RFC 8208 PROPOSED STANDARD ROUTING SECURITY · CRYPTOGRAPHY · BGPSEC
BGPsec Algorithms, Key Formats, and Signature Formats
The cryptographic algorithms and key formats used to sign and verify BGP route announcements.
RFC EDITOR
Turner, S. and O. Borchert, "BGPsec Algorithms, Key Formats, and Signature Formats", RFC 8208, DOI 10.17487/RFC8208, September 2017, <https://www.rfc-editor.org/info/rfc8208>.
BIBTEX
@misc{rfc8208,
series = {Request for Comments},
number = 8208,
howpublished = {RFC 8208},
publisher = {RFC Editor},
doi = {10.17487/RFC8208},
url = {https://www.rfc-editor.org/info/rfc8208},
author = {S. Turner and O. Borchert},
title = {{BGPsec Algorithms, Key Formats, and Signature Formats}},
pagetotal = 19,
year = 2017,
month = sep,
} LINEAGE · FROM THE RFC INDEXOpen full graph →
RFC text
Contents
Internet Engineering Task Force (IETF) S. Turner
Request for Comments: 8208 sn3rd
Updates: 7935 O. Borchert
Category: Standards Track NIST
ISSN: 2070-1721 September 2017
BGPsec Algorithms, Key Formats, and Signature Formats
Abstract
This document specifies the algorithms, algorithm parameters,
asymmetric key formats, asymmetric key sizes, and signature formats
used in BGPsec (Border Gateway Protocol Security). This document
updates RFC 7935 ("The Profile for Algorithms and Key Sizes for Use
in the Resource Public Key Infrastructure").
This document also includes example BGPsec UPDATE messages as well as
the private keys used to generate the messages and the certificates
necessary to validate those signatures.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in 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/rfc8208.
Copyright Notice
Copyright (c) 2017 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 Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction ....................................................3
1.1. Terminology ................................................3
2. Algorithms ......................................................4
3. Asymmetric Key Pair Formats .....................................4
3.1. Public Key Format ..........................................5
3.2. Private Key Format .........................................5
4. Signature Formats ...............................................5
5. Additional Requirements .........................................5
6. Security Considerations .........................................5
7. IANA Considerations .............................................6
8. References ......................................................7
8.1. Normative References .......................................7
8.2. Informative References .....................................8
Appendix A. Examples ...............................................9
A.1. Topology and Experiment Description .........................9
A.2. Keys ........................................................9
A.3. BGPsec IPv4 ................................................13
A.4. BGPsec IPv6 ................................................16
Acknowledgements ..................................................19
Authors' Addresses ................................................19
1. Introduction
This document specifies the following:
o the digital signature algorithm and parameters,
o the hash algorithm and parameters,
o the public and private key formats, and
o the signature formats
used by Resource Public Key Infrastructure (RPKI) Certification
Authorities (CAs) and BGPsec (Border Gateway Protocol Security)
speakers (i.e., routers). CAs use these algorithms when processing
requests for BGPsec Router Certificates [RFC8209]. Examples of when
BGPsec routers use these algorithms include requesting BGPsec
certificates [RFC8209], signing BGPsec UPDATE messages [RFC8205], and
verifying signatures on BGPsec UPDATE messages [RFC8205].
This document updates [RFC7935] to add support for a) a different
algorithm for BGPsec certificate requests, which are issued only by
BGPsec speakers; b) a different Subject Public Key Info format for
BGPsec certificates, which is needed for the specified BGPsec
signature algorithm; and c) different signature formats for BGPsec
signatures, which are needed for the specified BGPsec signature
algorithm. The BGPsec certificates are differentiated from other
RPKI certificates by the use of the BGPsec Extended Key Usage as
defined in [RFC8209]. BGPsec uses a different algorithm [RFC6090]
[DSS] as compared to the rest of the RPKI to minimize the size of the
protocol exchanged between routers.
Appendix A contains example BGPsec UPDATE messages as well as the
private keys used to generate the messages and the certificates
necessary to validate the signatures.
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. Algorithms
The algorithms used to compute signatures on CA certificates, BGPsec
Router Certificates, and Certificate Revocation Lists (CRLs) are as
specified in Section 2 of [RFC7935]. This section addresses BGPsec
algorithms; for example, these algorithms are used by BGPsec routers
to request BGPsec certificates, by RPKI CAs to verify BGPsec
certification requests, by BGPsec routers to generate BGPsec UPDATE
messages, and by BGPsec routers to verify BGPsec UPDATE messages:
o The signature algorithm used MUST be the Elliptic Curve Digital
Signature Algorithm (ECDSA) with curve P-256 [RFC6090] [DSS].
o The hash algorithm used MUST be SHA-256 [SHS].
Hash algorithms are not identified by themselves in certificates or
BGPsec UPDATE messages. They are represented by an OID that combines
the hash algorithm with the digital signature algorithm as follows:
o The ecdsa-with-SHA256 OID [RFC5480] MUST appear in the Public-Key
Cryptography Standards #10 (PKCS #10) signatureAlgorithm field
[RFC2986] or in the Certificate Request Message Format (CRMF)
POPOSigningKey algorithm field [RFC4211]; where the OID is placed
depends on the certificate request format generated.
o In BGPsec UPDATE messages, the ECDSA with SHA-256 algorithm suite
identifier value 0x1 (see Section 7) is included in the
Signature_Block List's Algorithm Suite Identifier field.
3. Asymmetric Key Pair Formats
The key formats used to compute signatures on CA certificates, BGPsec
Router Certificates, and CRLs are as specified in Section 3 of
[RFC7935]. This section addresses key formats found in the BGPsec
Router Certificate requests and in BGPsec Router Certificates.
The ECDSA private keys used to compute signatures for certificate
requests and BGPsec UPDATE messages MUST come from the P-256 curve
[RFC5480]. The public key pair MUST use the uncompressed form.
3.1. Public Key Format
The Subject's public key is included in subjectPublicKeyInfo
[RFC5280]. It has two sub-fields: algorithm and subjectPublicKey.
The values for the structures and their sub-structures follow:
o algorithm (an AlgorithmIdentifier type): The id-ecPublicKey OID
MUST be used in the algorithm field, as specified in Section 2.1.1
of [RFC5480]. The value for the associated parameters MUST be
secp256r1, as specified in Section 2.1.1.1 of [RFC5480].
o subjectPublicKey: ECPoint MUST be used to encode the certificate's
subjectPublicKey field, as specified in Section 2.2 of [RFC5480].
3.2. Private Key Format
Local policy determines private key format.
4. Signature Formats
The structure for the certificate's and CRL's signature field MUST be
as specified in Section 4 of [RFC7935]; this is the same format used
by other RPKI certificates. The structure for the certification
request's and BGPsec UPDATE message's signature field MUST be as
specified in Section 2.2.3 of [RFC3279].
5. Additional Requirements
It is anticipated that BGPsec will require the adoption of updated
key sizes and a different set of signature and hash algorithms over
time, in order to maintain an acceptable level of cryptographic
security. This profile should be updated to specify such future
requirements, when appropriate.
The recommended procedures to implement such a transition of key
sizes and algorithms are specified in [RFC6916].
6. Security Considerations
The security considerations of [RFC3279], [RFC5480], [RFC6090],
[RFC7935], and [RFC8209] apply to certificates. The security
considerations of [RFC3279], [RFC6090], [RFC7935], and [RFC8209]
apply to certification requests. The security considerations of
[RFC3279], [RFC6090], and [RFC8205] apply to BGPsec UPDATE messages.
No new security considerations are introduced as a result of this
specification.
7. IANA Considerations
The Internet Assigned Numbers Authority (IANA) has created the
"BGPsec Algorithm Suite Registry" in the Resource Public Key
Infrastructure (RPKI) group. The one-octet "BGPsec Algorithm Suite
Registry" identifiers assigned by IANA identify the digest algorithm
and signature algorithm used in the BGPsec Signature_Block List's
Algorithm Suite Identifier field.
IANA has registered a single algorithm suite identifier for the
digest algorithm SHA-256 [SHS] and for the signature algorithm ECDSA
on the P-256 curve [RFC6090] [DSS].
BGPsec Algorithm Suite Registry
Algorithm Digest Signature Specification
Suite Algorithm Algorithm Pointer
Identifier
+------------+------------+-------------+-----------------------+
| 0x0 | Reserved | Reserved | This document |
+------------+------------+-------------+-----------------------+
| 0x1 | SHA-256 | ECDSA P-256 | [SHS] [DSS] [RFC6090] |
| | | | This document |
+------------+------------+-------------+-----------------------+
| 0x2-0xEF | Unassigned | Unassigned | |
+------------+------------+-------------+-----------------------+
| 0xFF | Reserved | Reserved | This document |
+------------+------------+-------------+-----------------------+
Future assignments are to be made using the Standards Action process
defined in [RFC8126]. Assignments consist of the one-octet algorithm
suite identifier value and the associated digest algorithm name and
signature algorithm name.
8. References
8.1. 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>.
[RFC2986] Nystrom, M. and B. Kaliski, "PKCS #10: Certification
Request Syntax Specification Version 1.7", RFC 2986,
DOI 10.17487/RFC2986, November 2000,
<https://www.rfc-editor.org/info/rfc2986>.
[RFC3279] Bassham, L., Polk, W., and R. Housley, "Algorithms and
Identifiers for the Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 3279, DOI 10.17487/RFC3279,
April 2002, <https://www.rfc-editor.org/info/rfc3279>.
[RFC4211] Schaad, J., "Internet X.509 Public Key Infrastructure
Certificate Request Message Format (CRMF)", RFC 4211,
DOI 10.17487/RFC4211, September 2005,
<https://www.rfc-editor.org/info/rfc4211>.
[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>.
[RFC5480] Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk,
"Elliptic Curve Cryptography Subject Public Key
Information", RFC 5480, DOI 10.17487/RFC5480, March 2009,
<https://www.rfc-editor.org/info/rfc5480>.
[RFC6090] McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic
Curve Cryptography Algorithms", RFC 6090,
DOI 10.17487/RFC6090, February 2011,
<https://www.rfc-editor.org/info/rfc6090>.
[RFC6916] Gagliano, R., Kent, S., and S. Turner, "Algorithm Agility
Procedure for the Resource Public Key Infrastructure
(RPKI)", BCP 182, RFC 6916, DOI 10.17487/RFC6916,
April 2013, <https://www.rfc-editor.org/info/rfc6916>.
[RFC7935] Huston, G. and G. Michaelson, Ed., "The Profile for
Algorithms and Key Sizes for Use in the Resource Public
Key Infrastructure", RFC 7935, DOI 10.17487/RFC7935,
August 2016, <https://www.rfc-editor.org/info/rfc7935>.
[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, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[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>.
[RFC8205] Lepinski, M., Ed., and K. Sriram, Ed., "BGPsec Protocol
Specification", RFC 8205, DOI 10.17487/RFC8205,
September 2017,
<https://www.rfc-editor.org/info/rfc8205>.
[RFC8209] Reynolds, M., Turner, S., and S. Kent, "A Profile for
BGPsec Router Certificates, Certificate Revocation Lists,
and Certification Requests", RFC 8209,
DOI 10.17487/RFC8209, September 2017,
<https://www.rfc-editor.org/info/rfc8209>.
[DSS] National Institute of Standards and Technology, "Digital
Signature Standard (DSS)", NIST FIPS Publication 186-4,
DOI 10.6028/NIST.FIPS.186-4, July 2013,
<http://nvlpubs.nist.gov/nistpubs/FIPS/
NIST.FIPS.186-4.pdf>.
[SHS] National Institute of Standards and Technology, "Secure
Hash Standard (SHS)", NIST FIPS Publication 180-4,
DOI 10.6028/NIST.FIPS.180-4, August 2015,
<http://nvlpubs.nist.gov/nistpubs/FIPS/
NIST.FIPS.180-4.pdf>.
8.2. Informative References
[RFC6979] Pornin, T., "Deterministic Usage of the Digital Signature
Algorithm (DSA) and Elliptic Curve Digital Signature
Algorithm (ECDSA)", RFC 6979, DOI 10.17487/RFC6979,
August 2013, <https://www.rfc-editor.org/info/rfc6979>.
Appendix A. Examples
A.1. Topology and Experiment Description
Topology:
AS(64496)----AS(65536)----AS(65537)
Prefix Announcement: AS(64496), 192.0.2.0/24, 2001:db8::/32
A.2. Keys
For this example, the ECDSA algorithm was provided with a static k to
make the result deterministic.
The k used for all signature operations was taken from [RFC6979],
Appendix A.2.5, "Signatures With SHA-256, message = 'sample'".
k = A6E3C57DD01ABE90086538398355DD4C
3B17AA873382B0F24D6129493D8AAD60
Keys of AS64496:
================
ski: AB4D910F55CAE71A215EF3CAFE3ACC45B5EEC154
private key:
x = D8AA4DFBE2478F86E88A7451BF075565
709C575AC1C136D081C540254CA440B9
public key:
Ux = 7391BABB92A0CB3BE10E59B19EBFFB21
4E04A91E0CBA1B139A7D38D90F77E55A
Uy = A05B8E695678E0FA16904B55D9D4F5C0
DFC58895EE50BC4F75D205A25BD36FF5
Router Key Certificate example using OpenSSL 1.0.1e-fips 11 Feb 2013
--------------------------------------------------------------------
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 38655612 (0x24dd67c)
Signature Algorithm: ecdsa-with-SHA256
Issuer: CN=ROUTER-0000FBF0
Validity
Not Before: Jan 1 05:00:00 2017 GMT
Not After : Jul 1 05:00:00 2018 GMT
Subject: CN=ROUTER-0000FBF0
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:73:91:ba:bb:92:a0:cb:3b:e1:0e:59:b1:9e:bf:
fb:21:4e:04:a9:1e:0c:ba:1b:13:9a:7d:38:d9:0f:
77:e5:5a:a0:5b:8e:69:56:78:e0:fa:16:90:4b:55:
d9:d4:f5:c0:df:c5:88:95:ee:50:bc:4f:75:d2:05:
a2:5b:d3:6f:f5
ASN1 OID: prime256v1
X509v3 extensions:
X509v3 Key Usage:
Digital Signature
X509v3 Subject Key Identifier:
AB:4D:91:0F:55:CA:E7:1A:21:5E:
F3:CA:FE:3A:CC:45:B5:EE:C1:54
X509v3 Extended Key Usage:
1.3.6.1.5.5.7.3.30
sbgp-autonomousSysNum: critical
Autonomous System Numbers:
64496
Routing Domain Identifiers:
inherit
Signature Algorithm: ecdsa-with-SHA256
30:44:02:20:07:b7:b4:6a:5f:a4:f1:cc:68:36:39:03:a4:83:
ec:7c:80:02:d2:f6:08:9d:46:b2:ec:2a:7b:e6:92:b3:6f:b1:
02:20:00:91:05:4a:a1:f5:b0:18:9d:27:24:e8:b4:22:fd:d1:
1c:f0:3d:b1:38:24:5d:64:29:35:28:8d:ee:0c:38:29
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
Keys of AS(65536):
==================
ski: 47F23BF1AB2F8A9D26864EBBD8DF2711C74406EC
private key:
x = 6CB2E931B112F24554BCDCAAFD9553A9
519A9AF33C023B60846A21FC95583172
public key:
Ux = 28FC5FE9AFCF5F4CAB3F5F85CB212FC1
E9D0E0DBEAEE425BD2F0D3175AA0E989
Uy = EA9B603E38F35FB329DF495641F2BA04
0F1C3AC6138307F257CBA6B8B588F41F
Router Key Certificate example using OpenSSL 1.0.1e-fips 11 Feb 2013
--------------------------------------------------------------------
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 3752143940 (0xdfa52c44)
Signature Algorithm: ecdsa-with-SHA256
Issuer: CN=ROUTER-00010000
Validity
Not Before: Jan 1 05:00:00 2017 GMT
Not After : Jul 1 05:00:00 2018 GMT
Subject: CN=ROUTER-00010000
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:28:fc:5f:e9:af:cf:5f:4c:ab:3f:5f:85:cb:21:
2f:c1:e9:d0:e0:db:ea:ee:42:5b:d2:f0:d3:17:5a:
a0:e9:89:ea:9b:60:3e:38:f3:5f:b3:29:df:49:56:
41:f2:ba:04:0f:1c:3a:c6:13:83:07:f2:57:cb:a6:
b8:b5:88:f4:1f
ASN1 OID: prime256v1
X509v3 extensions:
X509v3 Key Usage:
Digital Signature
X509v3 Subject Key Identifier:
47:F2:3B:F1:AB:2F:8A:9D:26:86:
4E:BB:D8:DF:27:11:C7:44:06:EC
X509v3 Extended Key Usage:
1.3.6.1.5.5.7.3.30
sbgp-autonomousSysNum: critical
Autonomous System Numbers:
65536
Routing Domain Identifiers:
inherit
Signature Algorithm: ecdsa-with-SHA256
30:45:02:21:00:8c:d9:f8:12:96:88:82:74:03:a1:82:82:18:
c5:31:00:ee:35:38:e8:fa:ae:72:09:fe:98:67:01:78:69:77:
8c:02:20:5f:ee:3a:bf:10:66:be:28:d3:b3:16:a1:6b:db:66:
21:99:ed:a6:e4:ad:64:3c:ba:bf:44:fb:cb:b7:50:91:74
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
A.3. BGPsec IPv4
BGPsec IPv4 UPDATE from AS(65536) to AS(65537):
===============================================
Binary Form of BGPsec UPDATE (TCP-DUMP):
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
01 03 02 00 00 00 EC 40 01 01 02 80 04 04 00 00
00 00 80 0E 0D 00 01 01 04 C6 33 64 64 00 18 C0
00 02 90 1E 00 CD 00 0E 01 00 00 01 00 00 01 00
00 00 FB F0 00 BF 01 47 F2 3B F1 AB 2F 8A 9D 26
86 4E BB D8 DF 27 11 C7 44 06 EC 00 48 30 46 02
21 00 EF D4 8B 2A AC B6 A8 FD 11 40 DD 9C D4 5E
81 D6 9D 2C 87 7B 56 AA F9 91 C3 4D 0E A8 4E AF
37 16 02 21 00 90 F2 C1 29 AB B2 F3 9B 6A 07 96
3B D5 55 A8 7A B2 B7 33 3B 7B 91 F1 66 8F D8 61
8C 83 FA C3 F1 AB 4D 91 0F 55 CA E7 1A 21 5E F3
CA FE 3A CC 45 B5 EE C1 54 00 48 30 46 02 21 00
EF D4 8B 2A AC B6 A8 FD 11 40 DD 9C D4 5E 81 D6
9D 2C 87 7B 56 AA F9 91 C3 4D 0E A8 4E AF 37 16
02 21 00 8E 21 F6 0E 44 C6 06 6C 8B 8A 95 A3 C0
9D 3A D4 37 95 85 A2 D7 28 EE AD 07 A1 7E D7 AA
05 5E CA
Signature from AS(64496) to AS(65536):
--------------------------------------
Digest: 21 33 E5 CA A0 26 BE 07 3D 9C 1B 4E FE B9 B9 77
9F 20 F8 F5 DE 29 FA 98 40 00 9F 60 47 D0 81 54
Signature: 30 46 02 21 00 EF D4 8B 2A AC B6 A8 FD 11 40 DD
9C D4 5E 81 D6 9D 2C 87 7B 56 AA F9 91 C3 4D 0E
A8 4E AF 37 16 02 21 00 8E 21 F6 0E 44 C6 06 6C
8B 8A 95 A3 C0 9D 3A D4 37 95 85 A2 D7 28 EE AD
07 A1 7E D7 AA 05 5E CA
Signature from AS(65536) to AS(65537):
--------------------------------------
Digest: 01 4F 24 DA E2 A5 21 90 B0 80 5C 60 5D B0 63 54
22 3E 93 BA 41 1D 3D 82 A3 EC 26 36 52 0C 5F 84
Signature: 30 46 02 21 00 EF D4 8B 2A AC B6 A8 FD 11 40 DD
9C D4 5E 81 D6 9D 2C 87 7B 56 AA F9 91 C3 4D 0E
A8 4E AF 37 16 02 21 00 90 F2 C1 29 AB B2 F3 9B
6A 07 96 3B D5 55 A8 7A B2 B7 33 3B 7B 91 F1 66
8F D8 61 8C 83 FA C3 F1
The human-readable output is produced using bgpsec-io, a bgpsec
traffic generator that uses a wireshark-like printout.
Send UPDATE Message
+--marker: FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
+--length: 259
+--type: 2 (UPDATE)
+--withdrawn_routes_length: 0
+--total_path_attr_length: 236
+--ORIGIN: INCOMPLETE (4 bytes)
| +--Flags: 0x40 (Well-Known, Transitive, Complete)
| +--Type Code: ORIGIN (1)
| +--Length: 1 byte
| +--Origin: INCOMPLETE (1)
+--MULTI_EXIT_DISC (7 bytes)
| +--Flags: 0x80 (Optional, Non-transitive, Complete)
| +--Type Code: MULTI_EXIT_DISC (4)
| +--Length: 4 bytes
| +--data: 00 00 00 00
+--MP_REACH_NLRI (16 bytes)
| +--Flags: 0x80 (Optional, Non-transitive, Complete)
| +--Type Code: MP_REACH_NLRI (14)
| +--Length: 13 bytes
| +--Address family: IPv4 (1)
| +--Subsequent address family identifier: Unicast (1)
| +--Next hop network address: (4 bytes)
| | +--Next hop: 198.51.100.100
| +--Subnetwork points of attachment: 0
| +--Network layer reachability information: (4 bytes)
| +--192.0.2.0/24
| +--MP Reach NLRI prefix length: 24
| +--MP Reach NLRI IPv4 prefix: 192.0.2.0
+--BGPSEC Path Attribute (209 bytes)
+--Flags: 0x90 (Optional, Complete, Extended Length)
+--Type Code: BGPSEC Path Attribute (30)
+--Length: 205 bytes
+--Secure Path (14 bytes)
| +--Length: 14 bytes
| +--Secure Path Segment: (6 bytes)
| | +--pCount: 1
| | +--Flags: 0
| | +--AS number: 65536 (1.0)
| +--Secure Path Segment: (6 bytes)
| +--pCount: 1
| +--Flags: 0
| +--AS number: 64496 (0.64496)
+--Signature Block (191 bytes)
+--Length: 191 bytes
+--Algo ID: 1
+--Signature Segment: (94 bytes)
| +--SKI: 47F23BF1AB2F8A9D26864EBBD8DF2711C74406EC
| +--Length: 72 bytes
| +--Signature: 3046022100EFD48B 2AACB6A8FD1140DD
| 9CD45E81D69D2C87 7B56AAF991C34D0E
| A84EAF3716022100 90F2C129ABB2F39B
| 6A07963BD555A87A B2B7333B7B91F166
| 8FD8618C83FAC3F1
+--Signature Segment: (94 bytes)
+--SKI: AB4D910F55CAE71A215EF3CAFE3ACC45B5EEC154
+--Length: 72 bytes
+--Signature: 3046022100EFD48B 2AACB6A8FD1140DD
9CD45E81D69D2C87 7B56AAF991C34D0E
A84EAF3716022100 8E21F60E44C6066C
8B8A95A3C09D3AD4 379585A2D728EEAD
07A17ED7AA055ECA
A.4. BGPsec IPv6
BGPsec IPv6 UPDATE from AS(65536) to AS(65537):
===============================================
Binary Form of BGP/BGPsec UPDATE (TCP-DUMP):
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
01 10 02 00 00 00 F9 40 01 01 02 80 04 04 00 00
00 00 80 0E 1A 00 02 01 10 20 01 00 10 00 00 00
00 00 00 00 00 C6 33 64 64 00 20 20 01 0D B8 90
1E 00 CD 00 0E 01 00 00 01 00 00 01 00 00 00 FB
F0 00 BF 01 47 F2 3B F1 AB 2F 8A 9D 26 86 4E BB
D8 DF 27 11 C7 44 06 EC 00 48 30 46 02 21 00 EF
D4 8B 2A AC B6 A8 FD 11 40 DD 9C D4 5E 81 D6 9D
2C 87 7B 56 AA F9 91 C3 4D 0E A8 4E AF 37 16 02
21 00 D1 B9 4F 62 51 04 6D 21 36 A1 05 B0 F4 72
7C C5 BC D6 74 D9 7D 28 E6 1B 8F 43 BD DE 91 C3
06 26 AB 4D 91 0F 55 CA E7 1A 21 5E F3 CA FE 3A
CC 45 B5 EE C1 54 00 48 30 46 02 21 00 EF D4 8B
2A AC B6 A8 FD 11 40 DD 9C D4 5E 81 D6 9D 2C 87
7B 56 AA F9 91 C3 4D 0E A8 4E AF 37 16 02 21 00
E2 A0 2C 68 FE 53 CB 96 93 4C 78 1F 5A 14 A2 97
19 79 20 0C 91 56 ED F8 55 05 8E 80 53 F4 AC D3
Signature from AS(64496) to AS(65536):
--------------------------------------
Digest: 8A 0C D3 E9 8E 55 10 45 82 1D 80 46 01 D6 55 FC
52 11 89 DF 4D B0 28 7D 84 AC FC 77 55 6D 06 C7
Signature: 30 46 02 21 00 EF D4 8B 2A AC B6 A8 FD 11 40 DD
9C D4 5E 81 D6 9D 2C 87 7B 56 AA F9 91 C3 4D 0E
A8 4E AF 37 16 02 21 00 E2 A0 2C 68 FE 53 CB 96
93 4C 78 1F 5A 14 A2 97 19 79 20 0C 91 56 ED F8
55 05 8E 80 53 F4 AC D3
Signature from AS(65536) to AS(65537):
--------------------------------------
Digest: 44 49 EC 70 8D EC 5C 85 00 C2 17 8C 72 FE 4C 79
FF A9 3C 95 31 61 01 2D EE 7E EE 05 46 AF 5F D0
Signature: 30 46 02 21 00 EF D4 8B 2A AC B6 A8 FD 11 40 DD
9C D4 5E 81 D6 9D 2C 87 7B 56 AA F9 91 C3 4D 0E
A8 4E AF 37 16 02 21 00 D1 B9 4F 62 51 04 6D 21
36 A1 05 B0 F4 72 7C C5 BC D6 74 D9 7D 28 E6 1B
8F 43 BD DE 91 C3 06 26
The human-readable output is produced using bgpsec-io, a bgpsec
traffic generator that uses a wireshark-like printout.
Send UPDATE Message
+--marker: FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
+--length: 272
+--type: 2 (UPDATE)
+--withdrawn_routes_length: 0
+--total_path_attr_length: 249
+--ORIGIN: INCOMPLETE (4 bytes)
| +--Flags: 0x40 (Well-Known, Transitive, Complete)
| +--Type Code: ORIGIN (1)
| +--Length: 1 byte
| +--Origin: INCOMPLETE (1)
+--MULTI_EXIT_DISC (7 bytes)
| +--Flags: 0x80 (Optional, Non-transitive, Complete)
| +--Type Code: MULTI_EXIT_DISC (4)
| +--Length: 4 bytes
| +--data: 00 00 00 00
+--MP_REACH_NLRI (29 bytes)
| +--Flags: 0x80 (Optional, Non-transitive, Complete)
| +--Type Code: MP_REACH_NLRI (14)
| +--Length: 26 bytes
| +--Address family: IPv6 (2)
| +--Subsequent address family identifier: Unicast (1)
| +--Next hop network address: (16 bytes)
| | +--Next hop: 2001:0010:0000:0000:0000:0000:c633:6464
| +--Subnetwork points of attachment: 0
| +--Network layer reachability information: (5 bytes)
| +--2001:db8::/32
| +--MP Reach NLRI prefix length: 32
| +--MP Reach NLRI IPv6 prefix: 2001:db8::
+--BGPSEC Path Attribute (209 bytes)
+--Flags: 0x90 (Optional, Complete, Extended Length)
+--Type Code: BGPSEC Path Attribute (30)
+--Length: 205 bytes
+--Secure Path (14 bytes)
| +--Length: 14 bytes
| +--Secure Path Segment: (6 bytes)
| | +--pCount: 1
| | +--Flags: 0
| | +--AS number: 65536 (1.0)
| +--Secure Path Segment: (6 bytes)
| +--pCount: 1
| +--Flags: 0
| +--AS number: 64496 (0.64496)
+--Signature Block (191 bytes)
+--Length: 191 bytes
+--Algo ID: 1
+--Signature Segment: (94 bytes)
| +--SKI: 47F23BF1AB2F8A9D26864EBBD8DF2711C74406EC
| +--Length: 72 bytes
| +--Signature: 3046022100EFD48B 2AACB6A8FD1140DD
| 9CD45E81D69D2C87 7B56AAF991C34D0E
| A84EAF3716022100 D1B94F6251046D21
| 36A105B0F4727CC5 BCD674D97D28E61B
| 8F43BDDE91C30626
+--Signature Segment: (94 bytes)
+--SKI: AB4D910F55CAE71A215EF3CAFE3ACC45B5EEC154
+--Length: 72 bytes
+--Signature: 3046022100EFD48B 2AACB6A8FD1140DD
9CD45E81D69D2C87 7B56AAF991C34D0E
A84EAF3716022100 E2A02C68FE53CB96
934C781F5A14A297 1979200C9156EDF8
55058E8053F4ACD3
Acknowledgements
The authors wish to thank Geoff Huston and George Michaelson for
producing [RFC7935], which this document is entirely based on. The
authors would also like to thank Roque Gagliano, David Mandelberg,
Tom Petch, Sam Weiler, and Stephen Kent for their reviews and
comments. Mehmet Adalier, Kotikalapudi Sriram, and Doug Montgomery
were instrumental in developing the test vectors found in Appendix A.
Authors' Addresses
Sean Turner
sn3rd
Email: sean@sn3rd.com
Oliver Borchert
NIST
100 Bureau Drive
Gaithersburg, MD 20899
United States of America
Email: oliver.borchert@nist.gov
AI ELI5
On this page
PROBLEMBGPsec needs to sign and verify route announcements to prevent hijacking, but it must use algorithms that keep signatures small to avoid inflating BGP update messages. Standard RPKI algorithms are too large for route-level signing.
MECHANISMThis RFC specifies ECDSA with the P-256 curve and SHA-256 hashing for BGPsec signatures, which produces smaller signatures than RSA while maintaining strong security. It defines the exact key formats, certificate request formats, and signature encodings.
STATUS TODAYBGP routers can now cryptographically verify route origins using standardized, compact signatures. RFC 8608 later updated these specifications.
§1BGPsec and Cryptographic Signing
BGPsec is a set of security extensions for BGP that allow routers to cryptographically sign the route advertisements they propagate. This prevents an attacker from announcing routes they do not own or from modifying route announcements in transit. Each router in a chain of route announcements signs a message with its private key, and downstream routers verify the signature using the router's public key.
The challenge for BGPsec is scale. BGP update messages are already bandwidth-constrained, and adding signatures to every route announcement can quickly balloon message sizes. Regular RPKI (Resource Public Key Infrastructure) certificates use RSA signatures, which are large. BGPsec needs a more compact signature algorithm to keep update messages small while still providing strong cryptographic security.
This RFC specifies the algorithms, key sizes, and signature formats used by BGPsec. It also specifies how BGPsec routers request certificates from the RPKI hierarchy and defines the format of the signatures embedded in BGP UPDATE messages.
Routers need to sign their route announcements ("I own 192.0.2.0") to prove they are not lying. But BGP messages are already crowded, so signatures must be small. This says which math to use for small, strong signatures.
§2Signature and Hash Algorithms
BGPsec uses the Elliptic Curve Digital Signature Algorithm (ECDSA) on the P-256 curve for all signatures, paired with the SHA-256 hash function. The ECDSA signature on P-256 produces a 64-byte signature, which is significantly smaller than an RSA-2048 signature (256 bytes).
The combination of ECDSA with SHA-256 is identified by the OID ecdsa-with-SHA256. When a BGPsec router requests a certificate from the RPKI Certification Authority, it must use this algorithm suite in the PKCS#10 certificate request. The RPKI CA verifies the request signature using ECDSA-P256-SHA256.
This algorithm choice differs from the rest of the RPKI infrastructure, which predominantly uses RSA. The difference is justified by the need to minimize BGPsec update message sizes while maintaining equivalent cryptographic security.
BGPsec uses ECDSA on the P-256 curve (a specific elliptic curve math problem) with SHA-256 hashing. This produces signatures that are much smaller than RSA but just as secure.
| Algorithm | Signature size |
|---|---|
| RSA-2048 (standard RPKI) | 256 bytes |
| ECDSA P-256 (BGPsec) THIS RFC | 64 bytes |
§3Key Pair Formats and Sizes
BGPsec private keys are ECDSA keys on the P-256 curve. A P-256 private key is a single 256-bit integer (32 bytes). BGPsec routers generate these keys locally and keep them secure on the router hardware.
The public key is represented in uncompressed form, which means it is encoded as a single point on the P-256 elliptic curve: the X and Y coordinates, each 32 bytes. In certificates, the public key is placed in the subjectPublicKey field using the ECPoint encoding specified in RFC 5480. The algorithm identifier in the certificate MUST use the OID id-ecPublicKey with parameter secp256r1.
Private key format is left to local policy; BGPsec does not mandate how routers store or protect private keys (though hardware security modules are recommended for production deployments).
BGPsec private keys are 32-byte numbers generated by each router. Public keys are two 32-byte numbers (the X and Y coordinates on the curve) that the router shares with the certificate authority.
§4Signature Encoding in BGPsec UPDATE Messages
In BGPsec UPDATE messages, signatures appear in the Signature_Block list. Each signature is an ECDSA signature over the P-256 curve, which naturally produces two integers: r and s (each 256 bits). The signature is encoded as specified in RFC 3279 Section 2.2.3, which encodes both r and s in a fixed 64-byte format.
Each Signature_Block also includes an Algorithm Suite Identifier field, a single octet. For ECDSA with SHA-256, this identifier MUST be 0x1. The value 0x0 and 0xFF are reserved. This allows for future algorithm suites (like ECDSA with SHA-512) to be added without backward compatibility issues.
Certificates and Certificate Revocation Lists continue to use the standard RPKI signature format specified in RFC 7935, while only BGPsec UPDATE messages and certificate requests use the ECDSA signature format specified here.
In BGP UPDATE messages, each signature is 64 bytes (the two parts of an ECDSA signature: r and s). The message also includes a one-byte identifier saying which algorithm was used (0x1 means ECDSA with SHA-256).
- 0x0Reserved — Reserved for future use.
- 0x1ECDSA-P256-SHA256 — ECDSA on P-256 curve with SHA-256 hash.
- 0x2-0xEFUnassigned — Available for future algorithm suites.
- 0xFFReserved — Reserved for future use.
§5Algorithm Suite Registry
IANA maintains the BGPsec Algorithm Suite Registry. Currently, only one algorithm suite is registered: identifier 0x1 for ECDSA with SHA-256. The registry allocates identifiers in the range 0x2 through 0xEF for future algorithm suites via the Standards Action process.
Future algorithm suites might include ECDSA with different curves or hash functions. When a new suite is standardized, IANA will assign it an identifier that BGPsec routers can then reference in UPDATE messages, allowing for seamless algorithm agility without breaking existing deployments.
IANA keeps a list of which one-byte numbers mean which algorithm. Right now 0x1 means ECDSA-P256-SHA256. If new algorithms are invented, they get new numbers.
§6References
[RFC3279]RFC 3279Bassham, L., Polk, W., and R. Housley, "Algorithms and Identifiers for the Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 3279, April 2002.May 2002[RFC5480]RFC 5480Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk, "Elliptic Curve Cryptography Subject Public Key Information", RFC 5480, March 2009.March 2009[RFC6090]RFC 6090McGrew, D., Igoe, K., and M. Salter, "Fundamental Elliptic Curve Cryptography Algorithms", RFC 6090, February 2011.February 2011[RFC7935]RFC 7935Huston, G. and G. Michaelson, Ed., "The Profile for Algorithms and Key Sizes for Use in the Resource Public Key Infrastructure", RFC 7935, August 2016.August 2016[RFC8205]RFC 8205Lepinski, M., Ed., and K. Sriram, Ed., "BGPsec Protocol Specification", RFC 8205, September 2017.September 2017[RFC8209]RFC 8209Reynolds, M., Turner, S., and S. Kent, "A Profile for BGPsec Router Certificates, Certificate Revocation Lists, and Certification Requests", RFC 8209, September 2017.September 2017