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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>