draft-josefsson-dns-url-11.txt   draft-josefsson-dns-url-12.txt 
Network Working Group S. Josefsson Network Working Group S. Josefsson
Expires: August 11, 2005 Expires: November 26, 2005
Domain Name System Uniform Resource Identifiers Domain Name System Uniform Resource Identifiers
draft-josefsson-dns-url-11 draft-josefsson-dns-url-12
Status of this Memo Status of this Memo
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RFC 3668.
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Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2005). Copyright (C) The Internet Society (2005).
Abstract Abstract
This document define Uniform Resource Identifiers for Domain Name This document define Uniform Resource Identifiers for Domain Name
System resources. System resources.
See <http://josefsson.org/dns-url/> for more information.
Table of Contents Table of Contents
1. Introduction and Background . . . . . . . . . . . . . . . . . 3 1. Introduction and Background . . . . . . . . . . . . . . . . . 3
2. Usage Model . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Usage Model . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. DNS URI Registration . . . . . . . . . . . . . . . . . . . . . 5 3. DNS URI Registration . . . . . . . . . . . . . . . . . . . . . 5
4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8. Copying conditions . . . . . . . . . . . . . . . . . . . . . . 10 8. Copying conditions . . . . . . . . . . . . . . . . . . . . . . 10
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
9.1 Normative References . . . . . . . . . . . . . . . . . . . . 10 9.1 Normative References . . . . . . . . . . . . . . . . . . . 10
9.2 Informative References . . . . . . . . . . . . . . . . . . . 10 9.2 Informative References . . . . . . . . . . . . . . . . . . 10
Author's Address . . . . . . . . . . . . . . . . . . . . . . . 11 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 11
A. Revision Changes . . . . . . . . . . . . . . . . . . . . . . . 11 A. Revision Changes . . . . . . . . . . . . . . . . . . . . . . . 11
A.1 Changes since -06 . . . . . . . . . . . . . . . . . . . . 11 A.1 Changes since -06 . . . . . . . . . . . . . . . . . . . . 11
A.2 Changes since -07 . . . . . . . . . . . . . . . . . . . . 11 A.2 Changes since -07 . . . . . . . . . . . . . . . . . . . . 12
A.3 Changes since -08 . . . . . . . . . . . . . . . . . . . . 12 A.3 Changes since -08 . . . . . . . . . . . . . . . . . . . . 12
A.4 Changes since -09 . . . . . . . . . . . . . . . . . . . . 12 A.4 Changes since -09 . . . . . . . . . . . . . . . . . . . . 12
A.5 Changes since -10 . . . . . . . . . . . . . . . . . . . . 12 A.5 Changes since -10 . . . . . . . . . . . . . . . . . . . . 12
A.6 Changes since -11 . . . . . . . . . . . . . . . . . . . . 12
Intellectual Property and Copyright Statements . . . . . . . . 13 Intellectual Property and Copyright Statements . . . . . . . . 13
1. Introduction and Background 1. Introduction and Background
The Domain Name System (DNS) [1][2] is a widely deployed system used The Domain Name System (DNS) [1][2] is a widely deployed system used
to, among other things, translate host names into IP addresses. to, among other things, translate host names into IP addresses.
Recent work has added support for storing certificates and Recent work has added support for storing certificates and
certificate revocation lists (CRLs) in the DNS [9]. Several certificate revocation lists (CRLs) in the DNS [9]. Several
protocols use Uniform Resource Locators (URLs) to point at protocols use Uniform Resource Locators (URLs) to point at
certificates and CRLs. By defining a Uniform Resource Identifier certificates and CRLs. By defining a Uniform Resource Identifier
(URI) scheme for DNS resources, such protocols can reference (URI) scheme for DNS resources, such protocols can reference
certificates and CRLs stored in the DNS. certificates and CRLs stored in the DNS.
A few examples of protocols that may utilize DNS URIs: Two examples of data structures that may embed DNS URIs:
o The OpenPGP Message Format [7], where an end-user may indicate the o The OpenPGP Message Format [7], where an end-user may indicate the
location of a copy of any updates to her key, using the "preferred location of a copy of any updates to her key, using the "preferred
key server" field. key server" field.
o The X.509 Online Certificate Status Protocol [10], where the OCSP o The Internet X.509 Public Key Infrastructure [14] format, where
responder can indicate where a CRL is found, using the the issuer may use a DNS URI in a CRL Distribution Point
id-pkix-ocsp-crl extension. certificate extension field.
The DNS URI scheme defined here can be used to reference any data The DNS URI scheme defined here can be used to reference any data
stored in the DNS, and is not limited to certificates or CRLs. The stored in the DNS, and is not limited to certificates or CRLs. The
purpose of this specification is to define a generic DNS URI, not to purpose of this specification is to define a generic DNS URI, not to
specify a solution only for certificates stored in the DNS. specify a solution only for certificates stored in the DNS.
Data browsers may support DNS URIs by forming DNS queries and render Data browsers may support DNS URIs by forming DNS queries and render
DNS responses using HTML [13], similar to what is commonly done for DNS responses using HTML [13], similar to what is commonly done for
FTP [5] resources. FTP [6] resources.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [6]. document are to be interpreted as described in RFC 2119 [3].
2. Usage Model 2. Usage Model
The reader is referred to section 1 of [4] for an in-depth discussion The reader is referred to section 1 of [5] for an in-depth discussion
of URI classifications. In particular, the reader is assumed to be of URI classifications. In particular, the reader is assumed to be
familiar with the "name" vs "locator" distinction. This section familiar with the "name" vs "locator" distinction. This section
describe how the DNS URI scheme is intended to be used, and outline describe how the DNS URI scheme is intended to be used, and outline
future work that may be required to use URIs with the DNS for some future work that may be required to use URIs with the DNS for some
applications. applications.
The URI scheme described in this document focus on the data stored in The URI scheme described in this document focus on the data stored in
the DNS. As such, there is no provision to specify any of the fields the DNS. As such, there is no provision to specify any of the fields
in the actual DNS protocol. This is intentional, so that the URI may in the actual DNS protocol. This is intentional, so that the URI may
be used even in situations where the DNS protocol is not used be used even in situations where the DNS protocol is not used
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3. DNS URI Registration 3. DNS URI Registration
The section contain the registration template for the DNS URI scheme The section contain the registration template for the DNS URI scheme
in accordance with [12]. in accordance with [12].
URL scheme name: "dns". URL scheme name: "dns".
URL scheme syntax: A DNS URI designate a DNS resource record set, URL scheme syntax: A DNS URI designate a DNS resource record set,
referenced by domain name, class, type and optionally the authority. referenced by domain name, class, type and optionally the authority.
The DNS URI follows the generic syntax from RFC 3986 [4], and is The DNS URI follows the generic syntax from RFC 3986 [5], and is
described using ABNF [3]. Strings are not case sensitive and free described using ABNF [4]. Strings are not case sensitive and free
insertion of linear-white-space is not permitted. insertion of linear-white-space is not permitted.
dnsurl = "dns:" [ "//" dnsauthority "/" ] dnsurl = "dns:" [ "//" dnsauthority "/" ]
dnsname ["?" dnsquery] dnsname ["?" dnsquery]
dnsauthority = host [ ":" port ] dnsauthority = host [ ":" port ]
; See RFC 3986 for the ; See RFC 3986 for the
; definition of "host" and "port". ; definition of "host" and "port".
dnsname = *pchar dnsname = *pchar
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; "dnsname" value is to be ; "dnsname" value is to be
; interpreted as the root itself. ; interpreted as the root itself.
; See below on relative dnsname's. ; See below on relative dnsname's.
dnsquery = dnsqueryelement [";" dnsquery] dnsquery = dnsqueryelement [";" dnsquery]
dnsqueryelement = ( "CLASS=" dnsclassval ) / ( "TYPE=" dnstypeval ) dnsqueryelement = ( "CLASS=" dnsclassval ) / ( "TYPE=" dnstypeval )
; Each clause MUST NOT be used more ; Each clause MUST NOT be used more
; than once. ; than once.
dnsclassval = 1*digit / "IN" / "CH" / ... dnsclassval = 1*digit / "IN" / "CH" /
; Any IANA registered DNS class <Any IANA registered DNS class mnemonic>
; expressed as mnemonic or as
; decimal integer.
dnstypeval = 1*digit / "A" / "NS" / "MD" / ... dnstypeval = 1*digit / "A" / "NS" / "MD" /
; Any IANA registered DNS type <Any IANA registered DNS type mnemonic>
; expressed as mnemonic or as
; decimal integer.
Unless specified in the URI, the authority ("dnsauthority") is Unless specified in the URI, the authority ("dnsauthority") is
assumed to be locally known, the class ("dnsclassval") to be the assumed to be locally known, the class ("dnsclassval") to be the
Internet class ("IN"), and the type ("dnstypeval") to be the Address Internet class ("IN"), and the type ("dnstypeval") to be the Address
type ("A"). These default values match the typical use of DNS; to type ("A"). These default values match the typical use of DNS; to
look up addresses for host names. look up addresses for host names.
A dnsquery element MUST NOT contain more than one occurance of the A dnsquery element MUST NOT contain more than one occurance of the
"CLASS" and "TYPE" fields. For example, both "CLASS" and "TYPE" fields. For example, both "dns:
"dns:example?TYPE=A;TYPE=TXT" and "dns:example?TYPE=A;TYPE=A" are example?TYPE=A;TYPE=TXT" and "dns:example?TYPE=A;TYPE=A" are invalid.
invalid. However, the fields may occur in any order, so that both However, the fields may occur in any order, so that both "dns:
"dns:example?TYPE=A;CLASS=IN" and "dns:example?CLASS=IN;TYPE=A" are example?TYPE=A;CLASS=IN" and "dns:example?CLASS=IN;TYPE=A" are valid.
valid.
The digit representation of types and classes MAY be used when a The digit representation of types and classes MAY be used when a
mnemonic for the corresponding value is not well known (e.g., for mnemonic for the corresponding value is not well known (e.g., for
newly introduced types or classes), but SHOULD NOT be used for the newly introduced types or classes), but SHOULD NOT be used for the
types or classes defined in the DNS specification [2]. All types or classes defined in the DNS specification [2]. All
implementations MUST recognize the mnemonics defined in [2]. implementations MUST recognize the mnemonics defined in [2].
To avoid ambiguity, relative "dnsname" values (i.e., those not ending To avoid ambiguity, relative "dnsname" values (i.e., those not ending
with ".") are assumed to be relative to the root. For example, with ".") are assumed to be relative to the root. For example, "dns:
"dns:host.example" and "dns:host.example." both refer to the same host.example" and "dns:host.example." both refer to the same owner
owner name, namely "host.example.". Further, an empty "dnsname" name, namely "host.example.". Further, an empty "dnsname" value is
value is considered to be a degenerative form of a relative name, considered to be a degenerative form of a relative name, which refer
which refer to the root ("."). to the root (".").
To resolve a DNS URI using the DNS protocol [2] a query is created, To resolve a DNS URI using the DNS protocol [2] a query is created,
using as input the dnsname, dnsclassval and dnstypeval from the URI using as input the dnsname, dnsclassval and dnstypeval from the URI
string (or the appropriate default values). If an authority string (or the appropriate default values). If an authority
("dnsauthority") is given in the URI string, this indicate the server ("dnsauthority") is given in the URI string, this indicate the server
that should receive the DNS query, otherwise the default DNS server that should receive the DNS query, otherwise the default DNS server
should receive it. should receive it.
Note that DNS URIs could be resolved by other protocols than the DNS Note that DNS URIs could be resolved by other protocols than the DNS
protocol, or by using the DNS protocol in some other way than as protocol, or by using the DNS protocol in some other way than as
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usage. The previous paragraph only illustrate how DNS URIs are usage. The previous paragraph only illustrate how DNS URIs are
resolved using the DNS protocol. resolved using the DNS protocol.
A client MAY want to check that it understands the dnsclassval and A client MAY want to check that it understands the dnsclassval and
dnstypeval before sending a query, so that it will be able to dnstypeval before sending a query, so that it will be able to
understand the response. However, a typical example of a client that understand the response. However, a typical example of a client that
would not need to check dnsclassval and dnstypeval would be a proxy, would not need to check dnsclassval and dnstypeval would be a proxy,
that would just treat the received answer as opaque data. that would just treat the received answer as opaque data.
Character encoding considerations: The characters are encoded as per Character encoding considerations: The characters are encoded as per
RFC 3986 [4]. The DNS protocol do not consider character sets, it RFC 3986 [5]. The DNS protocol do not consider character sets, it
simply transports opaque data. In particular, the "dnsname" field of simply transports opaque data. In particular, the "dnsname" field of
the DNS URI is to be considered an internationalized domain name the DNS URI is to be considered an internationalized domain name
(IDN) unaware domain name slot, in the terminology of [15]. The (IDN) unaware domain name slot, in the terminology of [16]. The
considerations for "host" and "port" are discussed in [4] considerations for "host" and "port" are discussed in [5]
Because "." is used as the DNS label separator, an escaping mechanism Because "." is used as the DNS label separator, an escaping mechanism
is required to encode a "." that is part of a DNS label. The is required to encode a "." that is part of a DNS label. The
escaping mechanism is described in section 5.1 of RFC 1035. For escaping mechanism is described in section 5.1 of RFC 1035. For
example, a DNS label of "exa.mple" can be escaped as "exa\.mple" or example, a DNS label of "exa.mple" can be escaped as "exa\.mple" or
"exa\046mple". However, the URI specification disallow the "\" "exa\046mple". However, the URI specification disallow the "\"
character from occuring directly in URIs, so it must be escaped as character from occuring directly in URIs, so it must be escaped as
"%5c". The single DNS label "exa.mple" is thus encoded as "%5c". The single DNS label "exa.mple" is thus encoded as "exa%
"exa%5c.mple". The same mechanism can be used to encode other 5c.mple". The same mechanism can be used to encode other characters,
characters, for example "?" and ";". Note that "." and "%2e" are for example "?" and ";". Note that "." and "%2e" are equivalent
equivalent within dnsname, and are interchangable. within dnsname, and are interchangable.
This URI specification allows all possible domain names to be encoded This URI specification allows all possible domain names to be encoded
(of course following the encoding rules of [4]), however certain (of course following the encoding rules of [5]), however certain
applications may restrict the set of valid characters. Care should applications may restrict the set of valid characters. Care should
be taken so that invalid characters in these contexts does not cause be taken so that invalid characters in these contexts does not cause
harm. In particular, host names in the DNS have certain harm. In particular, host names in the DNS have certain
restrictions. It is up to these application to limit this subset, restrictions. It is up to these application to limit this subset,
this URI scheme places no restrictions. this URI scheme places no restrictions.
Intended usage: Whenever DNS resources are useful to reference by Intended usage: Whenever DNS resources are useful to reference by
protocol independent identifiers, often when the data is more protocol independent identifiers, often when the data is more
important than the access method. Since software in general has important than the access method. Since software in general has
coped without this so far, it is not anticipated to be implemented coped without this so far, it is not anticipated to be implemented
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The following illustrate a URI for a resource with the name The following illustrate a URI for a resource with the name
"ftp.example.org", in the Internet (IN) class and the address (A) "ftp.example.org", in the Internet (IN) class and the address (A)
type, but from the DNS authority 192.168.1.1 instead of the default type, but from the DNS authority 192.168.1.1 instead of the default
authority: authority:
dns://192.168.1.1/ftp.example.org?type=A dns://192.168.1.1/ftp.example.org?type=A
The following illustrate various escaping techniques. The owner name The following illustrate various escaping techniques. The owner name
would be "world wide web.example\.domain.org" where "\." denote the would be "world wide web.example\.domain.org" where "\." denote the
character "." as part of a label, and "." denote the label character "." as part of a label, and "." denote the label separator:
separator:
dns:world%20wide%20web.example%5c.domain.example?TYPE=TXT dns:world%20wide%20web.example%5c.domain.example?TYPE=TXT
The following illustrate a strange, but valid, DNS resource: The following illustrate a strange, but valid, DNS resource:
dns://fw.example.org/*.%20%00.example?type=TXT dns://fw.example.org/*.%20%00.example?type=TXT
5. Acknowledgments 5. Acknowledgments
Thanks to Stuart Cheshire, Donald Eastlake, Pasi Eronen, Ted Hardie, Thanks to Stuart Cheshire, Donald Eastlake, Pasi Eronen, Bill Fenner,
Peter Koch, Andrew Main, Larry Masinter, Michael Mealling, Steve Ted Hardie, Russ Housley, Peter Koch, Andrew Main, Larry Masinter,
Mattson, and Paul Vixie for comments and suggestions. The author Michael Mealling, Steve Mattson, Paul Vixie, Sam Weiler, and Bert
acknowledges the RSA Laboratories for supporting the work that led to Wijnen for comments and suggestions. The author acknowledges the RSA
this document. Laboratories for supporting the work that led to this document.
6. Security Considerations 6. Security Considerations
If a DNS URI references domains in the Internet DNS environment, both If a DNS URI references domains in the Internet DNS environment, both
the URI itself and the information referenced by the URI is public the URI itself and the information referenced by the URI is public
information. If a DNS URI is used within an "internal" DNS information. If a DNS URI is used within an "internal" DNS
environment, both the DNS URI and the data is referenced should be environment, both the DNS URI and the data is referenced should be
handled using the same considerations that apply to DNS data in the handled using the same considerations that apply to DNS data in the
environment. environment.
If information referenced by DNS URIs are used to make security If information referenced by DNS URIs are used to make security
decisions (examples of such data include, but is not limited to, decisions (examples of such data include, but is not limited to,
certificates stored in the DNS), implementations may need to employ certificates stored in the DNS), implementations may need to employ
security techniques such as Secure DNS [8], or even CMS [14] or security techniques such as Secure DNS [8], or even CMS [15] or
OpenPGP [7], to protect the data during transport. How to implement OpenPGP [7], to protect the data during transport. How to implement
this will depend on the usage scenario, and it is not up to this URI this will depend on the usage scenario, and it is not up to this URI
scheme to define how the data referenced by DNS URIs should be scheme to define how the data referenced by DNS URIs should be
protected. protected.
If applications accept unknown dnsqueryelement values (e.g., accepts If applications accept unknown dnsqueryelement values (e.g., accepts
the URI "dns:www.example.org?secret=value" without knowing what the the URI "dns:www.example.org?secret=value" without knowing what the
"secret=value" dnsqueryelement means), a covert channel used to "secret=value" dnsqueryelement means), a covert channel used to
"leak" information may be enabled. The implications of covert "leak" information may be enabled. The implications of covert
channels should be understood by applications that accepts unknown channels should be understood by applications that accepts unknown
dnsqueryelement values. dnsqueryelement values.
Slight variations, such as difference between upper and lower case in Slight variations, such as difference between upper and lower case in
the dnsname field, can be used as a covert channel to leak the dnsname field, can be used as a covert channel to leak
information. information.
7. IANA Considerations 7. IANA Considerations
The IANA is asked to register the DNS URI scheme, using the template The IANA is asked to register the DNS URI scheme, using the template
in section 2, in accordance with RFC 2717 [12]. in section 3, in accordance with RFC 2717 [12].
8. Copying conditions 8. Copying conditions
Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005 Simon Josefsson
Regarding this entire document or any portion of it, the author makes Regarding this entire document or any portion of it, the author makes
no guarantees and is not responsible for any damage resulting from no guarantees and is not responsible for any damage resulting from
its use. The author grants irrevocable permission to anyone to use, its use. The author grants irrevocable permission to anyone to use,
modify, and distribute it in any way that does not diminish the modify, and distribute it in any way that does not diminish the
rights of anyone else to use, modify, and distribute it, provided rights of anyone else to use, modify, and distribute it, provided
that redistributed derivative works do not contain misleading author that redistributed derivative works do not contain misleading author
or version information. Derivative works need not be licensed under or version information. Derivative works need not be licensed under
similar terms. similar terms.
9. References 9. References
9.1 Normative References 9.1 Normative References
[1] Mockapetris, P., "Domain names - concepts and facilities", STD [1] Mockapetris, P., "Domain names - concepts and facilities",
13, RFC 1034, November 1987. STD 13, RFC 1034, November 1987.
[2] Mockapetris, P., "Domain names - implementation and [2] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987. specification", STD 13, RFC 1035, November 1987.
[3] Crocker, D. and P. Overell, "Augmented BNF for Syntax [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[4] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997. Specifications: ABNF", RFC 2234, November 1997.
[4] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource [5] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Identifier (URI): Generic Syntax", STD 66, RFC 3986, January Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986,
2005. January 2005.
9.2 Informative References 9.2 Informative References
[5] Postel, J. and J. Reynolds, "File Transfer Protocol", STD 9, [6] Postel, J. and J. Reynolds, "File Transfer Protocol", STD 9,
RFC 959, October 1985. RFC 959, October 1985.
[6] Bradner, S., "Key words for use in RFCs to Indicate Requirement [7] Callas, J., Donnerhacke, L., Finney, H., and R. Thayer,
Levels", BCP 14, RFC 2119, March 1997. "OpenPGP Message Format", RFC 2440, November 1998.
[7] Callas, J., Donnerhacke, L., Finney, H. and R. Thayer, "OpenPGP
Message Format", RFC 2440, November 1998.
[8] Eastlake, D., "Domain Name System Security Extensions", RFC [8] Eastlake, D., "Domain Name System Security Extensions",
2535, March 1999. RFC 2535, March 1999.
[9] Eastlake, D. and O. Gudmundsson, "Storing Certificates in the [9] Eastlake, D. and O. Gudmundsson, "Storing Certificates in the
Domain Name System (DNS)", RFC 2538, March 1999. Domain Name System (DNS)", RFC 2538, March 1999.
[10] Myers, M., Ankney, R., Malpani, A., Galperin, S. and C. Adams, [10] Myers, M., Ankney, R., Malpani, A., Galperin, S., and C. Adams,
"X.509 Internet Public Key Infrastructure Online Certificate "X.509 Internet Public Key Infrastructure Online Certificate
Status Protocol - OCSP", RFC 2560, June 1999. Status Protocol - OCSP", RFC 2560, June 1999.
[11] Crawford, M., "Binary Labels in the Domain Name System", RFC [11] Crawford, M., "Binary Labels in the Domain Name System",
2673, August 1999. RFC 2673, August 1999.
[12] Petke, R. and I. King, "Registration Procedures for URL Scheme [12] Petke, R. and I. King, "Registration Procedures for URL Scheme
Names", BCP 35, RFC 2717, November 1999. Names", BCP 35, RFC 2717, November 1999.
[13] Connolly, D. and L. Masinter, "The 'text/html' Media Type", RFC [13] Connolly, D. and L. Masinter, "The 'text/html' Media Type",
2854, June 2000. RFC 2854, June 2000.
[14] Housley, R., "Cryptographic Message Syntax (CMS)", RFC 3369, [14] Housley, R., Polk, W., Ford, W., and D. Solo, "Internet X.509
Public Key Infrastructure Certificate and Certificate
Revocation List (CRL) Profile", RFC 3280, April 2002.
[15] Housley, R., "Cryptographic Message Syntax (CMS)", RFC 3369,
August 2002. August 2002.
[15] Faltstrom, P., Hoffman, P. and A. Costello, "Internationalizing [16] Faltstrom, P., Hoffman, P., and A. Costello,
Domain Names in Applications (IDNA)", RFC 3490, March 2003. "Internationalizing Domain Names in Applications (IDNA)",
RFC 3490, March 2003.
[16] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD [17] Yergeau, F., "UTF-8, a transformation format of ISO 10646",
63, RFC 3629, November 2003. STD 63, RFC 3629, November 2003.
Author's Address Author's Address
Simon Josefsson Simon Josefsson
EMail: [email protected] Email: [email protected]
Appendix A. Revision Changes Appendix A. Revision Changes
Note to RFC editor: Remove this appendix before publication. Note to RFC editor: Remove this appendix before publication.
A.1 Changes since -06 A.1 Changes since -06
The MIME registration templates for text/dns and application/dns was The MIME registration templates for text/dns and application/dns was
removed, and will be defined in separate documents. removed, and will be defined in separate documents.
skipping to change at page 13, line 5 skipping to change at page 12, line 44
dnsname field is made a IDN unaware domain name slot. Use standard dnsname field is made a IDN unaware domain name slot. Use standard
DNS escaping (i.e, "\." for ".") instead of broken approach that DNS escaping (i.e, "\." for ".") instead of broken approach that
violated the URI specification. Improve examples. Add security violated the URI specification. Improve examples. Add security
considerations. considerations.
A.5 Changes since -10 A.5 Changes since -10
Add section "Usage Model". Move acknowledgements, as per rfc2223bis. Add section "Usage Model". Move acknowledgements, as per rfc2223bis.
Add permissive copying condition. Updates to align with RFC 3986. Add permissive copying condition. Updates to align with RFC 3986.
A.6 Changes since -11
Fix typos. IESG feedback: Move RFC2119 reference to normative
section. Replace OCSP example with X.509 CRL Distribution Point
extension. Fix ABNF not to use "...".
Intellectual Property Statement Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
 End of changes. 

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