<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <title>Crypto++: HashTransformation Class Reference</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <link href="doxygen.css" rel="stylesheet" type="text/css"/> </head> <body> <!-- Generated by Doxygen 1.6.1 --> <div class="navigation" id="top"> <div class="tabs"> <ul> <li><a href="index.html"><span>Main Page</span></a></li> <li><a href="namespaces.html"><span>Namespaces</span></a></li> <li class="current"><a href="annotated.html"><span>Classes</span></a></li> <li><a href="files.html"><span>Files</span></a></li> </ul> </div> <div class="tabs"> <ul> <li><a href="annotated.html"><span>Class List</span></a></li> <li><a href="classes.html"><span>Class Index</span></a></li> <li><a href="hierarchy.html"><span>Class Hierarchy</span></a></li> <li><a href="functions.html"><span>Class Members</span></a></li> </ul> </div> </div> <div class="contents"> <h1>HashTransformation Class Reference</h1><!-- doxytag: class="HashTransformation" --><!-- doxytag: inherits="Algorithm" --> <p>interface for hash functions and data processing part of MACs <a href="#_details">More...</a></p> <p><code>#include <<a class="el" href="cryptlib_8h_source.html">cryptlib.h</a>></code></p> <div class="dynheader"> Inheritance diagram for HashTransformation:</div> <div class="dynsection"> <div class="center"> <img src="class_hash_transformation.gif" usemap="#HashTransformation_map" alt=""/> <map id="HashTransformation_map" name="HashTransformation_map"> <area href="class_algorithm.html" alt="Algorithm" shape="rect" coords="0,56,358,80"/> <area href="class_clonable.html" alt="Clonable" shape="rect" coords="0,0,358,24"/> <area href="class_adler32.html" alt="Adler32" shape="rect" coords="368,168,726,192"/> <area href="class_c_r_c32.html" alt="CRC32" shape="rect" coords="368,224,726,248"/> <area href="class_iterated_hash_base.html" alt="IteratedHashBase< T_HashWordType, HashTransformation >" shape="rect" coords="368,280,726,304"/> <area href="class_iterated_hash_base.html" alt="IteratedHashBase< word32, HashTransformation >" shape="rect" coords="368,336,726,360"/> <area href="class_iterated_hash_base.html" alt="IteratedHashBase< word64, HashTransformation >" shape="rect" coords="368,392,726,416"/> <area href="class_message_authentication_code.html" alt="MessageAuthenticationCode" shape="rect" coords="368,448,726,472"/> <area href="class_null_hash.html" alt="NullHash" shape="rect" coords="368,504,726,528"/> <area href="class_p_k___message_accumulator.html" alt="PK_MessageAccumulator" shape="rect" coords="368,560,726,584"/> <area href="class_truncated_hash_template.html" alt="TruncatedHashTemplate< T >" shape="rect" coords="368,616,726,640"/> <area href="class_weak1_1_1_m_d2.html" alt="Weak1::MD2" shape="rect" coords="368,672,726,696"/> </map> </div> </div> <p><a href="class_hash_transformation-members.html">List of all members.</a></p> <table border="0" cellpadding="0" cellspacing="0"> <tr><td colspan="2"><h2>Public Member Functions</h2></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="el" href="class_hash_transformation.html">HashTransformation</a> & </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a39b0a4c4cdc11fda358f9975b5e4137e">Ref</a> ()</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">return a reference to this object, <a href="#a39b0a4c4cdc11fda358f9975b5e4137e"></a><br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="aafabefaf445b65d3ba0d8e1c0294afe5"></a><!-- doxytag: member="HashTransformation::Update" ref="aafabefaf445b65d3ba0d8e1c0294afe5" args="(const byte *input, size_t length)=0" --> virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#aafabefaf445b65d3ba0d8e1c0294afe5">Update</a> (const byte *input, size_t length)=0</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">process more input <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a9fc0b332ef36900ca6ea5d949e95aba1"></a><!-- doxytag: member="HashTransformation::CreateUpdateSpace" ref="a9fc0b332ef36900ca6ea5d949e95aba1" args="(size_t &size)" --> virtual byte * </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a9fc0b332ef36900ca6ea5d949e95aba1">CreateUpdateSpace</a> (size_t &size)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">request space to write input into <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#aa0b8c7a110d8968268fd02ec32b9a8e8">Final</a> (byte *digest)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">compute hash for current message, then restart for a new message <a href="#aa0b8c7a110d8968268fd02ec32b9a8e8"></a><br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a92752eebac10497211d7a065faba8725"></a><!-- doxytag: member="HashTransformation::Restart" ref="a92752eebac10497211d7a065faba8725" args="()" --> virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a92752eebac10497211d7a065faba8725">Restart</a> ()</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">discard the current state, and restart with a new message <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a9f42cc280bac76b884ad12615c0dabb5"></a><!-- doxytag: member="HashTransformation::DigestSize" ref="a9f42cc280bac76b884ad12615c0dabb5" args="() const =0" --> virtual unsigned int </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a9f42cc280bac76b884ad12615c0dabb5">DigestSize</a> () const =0</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">size of the hash/digest/MAC returned by <a class="el" href="class_hash_transformation.html#aa0b8c7a110d8968268fd02ec32b9a8e8" title="compute hash for current message, then restart for a new message">Final()</a> <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a5e847d65a38ec354de1b28cc4bc66a81"></a><!-- doxytag: member="HashTransformation::TagSize" ref="a5e847d65a38ec354de1b28cc4bc66a81" args="() const " --> unsigned int </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a5e847d65a38ec354de1b28cc4bc66a81">TagSize</a> () const </td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">same as <a class="el" href="class_hash_transformation.html#a9f42cc280bac76b884ad12615c0dabb5" title="size of the hash/digest/MAC returned by Final()">DigestSize()</a> <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="ab5507c62376f6bea41d53ae9544d0ff0"></a><!-- doxytag: member="HashTransformation::BlockSize" ref="ab5507c62376f6bea41d53ae9544d0ff0" args="() const " --> virtual unsigned int </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#ab5507c62376f6bea41d53ae9544d0ff0">BlockSize</a> () const </td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">block size of underlying compression function, or 0 if not block based <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a981fce3f7d06c1f4ab2da853a1cf429d"></a><!-- doxytag: member="HashTransformation::OptimalBlockSize" ref="a981fce3f7d06c1f4ab2da853a1cf429d" args="() const " --> virtual unsigned int </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a981fce3f7d06c1f4ab2da853a1cf429d">OptimalBlockSize</a> () const </td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">input to <a class="el" href="class_hash_transformation.html#aafabefaf445b65d3ba0d8e1c0294afe5" title="process more input">Update()</a> should have length a multiple of this for optimal speed <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="ad44c14bc654ba3be366da88e0a27f169"></a><!-- doxytag: member="HashTransformation::OptimalDataAlignment" ref="ad44c14bc654ba3be366da88e0a27f169" args="() const " --> virtual unsigned int </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#ad44c14bc654ba3be366da88e0a27f169">OptimalDataAlignment</a> () const </td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">returns how input should be aligned for optimal performance <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="af8124c4fca23b74bbdc43660bdae692c"></a><!-- doxytag: member="HashTransformation::CalculateDigest" ref="af8124c4fca23b74bbdc43660bdae692c" args="(byte *digest, const byte *input, size_t length)" --> virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#af8124c4fca23b74bbdc43660bdae692c">CalculateDigest</a> (byte *digest, const byte *input, size_t length)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">use this if your input is in one piece and you don't want to call <a class="el" href="class_hash_transformation.html#aafabefaf445b65d3ba0d8e1c0294afe5" title="process more input">Update()</a> and <a class="el" href="class_hash_transformation.html#aa0b8c7a110d8968268fd02ec32b9a8e8" title="compute hash for current message, then restart for a new message">Final()</a> separately <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top">virtual bool </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a16c4aecd047015d513feef4ed5b929ba">Verify</a> (const byte *digest)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">verify that digest is a valid digest for the current message, then reinitialize the object <a href="#a16c4aecd047015d513feef4ed5b929ba"></a><br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="acad96df68e70d922683e5063057130b2"></a><!-- doxytag: member="HashTransformation::VerifyDigest" ref="acad96df68e70d922683e5063057130b2" args="(const byte *digest, const byte *input, size_t length)" --> virtual bool </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#acad96df68e70d922683e5063057130b2">VerifyDigest</a> (const byte *digest, const byte *input, size_t length)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">use this if your input is in one piece and you don't want to call <a class="el" href="class_hash_transformation.html#aafabefaf445b65d3ba0d8e1c0294afe5" title="process more input">Update()</a> and <a class="el" href="class_hash_transformation.html#a16c4aecd047015d513feef4ed5b929ba" title="verify that digest is a valid digest for the current message, then reinitialize the...">Verify()</a> separately <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a590ecda344aa0fb045abf42ec08823b2"></a><!-- doxytag: member="HashTransformation::TruncatedFinal" ref="a590ecda344aa0fb045abf42ec08823b2" args="(byte *digest, size_t digestSize)=0" --> virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a590ecda344aa0fb045abf42ec08823b2">TruncatedFinal</a> (byte *digest, size_t digestSize)=0</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">truncated version of <a class="el" href="class_hash_transformation.html#aa0b8c7a110d8968268fd02ec32b9a8e8" title="compute hash for current message, then restart for a new message">Final()</a> <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a0b6917657eaec935750fd83e28270d76"></a><!-- doxytag: member="HashTransformation::CalculateTruncatedDigest" ref="a0b6917657eaec935750fd83e28270d76" args="(byte *digest, size_t digestSize, const byte *input, size_t length)" --> virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a0b6917657eaec935750fd83e28270d76">CalculateTruncatedDigest</a> (byte *digest, size_t digestSize, const byte *input, size_t length)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">truncated version of <a class="el" href="class_hash_transformation.html#af8124c4fca23b74bbdc43660bdae692c" title="use this if your input is in one piece and you don't want to call Update() and...">CalculateDigest()</a> <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a0f6069eadf492d970c3eb8cdf656e742"></a><!-- doxytag: member="HashTransformation::TruncatedVerify" ref="a0f6069eadf492d970c3eb8cdf656e742" args="(const byte *digest, size_t digestLength)" --> virtual bool </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a0f6069eadf492d970c3eb8cdf656e742">TruncatedVerify</a> (const byte *digest, size_t digestLength)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">truncated version of <a class="el" href="class_hash_transformation.html#a16c4aecd047015d513feef4ed5b929ba" title="verify that digest is a valid digest for the current message, then reinitialize the...">Verify()</a> <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a7958e99717019e8b9f91672bdfe9e086"></a><!-- doxytag: member="HashTransformation::VerifyTruncatedDigest" ref="a7958e99717019e8b9f91672bdfe9e086" args="(const byte *digest, size_t digestLength, const byte *input, size_t length)" --> virtual bool </td><td class="memItemRight" valign="bottom"><a class="el" href="class_hash_transformation.html#a7958e99717019e8b9f91672bdfe9e086">VerifyTruncatedDigest</a> (const byte *digest, size_t digestLength, const byte *input, size_t length)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">truncated version of <a class="el" href="class_hash_transformation.html#acad96df68e70d922683e5063057130b2" title="use this if your input is in one piece and you don't want to call Update() and...">VerifyDigest()</a> <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="acd21c6715add4884fa043eaf51655039"></a><!-- doxytag: member="HashTransformation::AlgorithmName" ref="acd21c6715add4884fa043eaf51655039" args="() const " --> virtual std::string </td><td class="memItemRight" valign="bottom"><a class="el" href="class_algorithm.html#acd21c6715add4884fa043eaf51655039">AlgorithmName</a> () const </td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">returns name of this algorithm, not universally implemented yet <br/></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a24b43349a71e1f98508eeb10b31a0a62"></a><!-- doxytag: member="HashTransformation::Clone" ref="a24b43349a71e1f98508eeb10b31a0a62" args="() const " --> virtual <a class="el" href="class_clonable.html">Clonable</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="class_clonable.html#a24b43349a71e1f98508eeb10b31a0a62">Clone</a> () const </td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">this is not implemented by most classes yet <br/></td></tr> <tr><td colspan="2"><h2>Protected Member Functions</h2></td></tr> <tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a584846215692150d99d63f8b7ccd58d8"></a><!-- doxytag: member="HashTransformation::ThrowIfInvalidTruncatedSize" ref="a584846215692150d99d63f8b7ccd58d8" args="(size_t size) const " --> void </td><td class="memItemRight" valign="bottom"><b>ThrowIfInvalidTruncatedSize</b> (size_t size) const </td></tr> </table> <hr/><a name="_details"></a><h2>Detailed Description</h2> <p>interface for hash functions and data processing part of MACs </p> <p><a class="el" href="class_hash_transformation.html" title="interface for hash functions and data processing part of MACs">HashTransformation</a> objects are stateful. They are created in an initial state, change state as <a class="el" href="class_hash_transformation.html#aafabefaf445b65d3ba0d8e1c0294afe5" title="process more input">Update()</a> is called, and return to the initial state when <a class="el" href="class_hash_transformation.html#aa0b8c7a110d8968268fd02ec32b9a8e8" title="compute hash for current message, then restart for a new message">Final()</a> is called. This interface allows a large message to be hashed in pieces by calling <a class="el" href="class_hash_transformation.html#aafabefaf445b65d3ba0d8e1c0294afe5" title="process more input">Update()</a> on each piece followed by calling <a class="el" href="class_hash_transformation.html#aa0b8c7a110d8968268fd02ec32b9a8e8" title="compute hash for current message, then restart for a new message">Final()</a>. </p> <p>Definition at line <a class="el" href="cryptlib_8h_source.html#l00540">540</a> of file <a class="el" href="cryptlib_8h_source.html">cryptlib.h</a>.</p> <hr/><h2>Member Function Documentation</h2> <a class="anchor" id="a39b0a4c4cdc11fda358f9975b5e4137e"></a><!-- doxytag: member="HashTransformation::Ref" ref="a39b0a4c4cdc11fda358f9975b5e4137e" args="()" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname"><a class="el" href="class_hash_transformation.html">HashTransformation</a>& HashTransformation::Ref </td> <td>(</td> <td class="paramname"></td> <td> ) </td> <td><code> [inline]</code></td> </tr> </table> </div> <div class="memdoc"> <p>return a reference to this object, </p> <p>This function is useful for passing a temporary <a class="el" href="class_hash_transformation.html" title="interface for hash functions and data processing part of MACs">HashTransformation</a> object to a function that takes a non-const reference. </p> <p>Definition at line <a class="el" href="cryptlib_8h_source.html#l00546">546</a> of file <a class="el" href="cryptlib_8h_source.html">cryptlib.h</a>.</p> </div> </div> <a class="anchor" id="aa0b8c7a110d8968268fd02ec32b9a8e8"></a><!-- doxytag: member="HashTransformation::Final" ref="aa0b8c7a110d8968268fd02ec32b9a8e8" args="(byte *digest)" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">virtual void HashTransformation::Final </td> <td>(</td> <td class="paramtype">byte * </td> <td class="paramname"> <em>digest</em></td> <td> ) </td> <td><code> [inline, virtual]</code></td> </tr> </table> </div> <div class="memdoc"> <p>compute hash for current message, then restart for a new message </p> <dl class="pre"><dt><b>Precondition:</b></dt><dd>size of digest == <a class="el" href="class_hash_transformation.html#a9f42cc280bac76b884ad12615c0dabb5" title="size of the hash/digest/MAC returned by Final()">DigestSize()</a>. </dd></dl> <p>Definition at line <a class="el" href="cryptlib_8h_source.html#l00556">556</a> of file <a class="el" href="cryptlib_8h_source.html">cryptlib.h</a>.</p> <p>Referenced by <a class="el" href="pwdbased_8h_source.html#l00085">PKCS5_PBKDF2_HMAC< T >::DeriveKey()</a>, <a class="el" href="randpool_8cpp_source.html#l00026">RandomPool::IncorporateEntropy()</a>, and <a class="el" href="hmac_8cpp_source.html#l00067">HMAC_Base::TruncatedFinal()</a>.</p> </div> </div> <a class="anchor" id="a16c4aecd047015d513feef4ed5b929ba"></a><!-- doxytag: member="HashTransformation::Verify" ref="a16c4aecd047015d513feef4ed5b929ba" args="(const byte *digest)" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">virtual bool HashTransformation::Verify </td> <td>(</td> <td class="paramtype">const byte * </td> <td class="paramname"> <em>digest</em></td> <td> ) </td> <td><code> [inline, virtual]</code></td> </tr> </table> </div> <div class="memdoc"> <p>verify that digest is a valid digest for the current message, then reinitialize the object </p> <p>Default implementation is to call <a class="el" href="class_hash_transformation.html#aa0b8c7a110d8968268fd02ec32b9a8e8" title="compute hash for current message, then restart for a new message">Final()</a> and do a bitwise comparison between its output and digest. </p> <p>Definition at line <a class="el" href="cryptlib_8h_source.html#l00586">586</a> of file <a class="el" href="cryptlib_8h_source.html">cryptlib.h</a>.</p> </div> </div> <hr/>The documentation for this class was generated from the following files:<ul> <li><a class="el" href="cryptlib_8h_source.html">cryptlib.h</a></li> <li><a class="el" href="cryptlib_8cpp_source.html">cryptlib.cpp</a></li> </ul> </div> <hr size="1"/><address style="text-align: right;"><small>Generated on 9 Dec 2009 for Crypto++ by <a href="http://www.doxygen.org/index.html"> <img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.6.1 </small></address> </body> </html>