
RRSIG NS TBD2 1 3600 (
20230901000000 20220901000000 65042 example.
xXR6eAWSdv9KpEtX/GccI0AFafmUoARf9Q1i
CgtoJKjFCQySqBLVxlgiQQaTpZqY8taepygv
8g5o5mHsfmyPiw== )
DNSKEY 256 3 TBD2 (
7EQ32PTAp+1ac6R9Ze2nfB8pPc2OJqkHSjug
ALr4SuD9awuQxhfw7wMpiXv7JK4/VwwTrCxJ
wu+qUuDsgoBK4w==
) ; ZSK; alg = SM2SM3 ; key id = 65042
DNSKEY 257 3 TBD2 (
jZbZMBImG9dtGWSVEwnv2l32OVKcX7MMJv+8
3/+A41iaZuO0ajXMcuyJbTr8Ud+kae6Ulfqr
nsG6tgADIPHxXA==
) ; KSK; alg = SM2SM3 ; key id = 27215
RRSIG DNSKEY TBD2 1 3600 (
20230901000000 20220901000000 65042 example.
lF2eq49e62Nn4aT5x8ZI6PdRSTPHPDixZdyl
lM6GWu4lkRWkpTgWLE4lQK/+qHdNS4DdTd36
Jsuu0FSO5k48Qg== )
RRSIG DNSKEY TBD2 1 3600 (
20230901000000 20220901000000 27215 example.
+MDF1bnH/8zCeOwJQbWSfwb6OCB8fp16rxog
S9+PbxHEcKNTOUX3hPxdM8NblDgY19c+KDmr
xei2D84M2B50cQ== )
0 NSEC3PARAM 1 0 10 AABBCCDD
0 RRSIG NSEC3PARAM TBD2 1 0 (
20230901000000 20220901000000 65042 example.
aqntwEYEJzkVb8SNuJLwdx7f+vivv5IUIeAj
6/TGt2/bewiM/Hp9fqOysEcjgWZ7lZbqJsR5
HtKlddixnjmOFQ== )
ns2.example. A 192.0.2.2
RRSIG A TBD2 2 3600 (
20230901000000 20220901000000 65042 example.
xqot4urj885t1SDnAZnozl4s3t/El1HZVLwb
0N2Bb6IdEBtH/SNJdN1Zz/xBysCGkRwoMq2I
Uk+v3Yl6Uo8Eiw== )
ns1.example. A 192.0.2.1
RRSIG A TBD2 2 3600 (
20230901000000 20220901000000 65042 example.
5ZNwC4No82PeHZd5PgdGmBsvRxjBe3FlnA4S
g8/tDZlHM7QSbDDN17r8+qHq+AeXKy8cSF3n
U+byf9VjzV9IKA== )
www.example. A 192.0.2.3
RRSIG A TBD2 2 3600 (
20230901000000 20220901000000 65042 example.
vNTwnIQzImSG6b6F0dNhNz+mt8oSRITzfiNh
mzdvI0w1eHxTetA/3Tu3HLoDYDw+D5uGcoVZ
NlvZpyrIU1BIAA== )
S0OCR8EH8COF31Q1TO66KIDIT4A4RV8R.example. NSEC3 1 1 10 AABBCCDD (
62KP1QB93KRGR6LM7SEVPJVNG90BLUE8
A RRSIG )
RRSIG NSEC3 TBD2 2 3600 (
20230901000000 20220901000000 65042 example.
ai3O/vkgVX6DRJFjfwWJI71QNXucCaTpWBAQ
JyedgjRGC/XgX1WF60SglDzWmlHdyACPHV4S
1dBE344tnNgAtA== )
GTGVQIILTSSJ8FFO9J6DC8PRTFAEA8G2.example. NSEC3 1 1 10 AABBCCDD (
NIU1DMQS67H1PIN9JIMC33JCMO8MU99T
A RRSIG )
RRSIG NSEC3 TBD2 2 3600 (
20230901000000 20220901000000 65042 example.
3BUwHiacqHADK7Y31kFa4JnGOrURCXlZNmZq
B163jles9HCQHIDR60DFZdZhx1sVBsd8Rl+L
dUcia3aUgNqwlA== )
NIU1DMQS67H1PIN9JIMC33JCMO8MU99T.example. NSEC3 1 1 10 AABBCCDD (
OHVFQ9KQA23B5PM64EST8LNRQRLQ624H
A RRSIG )
RRSIG NSEC3 TBD2 2 3600 (
20230901000000 20220901000000 65042 example.
ctAutz6smtvUeeCyZPel3BTYJzkJcYGXEDRH
hosBrWRiipM/C94nZxFpYioK+mq5tw9yebwH
83Vq94AChHbabg== )
test.example. A 192.0.2.4
RRSIG A TBD2 2 3600 (
20230901000000 20220901000000 65042 example.
H9+NQdd9o4NTj8siRO8c5IrjJ/6BuNaZdgeh
AbcwTcxBvhE7D4XeHH9zUcZ0gVuhdR8WoA8H
FVbCrekKGgW7Gw== )
OHVFQ9KQA23B5PM64EST8LNRQRLQ624H.example. NSEC3 1 1 10 AABBCCDD (
S0OCR8EH8COF31Q1TO66KIDIT4A4RV8R
A RRSIG )
RRSIG NSEC3 TBD2 2 3600 (
20230901000000 20220901000000 65042 example.
eygDRIjsL+OXE4leoBuZOFptq+FMkWGfXA19
ojaJlnRfeLXEHKBrCFMEe+8l3qlTkGFsBo3N
E3tQU4uSMafViA== )
62KP1QB93KRGR6LM7SEVPJVNG90BLUE8.example. NSEC3 1 1 10 AABBCCDD (
GTGVQIILTSSJ8FFO9J6DC8PRTFAEA8G2
NS SOA RRSIG DNSKEY NSEC3PARAM )
RRSIG NSEC3 TBD2 2 3600 (
20230901000000 20220901000000 65042 example.
FOWLegTgFkFY9vCOo4kHwjEvZ+IL1NMl4s9V
hVyPOwokd5uOLKeXTP19HIeEtW73WcJ9XNe/
ie/knp7Edo/hxw== )
Authors' Addresses
Cuiling Zhang
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing, 100190
China
Email: zhangcuiling@cnnic.cn
Yukun Liu
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing, 100190
China
Email: liuyukun@cnnic.cn
Feng Leng
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing, 100190
China
Email: lengfeng@cnnic.cn
Qi Zhao
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing, 100190
China
Email: zhaoqi@cnnic.cn
Zheng He
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing, 100190
China
Email: hezh@cnnic.cn
