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<!DOCTYPE task
  PUBLIC "-//OASIS//DTD DITA Task//EN" "task.dtd">
<task id="GUID-98B0A83B-0064-598E-BE88-84305CA6A4F1" xml:lang="en"><title>Finding
Keys</title><abstract><shortdesc>You can find a specific set of keys using the unified
keystore. This section explains the process of finding keys. </shortdesc> <p>The
unified keystore allows you to search all keys on a device regardless of which
keystore they are in. </p> <p>You can specify a filter object that determines
which keys are returned. The criteria by which you can filter the keys are
as follows:<table id="GUID-3DF1621B-E407-43D7-B5EC-AE40FC7A9F27">
<tgroup cols="2"><colspec colname="col1"/><colspec colname="col2"/>
<tbody>
<row>
<entry><b>Filter Criteria</b></entry>
<entry><b>Description</b></entry>
</row>
<row>
<entry>The key identifier</entry>
<entry>Used when searching for a particular key.</entry>
</row>
<row>
<entry>The key usage</entry>
<entry>Used when searching for a key usage, for example encryption. </entry>
</row>
<row>
<entry>The key owner UID</entry>
<entry>Used when searching for a key owner.<p>Applications must use this to
prevent them seeing insecure keys  that might have been added by a malicious
application. </p></entry>
</row>
<row>
<entry>The key algorithm</entry>
<entry>Used when searching for a particular key algorithm, for example RSA.</entry>
</row>
</tbody>
</tgroup>
</table> </p> </abstract><prolog><metadata><keywords/></metadata></prolog><taskbody>
<context><p>The following steps explain the process of finding keys in a keystore:</p></context>
<steps id="GUID-E1B35E8F-3E58-4B3B-A816-CDEE0602224E">
<step id="GUID-3781197E-1F7E-43C7-BD97-47EE3322C38E"><cmd>Create a file system
session using an RFs object.</cmd>
</step>
<step id="GUID-29A3C0CB-A9B8-42CC-8A32-353664BCF8B6"><cmd>Create an object
of type CUnifiedKeyStore using CUnifiedKeyStore::NewL() or CUnifiedKeyStore::NewLC(). </cmd>
</step>
<step id="GUID-EFE9A46D-CDF9-444E-B1DF-9BB78AEA4553"><cmd>Initialize the member
functions and keystore using the asynchronous function CUnifiedKeyStore::Initialize().</cmd>
</step>
<step id="GUID-8A6A6604-F452-47CF-87C4-991444BB52C0"><cmd>Specify a filter
object corresponding to the type of keys that are to be returned. </cmd>
</step>
<step id="GUID-A67D52B9-39FD-4BAE-80F0-BC53E6D985FE"><cmd>Use the CUnifiedKeyStore::List()
function to list the filtered keys.</cmd>
</step>
</steps>
<result><p>Keys are listed based on the specified filter criteria. </p> </result>
<example><title>Example</title> <p>The following code snippet shows how to
set a file system session object, initialize the keystore and its member functions,
specify filter criteria for the types of keys to be listed, and then list
the specific set of keys. </p> <codeblock id="GUID-2513B075-350E-5EE1-94CC-EC386D7C09A8" xml:space="preserve">

//Create a file system session object
RFs iFs;
CleanupClosePushL(&amp;iFs);


//Initialise the keystore and member functions
CUnifiedKeyStore* keyStore = CUnifiedKeyStore::NewL(iFs);
keyStore-&gt;Initialize(iStatus); //iStatus is a TRequestStatus object


//Specify the filter criteria
RPointerArray&lt;CCTKeyInfo&gt; iKeys; // This variable will contain the keys found
TCTKeyAttributeFilter filter;
filter.iOwner = KApplicationUID; // The UID of the key owner application
filter.iUsage = EPKCS15UsageSign;    
filter.iKeyAlgorithm = CCTKeyInfo::EDSA;


//List keys based on specified filter criteria
iKeyStore-&gt;List(iKeys, filter, iStatus);


//Clean up
CleanupStack::PopAndDestroy(); // iFs</codeblock> </example>
</taskbody><related-links>
<link href="GUID-C4389D60-2A8D-532D-9D92-E57B0CCD14CF.dita"><linktext>Unified Keystore</linktext>
</link>
</related-links></task>