One document matched: draft-snell-atompub-link-extensions-04.xml
<?xml version='1.0'?>
<!DOCTYPE rfc SYSTEM "rfc2629.dtd" [
<!ENTITY rfc2616 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2616.xml'>
<!ENTITY rfc1864 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.1864.xml'>
<!ENTITY rfc2119 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml'>
<!ENTITY rfc4287 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4287.xml'>
<!ENTITY rfc3339 PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml/reference.RFC.3339.xml'>
<!ENTITY xmlnames PUBLIC ''
'http://xml.resource.org/public/rfc/bibxml4/reference.W3C.REC-xml-names-19990114.xml'>
]>
<?rfc compact="yes" ?>
<?rfc toc="yes" ?>
<?rfc symrefs="yes" ?>
<?rfc sortrefs="yes"?>
<?rfc iprnotified="no" ?>
<?rfc strict="yes" ?>
<rfc category="info" ipr="trust200811" updates="4287" docName="draft-snell-atompub-link-extensions-04.txt">
<front>
<title abbrev="Atom Link Extensions">Atom Link Extensions</title>
<author initials="J.M." surname="Snell" fullname="James M Snell">
<organization></organization>
<address>
<postal>
<street></street>
<city></city> <region></region> <code></code>
<country></country>
</postal>
<phone></phone>
<email>jasnell@us.ibm.com</email>
<uri>http://ibm.com</uri>
</address>
</author>
<date month="May" year="2010" />
<area>General</area>
<keyword>I-D</keyword>
<keyword>Internet-Draft</keyword>
<keyword>XML</keyword>
<keyword>Extensible Markup Language</keyword>
<keyword>Atom</keyword>
<keyword>RSS</keyword>
<keyword>Syndication</keyword>
<abstract><t>This specification adds additional attributes to the Atom
Syndication Format link and content elements that may be used to express
additional metadata about linked resources.</t></abstract>
</front>
<middle>
<section title="Introduction">
<t>This specification adds additional attribute to the Atom Syndication Format
<xref target="RFC4287" /> link and content elements that may be used to express
additional metadata about linked resources.</t>
</section>
<section title="Notational Conventions">
<t>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 BCP 14, <xref target="RFC2119" /></t>
<t>This specification uses XML Namespaces <xref target="W3C.REC-xml-names-19990114"/>
to uniquely identify XML element names. It uses the following namespace prefix
for the indicated namespace URI;</t>
<figure><artwork><![CDATA[
"atom": "http://www.w3.org/2005/Atom"
]]></artwork></figure>
</section>
<section title="Hash Attributes">
<section title="Computing Hash Digests">
<t>When the resource referenced by atom:link or atom:content elements is
retrievable using HTTP, hash digest values are computed by first performing
an HTTP GET request on the URL specified by the @href or @src attributes,
extracting the returned entity-body, then following the steps specified in
Section 14.15 of <xref target="RFC2616" />.</t>
<t>It should be noted, however, that there are a variety of factors that
influence whether the entity-body returned by the HTTP GET will yield a
hash digest value matching that specified by a hash attribute contained
by the atom:link or atom:content elements. Accordingly, hash attribute
values MUST be considered to be strictly advisory and cannot be used
reliably as an end-to-end integrity check.</t>
</section>
<section title="The 'md5' attribute">
<t>The 'md5' Attribute specifies a MD5 digest <xref target="RFC1864" />
of the resource identified by the atom:link/@href or atom:content/@src attributes.
The value is represented as a sequence of 32 hexadecimal digits.
The 'md5' attribute MAY appear as a child of the atom:link and atom:content
elements.</t>
<figure><artwork><![CDATA[
md5 = attribute md5 { md5-digest }
md5-digest = <hex of 128 bit MD5 digest as per RFC 1864>
]]></artwork></figure>
<t>An example MD5 digest of an enclosed MP3 file:</t>
<figure><artwork><![CDATA[
<atom:link rel="enclosure"
href="http://example.org/media/myfile.mp3"
md5="9e107d9d372bb6826bd81d3542a419d6" />
]]></artwork></figure>
</section>
<section title="The 'sha1' attribute">
<t>The 'sha1' Attribute specifies a SHA-1 digest
of the resource identified by the atom:link/@href or atom:content/@src attributes.
The value is represented as a sequence of 40 hexadecimal digits.
The 'sha1' attribute MAY appear as a child of the atom:link and atom:content
elements.</t>
<figure><artwork><![CDATA[
sha1 = attribute sha1 { sha1-digest }
sha1-digest = <hex of 180 bit SHA-1 digest>
]]></artwork></figure>
<t>An example SHA-1 digest of an enclosed MP3 file:</t>
<figure><artwork><![CDATA[
<atom:link rel="enclosure"
href="http://example.org/media/myfile.mp3"
sha1="2fd4e1c67a2d28fced849ee1bb76e7391b93eb12" />
]]></artwork></figure>
</section>
<section title="The 'sha224' attribute">
<t>The 'sha224' Attribute specifies a SHA-224 digest
of the resource identified by the atom:link/@href or atom:content/@src attributes.
The value is represented as a sequence of 56 hexadecimal digits.
The 'sha224' attribute MAY appear as a child of the atom:link and atom:content
elements.</t>
<figure><artwork><![CDATA[
sha224 = attribute sha224 { sha1-digest }
sha224-digest = <hex of 224 bit SHA-224 digest>
]]></artwork></figure>
<t>An example SHA-224 digest of an enclosed MP3 file:</t>
<figure><artwork><![CDATA[
<atom:link rel="enclosure"
href="http://example.org/media/myfile.mp3"
sha224="2f01b49601d93134b1b75e5046e53aff25ac29119b4465f02814aa15" />
]]></artwork></figure>
</section>
<section title="The 'sha256' attribute">
<t>The 'sha256' Attribute specifies a SHA-256 digest
of the resource identified by the atom:link/@href or atom:content/@src attributes.
The value is represented as a sequence of 64 hexadecimal digits.
The 'sha256' attribute MAY appear as a child of the atom:link and atom:content
elements.</t>
<figure><artwork><![CDATA[
sha256 = attribute sha256 { sha1-digest }
sha256-digest = <hex of 256 bit SHA-256 digest>
]]></artwork></figure>
<t>An example SHA-256 digest of an enclosed MP3 file:</t>
<figure><artwork><![CDATA[
<atom:link rel="enclosure"
href="http://example.org/media/myfile.mp3"
sha256="6bf05cbbde96d6...d5ffe91e29272d805c98b988dc" />
]]></artwork></figure>
</section>
<section title="The 'sha384' attribute">
<t>The 'sha384' Attribute specifies a SHA-384 digest
of the resource identified by the atom:link/@href or atom:content/@src attributes.
The value is represented as a sequence of 96 hexadecimal digits.
The 'sha384' attribute MAY appear as a child of the atom:link and atom:content
elements.</t>
<figure><artwork><![CDATA[
sha384 = attribute sha384 { sha1-digest }
sha384-digest = <hex of 384 bit SHA-384 digest>
]]></artwork></figure>
<t>An example SHA-384 digest of an enclosed MP3 file:</t>
<figure><artwork><![CDATA[
<atom:link rel="enclosure"
href="http://example.org/media/myfile.mp3"
sha384="2dbf127291a...d56a3c36ec9090ae3fd589abf4c4d" />
]]></artwork></figure>
</section>
<section title="The 'sha512' attribute">
<t>The 'sha512' Attribute specifies a SHA-512 digest
of the resource identified by the atom:link/@href or atom:content/@src attributes.
The value is represented as a sequence of 128 hexadecimal digits.
The 'sha512' attribute MAY appear as a child of the atom:link and atom:content
elements.</t>
<figure><artwork><![CDATA[
sha512 = attribute sha512 { sha1-digest }
sha512-digest = <hex of 512 bit SHA-512 digest>
]]></artwork></figure>
<t>An example SHA-512 digest of an enclosed MP3 file:</t>
<figure><artwork><![CDATA[
<atom:link rel="enclosure"
href="http://example.org/media/myfile.mp3"
sha512="6e42b2c...e56b2c42aab0a21bbcca67219dc53b472" />
]]></artwork></figure>
</section>
</section>
<section title="The 'etag' attribute">
<t>The 'etag' Attribute specifies an Entity Tag <xref target="RFC2616"/> for the
resource identified by the atom:link or atom:content element. The
'etag' attribute MAY appear as a child of the atom:link and atom:
content elements.</t>
<figure><artwork><![CDATA[
etag = attribute le:etag { entity-tag }
entity-tag = [ weak ] opaque-tag
weak = "W/"
opaque-tag = quoted-string
]]></artwork></figure>
<t>An example weak entity tag for an enclosed MP3 file:</t>
<figure><artwork><![CDATA[
<atom:link rel="enclosure"
href="http://example.org/media/myfile.mp3"
etag='W/"xyzzy"' />
]]></artwork></figure>
<t>Note that HTTP defines the Entity Tag production such that quotes are
significant. For example, the values "W/xyzzy" and W/"xyzzy" represent two
distinctly different Entity Tags, the former being considered a "strong"
entity tag, the latter a "weak" entity tag. The etag attribute value MUST
include the appropriate double quotation marks.</t>
<t>The presence and placement of the quotes in the entity tag value can
introduce some difficulty when inserting the value into the etag attribute.
Producers of Atom documents must either use single quotes when specifying
the value of the etag attribute, e.g. etag='W/"xyzzy"' or use the "
entity reference to escape the double quotes within the etag value, e.g.
etag="W/"xyzzy"". A strong entity tag would be encoded as either
etag='"xyzzy"' or etag=""xyzzy"".</t>
</section>
<section title="The 'modified' attribute">
<t>The 'modified' Attribute specifies the date and time when the
resource identified by the atom:link or atom:content element was last
modified. The value MUST conform to the "date-time" production defined by
<xref target="RFC3339" />. An uppercase "T" character MUST be used to separate
date and time, and an uppercase "Z" character MUST be present in the absence
of a numeric time zone offset. The 'modified' attribute MAY appear
as a child of the atom:link and atom:content elements.</t>
<figure><artwork><![CDATA[
modified = attribute modified { xsd:dateTime }
]]></artwork></figure>
<t>An example last-modified attribute for an enclosed MP3 file:</t>
<figure><artwork><![CDATA[
<atom:link rel="enclosure"
href="http://example.org/media/myfile.mp3"
modified="2010-12-12T12:12:12Z" />
]]></artwork></figure>
</section>
<section title="Security Considerations">
<t>TBD</t>
</section>
<section title="IANA Considerations">
<t>No IANA actions are required by this document.</t>
</section>
</middle>
<back>
<references title="Normative References">
&rfc1864;
&rfc2119;
&rfc2616;
&rfc3339;
&rfc4287;
&xmlnames;
</references>
</back>
</rfc>| PAFTECH AB 2003-2026 | 2026-04-24 02:38:35 |