draft-ietf-dkim-ssp-08.txt   draft-ietf-dkim-ssp-09.txt 
Network Working Group E. Allman Network Working Group E. Allman
Internet-Draft Sendmail, Inc. Internet-Draft Sendmail, Inc.
Intended status: Standards Track J. Fenton Intended status: Standards Track J. Fenton
Expires: June 20, 2009 Cisco Systems, Inc. Expires: August 9, 2009 Cisco Systems, Inc.
M. Delany M. Delany
Yahoo! Inc. Yahoo! Inc.
J. Levine J. Levine
Taughannock Networks Taughannock Networks
December 17, 2008 February 5, 2009
DomainKeys Identified Mail (DKIM) Author Domain Signing Practices (ADSP) DomainKeys Identified Mail (DKIM) Author Domain Signing Practices (ADSP)
draft-ietf-dkim-ssp-08 draft-ietf-dkim-ssp-09
Status of this Memo Status of this Memo
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Abstract Abstract
DomainKeys Identified Mail (DKIM) defines a domain-level DomainKeys Identified Mail (DKIM) defines a domain-level
authentication framework for email to permit verification of the authentication framework for email to permit verification of the
source and contents of messages. This document specifies an adjunct source and contents of messages. This document specifies an adjunct
mechanism to aid in assessing messages that do not contain a DKIM mechanism to aid in assessing messages that do not contain a DKIM
signature for the domain used in the author's address. It defines a signature for the domain used in the author's address. It defines a
record that can advertise whether a domain signs its outgoing mail, record that can advertise whether a domain signs its outgoing mail,
and how other hosts can access that record. and how other hosts can access that record.
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2. Language and Terminology . . . . . . . . . . . . . . . . . . . 4 2. Language and Terminology . . . . . . . . . . . . . . . . . . . 4
2.1. Terms Imported from DKIM Signatures Specification . . . . 4 2.1. Terms Imported from DKIM Signatures Specification . . . . 4
2.2. Valid Signature . . . . . . . . . . . . . . . . . . . . . 5 2.2. Valid Signature . . . . . . . . . . . . . . . . . . . . . 5
2.3. Author Address . . . . . . . . . . . . . . . . . . . . . . 5 2.3. Author Address . . . . . . . . . . . . . . . . . . . . . . 5
2.4. Author Domain . . . . . . . . . . . . . . . . . . . . . . 5 2.4. Author Domain . . . . . . . . . . . . . . . . . . . . . . 5
2.5. Alleged Author . . . . . . . . . . . . . . . . . . . . . . 5 2.5. Alleged Author . . . . . . . . . . . . . . . . . . . . . . 5
2.6. Author Domain Signing Practices . . . . . . . . . . . . . 5 2.6. Author Domain Signing Practices . . . . . . . . . . . . . 5
2.7. Author Signature . . . . . . . . . . . . . . . . . . . . . 5 2.7. Author Signature . . . . . . . . . . . . . . . . . . . . . 5
3. Operation Overview . . . . . . . . . . . . . . . . . . . . . . 6 3. Operation Overview . . . . . . . . . . . . . . . . . . . . . . 6
3.1. ADSP Applicability . . . . . . . . . . . . . . . . . . . . 6 3.1. ADSP Applicability . . . . . . . . . . . . . . . . . . . . 6
3.2. ADSP Usage . . . . . . . . . . . . . . . . . . . . . . . . 6 3.2. ADSP Usage . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3. ADSP Results . . . . . . . . . . . . . . . . . . . . . . . 7 3.3. ADSP Results . . . . . . . . . . . . . . . . . . . . . . . 7
4. Detailed Description . . . . . . . . . . . . . . . . . . . . . 7 4. Detailed Description . . . . . . . . . . . . . . . . . . . . . 7
4.1. DNS Representation . . . . . . . . . . . . . . . . . . . . 7 4.1. DNS Representation . . . . . . . . . . . . . . . . . . . . 7
4.2. Publication of ADSP Records . . . . . . . . . . . . . . . 8 4.2. Publication of ADSP Records . . . . . . . . . . . . . . . 8
4.3. ADSP Lookup Procedure . . . . . . . . . . . . . . . . . . 8 4.3. ADSP Lookup Procedure . . . . . . . . . . . . . . . . . . 9
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
5.1. ADSP Specification Tag Registry . . . . . . . . . . . . . 10 5.1. ADSP Specification Tag Registry . . . . . . . . . . . . . 10
5.2. ADSP Outbound Signing Practices Registry . . . . . . . . . 10 5.2. ADSP Outbound Signing Practices Registry . . . . . . . . . 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
6.1. ADSP Threat Model . . . . . . . . . . . . . . . . . . . . 11 6.1. ADSP Threat Model . . . . . . . . . . . . . . . . . . . . 11
6.2. DNS Considerations . . . . . . . . . . . . . . . . . . . . 12 6.2. DNS Considerations . . . . . . . . . . . . . . . . . . . . 12
6.3. DNS Wildcards . . . . . . . . . . . . . . . . . . . . . . 12 6.3. DNS Wildcards . . . . . . . . . . . . . . . . . . . . . . 12
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1. References - Normative . . . . . . . . . . . . . . . . . . 13 7.1. References - Normative . . . . . . . . . . . . . . . . . . 13
7.2. References - Informative . . . . . . . . . . . . . . . . . 13 7.2. References - Informative . . . . . . . . . . . . . . . . . 13
Appendix A. Lookup Examples . . . . . . . . . . . . . . . . . . . 13 Appendix A. Lookup Examples . . . . . . . . . . . . . . . . . . . 14
A.1. Domain and ADSP exist . . . . . . . . . . . . . . . . . . 14 A.1. Domain and ADSP exist . . . . . . . . . . . . . . . . . . 14
A.2. Domain exists, ADSP does not exist . . . . . . . . . . . . 14 A.2. Domain exists, ADSP does not exist . . . . . . . . . . . . 14
A.3. Domain does not exist . . . . . . . . . . . . . . . . . . 14 A.3. Domain does not exist . . . . . . . . . . . . . . . . . . 15
Appendix B. Usage Examples . . . . . . . . . . . . . . . . . . . 15 Appendix B. Usage Examples . . . . . . . . . . . . . . . . . . . 15
B.1. Single Location Domains . . . . . . . . . . . . . . . . . 15 B.1. Single Location Domains . . . . . . . . . . . . . . . . . 15
B.2. Bulk Mailing Domains . . . . . . . . . . . . . . . . . . . 15 B.2. Bulk Mailing Domains . . . . . . . . . . . . . . . . . . . 15
B.3. Bulk Mailing Domains with Discardable Mail . . . . . . . . 16 B.3. Bulk Mailing Domains with Discardable Mail . . . . . . . . 16
B.4. Third Party Senders . . . . . . . . . . . . . . . . . . . 16 B.4. Third Party Senders . . . . . . . . . . . . . . . . . . . 16
B.5. Domains with Independent Users and Liberal Use Policies . 16 B.5. Domains with Independent Users and Liberal Use Policies . 17
B.6. Non-email Domains . . . . . . . . . . . . . . . . . . . . 16 B.6. Non-email Domains . . . . . . . . . . . . . . . . . . . . 17
Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 17 Appendix C. Acknowledgements . . . . . . . . . . . . . . . . . . 17
Appendix D. Change Log . . . . . . . . . . . . . . . . . . . . . 17 Appendix D. Change Log . . . . . . . . . . . . . . . . . . . . . 17
D.1. Changes since -ietf-dkim-07 . . . . . . . . . . . . . . . 17 D.1. Changes since -ietf-dkim-08 . . . . . . . . . . . . . . . 17
D.2. Changes since -ietf-dkim-06 . . . . . . . . . . . . . . . 17 D.2. Changes since -ietf-dkim-07 . . . . . . . . . . . . . . . 17
D.3. Changes since -ietf-dkim-05 . . . . . . . . . . . . . . . 17 D.3. Changes since -ietf-dkim-06 . . . . . . . . . . . . . . . 18
D.4. Changes since -ietf-dkim-04 . . . . . . . . . . . . . . . 17 D.4. Changes since -ietf-dkim-05 . . . . . . . . . . . . . . . 18
D.5. Changes since -ietf-dkim-03 . . . . . . . . . . . . . . . 18 D.5. Changes since -ietf-dkim-04 . . . . . . . . . . . . . . . 18
D.6. Changes since -ietf-dkim-02 . . . . . . . . . . . . . . . 19 D.6. Changes since -ietf-dkim-03 . . . . . . . . . . . . . . . 18
D.7. Changes since -ietf-dkim-ssp-01 . . . . . . . . . . . . . 19 D.7. Changes since -ietf-dkim-02 . . . . . . . . . . . . . . . 19
D.8. Changes since -ietf-dkim-ssp-00 . . . . . . . . . . . . . 20 D.8. Changes since -ietf-dkim-ssp-01 . . . . . . . . . . . . . 20
D.9. Changes since -allman-ssp-02 . . . . . . . . . . . . . . . 21 D.9. Changes since -ietf-dkim-ssp-00 . . . . . . . . . . . . . 21
D.10. Changes since -allman-ssp-01 . . . . . . . . . . . . . . . 21 D.10. Changes since -allman-ssp-02 . . . . . . . . . . . . . . . 21
D.11. Changes since -allman-ssp-00 . . . . . . . . . . . . . . . 21 D.11. Changes since -allman-ssp-01 . . . . . . . . . . . . . . . 22
D.12. Changes since -allman-ssp-00 . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22
Intellectual Property and Copyright Statements . . . . . . . . . . 23
1. Introduction 1. Introduction
DomainKeys Identified Mail (DKIM) defines a mechanism by which email DomainKeys Identified Mail (DKIM) defines a mechanism by which email
messages can be cryptographically signed, permitting a signing domain messages can be cryptographically signed, permitting a signing domain
to claim responsibility for the introduction of a message into the to claim responsibility for the introduction of a message into the
mail stream. Message recipients can verify the signature by querying mail stream. Message recipients can verify the signature by querying
the signer's domain directly to retrieve the appropriate public key, the signer's domain directly to retrieve the appropriate public key,
and thereby confirm that the message was attested to by a party in and thereby confirm that the message was attested to by a party in
possession of the private key for the signing domain. possession of the private key for the signing domain.
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2.6. Author Domain Signing Practices 2.6. Author Domain Signing Practices
"Author Domain Signing Practices" (or just "practices") consist of a "Author Domain Signing Practices" (or just "practices") consist of a
machine-readable record published by the domain of an Alleged Author machine-readable record published by the domain of an Alleged Author
which includes statements about the domain's practices with respect which includes statements about the domain's practices with respect
to mail it sends with its domain in the From: line. to mail it sends with its domain in the From: line.
2.7. Author Signature 2.7. Author Signature
An "Author Signature" is any Valid Signature where the identity of An "author signature" is a Valid Signature that has the same domain
the user or agent on behalf of which the message is signed (listed in name in the DKIM signing identity as the domain name in the Author
the "i=" tag or its default value from the "d=" tag) matches an Address. If the DKIM signing identity has a Local-part, it is be
Author Address in the message. When the identity of the user or identical to the Local-part in the Author Address. Following
agent includes a Local-part, the identities match if the Local-parts
are the same string, and the domains are the same string. Otherwise,
the identities match if the domains are the same string. Following
[RFC5321], Local-part comparisons are case sensitive, but domain [RFC5321], Local-part comparisons are case sensitive, but domain
comparisons are case insensitive. comparisons are case insensitive.
For example, if a message has a Valid Signature, with the DKIM- For example, if a message has a Valid Signature, with the DKIM-
Signature field containing "i=a@domain.example", then domain.example Signature field containing "i=a@domain.example", then domain.example
is asserting that it takes responsibility for the message. If the is asserting that it takes responsibility for the message. If the
message's From: field contains the address "b@domain.example" and an message's From: field contains the address "b@domain.example", that
ADSP query produces a "dkim=all" or "dkim=discardable" result, that
would mean that the message does not have a valid Author Signature. would mean that the message does not have a valid Author Signature.
Even though the message is signed by the same domain, it fails to Even though the message is signed by the same domain, it will not
satisfy ADSP. satisfy ADSP that specifies "dkim=all" or "dkim=discardable".
Note: ADSP is incompatible with valid DKIM usage in which a signer
uses "i=" with values that are not the same as addresses in mail
headers. In that case, a possible workaround could be to add a
second DKIM signature a "d=" value that matches the Author
Address, but no "i=".
3. Operation Overview 3. Operation Overview
Domain owners can publish ADSP information via a query mechanism such Domain owners publish ADSP information via a query mechanism such as
as the Domain Name System; specific details are given in Section 4.1. the Domain Name System; specific details are given in Section 4.1.
Hosts can look up the ADSP information of the domain(s) specified by Hosts can look up the ADSP information of the domain(s) specified by
the Author Address(es) as described in Section 4.3. If a message has the Author Address(es) as described in Section 4.3. If a message has
multiple Author Addresses the ADSP lookups SHOULD be performed multiple Author Addresses the ADSP lookups SHOULD be performed
independently on each address. This document does not address the independently on each address. This document does not address the
process a host might use to combine the lookup results. process a host might use to combine the lookup results.
3.1. ADSP Applicability 3.1. ADSP Applicability
ADSP as defined in this document is bound to DNS. For this reason, ADSP as defined in this document is bound to DNS. For this reason,
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scope of ADSP. scope of ADSP.
ADSP applies to specific domains, not domain subtrees. If, for ADSP applies to specific domains, not domain subtrees. If, for
example, an Author Address were user@domain.example, the Author example, an Author Address were user@domain.example, the Author
Domain would be domain.example, and the applicable ADSP record would Domain would be domain.example, and the applicable ADSP record would
be at _adsp._domainkey.domain.example. An Author Address in a be at _adsp._domainkey.domain.example. An Author Address in a
subdomain such as user@sub.domain.example would have a different ADSP subdomain such as user@sub.domain.example would have a different ADSP
record at _adsp._domainkey.sub.domain.example. ADSP makes no record at _adsp._domainkey.sub.domain.example. ADSP makes no
connection between a domain and its parent or child domains. connection between a domain and its parent or child domains.
Note: If an organization wants to publish Author Domain Signing
Practices for all the subdomains it uses, such as host names of
servers within the domain, it does so by creating ADSP records for
every _adsp._domainkey.<sub>.domain.example. Wildcards cannot be
used (see Section 6.3.); however, suitable DNS management tools
could automate creation of the ADSP records.
Note: The results from DNS queries that are intended to validate a Note: The results from DNS queries that are intended to validate a
domain name unavoidably approximate the set of Author Domains that domain name unavoidably approximate the set of Author Domains that
can appear in legitimate email. For example, a DNS A record could can appear in legitimate email. For example, a DNS A record could
belong to a device that does not even have an email belong to a device that does not even have an email
implementation. It is up to the checker to decide what degree of implementation. It is up to the checker to decide what degree of
approximation is acceptable. approximation is acceptable.
3.2. ADSP Usage 3.2. ADSP Usage
Depending on the Author Domain(s) and the signatures in a message, a Depending on the Author Domain(s) and the signatures in a message, a
recipient gets varying amounts of useful information from each ADSP recipient gets varying amounts of useful information from each ADSP
lookup. lookup.
o If a message has no Valid Signature, the ADSP result is directly o If a message has no Valid Signature, the ADSP result is directly
relevant to the message. relevant to the message.
o If a message has a Valid Signature from an Author Domain, ADSP o If a message has an Author Signature, ADSP provides no benefit
provides no benefit relative to that domain since the message is relative to that domain since the message is already known to be
already known to be compliant with any possible ADSP for that compliant with any possible ADSP for that domain.
domain.
o If a message has a Valid Signature from a domain other than an o If a message has a Valid Signature other than an Author Signature,
Author Domain, the receiver can use both the Signature and the the receiver can use both the Signature and the ADSP result in its
ADSP result in its evaluation of the message. evaluation of the message.
3.3. ADSP Results 3.3. ADSP Results
An ADSP lookup for an Author Address produces one of four possible An ADSP lookup for an Author Address produces one of four possible
results: results:
o Messages from this domain might or might not have an author o Messages from this domain might or might not have an author
signature. This is the default if the domain exists in the DNS signature. This is the default if the domain exists in the DNS
but no ADSP record is found. but no ADSP record is found.
o All messages from this domain are signed. o All messages from this domain are signed with an Author Signature.
o All messages from this domain are signed and discardable, i.e., if o All messages from this domain are signed with an Author Signature
a message arrives without a valid Author Signature, the domain and discardable, i.e., if a message arrives without a valid Author
encourages the recipient(s) to discard it. Signature, the domain encourages the recipient(s) to discard it.
o This domain is out of scope, i.e., the domain does not exist in o This domain is out of scope, i.e., the domain does not exist in
the DNS. the DNS.
An ADSP lookup could terminate without producing any result if a DNS An ADSP lookup could terminate without producing any result if a DNS
lookup results in a temporary failure. lookup results in a temporary failure.
4. Detailed Description 4. Detailed Description
4.1. DNS Representation 4.1. DNS Representation
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approximation is acceptable. The checker MUST return an approximation is acceptable. The checker MUST return an
appropriate error result for Author Domains that are outside the appropriate error result for Author Domains that are outside the
scope of ADSP. scope of ADSP.
The host MUST perform a DNS query for a record corresponding to The host MUST perform a DNS query for a record corresponding to
the Author Domain (with no prefix). The type of the query can be the Author Domain (with no prefix). The type of the query can be
of any type, since this step is only to determine if the domain of any type, since this step is only to determine if the domain
itself exists in DNS. This query MAY be done in parallel with the itself exists in DNS. This query MAY be done in parallel with the
query to fetch the named ADSP Record. If the result of this query query to fetch the named ADSP Record. If the result of this query
is that the Author domain does not exist in the DNS (often called is that the Author domain does not exist in the DNS (often called
an "NXDOMAIN" error, rcode=3 in [RFC1035]), the algorithm MUST an NXDOMAIN error, rcode=3 in [RFC1035]), the algorithm MUST
terminate with an error indicating that the domain is out of terminate with an error indicating that the domain is out of
scope. Note that a result with rcode=0 but no records (often scope. Note that a result with rcode=0 but no records (often
called "NODATA") is not the same as NXDOMAIN. called NODATA) is not the same as NXDOMAIN.
NON-NORMATIVE DISCUSSION: Any resource record type could be NON-NORMATIVE DISCUSSION: Any resource record type could be
used for this query since the existence of a resource record of used for this query since the existence of a resource record of
any type will prevent an "NXDOMAIN" error. MX is a reasonable any type will prevent an NXDOMAIN error. MX is a reasonable
choice for this purpose because this record type is thought to choice for this purpose because this record type is thought to
be the most common for domains used in e-mail, and will be the most common for domains used in e-mail, and will
therefore produce a result which can be more readily cached therefore produce a result which can be more readily cached
than a negative result. than a negative result.
If the domain does exist, the checker MAY make more extensive If the domain does exist, the checker MAY make more extensive
checks to verify the existence of the domain, such as the ones checks to verify the existence of the domain, such as the ones
described in Section 5 of [RFC5321]. If those checks indicate described in Section 5 of [RFC5321]. If those checks indicate
that the Author domain does not exist for mail, e.g., the domain that the Author domain does not exist for mail, e.g., the domain
has no MX, A, or AAAA record, the checker SHOULD terminate with an has no MX, A, or AAAA record, the checker SHOULD terminate with an
error indicating that the domain is out of scope. error indicating that the domain is out of scope.
Fetch Named ADSP Record: The host MUST query DNS for a TXT record Fetch Named ADSP Record: The host MUST query DNS for a TXT record
corresponding to the Author Domain prefixed by "_adsp._domainkey." corresponding to the Author Domain prefixed by "_adsp._domainkey."
(note the trailing dot). (note the trailing dot).
If the result of this query is a "NOERROR" response (rcode=0 in If the result of this query is a NOERROR response (rcode=0 in
[RFC1035]) with an answer which is a single record that is a valid [RFC1035]) with an answer which is a single record that is a valid
ADSP record, use that record, and the algorithm terminates. ADSP record, use that record, and the algorithm terminates.
If the result of the query is NXDOMAIN or NOERROR with zero If the result of the query is NXDOMAIN or NOERROR with zero
records, there is no ADSP record. If the result of the query records, there is no ADSP record. If the result of the query
contains more than one record, or a record that is not a valid contains more than one record, or a record that is not a valid
ADSP record, the ADSP result is undefined. ADSP record, the ADSP result is undefined.
If a query results in a "SERVFAIL" error response (rcode=2 in If a query results in a "SERVFAIL" error response (rcode=2 in
[RFC1035]), the algorithm terminates without returning a result; [RFC1035]), the algorithm terminates without returning a result;
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B.6. Non-email Domains B.6. Non-email Domains
If a domain sends no mail at all, it can safely publish a If a domain sends no mail at all, it can safely publish a
"discardable" ADSP record, since any mail with an author address in "discardable" ADSP record, since any mail with an author address in
the domain is a forgery. the domain is a forgery.
Appendix C. Acknowledgements Appendix C. Acknowledgements
This document greatly benefited from comments by Steve Atkins, Jon This document greatly benefited from comments by Steve Atkins, Jon
Callas, Dave Crocker, JD Falk, Arvel Hathcock, Ellen Siegel, Michael Callas, Dave Crocker, Pasi Eronen, JD Falk, Arvel Hathcock, Ellen
Thomas, and Wietse Venema. Siegel, Michael Thomas, and Wietse Venema.
Appendix D. Change Log Appendix D. Change Log
*NOTE TO RFC EDITOR: This section may be removed upon publication of *NOTE TO RFC EDITOR: This section may be removed upon publication of
this document as an RFC.* this document as an RFC.*
D.1. Changes since -ietf-dkim-07 D.1. Changes since -ietf-dkim-08
o Simplify and clarify interpretation of d= and i=.
o Add note pointing out that i= usage conflicts with normal usage,
and suggest workaround.
o Add note pointing out that you can mechanically add ADSP records
for all the subdomains you use.
o in Section 3.2 fix text to say that only an Author Signature
counts.
D.2. Changes since -ietf-dkim-07
Clarify that ADSP records use WSP rather than FWS in 4.1 and 4.2.1. Clarify that ADSP records use WSP rather than FWS in 4.1 and 4.2.1.
D.2. Changes since -ietf-dkim-06 D.3. Changes since -ietf-dkim-06
Minor editorial changes suggested by AD: Minor editorial changes suggested by AD:
o expand DKIM in title o expand DKIM in title
o clarify that there's no subdomain matching in Section 3.1 o clarify that there's no subdomain matching in Section 3.1
o ADSP lookup can terminate without a result if the DNS lookup fails o ADSP lookup can terminate without a result if the DNS lookup fails
o random dkim= values are treated as unknown o random dkim= values are treated as unknown
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o in 4.2 note WSP not FWS o in 4.2 note WSP not FWS
o in 4.3 note that NODATA is not NXDOMAIN o in 4.3 note that NODATA is not NXDOMAIN
o add new Appendix A with lookup examples o add new Appendix A with lookup examples
Also address Tony's nits in Also address Tony's nits in
http://mipassoc.org/pipermail/ietf-dkim/2008q3/010720.html. Make the http://mipassoc.org/pipermail/ietf-dkim/2008q3/010720.html. Make the
examples consistently use the .example domain. examples consistently use the .example domain.
D.3. Changes since -ietf-dkim-05 D.4. Changes since -ietf-dkim-05
Minor editorial nits: define NOERROR, SERVFAIL, NXDOMAIN as rfc1035 Minor editorial nits: define NOERROR, SERVFAIL, NXDOMAIN as rfc1035
rcodes, change some punctuation, IANA section change IETF Consensus rcodes, change some punctuation, IANA section change IETF Consensus
to the new IETF Review. to the new IETF Review.
D.4. Changes since -ietf-dkim-04 D.5. Changes since -ietf-dkim-04
o Require dkim at the front of each record. o Require dkim at the front of each record.
o Disparage wildcard records. o Disparage wildcard records.
o Changed ABNF use of whitespace from FWS back to WSP, dkim-base is o Changed ABNF use of whitespace from FWS back to WSP, dkim-base is
wrong. wrong.
o RFC 2434 -> 5226, make ref to 4686 informational since it's not o RFC 2434 -> 5226, make ref to 4686 informational since it's not
standards track. standards track.
o Improve examples with material from Ellen. o Improve examples with material from Ellen.
D.5. Changes since -ietf-dkim-03 D.6. Changes since -ietf-dkim-03
o Name change for title and filename, to be ADSP o Name change for title and filename, to be ADSP
o String changes throughout, to author Domain signing practices and o String changes throughout, to author Domain signing practices and
to aDsp. to aDsp.
o Added some keywords. o Added some keywords.
o Clarified comparison of local part and domain in Author Address. o Clarified comparison of local part and domain in Author Address.
skipping to change at page 19, line 5 skipping to change at page 19, line 34
o Revised wildcard text. o Revised wildcard text.
o Removed 't' tag. o Removed 't' tag.
o Removed ADSP Flags Registry section. o Removed ADSP Flags Registry section.
o Changed ABNF use of whitespace from WSP back to FWS, for o Changed ABNF use of whitespace from WSP back to FWS, for
consistency with dkim-base. consistency with dkim-base.
D.6. Changes since -ietf-dkim-02 D.7. Changes since -ietf-dkim-02
o Merge in more text from ADSP draft. o Merge in more text from ADSP draft.
o Phrase actions as host's rather than checker. o Phrase actions as host's rather than checker.
o Explanatory description of i= matching. o Explanatory description of i= matching.
o Lookup procedure consistently refers to one ADSP record per o Lookup procedure consistently refers to one ADSP record per
lookup. lookup.
skipping to change at page 19, line 27 skipping to change at page 20, line 9
o Simplify imports of terms from other RFCs, add Local-part, 4234 -> o Simplify imports of terms from other RFCs, add Local-part, 4234 ->
5234. 5234.
o Add usage example appendix. o Add usage example appendix.
o Add IANA considerations. o Add IANA considerations.
o Update authors list o Update authors list
D.7. Changes since -ietf-dkim-ssp-01 D.8. Changes since -ietf-dkim-ssp-01
o Reworded introduction for clarity. o Reworded introduction for clarity.
o Various definition clarifications. o Various definition clarifications.
o Changed names of practices to unknown, all, and discardable. o Changed names of practices to unknown, all, and discardable.
o Removed normative language mandating use of SSP in particular o Removed normative language mandating use of SSP in particular
situations (issue 1538). situations (issue 1538).
skipping to change at page 20, line 27 skipping to change at page 21, line 10
o Introduced the concepts of "SSP Checker" and "Evaluator". o Introduced the concepts of "SSP Checker" and "Evaluator".
o Multiple author case now handled my separate invocations of SSP o Multiple author case now handled my separate invocations of SSP
checker by Evaluator (issue 1525). checker by Evaluator (issue 1525).
o Removed check to avoid querying top-level domains. o Removed check to avoid querying top-level domains.
o Changed ABNF use of whitespace from [FWS] to *WSP (partially o Changed ABNF use of whitespace from [FWS] to *WSP (partially
addresses issue 1543). addresses issue 1543).
D.8. Changes since -ietf-dkim-ssp-00 D.9. Changes since -ietf-dkim-ssp-00
o Clarified Operation Overview and eliminated use of Legitimate as o Clarified Operation Overview and eliminated use of Legitimate as
the counterpart of Suspicious since the words have different the counterpart of Suspicious since the words have different
meanings. meanings.
o Improved discussion (courtesy of Arvel Hathcock) of the use of TXT o Improved discussion (courtesy of Arvel Hathcock) of the use of TXT
records in DNS vs. a new RR type. records in DNS vs. a new RR type.
o Clarified publication rules for multilevel names. o Clarified publication rules for multilevel names.
skipping to change at page 21, line 9 skipping to change at page 21, line 39
o Added "handling" tag to express alleged sending domain's o Added "handling" tag to express alleged sending domain's
preference about handling of Suspicious messages. preference about handling of Suspicious messages.
o Clarified handling of SERVFAIL error in SSP check. o Clarified handling of SERVFAIL error in SSP check.
o Replaced "entity" with "domain", since with the removal of user- o Replaced "entity" with "domain", since with the removal of user-
granularity SSP, the only entities having sender signing policies granularity SSP, the only entities having sender signing policies
are domains. are domains.
D.9. Changes since -allman-ssp-02 D.10. Changes since -allman-ssp-02
o Removed user-granularity SSP and u= tag. o Removed user-granularity SSP and u= tag.
o Replaced DKIMP resource record with a TXT record. o Replaced DKIMP resource record with a TXT record.
o Changed name of the primary tag from "p" to "dkim". o Changed name of the primary tag from "p" to "dkim".
o Replaced lookup algorithm with one which traverses upward at most o Replaced lookup algorithm with one which traverses upward at most
one level. one level.
o Added description of records to be published, and effect of o Added description of records to be published, and effect of
wildcard records within the domain, on SSP. wildcard records within the domain, on SSP.
D.10. Changes since -allman-ssp-01 D.11. Changes since -allman-ssp-01
o Changed term "Sender Signing Policy" to "Sender Signing o Changed term "Sender Signing Policy" to "Sender Signing
Practices". Practices".
o Changed query methodology to use a separate DNS resource record o Changed query methodology to use a separate DNS resource record
type, DKIMP. type, DKIMP.
o Changed tag values from SPF-like symbols to words. o Changed tag values from SPF-like symbols to words.
o User level policies now default to that of the domain if not o User level policies now default to that of the domain if not
specified. specified.
o Removed the "Compliance" section since we're still not clear on o Removed the "Compliance" section since we're still not clear on
what goes here. what goes here.
o Changed the "parent domain" policy to only search up one level o Changed the "parent domain" policy to only search up one level
(assumes that subdomains will publish SSP records if appropriate). (assumes that subdomains will publish SSP records if appropriate).
o Added detailed description of SSP check procedure. o Added detailed description of SSP check procedure.
D.11. Changes since -allman-ssp-00 D.12. Changes since -allman-ssp-00
From a "diff" perspective, the changes are extensive. Semantically, From a "diff" perspective, the changes are extensive. Semantically,
the changes are: the changes are:
o Added section on "Third-Party Signatures and Mailing Lists" o Added section on "Third-Party Signatures and Mailing Lists"
o Added "Compliance" (transferred from -base document). I'm not o Added "Compliance" (transferred from -base document). I'm not
clear on what needs to be done here. clear on what needs to be done here.
o Extensive restructuring. o Extensive restructuring.
skipping to change at page 23, line 4 skipping to change at line 1021
Email: markd+dkim@yahoo-inc.com Email: markd+dkim@yahoo-inc.com
John Levine John Levine
Taughannock Networks Taughannock Networks
PO Box 727 PO Box 727
Trumansburg, NY 14886 Trumansburg, NY 14886
Phone: +1 831 480 2300 Phone: +1 831 480 2300
Email: standards@taugh.com Email: standards@taugh.com
URI: http://www.taugh.com URI: http://www.taugh.com
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