RFC 9102: TLS DNSSEC Chain Extension
- V. Dukhovni,
- S. Huque,
- W. Toorop,
- P. Wouters,
- M. Shore
Abstract
This document describes an experimental TLS extension for the in-band
transport of the complete set of records that can be validated by DNSSEC and that are needed to
perform DNS-Based Authentication of Named Entities (DANE) of a TLS server. This extension obviates the need to
perform separate, out-of-band DNS lookups. When the requisite DNS
records do not exist, the extension conveys a denial
This experimental extension is developed outside the IETF and is
published here to guide implementation of the extension and to ensure
interoperabilit
Status of This Memo
This document is not an Internet Standards Track specification; it is published for examination, experimental implementation, and evaluation.¶
This document defines an Experimental Protocol for the Internet community. 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://
Copyright Notice
Copyright (c) 2021 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://
1. Introduction
This document describes an experimental TLS [RFC5246] [RFC8446] extension for in-band transport of the complete set of resource records (RRs) validated by DNSSEC [RFC4033] [RFC4034] [RFC4035]. This extension enables a TLS client to perform DANE authentication [RFC6698] [RFC7671] of a TLS server without the need to perform out-of-band DNS lookups. Retrieval of the required DNS records may be unavailable to the client [DISCOVERY] or may incur undesirable additional latency.¶
The extension described here allows a TLS client to request that the
TLS server return the DNSSEC authentication chain corresponding to
its DNSSEC
In the absence of TLSA records, this extension conveys the required
authenticated denial of existence. Such proofs are needed to securely
signal that specified TLSA records are not available so that TLS clients
can safely fall back to authentication based on Public Key Infrastructure X.509 (PKIX, sometimes called
WebPKI) if allowed by local policy. These proofs
are also needed to avoid downgrade from opportunistic authenticated TLS
(when DANE TLSA records are present) to unauthenticated opportunistic TLS
(in the absence of DANE). Denial
This extension supports DANE authentication of either X.509 certificates or raw public keys, as described in the DANE specification [RFC6698] [RFC7671] [RFC7250].¶
This extension also mitigates against an unknown key share (UKS) attack [DANE-UKS] when using raw public keys since the server commits to its DNS name (normally found in its certificate) via the content of the returned TLSA RRset.¶
This experimental extension is developed outside the IETF and is
published here to guide implementation of the extension and to ensure
interoperabilit
1.1. Scope of the Experiment
The mechanism described in this document is intended to be used with applications on the wider internet. One application of TLS well suited for the TLS DNSSEC Chain extension is DNS over TLS [RFC7858]. In fact, one of the authentication methods for DNS over TLS is the mechanism described in this document, as specified in Section 8.2.2 of [RFC8310].¶
The need for this mechanism when using DANE to authenticate a DNS-over-TLS resolver is obvious, since DNS may not be available to perform the required DNS lookups. Other applications of TLS would benefit from using this mechanism as well. The client sides of those applications would not be required to be used on endpoints with a working DNSSEC resolver in order for them to use the DANE authentication of the TLS service. Therefore, we invite other TLS services to try out this mechanism as well.¶
In the TLS Working Group, concerns have been raised that the pinning technique as described in Section 7 would complicate deployability of the TLS DNSSEC chain extension. The goal of the experiment is to study these complications in real-world deployments. This experiment hopefully will give the TLS Working Group some insight into whether or not this is a problem.¶
If the experiment is successful, it is expected that the findings of the experiment will result in an updated document for Standards Track approval.¶
1.2. Requirements Notation
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. DNSSEC Authentication Chain Extension
2.1. Protocol, TLS 1.2
A client MAY include an extension of type dnssec_chain in the
(extended) ClientHello. The extension_data field of this extension
consists of the server's 16-bit TCP port number in network
(big-endian) byte order. Clients sending this extension MUST also
send the Server Name Identification (SNI) extension [RFC6066].
Together, these make it possible for the TLS server to
determine which authenticated TLSA RRset chain needs to be used for
the dnssec_chain extension.¶
When a server that implements (and is configured to enable the use
of) this extension receives a dnssec_chain extension in the
ClientHello, it MUST first check whether the requested TLSA RRset
(based on the port number in this extension and hostname in the SNI
extension) is associated with the server. If the extension, the SNI
hostname, or the port number is unsupported, the server's extended
ServerHello message MUST NOT include the dnssec_chain extension.¶
Otherwise, the server's extended ServerHello message MUST contain a
serialized authentication chain using the format described below. If
the server does not have access to the requested DNS chain -- for
example, due to a misconfiguratio
The set of supported combinations of a port number and SNI name may be configured explicitly by server administrators or could be inferred from the available certificates combined with a list of supported ports. It is important to note that the client's notional port number may be different from the actual port on which the server is receiving connections.¶
Differences between the client's notional port number and the actual port at the server could be a result of intermediate systems performing network address translation or a result of a redirect via HTTPS or SVCB records (both defined in [DNSOP-SVCB-HTTPS]).¶
Though a DNS zone's HTTPS or SVCB records may be signed, a client using this protocol might not have direct access to a validating resolver and might not be able to check the authenticity of the target port number or hostname. In order to avoid downgrade attacks via forged DNS records, the SNI name and port number inside the client extension MUST be based on the original SNI name and port and MUST NOT be taken from the encountered HTTPS or SVCB record. The client supporting this document and HTTPS or SVCB records MUST still use the HTTPS or SVCB records to select the target transport endpoint. Servers supporting this extension that are targets of HTTPS or SVCB records MUST be provisioned to process client extensions based on the client's logical service endpoint's SNI name and port as it is prior to HTTPS or SVCB indirection.¶
2.2. Protocol, TLS 1.3
In TLS 1.3 [RFC8446], when the server receives the dnssec_chain extension,
it adds its dnssec_chain extension to the extension block of the Certificate
message containing the end-entity certificate being validated rather than to
the extended ServerHello message.¶
The extension protocol behavior otherwise follows that specified for TLS version 1.2 [RFC5246].¶
2.3. DNSSEC Authentication Chain Data
The extension_data field of the client's dnssec_chain extension
MUST contain the server's 16-bit TCP port number in network
(big-endian) byte order:¶
The extension_data field of the server's dnssec_chain extension
MUST contain a DNSSEC authentication chain encoded in the following
form:¶
The Ext
The Authentication
The order of returned RRs is unspecified, and a TLS client MUST NOT assume any ordering of RRs.¶
Use of DNS wire format records enables easier generation of the data structure on the server and easier verification of the data on the client by means of existing DNS library functions.¶
The returned RRsets MUST contain either the TLSA RRset or the
associated denial
When some subtree in the chain is subject to redirection via DNAME records, the associated inferred CNAME records need not be included. They can be inferred by the DNS validation code in the client. Any applicable ordinary CNAME records that are not synthesized from DNAME records MUST be included along with their RRSIGs.¶
In case of a server-side DNS problem, servers may be unable to construct the authentication chain and would then have no choice but to omit the extension.¶
In the case of a denial
Names that are aliased via CNAME and/or DNAME records may involve multiple branches of the DNS tree. In this case, the authentication chain structure needs to include DS and DNSKEY record sets that cover all the necessary branches.¶
The returned chain SHOULD also include the DNSKEY RRsets of all relevant trust anchors (typically just the root DNS zone). Though the same trust anchors are presumably also preconfigured in the TLS client, including them in the response from the server permits TLS clients to use the automated trust anchor rollover mechanism defined in [RFC5011] to update their configured trust anchors.¶
Barring prior knowledge of particular trust anchors that the server shares with its clients, the chain constructed by the server MUST be extended as closely as possible to the root zone. Truncation of the chain at some intermediate trust anchor is generally only appropriate inside private networks where all clients and the server are expected to be configured with DNS trust anchors for one or more non-root domains.¶
The following is an example of the records in the Authenticationwww.example.com, where there are
zone cuts at com and example.com (record data are omitted here
for brevity):¶
The following is an example of denial of existence for a TLSA RRset
at _443. The NSEC record in this example
asserts the nonexistence of both the requested RRset and any
potentially relevant wildcard records.¶
The following is an example of (hypothetical) insecure delegation of
example.com from the .com zone. This example shows NSEC3 records [RFC5155]
with opt-out.¶
2.3.1. Authenticated Denial of Existence
TLS servers that support this extension and respond to a request containing this extension that do not have a signed TLSA record for the configured (and requested) SNI name and port MUST instead return a DNSSEC chain that provides authenticated denial of existence for the configured SNI name and port. A TLS client receiving proof of authenticated denial of existence MUST use an alternative method to verify the TLS server identity or close the connection. Such an alternative could be the classic PKIX model of preinstalled root certificate authorities (CAs).¶
Authenticated denial chains include NSEC or NSEC3 records that demonstrate one of the following facts:¶
3. Construction of Serialized Authentication Chains
This section describes a possible procedure for the server to use to build the serialized DNSSEC chain.¶
When the goal is to perform DANE authentication [RFC6698] [RFC7671] of the server, the DNS record set to be serialized is a TLSA record set corresponding to the server's domain name, protocol, and port number.¶
The domain name of the server MUST be that included in the TLS
server_name (SNI) extension [RFC6066]. If the server
does not recognize the SNI name as one of its own names but wishes
to proceed with the handshake rather than abort the connection,
the server MUST NOT send a dnssec_chain extension to the client.¶
The name in the client's SNI extension MUST NOT be CNAME expanded by the server. The TLSA base domain (Section 3 of [RFC6698]) SHALL be the hostname from the client's SNI extension, and the guidance in Section 7 of [RFC7671] does not apply. See Section 9 for further discussion.¶
The TLSA record to be queried is constructed by prepending
underscorednssec_chain extension. The transport name is "tcp" for TLS
servers and "udp" for DTLS servers. The port number label is the
leftmost label, followed by the transport name label, followed by the
server domain name (from SNI).¶
The components of the authentication chain are typically built by starting at the target record set and its corresponding RRSIG, then traversing the DNS tree upwards towards the trust anchor zone (normally the DNS root). For each zone cut, the DNSKEY, DS RRsets, and their signatures are added. However, see Section 2.3 for specific processing needed for aliases. If DNS response messages contain any domain names utilizing name compression [RFC1035], then they MUST be uncompressed prior to inclusion in the chain.¶
Implementations of EDNS CHAIN query requests as specified in [RFC7901] may offer an easier way to obtain all of the chain data in one transaction with an upstream DNSSEC-aware recursive server.¶
4. Caching and Regeneration of the Authentication Chain
DNS records have Time To Live (TTL) parameters, and DNSSEC signatures
have validity periods (specifically signature expiration times).
After the TLS server constructs the serialized authentication chain,
it SHOULD cache and reuse it in multiple TLS connection handshakes.
However, it SHOULD refresh and rebuild the chain as TTL values require.
A server implementation could carefully track TTL parameters and requery
component records in the chain correspondingly
5. Expired Signatures in the Authentication Chain
A server MAY look at the signature expiration of RRSIG records. While these should never expire before the TTL of the corresponding DNS record is reached, if this situation is nevertheless encountered, the server MAY lower the TTL to prevent serving expired RRSIGs if possible. If the signatures are already expired, the server MUST still include these records in the authentication chain. This allows the TLS client to either support a grace period for staleness or give a detailed error, either as a log message or a message to a potential interactive user of the TLS connection. The TLS client SHOULD handle expired RRSIGs similarly to how it handles expired PKIX certificates.¶
6. Verification
A TLS client performing DANE-based verification might not need to use this extension. For example, the TLS client could perform DNS lookups and DANE verification without this extension, or it could fetch authentication chains via another protocol. If the TLS client already possesses a valid TLSA record, it MAY bypass use of this extension. However, if it includes this extension, it MUST use the TLS server reply to update the extension pinning status of the TLS server's extension lifetime. See Section 7.¶
A TLS client making use of this specification that receives a valid DNSSEC authentication chain extension from a TLS server MUST use this information to perform DANE authentication of the TLS server. In order to perform the validation, it uses the mechanism specified by the DNSSEC protocol [RFC4035] [RFC5155]. This mechanism is sometimes implemented in a DNSSEC validation engine or library.¶
If the authentication chain validates, the TLS client then performs DANE authentication of the server according to the DANE TLS protocol [RFC6698] [RFC7671].¶
Clients MAY cache the server's validated TLSA RRset to amortize the
cost of receiving and validating the chain over multiple connections.
The period of such caching MUST NOT exceed the TTL associated with
those records. A client that possesses a validated and unexpired TLSA
RRset or the full chain in its cache does not need to send the
dnssec_chain extension for subsequent connections to the same TLS
server. It can use the cached information to perform DANE
authentication.¶
Note that when a client and server perform TLS session resumption, the
server sends no dnssec_chain. This is particularly clear with TLS
1.3, where the certificate message to which the chain might be
attached is also not sent on resumption.¶
7. Extension Pinning
TLS applications can be designed to unconditionally mandate this extension. Such TLS clients requesting this extension would abort a connection to a TLS server that does not respond with an extension reply that can be validated.¶
However, in a mixed-use deployment of PKIX and DANE, there is the possibility that the security of a TLS client is downgraded from DANE to PKIX. This can happen when a TLS client connection is intercepted and redirected to a rogue TLS server presenting a TLS certificate that is considered valid from a PKIX point of view but does not match the legitimate server's TLSA records. By omitting this extension, such a rogue TLS server could downgrade the TLS client to validate the mis-issued certificate using only PKIX and not via DANE, provided the TLS client is also not able to fetch the TLSA records directly from DNS.¶
The Ext
Any existing extension pin for the server instance (name and port)
MUST be cleared on receipt of a valid denial of existence for the
associated TLSA RRset. The same also applies if the client obtained
the denial
Extension pins MUST also be cleared upon the completion of a DANEdnssec_chain
extension with a zero Ext
Upon completion of a fully validated handshake with a server that
returns a dnssec_chain extension with a non-zero ExtSupport lifetime,
the client MUST update any existing pin lifetime for the service
(name and port) to a value that is not longer than that indicated by
the server. The client MAY, subject to local policy, create a
previously nonexistent pin, again for a lifetime that is not longer
than that indicated by the server.¶
The extension support lifetime is not constrained by any DNS TTLs or
RRSIG expirations in the returned chain. The extension support lifetime
is the time for which the TLS server is committing itself to serve the
extension; it is not a validity time for the returned chain data.
During this period, the DNSSEC chain may be updated. Therefore, the
Ext
Clients MAY implement support for a subset of DANE certificate usages. For example, clients may support only DANE-EE(3) and DANE-TA(2) [RFC7218], only PKIX-EE(1) and PKIX-TA(0), or all four. Clients that implement DANE-EE(3) and DANE-TA(2) MUST implement the relevant updates in [RFC7671].¶
For a non-zero saved value ("pin") of the Ext
A TLS client that has a cached validated TLSA RRset and a valid non-zero extension pin time MAY still refrain from requesting the extension as long as it uses the cached TLSA RRset to authenticate the TLS server. This RRset MUST NOT be used beyond its received TTL. Once the TLSA RRset's TTL has expired, the TLS client with a valid non-zero extension pin time MUST request the extension and MUST abort the TLS connection if the server responds without the extension. A TLS client MAY attempt to obtain the valid TLSA RRset by some other means before initiating a new TLS connection.¶
Note that requiring the extension is NOT the same as requiring the
use of DANE TLSA records or even DNSSEC. A DNS zone operator may at
any time delete the TLSA records or even remove the DS records to
disable the secure delegation of the server's DNS zone. The TLS
server will replace the chain with the corresponding denial
8. Trust Anchor Maintenance
The trust anchor may change periodically, e.g., when the operator of the trust anchor zone performs a DNSSEC key rollover. TLS clients using this specification MUST implement a mechanism to keep their trust anchors up to date. They could use the method defined in [RFC5011] to perform trust anchor updates in-band in TLS by tracking the introduction of new keys seen in the trust anchor DNSKEY RRset. However, alternative mechanisms external to TLS may also be utilized. Some operating systems may have a system-wide service to maintain and keep the root trust anchor up to date. In such cases, the TLS client application could simply reference that as its trust anchor, periodically checking whether it has changed. Some applications may prefer to implement trust anchor updates as part of their automated software updates.¶
9. Virtual Hosting
Delivery of application services is often provided by a third party on behalf of the domain owner (hosting customer). Since the domain owner may want to be able to move the service between providers, non-zero support lifetimes for this extension should only be enabled by mutual agreement between the provider and domain owner.¶
When CNAME records are employed to redirect network connections to the provider's network, as mentioned in Section 3, the server uses the client's SNI hostname as the TLSA base domain without CNAME expansion. When the certificate chain for the service is managed by the provider, it is impractical to coordinate certificate changes by the provider with updates in the hosting customer's DNS. Therefore, the TLSA RRset for the hosted domain is best configured as a CNAME from the customer's domain to a TLSA RRset that is managed by the provider as part of delivering the hosted service. For example:¶
Clients that obtain TLSA records directly from DNS, bypassing this extension, may perform CNAME expansion as in Section 7 of [RFC7671]. If TLSA records are associated with the fully expanded name, that name may be used as the TLSA base domain and SNI name for the TLS handshake.¶
To avoid confusion, it is RECOMMENDED that server operators not publish TLSA RRs (_port._tcp. + base domain) based on the expanded CNAMEs used to locate their network addresses. Instead, the server operator SHOULD publish TLSA RRs at an alternative DNS node (as in the example above), to which the hosting customer will publish a CNAME alias. This results in all clients (whether they obtain TLSA records from DNS directly or employ this extension) seeing the same TLSA records and sending the same SNI name.¶
10. Operational Considerations
When DANE is being introduced incrementally into an existing PKIX environment, there may be scenarios in which DANE authentication for a server fails but PKIX succeeds, or vice versa. What happens here depends on TLS client policy. If DANE authentication fails, the client may decide to fall back to regular PKIX authentication. In order to do so efficiently within the same TLS handshake, the TLS server needs to have provided the full X.509 certificate chain. When TLS servers only support DANE-EE or DANE-TA modes, they have the option to send a much smaller certificate chain: just the EE certificate for the former and a short certificate chain from the DANE trust anchor to the EE certificate for the latter. If the TLS server supports both DANE and regular PKIX and wants to allow efficient PKIX fallback within the same handshake, they should always provide the full X.509 certificate chain.¶
When a TLS server operator wishes to no longer deploy this extension,
it must properly decommission its use. If a non-zero pin lifetime is
presently advertised, it must first be changed to 0. The extension
can be disabled once all previously advertised pin lifetimes have
expired. Removal of TLSA records or even DNSSEC signing of the zone
can be done at any time, but the server MUST still be able to return
the associated denial
TLS clients MAY reduce the received extension pin value to a maximum set by local policy. This can mitigate a theoretical yet unlikely attack where a compromised TLS server is modified to advertise a pin value set to the maximum of 7 years. Care should be taken not to set a local maximum that is too short as that would reduce the downgrade attack protection that the extension pin offers.¶
If the hosting provider intends to use end-entity TLSA records (certificate usage PKIX-EE(1) or DANE-EE(3)), then the simplest approach is to use the same key pair for all the certificates at a given hosting node and publish "1 1 1" or "3 1 1" RRs matching the common public key. Since key rollover cannot be simultaneous across multiple certificate updates, there will be times when multiple "1 1 1" (or "3 1 1") records will be required to match all the extant certificates. Multiple TLSA records are, in any case, needed a few TTLs before certificate updates as explained in Section 8 of [RFC7671].¶
If the hosting provider intends to use trust anchor TLSA records (certificate usage PKIX-TA(0) or DANE-TA(2)), then the same TLSA record can match all end-entity certificates issues by the certification authority in question and continues to work across end-entity certificate updates so long as the issuer certificate or public keys remain unchanged. This can be easier to implement at the cost of greater reliance on the security of the selected certification authority.¶
The provider can, of course, publish separate TLSA records for each customer, which increases the number of such RRsets that need to be managed but makes each one independent of the rest.¶
11. Security Considerations
The security considerations of the normatively referenced RFCs all pertain to this extension. Since the server is delivering a chain of DNS records and signatures to the client, it MUST rebuild the chain in accordance with TTL and signature expiration of the chain components as described in Section 4. TLS clients need roughly accurate time in order to properly authenticate these signatures. This could be achieved by running a time synchronization protocol like NTP [RFC5905] or SNTP [RFC5905], which are already widely used today. TLS clients MUST support a mechanism to track and roll over the trust anchor key or be able to avail themselves of a service that does this, as described in Section 8. Security considerations related to mandating the use of this extension are described in Section 7.¶
The received DNSSEC chain could contain DNS RRs that are not related to the TLSA verification of the intended DNS name. If such an unrelated RR is not DNSSEC signed, it MUST be discarded. If the unrelated RRset is DNSSEC signed, the TLS client MAY decide to add these RRsets and their DNSSEC signatures to its cache. It MAY even pass this data to the local system resolver for caching outside the application. However, care must be taken because caching these records could be used for timing and caching attacks to de-anonymize the TLS client or its user. A TLS client that wants to present the strongest anonymity protection to their users MUST refrain from using and caching all unrelated RRs.¶
12. IANA Considerations
IANA has made the following assignment in the "TLS ExtensionType Values" registry:¶
13. References
13.1. Normative References
- [RFC1035]
-
Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, DOI 10
.17487 , , <https:///RFC1035 www >..rfc -editor .org /info /rfc1035 - [RFC2119]
-
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10
.17487 , , <https:///RFC2119 www >..rfc -editor .org /info /rfc2119 - [RFC4033]
-
Arends, R., Austein, R., Larson, M., Massey, D., and S. Rose, "DNS Security Introduction and Requirements", RFC 4033, DOI 10
.17487 , , <https:///RFC4033 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 , , <https:///RFC4034 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 , , <https:///RFC4035 www >..rfc -editor .org /info /rfc4035 - [RFC5155]
-
Laurie, B., Sisson, G., Arends, R., and D. Blacka, "DNS Security (DNSSEC) Hashed Authenticated Denial of Existence", RFC 5155, DOI 10
.17487 , , <https:///RFC5155 www >..rfc -editor .org /info /rfc5155 - [RFC5246]
-
Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10
.17487 , , <https:///RFC5246 www >..rfc -editor .org /info /rfc5246 - [RFC6066]
-
Eastlake 3rd, D., "Transport Layer Security (TLS) Extensions: Extension Definitions", RFC 6066, DOI 10
.17487 , , <https:///RFC6066 www >..rfc -editor .org /info /rfc6066 - [RFC6698]
-
Hoffman, P. and J. Schlyter, "The DNS-Based Authentication of Named Entities (DANE) Transport Layer Security (TLS) Protocol: TLSA", RFC 6698, DOI 10
.17487 , , <https:///RFC6698 www >..rfc -editor .org /info /rfc6698 - [RFC7218]
-
Gudmundsson, O., "Adding Acronyms to Simplify Conversations about DNS-Based Authentication of Named Entities (DANE)", RFC 7218, DOI 10
.17487 , , <https:///RFC7218 www >..rfc -editor .org /info /rfc7218 - [RFC7671]
-
Dukhovni, V. and W. Hardaker, "The DNS-Based Authentication of Named Entities (DANE) Protocol: Updates and Operational Guidance", RFC 7671, DOI 10
.17487 , , <https:///RFC7671 www >..rfc -editor .org /info /rfc7671 - [RFC7858]
-
Hu, Z., Zhu, L., Heidemann, J., Mankin, A., Wessels, D., and P. Hoffman, "Specification for DNS over Transport Layer Security (TLS)", RFC 7858, DOI 10
.17487 , , <https:///RFC7858 www >..rfc -editor .org /info /rfc7858 - [RFC8174]
-
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10
.17487 , , <https:///RFC8174 www >..rfc -editor .org /info /rfc8174 - [RFC8310]
-
Dickinson, S., Gillmor, D., and T. Reddy, "Usage Profiles for DNS over TLS and DNS over DTLS", RFC 8310, DOI 10
.17487 , , <https:///RFC8310 www >..rfc -editor .org /info /rfc8310 - [RFC8446]
-
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10
.17487 , , <https:///RFC8446 www >..rfc -editor .org /info /rfc8446
13.2. Informative References
- [DANE-UKS]
-
Barnes, R., Thomson, M., and E. Rescorla, "Unknown Key-Share Attacks on DNS-Based Authentications of Named Entities (DANE)", Work in Progress, Internet-Draft, draft
-barnes , , <https://-dane -uks -00 datatracker >..ietf .org /doc /html /draft -barnes -dane -uks -00 - [DISCOVERY]
-
Gorjon, X. and W. Toorop, "Discovery method for a DNSSEC validating stub resolver", , <https://
www >..nlnetlabs .nl /downloads /publications /os3 -2015 -rp2 -xavier -torrent -gorjon .pdf - [DNSOP
-SVCB -HTTPS] -
Schwartz, B., Bishop, M., and E. Nygren, "Service Binding and Parameter Specification via the DNS (DNS SVCB and HTTPS RRs)", Work in Progress, Internet-Draft, draft
-ietf , , <https://-dnsop -svcb -https -07 datatracker >..ietf .org /doc /html /draft -ietf -dnsop -svcb -https -07 - [RFC5011]
-
StJohns, M., "Automated Updates of DNS Security (DNSSEC) Trust Anchors", STD 74, RFC 5011, DOI 10
.17487 , , <https:///RFC5011 www >..rfc -editor .org /info /rfc5011 - [RFC5905]
-
Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, DOI 10
.17487 , , <https:///RFC5905 www >..rfc -editor .org /info /rfc5905 - [RFC7250]
-
Wouters, P., Ed., Tschofenig, H., Ed., Gilmore, J., Weiler, S., and T. Kivinen, "Using Raw Public Keys in Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)", RFC 7250, DOI 10
.17487 , , <https:///RFC7250 www >..rfc -editor .org /info /rfc7250 - [RFC7901]
-
Wouters, P., "CHAIN Query Requests in DNS", RFC 7901, DOI 10
.17487 , , <https:///RFC7901 www >..rfc -editor .org /info /rfc7901 - [SERIALIZECHAIN]
-
Langley, A., "Serializing DNS Records with DNSSEC Authentication", Work in Progress, Internet-Draft, draft
-agl , , <https://-dane -serializechain -01 datatracker >..ietf .org /doc /html /draft -agl -dane -serializechain -01
Appendix A. Test Vectors
The test vectors in this appendix are representations of the content
of the "opaque Authenticationextension_data in Appendix A.1, do not contain
the "uint16 Ext
For brevity and reproducibility
To reflect operational practice, different zones in the examples are in different phases of rolling their signing keys:¶
The test vectors are DNSSEC valid in the same period as the certificate is valid, which is between November 28, 2018 and December 2, 2020 with the following root trust anchor:¶
The test vectors will authenticate the certificate used with
https://, https://, and https://
at the time of writing:¶
A.1. _443._tcp.www.example.com
A hex dump of the extension_data of the server's dnssec_chain
extension representation of this with an Ext
Acknowledgments
Many thanks to Adam Langley for laying the groundwork for this extension in [SERIALIZECHAIN]. The original idea is his, but our acknowledgment in no way implies his endorsement. This document also benefited from discussions with and review from the following people: Daniel Kahn Gillmor, Jeff Hodges, Allison Mankin, Patrick McManus, Rick van Rein, Ilari Liusvaara, Eric Rescorla, Gowri Visweswaran, Duane Wessels, Nico Williams, and Richard Barnes.¶