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<concept id="GUID-B89D2828-0FEE-5206-97D2-C7D4BBD35799" xml:lang="en"><title>How
is the Comms Database secured</title><shortdesc>This topic describes the security issues that govern access to
the Comms Database. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
<p>Symbian platform uses platform security capabilities to protect
the data in the Comms Database. The CommsDat API accesses the Comms Database
through a client/server mechanism. Capabilities are policed at the client/server
interface. </p>
<p>All elements in the Comms Database can have an access level. This means
that all tables, records, columns, and fields can have an access level. The
access level defines the type of access that elements offer to tools and applications.
The access level available to tools and applications also depends on the platform
security capabilities assigned to those tools and applications. </p>
<section id="GUID-01939D1C-B904-5388-AC5E-C727BEA808C8"><title>Access levels</title> <p>The
CommsDat API offers tools and applications 5 access levels to an element : </p> <ul>
<li id="GUID-60820978-310E-5785-A11B-47E132F07330"><p>hidden : the element
contains data that must not be seen. </p> </li>
<li id="GUID-3414C7B7-8A30-5320-B49F-53527793148D"><p>private : the element
contains private data. For example, username or password data. </p> </li>
<li id="GUID-EA1DFE7F-5F9D-5E32-9211-3742169175D9"><p>protected write : the
element contains data that must be protected from most processes. For example,
this can be data set by network operators. </p> </li>
<li id="GUID-08E8B6B9-DE74-574F-9382-1CE85D0B2B94"><p>basic read-only guard
: this access level is not used by the CommsDat API but exists for backward
compatibilty with the legacy CommDb. </p> </li>
<li id="GUID-AA0B2EA9-63DA-53B4-B1CA-3106A54148E8"><p>default : the element
has no explicit access level. </p> </li>
</ul> <p>The CommsDat API uses the flag bits defined by the <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>TCDAttributeFlags</apiname></xref> enum
to indicate the levels of access to an element. The bits are known as the
access control attributes of an element. </p> <p>Tools and applications use
the CommsDat API functions <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>CommsDat::CMDBElement::SetAttributes()</apiname></xref> and <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>CommsDat::CMDBElement::ClearAttributes()</apiname></xref> to set
the access control bits in the <codeph>iElementId</codeph> member of <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>CMDBElement</apiname></xref> and to set the access levels into
the element in the Comms Database. </p> </section>
<section id="GUID-834A910B-336E-5DB0-94B3-BB41E9691D28"><title>How platform
security capabilities work with access           levels</title> <p>Tools and
application processes without capabilities cannot write to the Comms Datababase.
Processes without capabilities cannot damage the integrity of data in the
Comms Database. Platform security makes sure that processes without capability
cannot deny use of the database to other clients. </p> <p>To read or write
elements in the Comms Database, tools and application processes must have
the correct platform security capabilities. The following table lists the
combination of capabilities and access levels to read and write elements. </p> <table id="GUID-1AEB546F-72E3-5AF9-98FA-2E8ABE75EF0B">
<tgroup cols="3"><colspec colname="col0"/><colspec colname="col1"/><colspec colname="col2"/>
<tbody>
<row>
<entry><p> <b> Access</b>  </p> </entry>
<entry><p> <b> Capability needed to read data</b>  </p> </entry>
<entry><p> <b>Capability needed to write data</b>  </p> </entry>
</row>
<row>
<entry><p> <codeph> hidden</codeph>  </p> <p>This is indicated by the <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>ECDHidden</apiname></xref> bit set in the in the <codeph>iElementId</codeph> member
of an element. </p> </entry>
<entry><p>None </p> </entry>
<entry><p>WriteDeviceData </p> </entry>
</row>
<row>
<entry><p> <codeph> Private</codeph>  </p> <p>This is indicated by the <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>ECDPrivate</apiname></xref> bit set in the <codeph>iElementId</codeph> member
of an element. </p> </entry>
<entry><p> <codeph>ReadDeviceData</codeph>  </p> </entry>
<entry><p> <codeph>WriteDeviceData</codeph> + <codeph>ReadDeviceData</codeph>  </p> </entry>
</row>
<row>
<entry><p> <codeph> Protected write</codeph>  </p> <p>This is indicated by
the <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>ECDProtectedWrite</apiname></xref> bit set in the <codeph>iElementId</codeph> member
of an element. </p> </entry>
<entry><p> <codeph>None</codeph>  </p> </entry>
<entry><p> <codeph>WriteDeviceData</codeph> + <codeph>NetworkControl</codeph>  </p> </entry>
</row>
<row>
<entry><p> <codeph> Basic read-only guard</codeph>  </p> <p>This is indicated
by the <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>ECDNoWriteButDeletee</apiname></xref> bit set in
the <codeph>iElementId</codeph> member of an element. </p> </entry>
<entry><p> <codeph>None</codeph>  </p> </entry>
<entry><p> <codeph>WriteDeviceData</codeph>  </p> </entry>
</row>
<row>
<entry><p> <codeph> Default</codeph>  </p> <p>None of the <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>TCDAttributeFlags</apiname></xref> bits
set in the <codeph>iElementId</codeph> member of an element. </p> </entry>
<entry><p> <codeph>None</codeph>  </p> </entry>
<entry><p> <codeph>WriteDeviceData</codeph>  </p> </entry>
</row>
</tbody>
</tgroup>
</table> <p>Tools and applications that have the capability to change the
access control attributes must follow data access control protocols. </p> <p>Tools
and applications must also have <codeph>WriteDeviceData</codeph> capability
to use database functions. For example, to open a transaction to write to
the database. </p> <p>The platform security settings are cumulative. For example,
to change an element that is marked <i>private </i> and has <i>protected write
access</i> in the database requires: </p> <ul>
<li id="GUID-9378062D-31AB-50C7-99D7-116184077C74"><p>the <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>ECDPrivate</apiname></xref> bit
and the <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>ECDProtectedWrite</apiname></xref> bit to be set
set. </p> </li>
<li id="GUID-99D1C214-BE33-53E1-8A26-687BE22ACE3D"><p>the tools and application
process to have the <codeph>WriteDeviceData</codeph>, <codeph>ReadDeviceData</codeph> and <codeph>NetworkControl</codeph> capabilities. </p> </li>
</ul> </section>
<section id="GUID-3FDDACD8-25E5-54B2-B105-65C147B620FE"><title>Changing the
access attributes for each session</title> <p>Tools and applications can choose
to change the access levels of elements for the period of a session. For example,
tools and applications can choose to view elements that have the <codeph>hidden</codeph> access
level. Tools and applications set an <i>attribute mask</i> to change the access
levels of elements for a session. </p> <p>An attribute mask does not change
the access levels of elements in the database. The functions that set an attribute
mask do not make a call to the Comms Database and do not check the capabilities
of the process of the tool or application. An attribute mask does not remove
platform security checks. For example, a tools or application process without <codeph>NetworkControl</codeph> capability
can not update elements protected with <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>ECDProtectedWrite</apiname></xref>. </p> <p>The
most common use for this behaviour is to view elements that are hidden. </p> <p>For
example, to view hidden records, call the session function <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>CommsDat::CMDBSession::SetAttributeMask()</apiname></xref> and
pass the value for <i>hidden</i> to this function. The attribute value for <i>hidden</i> is
the enum value <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>ECDHidden</apiname></xref>. </p> <p>Use
the session function <xref href="GUID-1CDD0B97-8B00-3373-9908-512C9BC1CF51.dita"><apiname>CommsDat::CMDBSession::ClearAttributeMask()</apiname></xref> to
clear an attribute mask. </p> </section>
</conbody><related-links>
<link href="GUID-4BFEDD79-9502-526A-BA7B-97550A6F0601.dita"><linktext>Platfom Security</linktext>
</link>
</related-links></concept>