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+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
+<!-- This component and the accompanying materials are made available under the terms of the License 
+"Eclipse Public License v1.0" which accompanies this distribution, 
+and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
+<!-- Initial Contributors:
+    Nokia Corporation - initial contribution.
+Contributors: 
+-->
+<!DOCTYPE concept
+  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="GUID-BCDCB147-865F-58B0-816F-5FBF0E7CCDD7" xml:lang="en"><title>CryptoSPI
+Overview</title><prolog><metadata><keywords/></metadata></prolog><conbody>
+<section id="GUID-3DAB2F6F-85F6-4AD9-97D9-90B380F8077D"><title>Introduction</title> <p>CryptoSPI
+(<filepath>cryptospi.dll</filepath>) is a library introduced in Symbian^3
+that manages the selection and loading of cryptographic algorithms. Cryptographic
+algorithms enable data to be encrypted and decrypted. The services provided
+by CryptoSPI are used by the following components: Certman (Certificate Management),
+Software Installation, Secure Communication Protocols (for example, SSL, TLS,
+IPSEC), and WTLS. </p> <p>CryptoSPI also provides a framework that allows
+licensees and partners to implement additional cryptographic algorithms as
+plug-ins to CryptoSPI. </p> <p>The benefits of CryptoSPI are: </p> <ul>
+<li id="GUID-32F02DC3-54AD-5520-AD1B-E85317BB4AFE"><p>Plug-ins can use cryptographic
+acceleration hardware, which can improve performance and reduce power consumption.
+Client applications do not need to know whether an operation is implemented
+in software or hardware. </p> </li>
+<li id="GUID-B2880123-00C8-58E7-8475-9B3D68059BF4"><p>Its architecture allows
+new algorithms or modes of operation to be added by licensees without impacting
+the existing APIs or client code. </p> </li>
+<li id="GUID-AC37BE3F-52BE-56E9-9E34-F25277F51434"><p>The legacy cryptography
+libraries (<filepath>cryptography.dll</filepath>, <filepath>hash.dll</filepath> and <filepath>random.dll</filepath>)
+have been preserved. Legacy client code can continue to use them without needing
+modification or re-compilation. This is achieved via an internal BC layer
+that routes legacy function calls to use the new SPI. </p> </li>
+<li id="GUID-2085DF2B-E97F-5B4F-B01D-84B76ED5FDE7"><p>CryptoSPI adds support
+for non-extractable keys, which may be used to protect sensitive or high-value
+content. </p> </li>
+<li id="GUID-F27670BD-8CAA-5EEA-9A82-6AB2C8741145"><p>CryptoSPI is more secure
+against malicious code than the legacy API, because it does not store any
+data, it has no server component and plugins must be located in ROM, so cannot
+be replaced or eclipsed. </p> </li>
+</ul> </section>
+<section id="GUID-5038F0E4-7FA2-4D9B-8EC0-D6670B4CCFA2"><title>Architectural
+relationships</title> <p>CryptoSPI was introduced in Symbian^3. Before Symbian^3,
+cryptographic algorithms, hash algorithms and random number generation were
+implemented by Symbian in <filepath>cryptography.dll</filepath>, <filepath>hash.dll</filepath> and <filepath>random.dll</filepath>.
+As shown in the CryptoSPI dependencies diagram, Symbian's legacy implementations
+and APIs were retained in Symbian^3, so that existing code does not need to
+be modified or recompiled. </p> <p> <filepath>softwarecrypto.dll</filepath> is
+a plug-in module implemented by Symbian that provides software-based implementations
+of all the cryptographic algorithms that were previously implemented by the
+legacy components (<filepath>cryptography.dll</filepath>, <filepath>hash.dll</filepath> and <filepath>random.dll</filepath>).
+The legacy APIs have been re-implemented internally to use the new framework
+via shim classes. <filepath>hardwarecrypto.dll</filepath> is an arbitrary
+name used in the diagram to represent a licensee-provided plug-in module.
+The plug-ins and <filepath>cryptospi.dll</filepath> have a dependency on <filepath>cryptography.dll</filepath> because
+it implements <xref href="GUID-C75726D3-E815-503D-8267-26DA27AD4787.dita">big integers</xref>. </p> <fig id="GUID-81B9B94D-07B8-512F-8553-0C98F557A21A">
+<title>              CryptoSPI dependencies</title>
+<image href="GUID-7501D3AC-16FB-58E9-B55C-2598ECCD2FFA_d0e381250_href.png" placement="inline"/>
+</fig> </section>
+<section id="GUID-BA9876DF-7166-4336-8BAC-D0B9AB051B47"><title>API summary</title> <p>The <codeph>CryptoSpi</codeph> namespace
+is defined for all CryptoSPI classes to differentiate them from the legacy
+APIs with the same names. </p> <p><b>CryptoSPI scope</b> </p> <p>CryptoSPI
+provides equivalent implementations of all algorithms supported by the legacy
+APIs, including hashing and random number generation. The following algorithms
+are implemented by Symbian in <filepath>softwarecrypto.dll</filepath>  </p> <p>This
+section includes summary details of the following: </p> <ul>
+<li id="GUID-B57702C1-A525-5F77-9BB5-D6CCB4E45929"><p>cryptographic algorithms </p> </li>
+<li id="GUID-4148CBE5-77D8-5455-9A84-E6B978EF1017"><p>hash algorithms. </p> </li>
+<li><p>random number generator</p></li>
+</ul> <p><b>Cryptographic algorithms</b> </p><ul>
+<li><p><b>Symmetric ciphers</b> - The following symmetric algorithms are supported: </p><table id="GUID-EE0B2BF7-BD22-5A03-B4DB-A82D713BB52F">
+<tgroup cols="3"><colspec colname="col0"/><colspec colname="col1"/><colspec colname="col2"/>
+<thead>
+<row>
+<entry>Symmetric algorithm</entry>
+<entry>Type</entry>
+<entry>Specified in:</entry>
+</row>
+</thead>
+<tbody>
+<row>
+<entry><p>AES (Advanced Encryption Standard) </p> </entry>
+<entry><p>Block cipher </p> </entry>
+<entry><p> <xref href="http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf" scope="external">FIPS-197</xref> </p> </entry>
+</row>
+<row>
+<entry><p>DES (Data Encryption Standard) </p> </entry>
+<entry><p>Block cipher </p> </entry>
+<entry><p> <xref href="http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf" scope="external">FIPS 46-3</xref>  </p> </entry>
+</row>
+<row>
+<entry><p>3DES (Triple Data Encryption Standard) </p> </entry>
+<entry><p>Block cipher </p> </entry>
+<entry><p> <xref href="http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf" scope="external">FIPS 46-3</xref>  </p> </entry>
+</row>
+<row>
+<entry><p>RC2-128 </p> </entry>
+<entry><p>Block cipher </p> </entry>
+<entry><p> <xref href="ftp://ftp.rfc-editor.org/in-notes/rfc2268.txt" scope="external">RFC
+2268</xref>  </p> </entry>
+</row>
+<row>
+<entry><p>ARC4 ('alleged' RC4) </p> </entry>
+<entry><p>Stream cipher </p> </entry>
+<entry><p>The internet and a posting to sci.crypt in 1994. </p> </entry>
+</row>
+</tbody>
+</tgroup>
+</table> <p> <b> Note:</b> Algorithm identifiers for MISTY1, MISTY2 and Kasumi
+(A5/3) block ciphers are in the cryptography library. These identifiers allow
+clients of the cryptography library to request implementations of these algorithms
+from the symmetric cipher factory. Symbian does not provide implementations
+of these algorithms, so the default behavior is for the factory function to
+return an error indicating that there is no implementation available. </p> <p><b>Note</b>:
+Until Symbian^3, the classes implementing the symmetric and asymmetric ciphers
+were provided in <filepath>cryptography.dll</filepath>. </p></li>
+<li><p><b>Asymmetric ciphers </b> - The following asymmetric algorithms are
+supported: </p><table id="GUID-EF226280-A0A6-5CDC-A561-E2CA11D551B0">
+<tgroup cols="3"><colspec colname="col0"/><colspec colname="col1"/><colspec colname="col2"/>
+<thead>
+<row>
+<entry>Asymmetric algorithm</entry>
+<entry>What is's used for</entry>
+<entry>Specified in:</entry>
+</row>
+</thead>
+<tbody>
+<row>
+<entry><p>RSA PKCS#1 v1.5 </p> </entry>
+<entry><p>Signing data </p> <p>Key pair generation </p> </entry>
+<entry><p> <xref href="http://www.rsasecurity.com/rsalabs/node.asp?id=2125" scope="external">PKCS#1</xref> v1.5 </p> </entry>
+</row>
+<row>
+<entry><p>DSA </p> </entry>
+<entry><p>Signing data </p> <p>Key pair generation </p> </entry>
+<entry><p> <xref href="http://csrc.nist.gov/publications/fips/fips186-2/fips186-2-change1.pdf" scope="external">FIPS 186-2</xref> CR1 </p> </entry>
+</row>
+<row>
+<entry><p>Diffie Hellman </p> </entry>
+<entry><p>Key agreement </p> <p>Key pair generation </p> </entry>
+<entry><p> <xref href="http://www.rsasecurity.com/rsalabs/node.asp?id=2126" scope="external">PKCS#3</xref>  </p> </entry>
+</row>
+</tbody>
+</tgroup>
+</table></li>
+<li><p><b>Hash algorithms</b> - The following hash algorithms are supported:</p><p><table id="GUID-ABBDB728-AC1E-4C93-949C-401938589A22">
+<tgroup cols="2"><colspec colname="col1"/><colspec colname="col2"/>
+<thead>
+<row>
+<entry valign="top"><p>Hash algorithms</p></entry>
+<entry valign="top"><p>Specified in</p></entry>
+</row>
+</thead>
+<tbody>
+<row>
+<entry><p>MD2</p></entry>
+<entry><p><xref href="http://www.ietf.org/rfc/rfc1319.txt" scope="external">RFC
+1319</xref></p></entry>
+</row>
+<row>
+<entry><p>MD4</p></entry>
+<entry><p><xref href="http://www.ietf.org/rfc/rfc1320.txt" scope="external">RFC
+1320</xref></p></entry>
+</row>
+<row>
+<entry><p>MD5</p></entry>
+<entry><p><xref href="http://www.ietf.org/rfc/rfc1321.txt" scope="external">RFC
+1321</xref></p></entry>
+</row>
+<row>
+<entry><p>SHA1</p></entry>
+<entry><p><xref href="http://www.itl.nist.gov/fipspubs/fip180-1.htm" scope="external">FIPS
+180-1</xref> and <xref href="http://www.ietf.org/rfc/rfc3174.txt" scope="external">RFC
+3174</xref></p></entry>
+</row>
+<row>
+<entry><p>SHA-224</p></entry>
+<entry><p><xref href="http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf " scope="external">FIPS 180-2</xref></p></entry>
+</row>
+<row>
+<entry><p>SHA-256</p></entry>
+<entry><p><xref href="http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf " scope="external">FIPS 180-2</xref></p></entry>
+</row>
+<row>
+<entry><p>SHA-384</p></entry>
+<entry><p><xref href="http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf " scope="external">FIPS 180-2</xref></p></entry>
+</row>
+<row>
+<entry><p>SHA-512</p></entry>
+<entry><p><xref href="http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf " scope="external">FIPS 180-2</xref></p></entry>
+</row>
+</tbody>
+</tgroup>
+</table></p></li>
+<li><p><b>Hashes in HMAC mode</b></p><ul>
+<li><p>MD2</p></li>
+<li><p>MD4</p></li>
+<li><p>MD5</p></li>
+<li><p>SHA1</p></li>
+<li><p>SHA-224</p></li>
+<li><p>SHA-256</p></li>
+<li><p>SHA-384</p></li>
+<li><p>SHA-512</p></li>
+</ul><p> HMAC mode is specified in <xref href="http://www.ietf.org/rfc/rfc2104.txt" scope="external">RFC 2104</xref></p></li>
+</ul> <p><b>Instantiating algorithms</b> </p> <p>Clients request cryptographic
+algorithms using static factory functions. </p> <p>For instance, to create
+a hash algorithm, use the generic hash factory function <xref href="GUID-D2231146-4F0D-3F70-8249-C166375D78DC.dita#GUID-D2231146-4F0D-3F70-8249-C166375D78DC/GUID-2C0F6052-76A8-3E45-AF72-F567E1161212"><apiname>CryptoSpi::CHashFactory::CreateHashL()</apiname></xref>,
+specifying the UID of the required algorithm. UIDs are defined in <filepath>cryptospidef.h</filepath>,
+for instance <codeph>KMd2Uid</codeph>, <codeph>KMd5Uid</codeph>, <codeph>KSha1Uid</codeph>.
+CryptoSPI uses a <xref href="GUID-BCDCB147-865F-58B0-816F-5FBF0E7CCDD7.dita#GUID-BCDCB147-865F-58B0-816F-5FBF0E7CCDD7/GUID-15969DD8-8F8A-534D-8445-A5CC95112B63">plug-in
+selector</xref> to search for a plug-in that implements the requested algorithm.
+When a plug-in is found, CryptoSPI loads it if required, and calls the function
+defined at the relevant ordinal in the plug-in DLL, in this case <codeph>ECreateHashOrdinal</codeph>,
+to instantiate a hash object, which is returned to the caller. </p> <p><b>Operation
+and padding modes</b> </p> <p>CryptoSPI has been designed to be simpler and
+more compact than the API that it replaces. Rather than defining separate
+classes to do encryption and decryption, for instance, <codeph>C3DESEncryptor</codeph> and <codeph>C3DESDecryptor</codeph>,
+CryptoSPI implements a single, generic symmetric cipher class, <codeph>CryptoSpi::CSymmetricCipher</codeph>.
+The characteristics of the algorithm, for instance whether it does encryption
+or decryption, the operation mode for block ciphers (<codeph>KOperationModeECB</codeph>, <codeph>KOperationModeCBC</codeph> etc.),
+and the padding mode (<codeph>KPaddingModeSSLv3</codeph>, <codeph>KPaddingModePKCS7</codeph> etc.)
+are all passed by the client to the factory function as UIDs — see <xref href="GUID-5463D9D7-2DE0-3DC1-A415-910636125935.dita#GUID-5463D9D7-2DE0-3DC1-A415-910636125935/GUID-43F80501-62A9-3987-B057-852A1E80E483"><apiname>CryptoSpi::CSymmetricCipherFactory::CreateSymmetricCipherL()</apiname></xref>. </p> <p>The client can switch the algorithm between modes by setting a
+flag, see for example <xref href="GUID-699F30D8-BC52-3F83-9188-8CF86B2B0800.dita#GUID-699F30D8-BC52-3F83-9188-8CF86B2B0800/GUID-121C4AC5-0D1C-33E7-A534-A4A6AA4DF6FD"><apiname>CSymmetricCipherBase::SetCryptoModeL()</apiname></xref>, <xref href="GUID-699F30D8-BC52-3F83-9188-8CF86B2B0800.dita#GUID-699F30D8-BC52-3F83-9188-8CF86B2B0800/GUID-22633D2E-2D3A-3B30-91D2-A5A97C5274BC"><apiname>CSymmetricCipherBase::SetPaddingModeL()</apiname></xref> and <xref href="GUID-699F30D8-BC52-3F83-9188-8CF86B2B0800.dita#GUID-699F30D8-BC52-3F83-9188-8CF86B2B0800/GUID-8D992640-AFCE-3839-AD50-0543AFBE564D"><apiname>CSymmetricCipherBase::SetOperationModeL()</apiname></xref>. </p> <p><ul>
+<li><p><b>Operation modes </b></p><p>Symbian platform provides default software
+implementations of the following operation modes: </p><ul>
+<li id="GUID-A7FBAF70-5202-5958-866F-9BACB7D3E0B3"><p>ECB </p> </li>
+<li id="GUID-3C51459C-C660-5F38-AD61-3F954DFF3ECF"><p>CBC </p> </li>
+<li id="GUID-A718E6C7-59D2-5324-8EE3-764E627D7AF4"><p>CTR (counter) </p> </li>
+</ul><p>They are specified in <xref href="http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf" scope="external">NIST Special Publication 800-38A</xref>. </p></li>
+<li><p><b>Padding modes </b></p><p>Symbian platform supports the following
+padding modes: </p><ul>
+<li id="GUID-8BC577C7-6A7E-5A0F-B8C9-1D7E93CE2E80"><p>SSLv3-style padding </p> </li>
+<li id="GUID-FA955DDF-CC6C-5CB3-878F-EE319C82EC3F"><p>PKCS#7-style padding </p> </li>
+<li id="GUID-93D60F44-17F9-54DD-B947-41D63C943B3F"><p>PKCS#1 v1.5 Encryption-style
+padding </p> </li>
+<li id="GUID-EF45D638-105A-5DDB-AC22-B37CA5868D97"><p>PKCS#1 v1.5 Signature-style
+padding </p> </li>
+</ul></li>
+</ul> </p> <p><b>Asynchronous operation and cancellation</b> </p> <p>The legacy
+cryptography library only supports synchronous operations. By enabling cryptographic
+acceleration hardware, CryptoSPI supports more advanced use cases. In order
+for users to be able to cancel potentially long-running operations such as
+the decryption of high-quality audio/visual content, CryptoSPI supports both
+synchronous and asynchronous interfaces for each cryptographic operation,
+the latter providing a <codeph>Cancel()</codeph> function. </p> <p><b>Note</b>:
+Symbian's software plug-in module (<filepath>softwarecrypto.dll</filepath>)
+only implements the synchronous interfaces. </p> <p><b>Plug-ins</b> </p> <p>A
+CryptoSPI plugin DLL can implement zero, one or more algorithms, and may provide
+alternative implementations of the same algorithm. The set of plugin DLLs
+is defined in a configuration file in ROM (<filepath>Z:\resource\cryptospi\plug-ins.txt</filepath>).
+CryptoSPI will only load plugins stored in ROM (<filepath>Z:\sys\bin\</filepath>),
+so plug-in modules cannot be added by third parties after-market. </p> <p> <filepath>cryptospi.dll</filepath> and
+all plug-ins have <codeph>ALL</codeph> capabilities, which ensures that they
+can be loaded by client applications with any capabilities. </p> <p>The abstract
+base class for all cryptographic plug-ins is <xref href="GUID-48BB2346-6840-3A26-B43C-4DF70A322B17.dita#GUID-48BB2346-6840-3A26-B43C-4DF70A322B17/GUID-8390A214-1E1B-3E8F-A6C9-6030D99F532C"><apiname>CryptoSpi::MPlugin()</apiname></xref>. </p> <p>See
+also: <xref href="GUID-2DA8C6F2-93BD-5D39-9E5A-5FF8B8777CE7.dita">How to create
+a CryptoSPI plugin</xref>. </p> <p><b>UIDs and plug-in characteristics</b> </p> <p>Plug-ins
+are identified by three UIDs: </p> <ul>
+<li id="GUID-3A357C90-9E3B-5620-93E0-CF45ABD57993"><p>the interface supported,
+for instance hash (<codeph>KHashInterfaceUid</codeph>), </p> </li>
+<li id="GUID-E2FAF159-EE47-5DE6-AB03-D133D815C690"><p>the algorithm implemented,
+for instance MD2 (<codeph>KMd2Uid</codeph>), and </p> </li>
+<li id="GUID-4EB6A03E-F3C5-5577-8C68-4761C25361E8"><p>the unique implementation
+ID. </p> </li>
+</ul> <p>These three UIDs are part of the plug-in's <i>characteristics</i>.
+Plug-in characteristics are defined at compile time as constant data. They
+describe the type and capabilities of a plug-in implementation. Some characteristics
+are relevant to all plug-in types, for instance the name and UID of the algorithm
+implemented, the name of the plug-in vendor and whether the plug-in uses hardware
+acceleration. These are termed <i>common characteristics</i> and are defined
+in <xref href="GUID-48BB2346-6840-3A26-B43C-4DF70A322B17.dita#GUID-48BB2346-6840-3A26-B43C-4DF70A322B17/GUID-704C9275-4009-3E20-82F1-FBED2B29976E"><apiname>CryptoSpi::TCommonCharacteristics()</apiname></xref>. Other characteristics
+are specific to a particular interface type, for instance the modes of operation
+for a symmetric cipher. These are defined in an interface-specific characteristics
+class, for instance <xref href="GUID-48BB2346-6840-3A26-B43C-4DF70A322B17.dita#GUID-48BB2346-6840-3A26-B43C-4DF70A322B17/GUID-CC81BF89-1AA4-3779-B7DB-A01C89041965"><apiname>CryptoSpi::TSymmetricCipherCharacteristics()</apiname></xref>,
+that have a <codeph>TCommonCharacteristics</codeph> data member. Plug-in characteristics
+can be retrieved using <xref href="GUID-ED01CE2C-30E8-344F-B3C9-895FA576D33F.dita#GUID-ED01CE2C-30E8-344F-B3C9-895FA576D33F/GUID-8D93089E-1F97-376B-8CC0-08E0E34158F4"><apiname>CCryptoBase::GetCharacteristicsL()</apiname></xref>. </p> <p>Plug-ins
+may optionally also have 'extended' characteristics. These are set at runtime,
+for instance the number of concurrent operations supported by the plug-in,
+and can be retrieved using <xref href="GUID-87D367F5-0FD8-3BEE-AFB0-B48706902C99.dita#GUID-87D367F5-0FD8-3BEE-AFB0-B48706902C99/GUID-720996CA-353D-37A2-A40E-3A18EC8EF4EB"><apiname>CryptoSpi::MPlugin::GetExtendedCharacteristicsL()</apiname></xref>. </p> <p id="GUID-15969DD8-8F8A-534D-8445-A5CC95112B63"><b>Selection rules</b> </p><p>Symbian
+has implemented a plug-in selector, <xref href="GUID-48BB2346-6840-3A26-B43C-4DF70A322B17.dita#GUID-48BB2346-6840-3A26-B43C-4DF70A322B17/GUID-2E6D755A-2170-3A7A-8F89-1748CE1FEBDE"><apiname>CryptoSpi::CLegacySelector()</apiname></xref>,
+which is used both by the legacy API and by default by CryptoSPI to select
+algorithms implemented in <filepath>softwarecrypto.dll</filepath>. In other
+words, by default, CryptoSPI and the legacy API use the same algorithm implementations.
+The legacy selector works by loading DLLs one by one according to their order
+in the ROM configuration file until a suitable implementation is found. </p> <p>As
+an alternative to using the default selector, clients can specify a rule-based
+selector (<xref href="GUID-48BB2346-6840-3A26-B43C-4DF70A322B17.dita#GUID-48BB2346-6840-3A26-B43C-4DF70A322B17/GUID-DAA57D69-9E75-3333-9227-76D7B0719B7E"><apiname>CryptoSpi::CRuleSelector()</apiname></xref>). This causes CryptoSPI
+to re-generate the list of plug-ins, according to a set of selection rules.
+The API is described in <xref href="GUID-5857377F-B90D-5149-9485-5919C12B8F13.dita">How
+to use a rule-based selector</xref>. </p> <p>In general, it is recommended
+that applications should not specify selection rules unless it is critical
+to the operation of the application. The preferred approach is to use the
+plugin chosen by the default selector, which can be assumed to provide good
+performance for the most common use cases. </p> </section>
+</conbody><related-links>
+<link href="GUID-679390E8-1DE6-55F0-9A0C-60D58956A1E3.dita"><linktext>Hash (message
+digest) algorithms</linktext></link>
+<link href="GUID-0CD273A2-434C-52E0-B840-CCF24B2853B8.dita"><linktext>Generating
+random bytes</linktext></link>
+<link href="GUID-D2D17EF9-FFC6-5FBD-A992-55746A12B625.dita"><linktext>Basic encryption
+and decryption using a symmetric cipher</linktext></link>
+<link href="GUID-38C8F8B0-C259-5B03-A13E-10DBED4071F2.dita"><linktext>Signing and
+verification</linktext></link>
+<link href="GUID-5857377F-B90D-5149-9485-5919C12B8F13.dita"><linktext>How to use
+a rule-based selector</linktext></link>
+</related-links></concept>
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