draft-ietf-dnsext-restrict-key-for-dnssec-02.txt   draft-ietf-dnsext-restrict-key-for-dnssec-03.txt 
D. Massey
USC/ISI DNS Extensions D. Massey
S. Rose Internet-Draft USC/ISI
Expires: December 27, 2002 S. Rose
NIST NIST
June 28, 2002
Limiting the Scope of the KEY Resource Record Limiting the Scope of the KEY Resource Record
draft-ietf-dnsext-restrict-key-for-dnssec-03
draft-ietf-dnsext-restrict-key-for-dnssec-02.txt Status of this Memo
Status of this Document
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Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved.
Abstract Abstract
This document limits the Domain Name System KEY resource This document limits the Domain Name System KEY resource record to
record to only keys used by the Domain Name System Security only keys used by the Domain Name System Security Extensions
Extensions (DNSSEC). The original KEY resource record used (DNSSEC). The original KEY resource record used sub-typing to store
sub-typing to store both DNSSEC keys and arbitrary application both DNSSEC keys and arbitrary application keys. Storing both DNSSEC
keys. Storing both DNSSEC and application keys in one record and application keys in one record was a mistake. This document
was a mistake. This document removes application keys from removes application keys from the KEY record by redefining the
the KEY record by redefining the Protocol Octet field in Protocol Octet field in the KEY Resource Record Data. As a result of
the KEY Resource Record Data. As a result of removing application removing application keys, all but one of the flags in the KEY record
keys, all but one of the flags in the KEY record become become unnecessary and are removed. Three existing application key
unnecessary and are removed. Three existing application sub-types are changed to reserved, but the format of the KEY record
key sub-types are changed to reserved, but the format of is not changed. This document updates RFC 2535.
the KEY record is not changed. This document updates RFC
2535.
1 Introduction 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.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Motivation for Restricting the KEY Record . . . . . . . . . . 4
2.1 Differences Between DNSSEC and Application Keys . . . . . . . 4
3. Definition of the KEY Resource Record . . . . . . . . . . . . 7
4. Changes from RFC 2535 KEY Record . . . . . . . . . . . . . . . 8
5. Backward Compatibility . . . . . . . . . . . . . . . . . . . . 10
6. Storing Application Keys in the DNS . . . . . . . . . . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
8. Security Considerations . . . . . . . . . . . . . . . . . . . 13
References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 14
Full Copyright Statement . . . . . . . . . . . . . . . . . . . 15
1. Introduction
This document limits the scope the KEY resource record. The KEY This document limits the scope the KEY resource record. The KEY
resource record was defined in [1] and used resource record sub-typing resource record was defined in [2] and used resource record sub-
to hold arbitrary public keys such as Email, IPSEC, DNSSEC, and TLS typing to hold arbitrary public keys such as Email, IPSEC, DNSSEC,
keys. This document eliminates the existing Email, IPSEC, and TLS and TLS keys. This document eliminates the existing Email, IPSEC,
sub-types and prohibits the introduction of new sub-types. DNSSEC and TLS sub-types and prohibits the introduction of new sub-types.
will be the only allowable sub-type for the KEY record (hence sub-typing DNSSEC will be the only allowable sub-type for the KEY record (hence
is essentially eliminated) and all but one of the KEY record flags sub-typing is essentially eliminated) and all but one of the KEY
are also eliminated. record flags are also eliminated.
Section 2 presents the motivation for restricting the KEY record Section 2 presents the motivation for restricting the KEY record and
and Section 3 defines the revised KEY record. Section 4 and 5 summarize Section 3 defines the revised KEY record. Sections 4 and 5 summarize
the changes from RFC 2535 and discuss backwards compatibility. It the changes from RFC 2535 and discuss backwards compatibility. It is
is important to note that this document restricts the use of the important to note that this document restricts the use of the KEY
KEY record and simplifies the flags, but does not change the definition record and simplifies the flags, but does not change the definition
or use of DNSSEC keys. or use of DNSSEC keys.
2 Motivation for Restricting the KEY Record 2. Motivation for Restricting the KEY Record
The KEY record RDATA [1] consists of Flags, a Protocol Octet, an The KEY record RDATA [2] consists of Flags, a Protocol Octet, an
Algorithm type, and a Public Key. The Protocol Octet identifies Algorithm type, and a Public Key. The Protocol Octet identifies the
the KEY record sub-type. DNSSEC public keys are stored in the KEY KEY record sub-type. DNSSEC public keys are stored in the KEY record
record using a Protocol Octet value of 3. Email, IPSEC, and TLS using a Protocol Octet value of 3. Email, IPSEC, and TLS keys were
keys were also stored in the KEY record and used Protocol Octet values also stored in the KEY record and used Protocol Octet values of 1,2,
of 1,2, and 4 (respectively). Protocol Octet values 5-254 were available and 4 (respectively). Protocol Octet values 5-254 were available for
for assignment by IANA and values were requested (but not assigned) assignment by IANA and values were requested (but not assigned) for
for applications such as SSH. applications such as SSH.
Any use of sub-typing has inherent limitations. A resolver can not Any use of sub-typing has inherent limitations. A resolver can not
specify the desired sub-type in a DNS query and most DNS operations specify the desired sub-type in a DNS query and most DNS operations
apply only to resource records sets. For a example, a resolver can apply only to resource records sets. For example, a resolver can not
not directly request KEY records with a particular sub-type. Instead, directly request the DNSSEC subtype KEY records. Instead, the
the resolver has to request all KEY records associated with a DNS resolver has to request all KEY records associated with a DNS name
name and then search the set for the desired sub-type. DNSSEC signatures and then search the set for the desired DNSSEC sub-type. DNSSEC
also apply to the set of all KEY resource records associated with signatures also apply to the set of all KEY resource records
the DNS name, regardless of sub-type. associated with the DNS name, regardless of sub-type.
In the case of the KEY record, the inherent sub-type limitations
are exacerbated since the sub-type is used to distinguish between
DNSSEC keys and application keys. DNSSEC keys and application keys
differ in virtually every respect and Section 2.1 discusses these
differences in more detail. Combining these very different types
of keys into a single sub-typed resource record adds unnecessary
complexity and increases the potential for implementation and deployment
errors. Limited experimental deployment has shown that application In the case of the KEY record, the inherent sub-type limitations are
keys stored in KEY records are problematic. exacerbated since the sub-type is used to distinguish between DNSSEC
keys and application keys. DNSSEC keys and application keys differ
in virtually every respect and Section 2.1 discusses these
differences in more detail. Combining these very different types of
keys into a single sub-typed resource record adds unnecessary
complexity and increases the potential for implementation and
deployment errors. Limited experimental deployment has shown that
application keys stored in KEY records are problematic.
This document addresses these issues by removing all application keys This document addresses these issues by removing all application keys
from the KEY resource record. Note that the scope of this document from the KEY resource record. Note that the scope of this document
is strictly limited to the KEY record and this document does not is strictly limited to the KEY record and this document does not
endorse or restrict the storage of application keys in other resource endorse or restrict the storage of application keys in other resource
records. records.
2.1 Differences Between DNSSEC and Application Keys 2.1 Differences Between DNSSEC and Application Keys
DNSSEC keys are an essential part of the DNSSEC protocol and are DNSSEC keys are an essential part of the DNSSEC protocol and are used
used by both name servers and resolvers in order to perform DNS tasks. by both name servers and resolvers in order to perform DNS tasks. A
A DNS zone key, used to sign and authenticate RR sets, is the most DNS zone key, used to sign and authenticate RR sets, is the most
common example of a DNSSEC key. SIG(0) [3] and TKEY [2] also use common example of a DNSSEC key. SIG(0) [3] and TKEY [2] also use
DNSSEC keys. DNSSEC keys.
Application keys such as Email keys, IPSEC keys, and TLS keys are Application keys such as Email keys, IPSEC keys, and TLS keys are
simply another type data. These keys have no special meaning to simply another type data. These keys have no special meaning to a
a name server or resolver. name server or resolver.
The following table summarizes some of the differences between DNSSEC The following table summarizes some of the differences between DNSSEC
keys and Application keys: keys and Application keys:
1. They serve different purposes. 1. They serve different purposes.
2. They are managed by different administrators. 2. They are managed by different administrators.
3. They are authenticated according to different rules. 3. They are authenticated according to different rules.
4. Nameservers use different rules when including them in responses. 4. Nameservers use different rules when including them in responses.
5. Resolvers process them in different ways. 5. Resolvers process them in different ways.
6. Faults/key compromises have different consequences. 6. Faults/key compromises have different consequences.
1. The purpose of a DNSSEC key is to sign resource records associated 1. The purpose of a DNSSEC key is to sign resource records
with a DNS zone (or generate DNS transaction signatures in the case associated with a DNS zone (or generate DNS transaction signatures
of SIG(0)/TKEY). But the purpose of an application key is specific in the case of SIG(0)/TKEY). But the purpose of an application key
to the application. Application keys, such as PGP/email, IPSEC, TLS, is specific to the application. Application keys, such as PGP/email,
and SSH keys, are not a mandatory part of any zone and the purpose IPSEC, TLS, and SSH keys, are not a mandatory part of any zone and
and proper use of application keys is outside the scope of DNS. the purpose and proper use of application keys is outside the scope
of DNS.
2. DNSSEC keys are managed by DNS administrators, but application 2. DNSSEC keys are managed by DNS administrators, but application
keys are managed by application administrators. The DNS zone administrator keys are managed by application administrators. The DNS zone
determines the key lifetime, handles any suspected key compromises, administrator determines the key lifetime, handles any suspected key
and manages any DNSSEC key changes. Likewise, the application administrator compromises, and manages any DNSSEC key changes. Likewise, the
application administrator is responsible for the same functions for
is responsible for the same functions for the application keys related the application keys related to the application. For example, a user
to the application. For example, a user typically manages her own typically manages her own PGP key and a server manages its own TLS
PGP key and a server manages its own TLS key. Application key management key. Application key management tasks are outside the scope of DNS
tasks are outside the scope of DNS administration. administration.
3. DNSSEC zone keys are used to authenticate application keys, but 3. DNSSEC zone keys are used to authenticate application keys, but
application keys MUST NOT be used to authenticate DNS zone keys. application keys MUST NOT be used to authenticate DNS zone keys. A
A DNS zone key is either configured as trusted key or authenticated DNS zone key is either configured as trusted key or authenticated by
by constructing a chain of trust in the DNS hierarchy. To participate constructing a chain of trust in the DNS hierarchy. To participate
in the chain of trust, a DNS zone needs to exchange zone key information in the chain of trust, a DNS zone needs to exchange zone key
with its parent zone [1]. Application keys are not configured as information with its parent zone [2]. Application keys are not
trusted keys in the DNS and are never part of any DNS chain of trust. configured as trusted keys in the DNS and are never part of any DNS
Application key data SHOULD not be exchanged with the parent zone. chain of trust. Application key data SHOULD not be exchanged with
A resolver considers an application key authenticated if it has a the parent zone. A resolver considers an application key
valid signature from the local DNS zone keys, but applications could authenticated if it has a valid signature from the local DNS zone
impose additional requirements before the application key is accepted keys, but applications could impose additional requirements before
as authentic. the application key is accepted as authentic.
4. It MAY be useful for nameservers to include DNS zone keys in
the additional section of a response, but application keys are typically
not useful unless they have been specifically requested. For example,
it could be useful to include the isi.edu zone key along with a response
that contain the www.isi.edu A record and SIG record. A secure resolver
will need the isi.edu zone key in order to check the SIG and authenticate
the www.isi.edu A record. It is typical not useful to include the
IPSEC, email, and TLS keys along with the A record. Note that by
placing application keys in the KEY record, a resolver will need
the IPSEC, email, TLS, and other key associated with isi.edu if the
resolver intends to authenticate the isi.edu zone key (since signatures
only apply to the entire KEY set).
5. DNS zone keys require special handling by resolvers, but application 4. It MAY be useful for nameservers to include DNS zone keys in the
keys are treated the same as any other type of DNS data. The DNSSEC additional section of a response, but application keys are typically
keys are of no value to end applications, unless the applications not useful unless they have been specifically requested. For
plan to do their own DNS authentication. Secure resolvers MUST NOT example, it could be useful to include the isi.edu zone key along
use application keys as part of the authentication process. Application with a response that contain the www.isi.edu A record and SIG record.
keys have no unique value to resolvers and are only useful to the A secure resolver will need the isi.edu zone key in order to check
application requesting the key. Note that if sub-types are used the SIG and authenticate the www.isi.edu A record. It is typical not
to identify the application key, then either the interface to the useful to include the IPSEC, email, and TLS keys along with the A
resolver needs to specify the sub-type or the application needs to record. Note that by placing application keys in the KEY record, a
be able to accept all KEY records and pick out the desired the sub-type. resolver will need the IPSEC, email, TLS, and other key associated
with isi.edu if the resolver intends to authenticate the isi.edu zone
key (since signatures only apply to the entire KEY RR set).
6. A fault or compromise of a DNS zone key can lead to invalid 5. DNS zone keys require special handling by resolvers, but
or forged DNS data, but a fault or compromise of an application key application keys are treated the same as any other type of DNS data.
SHOULD have no impact on other DNS data. Incorrectly adding or changing The DNSSEC keys are of no value to end applications, unless the
a DNS zone key can invalidate all of the DNS data in zone and in applications plan to do their own DNS authentication. Secure
all of its subzones. By using a compromised key, an attacker can resolvers MUST NOT use application keys as part of the authentication
process. Application keys have no unique value to resolvers and are
only useful to the application requesting the key. Note that if sub-
types are used to identify the application key, then either the
interface to the resolver needs to specify the sub-type or the
application needs to be able to accept all KEY records and pick out
the desired the sub-type.
forge data from the effected zone and any for any of its sub-zones. 6. A fault or compromise of a DNS zone key can lead to invalid or
A fault or compromise of an application key has implications for forged DNS data, but a fault or compromise of an application key
that application, but it SHOULD not have an impact on the DNS. Note SHOULD have no impact on other DNS data. Incorrectly adding or
that application key faults and key compromises can have an impact changing a DNS zone key can invalidate all of the DNS data in zone
on the entire DNS if the application key and DNS zone keys are both and in all of its subzones. By using a compromised key, an attacker
stored in the KEY record. can forge data from the effected zone and any for any of its sub-
zones. A fault or compromise of an application key has implications
for that application, but it SHOULD not have an impact on the DNS.
Note that application key faults and key compromises can have an
impact on the entire DNS if the application key and DNS zone keys are
both stored in the KEY record.
In summary, DNSSEC keys and application keys differ in most every In summary, DNSSEC keys and application keys differ in most every
respect. DNSSEC keys are an essential part of the DNS infrastructure respect. DNSSEC keys are an essential part of the DNS infrastructure
and require special handling by DNS administrators and DNS resolvers. and require special handling by DNS administrators and DNS resolvers.
Application keys are simply another type of data and have no special Application keys are simply another type of data and have no special
meaning to DNS administrators or resolvers. These two different types meaning to DNS administrators or resolvers. These two different
of data do not belong in the same resource record. types of data do not belong in the same resource record.
3 Definition of the KEY Resource Record 3. Definition of the KEY Resource Record
The KEY record uses type 25 and is used as resource record for storing The KEY record uses type 25 and is used as resource record for
DNSSEC keys. The RDATA for a KEY RR consists of flags, a protocol storing DNSSEC keys. The RDATA for a KEY RR consists of flags, a
octet, the algorithm number octet, and the public key itself. The protocol octet, the algorithm number octet, and the public key
format is as follows: itself. The format is as follows:
---------------------------------------------------------------------
1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| flags | protocol | algorithm | | flags | protocol | algorithm |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| / | /
/ public key / / public key /
/ / / /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
In the flags field, all bits except bit 7 are reserved and SHOULD KEY RR Format
be zero. If Bit 7 (Zone bit) is set to 1, then the KEY is a DNS
Zone key. If Bit 7 is set to 0, the KEY is not a zone key. SIG(0)/TKEY ---------------------------------------------------------------------
In the flags field, all bits except bit 7 are reserved and SHOULD be
zero. If Bit 7 (Zone bit) is set to 1, then the KEY is a DNS Zone
key. If Bit 7 is set to 0, the KEY is not a zone key. SIG(0)/TKEY
are examples of DNSSEC keys that are not zone keys. are examples of DNSSEC keys that are not zone keys.
The protocol field MUST be set to 3. The protocol field MUST be set to 3.
The algorithm and public key fields are not changed. The algorithm and public key fields are not changed.
4 Changes from RFC 2535 KEY Record 4. Changes from RFC 2535 KEY Record
The KEY RDATA format is not changed. The KEY RDATA format is not changed.
All flags except for the zone key flag are eliminated: All flags except for the zone key flag are eliminated:
o The A/C bits (bits 0 and 1) are eliminated. They SHOULD be The A/C bits (bits 0 and 1) are eliminated. They MUST be set to 0
set to 0 by the sender and MUST be ignored by the receiver. and MUST be ignored by the receiver.
o The extended flags bit (bit 3) is eliminated. It SHOULD be The extended flags bit (bit 3) is eliminated. It MUST be set to 0
set to 0 by the sender and MUST be ignored by the receiver. and MUST be ignored by the receiver.
o The host/user bit (bit 6) is eliminated. It SHOULD be set to The host/user bit (bit 6) is eliminated. It MUST be set to 0 and
0 by the sender and MUST be ignored by the receiver. MUST be ignored by the receiver.
o The zone bit (bit 7) remains unchanged. The zone bit (bit 7) remains unchanged.
o The signatory field (bits 12-15) are eliminated by [4]. They The signatory field (bits 12-15) are eliminated by [4]. They MUST
SHOULD be set to 0 by the sender and MUST be ignored by the be set to 0 and MUST be ignored by the receiver.
receiver.
o Bits 2,4,5,8,9,10,11 remain unchanged. They are reserved, SHOULD Bits 2,4,5,8,9,10,11 remain unchanged. They are reserved, MUST be
be set to zero by the sender, and MUST be ignored by the receiver. set to zero and MUST be ignored by the receiver.
Assignment of any future KEY record Flag values requires a standards Assignment of any future KEY record Flag values requires a standards
action. action.
All Protocol Octet values except DNSSEC (3) are eliminated: All Protocol Octet values except DNSSEC (3) are eliminated:
o Value 1 (Email) is renamed to reserved. Value 1 (Email) is renamed to reserved.
o Value 2 (IPSEC) is renamed to reserved. Value 2 (IPSEC) is renamed to reserved.
o Value 3 (DNSSEC) is unchanged. Value 3 (DNSSEC) is unchanged.
o Value 4 (TLS) is renamed to reserved. Value 4 (TLS) is renamed to reserved.
o Value 5-254 remains unchanged (reserved). Value 5-254 remains unchanged (reserved).
o Value 255 (ANY) is renamed to reserved. Value 255 (ANY) is renamed to reserved.
Name servers and resolvers SHOULD reject any KEY with a Protocol The authoritative data for a zone MUST NOT include any KEY records
other than 3. Assignment of any future KEY record Protocol Octet with a protocol octet other than 3. Any future KEY record Protocol
values requires a standards action. Octet values requires a standards action.
Name servers and resolvers SHOULD accept KEY RR sets that contain KEY
records with a value other than 3. If out of date DNS zones contain
deprecated KEY records with a protocol octet value other than 3, then
simply dropping the deprecated KEY records from the KEY RR set would
invalidate any associated SIG record(s) and could create caching
consistency problems. Note that KEY records with a protocol octet
value other than 3 MUST NOT be used to authenticate DNS data.
The algorithm and public key fields are not changed. The algorithm and public key fields are not changed.
5 Backward Compatibility 5. Backward Compatibility
DNSSEC zone key records are not change and remain backwards compatible. DNSSEC zone key records are not changed and remain backwards
A properly formatted RFC 2535 zone KEY would have all flag bits, compatible. A properly formatted RFC 2535 zone KEY would have all
other than the Zone Bit (Bit 7), set to 0 and would have the Protocol flag bits, other than the Zone Bit (Bit 7), set to 0 and would have
Octet set to 3. This remains true under the restricted KEY. the Protocol Octet set to 3. This remains true under the restricted
KEY.
DNSSEC non-zone key records (SIG(0)/TKEY keys) are backwards compatible, DNSSEC non-zone key records (SIG(0)/TKEY keys) are backwards
but the distinction between host and user keys (flag bit 6) is lost. compatible, but the distinction between host and user keys (flag bit
6) is lost.
No backwards compatibility is provided for application keys. Any No backwards compatibility is provided for application keys. Any
Email, IPSEC, or TLS keys are now deprecated and SHOULD be rejected Email, IPSEC, or TLS keys are now deprecated. Storing application
by name servers and resolvers. Storing application keys in the KEY keys in the KEY record created problems such as keys at the apex and
record created problems such as keys at the apex and large RR sets large RR sets and some change in the definition and/or usage of the
and some change in the definition and/or usage of the KEY record KEY record would have been required even if the approach described
would have been required even if the approach described here were here were not adopted.
not adopted.
Overall, existing nameservers and resolvers will continue to correctly Overall, existing nameservers and resolvers will continue to
process KEY records with a sub-type of DNSSEC keys. correctly process KEY records with a sub-type of DNSSEC keys.
6 Storing Application Keys in the DNS 6. Storing Application Keys in the DNS
The scope of this document is strictly limited to the KEY record. The scope of this document is strictly limited to the KEY record.
This document prohibits storing application keys in the KEY record, This document prohibits storing application keys in the KEY record,
but it does not endorse or restrict the storing application keys but it does not endorse or restrict the storing application keys in
in other record types. Other documents can describe how DNS handles other record types. Other documents can describe how DNS handles
application keys. application keys.
7 IANA Consideration 7. IANA Considerations
RFC 2535 created an IANA registry for DNS KEY Resource Record Protocol RFC 2535 created an IANA registry for DNS KEY Resource Record
Octet values. Values to 1,2,3, 4, and 255 were assigned by RFC 2535 Protocol Octet values. Values to 1,2,3, 4, and 255 were assigned by
and values 5-254 were made available for assignment by IANA. This RFC 2535 and values 5-254 were made available for assignment by IANA.
document makes two sets of changes to this registry. This document makes two sets of changes to this registry.
First, this document re-assigns DNS KEY Resource Record Protocol Octet First, this document re-assigns DNS KEY Resource Record Protocol
values 1, 2, 4, and 255 to ``reserved''. DNS Key Resource Record Octet values 1, 2, 4, and 255 to ``reserved''. DNS Key Resource
Protocol Octet Value 3 remains unchanged as ``DNSSEC''. Record Protocol Octet Value 3 remains unchanged as ``DNSSEC''.
Second, new values are no longer available for assignment by IANA Second, new values are no longer available for assignment by IANA and
and this document closes the IANA registry for DNS KEY Resource Record this document closes the IANA registry for DNS KEY Resource Record
Protocol Octet Values. Assignment of any future KEY Resource Record Protocol Octet Values. Assignment of any future KEY Resource Record
Protocol Octet values requires a standards action. Protocol Octet values requires a standards action.
8 Security Consideration 8. Security Considerations
This document eliminates potential security problems that could arise This document eliminates potential security problems that could arise
due to the coupling of DNS zone keys and application keys. Prior due to the coupling of DNS zone keys and application keys. Prior to
to the change described in this document, a correctly authenticated the change described in this document, a correctly authenticated KEY
KEY set could include both application keys and DNSSEC keys. If set could include both application keys and DNSSEC keys. If one of
one of the application keys is compromised, it could be used as a the application keys is compromised, it could be used as a false zone
false zone key to create false DNS signatures (SIG records). Resolvers key to create false DNS signatures (SIG records). Resolvers that do
that do not carefully check the KEY sub-type could believe these not carefully check the KEY sub-type could believe these false
false signatures and incorrectly authenticate DNS data. With this signatures and incorrectly authenticate DNS data. With this change,
change, application keys cannot appear in an authenticated KEY set application keys cannot appear in an authenticated KEY set and this
and this vulnerability is eliminated. vulnerability is eliminated.
The format and correct usage of DNSSEC keys is not changed by this The format and correct usage of DNSSEC keys is not changed by this
document and no new security considerations are introduced. document and no new security considerations are introduced.
9 Intellectual Property References (Normative)
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to pertain
to the implementation or use of the technology described in this
document or the extent to which any license under such rights might
or might not be available; neither does it represent that it has
made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and standards-
related documentation can be found in BCP-11.
Copies of claims of rights made available for publication and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use
of such proprietary rights by implementors or users of this specification
can be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary rights
which may cover technology that may be required to practice this
standard. Please address the information to the IETF Executive Director.
10 References (Normative)
[1] Eastlake, D., "Domain Name System Security Extensions", RFC 2535, [1] Eastlake, D., "Domain Name System Security Extensions", RFC
March 1999. 2535, March 1999.
[2] Eastlake, D., "Secret Key Establishment for DNS (TKEY RR)", RFC [2] Eastlake, D., "Secret Key Establishment for DNS (TKEY RR)", RFC
2930, September 2000. 2930, September 2000.
[3] Eastlake, D., "DNS Request and Transaction Signatures ( SIG(0)s)", [3] Eastlake, D., "DNS Request and Transaction Signatures (
RFC 2931, September 2000. SIG(0)s)", RFC 2931, September 2000.
[4] Wellington, B., "Secure Domain Name System (DNS) Dynamic Update", [4] Wellington, B., "Secure Domain Name System (DNS) Dynamic
RFC 3007, November 2000. Update", RFC 3007, November 2000.
11 Author Information Authors' Addresses
Daniel Massey <masseyd@isi.edu> Dan Massey
USC Information Sciences Institute USC Information Sciences Institute
3811 North Fairfax Drive, Suite 200 3811 N. Fairfax Drive
Arlington, VA 22203 Arlington, VA 22203
USA
Scott Rose <scott.rose@nist.gov> EMail: masseyd@isi.edu
Scott Rose
National Institute for Standards and Technology National Institute for Standards and Technology
Gaithersburg, MD 100 Bureau Drive
Gaithersburg, MD 20899-3460
USA
EMail: scott.rose@nist.gov
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