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<concept id="GUID-84B6389A-55CC-53EB-8725-65F753FD7217" xml:lang="en"><title>Content
Access Framework Overview</title><prolog><metadata><keywords/></metadata></prolog><conbody>
<p>The Content Access Framework (CAF) provides a common interface for applications
to access Digital Rights Management (DRM) protected content. An application
might be a video or sound player or an internet browser and DRM content might
be a media files or a game. </p>
<section><title>Purpose</title> <p>CAF provides a single point of access to
all functionality related to DRM-protected content. </p> <ul>
<li id="GUID-15DE43E1-3623-54FF-8AA5-0156D4809199"><p>Access to DRM-protected
content for content consumers, such as media players or software installers </p> </li>
<li id="GUID-CAD976B3-5AF4-53D2-B4C9-BB20D329AA88"><p>Management of DRM protected
content </p> </li>
<li id="GUID-FC614936-1F4A-557D-A61C-BF876050F5A2"><p>Import DRM protected
information </p> </li>
<li id="GUID-1DA7B843-171D-5C58-8157-B984C8218987"><p>Notification on DRM
related events, such as rights expiry </p> </li>
<li id="GUID-BE79AE4B-4DAD-5F91-A7BC-8FAC2143E858"><p>Implementation of new
DRM schemes </p> </li>
</ul> </section>
<section id="GUID-290C30C0-B088-534F-992E-CA2ED277F07D"><title>Key concepts
and terms</title> <dl>
<dlentry>
<dt>Content</dt>
<dd><p>Content is logically-coupled data such as a movie, a soundtrack or
a ringtone forming a content file. </p> </dd>
</dlentry>
</dl> <dl>
<dlentry>
<dt>Content consumer</dt>
<dd><p>Content consumers are applications such as media players or software
installers that access DRM-protected content. </p> </dd>
</dlentry>
</dl> <dl>
<dlentry>
<dt>Content access agent</dt>
<dd><p>A content access agent is an ECom plug-in which implements the CAF
interface and performs the following functions: </p> <ul>
<li id="GUID-96ACA45F-F89C-5F83-B2FC-FE19F7EEECB0"><p>Provides access to protected
content such as MPEG and MP3, and allows viewing them as plain text (even
if the content is encrypted). </p> </li>
<li id="GUID-2B5D35F4-71F7-52A2-A596-24817C68E769"><p>Provides indirect access
to a private server directory. </p> </li>
<li id="GUID-A2DA01FB-721E-5E9C-B61C-3A5E28034971"><p>Provides platform security
enforcement. CAF does not provide any capability enforcement so the agent
must police access to the APIs. The agent can choose to deny some operations
in the CAF API based upon both the application's capabilities and the agent's
policy. </p> </li>
</ul> </dd>
</dlentry>
</dl> <dl>
<dlentry>
<dt>F32 agent</dt>
<dd><p>The F32 agent provides access to unprotected files. CAF treats the
F32 agent as a special case. If no other agent is responsible for a file or
directory, the F32 Agent is used. </p> <p>The F32 agent runs in the same process
and thread as the calling application, so its file operations are limited
to the capability of the calling application's. </p> </dd>
</dlentry>
</dl> <dl>
<dlentry>
<dt>Handling and sharing content in a private directory </dt>
<dd><p>Few agents can provide access to files stored in their private directory.
They can share their files existence to applications through implementation
of the <xref href="GUID-D7457871-5361-3684-9A95-FBDB9C2689DD.dita#GUID-D7457871-5361-3684-9A95-FBDB9C2689DD/GUID-0306A1CE-9EAA-3008-A9D7-1AACA95A6081"><apiname>ContentAccess::CAgentManager::GetDir()</apiname></xref> function.
In the file system the private directories have the format: </p> <p> <codeph>\private\xxxxxxxx\directory_1\...directory_n\filename.ext</codeph> </p> <p>where <codeph>xxxxxxxx</codeph> is the UID of the agent. </p> <p>CAF
will translate that path so applications see the file as: </p> <p> <codeph>\private\agent_name\directory_1\...directory_n\filename.ext</codeph> </p> <p>where <codeph>agent_name</codeph> is the name of the agent. </p> <p>When
an application opens a file stored in the private directory, CAF selects the
agent which handles that content based upon the name in the path. If the file
is not stored in a private directory, CAF asks each of the agents in turn
whether they support the file. If no agent supports the file, it will be read
as plaintext using the F32Agent. </p> </dd>
</dlentry>
</dl> </section>
<section><title>Architecture</title> <p>CAF provides interfaces for applications
to read both unprotected and DRM protected content. It behaves as a switch
between different Content Access Agents. </p> <p>CAF uses a client-server
architecture. The CAF client DLL must be linked with the client process. CAF
agents can be implemented as plug-ins to the CAF client if they do not require
access to keys or rights. An agent requiring access to encryption or decryption
of keys, or rights must be implemented as a server-side plug-in. A server
side plug-in must ensure that only applications with the right capabilities
can access the content. </p> <p>Each agent is an ECOM plug-in implementing
the content access agent interface UID 0x10204740. The agents can run in separate
processes and need not have the capability to open files in the TCB or private
server directories using just a file name. Files must be opened by the process
that owns them and an open <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita"><apiname>RFile</apiname></xref> handle passed to CAF to
read it. </p> <p>In the following diagram the yellow blocks represent the
components provided by Symbian and the blue blocks represent the components
that must be implemented by device creators. </p> <fig id="GUID-40498A21-44F3-5250-9E02-3ACF30EC2BF9">
<title>              CAF Architecture            </title>
<image href="GUID-B93C26B8-D767-5341-A629-1A5714A20992_d0e586844_href.jpg" placement="inline"/>
</fig> <p> <b>Note</b>: The F32 agent is a client-side implementation as it
is used for accessing unprotected content only. </p> </section>
<section><title>Key classes</title> <p>The following table summarizes the
important classes provided by CAF: </p> <p> <b>Note</b>: The classes below
are defined within the namespace <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita"><apiname>ContentAccess</apiname></xref>  </p> <table id="GUID-7399345A-ADC8-57B1-B3D5-C8DD93F0F626">
<tgroup cols="2"><colspec colname="col0"/><colspec colname="col1"/>
<thead>
<row>
<entry>Class</entry>
<entry>Description</entry>
</row>
</thead>
<tbody>
<row>
<entry><p> <xref href="GUID-45942AF3-2D3E-3D22-88D0-904D70074357.dita"><apiname>CSupplier</apiname></xref>  </p> </entry>
<entry><p>Delivers and transforms content into a secure format for storing
it in the device </p> </entry>
</row>
<row>
<entry><p> <xref href="GUID-EF3C33C0-F02E-3C35-B289-3800631EDC3A.dita"><apiname>CContent</apiname></xref>  </p> </entry>
<entry><p>Provides read access to content (including protected content) stored
in a device. </p> </entry>
</row>
<row>
<entry><p> <xref href="GUID-7F3D9E35-A8FC-35A6-8036-23396BAADFDC.dita"><apiname>CManager</apiname></xref>  </p> </entry>
<entry><p>Manages files and content access agents </p> </entry>
</row>
<row>
<entry><p> <xref href="GUID-C4B8AE31-6ABD-3FEA-88DD-3B4EE13ACF49.dita"><apiname>CRightsManager</apiname></xref>  </p> </entry>
<entry><p>Manages DRM rights for a specific CAF agent </p> </entry>
</row>
<row>
<entry><p> <xref href="GUID-136D0282-4C73-33E9-B9D4-9CE92A33BF75.dita"><apiname>CData</apiname></xref>  </p> </entry>
<entry><p>Allows clients to read data from a content object </p> </entry>
</row>
<row>
<entry><p> <xref href="GUID-D90E390E-0A4F-357D-98BF-C445CC2E7EB0.dita"><apiname>CAgentFactory</apiname></xref>  </p> </entry>
<entry><p>Represents the ECom interface for a CAF Agent. A CAF agent must
implement a concrete factory derived from <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-798F4B18-D6AE-36B9-B03F-C1FC55266CB5"><apiname>ContentAccess::CAgentFactory</apiname></xref>. </p> </entry>
</row>
</tbody>
</tgroup>
</table> <p>The above APIs are grouped as follows: </p> <p><b>Supplier API </b> </p> <p>The
classes <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-0CE549BA-2F8C-3101-AD01-A1BF15C4EAE4"><apiname>ContentAccess::CSupplier</apiname></xref> and <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-E952CB96-3638-321A-B9BC-01C559FB8F4C"><apiname>ContentAccess::CImportFile</apiname></xref> together
represents the supplier API. </p> <p>The Supplier API handles the delivery
and transformation of content. It is used to transform DRM protected files
when they arrive on a device into a compatible format for storing it securely
on the device. It is also used to intercept content and ensure it is stored
in an agent's private directory. </p> <p><b>Consumer API </b> </p> <p>The
classes <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-FC40011B-32D3-328B-BB59-35BEF46A215A"><apiname>ContentAccess::CContent</apiname></xref> and <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-B54C8391-FE69-324C-AC0A-1E88C2555F00"><apiname>ContentAccess::CData</apiname></xref> together
represents the consumer API. </p> <p>The consumer API allows applications
to view the content as plain text, regardless of how it is actually stored
on the device. (For instance, it might be encrypted). It is used by applications
to render content and multimedia plug-ins. <b>Note</b>: Rendering implies
reading data from a file, transforming it, then playing or displaying it on
the device. </p> <p><b>Manager API </b> </p> <p>The <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-671191B1-B249-3DD3-A5E8-6F1A41A371C8"><apiname>ContentAccess::CManager</apiname></xref> class,
which manages the files and content access agents forms the manager API. </p> <p><b>Rights
Manager API </b> </p> <p>The <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-2CBEF3AA-7101-3247-BAED-79B624CEBBD1"><apiname>ContentAccess::CRightsManager</apiname></xref> class,
which manages DRM rights within a particular DRM agent forms the rights manager
API. </p> <p><b>Agent API </b> </p> <p>The <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-798F4B18-D6AE-36B9-B03F-C1FC55266CB5"><apiname>ContentAccess::CAgentFactory</apiname></xref> class
forms the agent interface. It allows to integrate new agents at a later date,
dynamically if required. The agent's factory produces products derived from
the following: </p> <ul>
<li id="GUID-72BCBDF7-5352-5907-902F-42CAB9C9BF55"><p> <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-983AF0B0-F0FD-31C6-94DF-C695A5D2B2D0"><apiname>ContentAccess::CAgentContent</apiname></xref>  </p> </li>
<li id="GUID-35289C35-01FA-52A5-8AFF-BBF3F870AA87"><p> <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-D9B55B22-9A2D-3475-80CB-37D44E11F34B"><apiname>ContentAccess::CAgentData</apiname></xref>  </p> </li>
<li id="GUID-4CF57B3A-8D8F-5B03-9E4A-A0A12A71FF53"><p> <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-89000D71-032A-3F08-947C-AF7006A06D2F"><apiname>ContentAccess::CAgentImportFile</apiname></xref>  </p> </li>
<li id="GUID-B7CA6E3F-59CA-5CA1-A65B-E055B5ECCC8B"><p> <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-D7457871-5361-3684-9A95-FBDB9C2689DD"><apiname>ContentAccess::CAgentManager</apiname></xref>  </p> </li>
<li id="GUID-871A9A11-7705-50DC-B528-8357FCD1A997"><p> <xref href="GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601.dita#GUID-0F5CE9B5-E674-3962-8376-CFB1ECB2F601/GUID-441831EC-2FC0-340E-B276-BFFA00665FD2"><apiname>ContentAccess::CAgentRightsManager</apiname></xref>  </p> </li>
</ul> </section>
<section><title>Typical uses</title> <p>CAF provides interfaces for implementing
and using CAF agents. CAF agents allows authorised users to access the DRM
protected content for installation and playback. CAF APIs can be used to perform
the following tasks: </p> <ul>
<li id="GUID-02285849-C4FA-58AC-BFE1-0D77A9A5FF51"><p>Handling delivery and
transformation of DRM protected content. For more information, see <xref href="GUID-1B20D403-5FC9-5A61-9D2B-8ACB9D73423C.dita">Supplier
API Tutorial</xref>. </p> </li>
<li id="GUID-E039C0ED-5A67-5326-8431-047985855B23"><p>Providing services for
applications that render content and multimedia plug-ins. For more information,
see <xref href="GUID-09A760FD-4C2A-5F79-91F2-DCC25A63699C.dita">Consumer API Tutorial</xref>. </p> </li>
<li id="GUID-769084EB-0B7A-514B-9453-9277DBD9D4E1"><p>Managing files and CAF
agents. For more information, see <xref href="GUID-920CF819-645B-5705-8017-C1FAD7C6ABAF.dita">Manager
API Tutorials</xref>. </p> </li>
<li id="GUID-E8EF07A8-4348-5F42-918C-F2BE7877EF31"><p>Managing DRM rights
within a particular DRM agent. For more information, see <xref href="GUID-77578F7E-E6E0-5177-99B2-E586DD6DD0C6.dita">Rights
Manager API Tutorial</xref>. </p> </li>
</ul> </section>
</conbody><related-links>
<link href="GUID-986EBD34-DE90-59BA-8A5F-E6E48845F18E.dita"><linktext>CAF Recogniser
Config</linktext></link>
<link href="GUID-AD61E913-9720-5F6B-8386-680384165E87.dita"><linktext>CAF Streaming
Support</linktext></link>
</related-links></concept>