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<div class="title">authenc.cpp</div> </div>
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<div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">// authenc.cpp - written and placed in the public domain by Wei Dai</span>
<a name="l00002"></a>00002
<a name="l00003"></a>00003 <span class="preprocessor">#include "pch.h"</span>
<a name="l00004"></a>00004
<a name="l00005"></a>00005 <span class="preprocessor">#ifndef CRYPTOPP_IMPORTS</span>
<a name="l00006"></a>00006 <span class="preprocessor"></span>
<a name="l00007"></a>00007 <span class="preprocessor">#include "authenc.h"</span>
<a name="l00008"></a>00008
<a name="l00009"></a>00009 NAMESPACE_BEGIN(CryptoPP)
<a name="l00010"></a>00010
<a name="l00011"></a>00011 void <a class="code" href="class_authenticated_symmetric_cipher_base.html" title=".">AuthenticatedSymmetricCipherBase</a>::AuthenticateData(const byte *input, <span class="keywordtype">size_t</span> len)
<a name="l00012"></a>00012 {
<a name="l00013"></a>00013 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> blockSize = AuthenticationBlockSize();
<a name="l00014"></a>00014 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> &num = m_bufferedDataLength;
<a name="l00015"></a>00015 byte* data = m_buffer.begin();
<a name="l00016"></a>00016
<a name="l00017"></a>00017 <span class="keywordflow">if</span> (num != 0) <span class="comment">// process left over data</span>
<a name="l00018"></a>00018 {
<a name="l00019"></a>00019 <span class="keywordflow">if</span> (num+len >= blockSize)
<a name="l00020"></a>00020 {
<a name="l00021"></a>00021 memcpy(data+num, input, blockSize-num);
<a name="l00022"></a>00022 AuthenticateBlocks(data, blockSize);
<a name="l00023"></a>00023 input += (blockSize-num);
<a name="l00024"></a>00024 len -= (blockSize-num);
<a name="l00025"></a>00025 num = 0;
<a name="l00026"></a>00026 <span class="comment">// drop through and do the rest</span>
<a name="l00027"></a>00027 }
<a name="l00028"></a>00028 <span class="keywordflow">else</span>
<a name="l00029"></a>00029 {
<a name="l00030"></a>00030 memcpy(data+num, input, len);
<a name="l00031"></a>00031 num += (<span class="keywordtype">unsigned</span> int)len;
<a name="l00032"></a>00032 <span class="keywordflow">return</span>;
<a name="l00033"></a>00033 }
<a name="l00034"></a>00034 }
<a name="l00035"></a>00035
<a name="l00036"></a>00036 <span class="comment">// now process the input data in blocks of blockSize bytes and save the leftovers to m_data</span>
<a name="l00037"></a>00037 <span class="keywordflow">if</span> (len >= blockSize)
<a name="l00038"></a>00038 {
<a name="l00039"></a>00039 <span class="keywordtype">size_t</span> leftOver = AuthenticateBlocks(input, len);
<a name="l00040"></a>00040 input += (len - leftOver);
<a name="l00041"></a>00041 len = leftOver;
<a name="l00042"></a>00042 }
<a name="l00043"></a>00043
<a name="l00044"></a>00044 memcpy(data, input, len);
<a name="l00045"></a>00045 num = (<span class="keywordtype">unsigned</span> int)len;
<a name="l00046"></a>00046 }
<a name="l00047"></a>00047
<a name="l00048"></a><a class="code" href="class_authenticated_symmetric_cipher_base.html#aea1353c1d0a94c3f81ebcf53f6b7ea57">00048</a> <span class="keywordtype">void</span> <a class="code" href="class_authenticated_symmetric_cipher_base.html#aea1353c1d0a94c3f81ebcf53f6b7ea57" title="set or reset the key of this object">AuthenticatedSymmetricCipherBase::SetKey</a>(<span class="keyword">const</span> byte *userKey, <span class="keywordtype">size_t</span> keylength, <span class="keyword">const</span> <a class="code" href="class_name_value_pairs.html" title="interface for retrieving values given their names">NameValuePairs</a> &params)
<a name="l00049"></a>00049 {
<a name="l00050"></a>00050 m_bufferedDataLength = 0;
<a name="l00051"></a>00051 m_state = State_Start;
<a name="l00052"></a>00052
<a name="l00053"></a>00053 SetKeyWithoutResync(userKey, keylength, params);
<a name="l00054"></a>00054 m_state = State_KeySet;
<a name="l00055"></a>00055
<a name="l00056"></a>00056 <span class="keywordtype">size_t</span> length;
<a name="l00057"></a>00057 <span class="keyword">const</span> byte *iv = GetIVAndThrowIfInvalid(params, length);
<a name="l00058"></a>00058 <span class="keywordflow">if</span> (iv)
<a name="l00059"></a>00059 <a class="code" href="class_authenticated_symmetric_cipher_base.html#a2569e019253053096a8ba1064be4e48e" title="resynchronize with an IV. ivLength=-1 means use IVSize()">Resynchronize</a>(iv, (<span class="keywordtype">int</span>)length);
<a name="l00060"></a>00060 }
<a name="l00061"></a>00061
<a name="l00062"></a><a class="code" href="class_authenticated_symmetric_cipher_base.html#a2569e019253053096a8ba1064be4e48e">00062</a> <span class="keywordtype">void</span> <a class="code" href="class_authenticated_symmetric_cipher_base.html#a2569e019253053096a8ba1064be4e48e" title="resynchronize with an IV. ivLength=-1 means use IVSize()">AuthenticatedSymmetricCipherBase::Resynchronize</a>(<span class="keyword">const</span> byte *iv, <span class="keywordtype">int</span> length)
<a name="l00063"></a>00063 {
<a name="l00064"></a>00064 <span class="keywordflow">if</span> (m_state < State_KeySet)
<a name="l00065"></a>00065 <span class="keywordflow">throw</span> <a class="code" href="class_authenticated_symmetric_cipher_1_1_bad_state.html" title="this indicates that a member function was called in the wrong state, for example trying to encrypt a ...">BadState</a>(<a class="code" href="class_authenticated_symmetric_cipher.html#aae9cc715b7640cfc1f5fcad980ea34a2" title="returns name of this algorithm, not universally implemented yet">AlgorithmName</a>(), <span class="stringliteral">"Resynchronize"</span>, <span class="stringliteral">"key is set"</span>);
<a name="l00066"></a>00066
<a name="l00067"></a>00067 m_bufferedDataLength = 0;
<a name="l00068"></a>00068 m_totalHeaderLength = m_totalMessageLength = m_totalFooterLength = 0;
<a name="l00069"></a>00069 m_state = State_KeySet;
<a name="l00070"></a>00070
<a name="l00071"></a>00071 Resync(iv, this->ThrowIfInvalidIVLength(length));
<a name="l00072"></a>00072 m_state = State_IVSet;
<a name="l00073"></a>00073 }
<a name="l00074"></a>00074
<a name="l00075"></a><a class="code" href="class_authenticated_symmetric_cipher_base.html#a7e63b051cf0ea30d9c69a5355424c0bc">00075</a> <span class="keywordtype">void</span> <a class="code" href="class_authenticated_symmetric_cipher_base.html#a7e63b051cf0ea30d9c69a5355424c0bc" title="process more input">AuthenticatedSymmetricCipherBase::Update</a>(<span class="keyword">const</span> byte *input, <span class="keywordtype">size_t</span> length)
<a name="l00076"></a>00076 {
<a name="l00077"></a>00077 <span class="keywordflow">if</span> (length == 0)
<a name="l00078"></a>00078 <span class="keywordflow">return</span>;
<a name="l00079"></a>00079
<a name="l00080"></a>00080 <span class="keywordflow">switch</span> (m_state)
<a name="l00081"></a>00081 {
<a name="l00082"></a>00082 <span class="keywordflow">case</span> State_Start:
<a name="l00083"></a>00083 <span class="keywordflow">case</span> State_KeySet:
<a name="l00084"></a>00084 <span class="keywordflow">throw</span> <a class="code" href="class_authenticated_symmetric_cipher_1_1_bad_state.html" title="this indicates that a member function was called in the wrong state, for example trying to encrypt a ...">BadState</a>(<a class="code" href="class_authenticated_symmetric_cipher.html#aae9cc715b7640cfc1f5fcad980ea34a2" title="returns name of this algorithm, not universally implemented yet">AlgorithmName</a>(), <span class="stringliteral">"Update"</span>, <span class="stringliteral">"setting key and IV"</span>);
<a name="l00085"></a>00085 <span class="keywordflow">case</span> State_IVSet:
<a name="l00086"></a>00086 AuthenticateData(input, length);
<a name="l00087"></a>00087 m_totalHeaderLength += length;
<a name="l00088"></a>00088 <span class="keywordflow">break</span>;
<a name="l00089"></a>00089 <span class="keywordflow">case</span> State_AuthUntransformed:
<a name="l00090"></a>00090 <span class="keywordflow">case</span> State_AuthTransformed:
<a name="l00091"></a>00091 AuthenticateLastConfidentialBlock();
<a name="l00092"></a>00092 m_bufferedDataLength = 0;
<a name="l00093"></a>00093 m_state = State_AuthFooter;
<a name="l00094"></a>00094 <span class="comment">// fall through</span>
<a name="l00095"></a>00095 <span class="keywordflow">case</span> State_AuthFooter:
<a name="l00096"></a>00096 AuthenticateData(input, length);
<a name="l00097"></a>00097 m_totalFooterLength += length;
<a name="l00098"></a>00098 <span class="keywordflow">break</span>;
<a name="l00099"></a>00099 <span class="keywordflow">default</span>:
<a name="l00100"></a>00100 assert(<span class="keyword">false</span>);
<a name="l00101"></a>00101 }
<a name="l00102"></a>00102 }
<a name="l00103"></a>00103
<a name="l00104"></a><a class="code" href="class_authenticated_symmetric_cipher_base.html#a2887c0e4c7e303bdb51dfd869b16189f">00104</a> <span class="keywordtype">void</span> <a class="code" href="class_authenticated_symmetric_cipher_base.html#a2887c0e4c7e303bdb51dfd869b16189f" title="encrypt or decrypt an array of bytes of specified length">AuthenticatedSymmetricCipherBase::ProcessData</a>(byte *outString, <span class="keyword">const</span> byte *inString, <span class="keywordtype">size_t</span> length)
<a name="l00105"></a>00105 {
<a name="l00106"></a>00106 m_totalMessageLength += length;
<a name="l00107"></a>00107 <span class="keywordflow">if</span> (m_state >= State_IVSet && m_totalMessageLength > <a class="code" href="class_authenticated_symmetric_cipher.html#a89bf90afafec009ac52321e1a97698d1" title="the maximum length of encrypted data">MaxMessageLength</a>())
<a name="l00108"></a>00108 <span class="keywordflow">throw</span> <a class="code" href="class_invalid_argument.html" title="exception thrown when an invalid argument is detected">InvalidArgument</a>(<a class="code" href="class_authenticated_symmetric_cipher.html#aae9cc715b7640cfc1f5fcad980ea34a2" title="returns name of this algorithm, not universally implemented yet">AlgorithmName</a>() + <span class="stringliteral">": message length exceeds maximum"</span>);
<a name="l00109"></a>00109
<a name="l00110"></a>00110 reswitch:
<a name="l00111"></a>00111 <span class="keywordflow">switch</span> (m_state)
<a name="l00112"></a>00112 {
<a name="l00113"></a>00113 <span class="keywordflow">case</span> State_Start:
<a name="l00114"></a>00114 <span class="keywordflow">case</span> State_KeySet:
<a name="l00115"></a>00115 <span class="keywordflow">throw</span> <a class="code" href="class_authenticated_symmetric_cipher_1_1_bad_state.html" title="this indicates that a member function was called in the wrong state, for example trying to encrypt a ...">BadState</a>(<a class="code" href="class_authenticated_symmetric_cipher.html#aae9cc715b7640cfc1f5fcad980ea34a2" title="returns name of this algorithm, not universally implemented yet">AlgorithmName</a>(), <span class="stringliteral">"ProcessData"</span>, <span class="stringliteral">"setting key and IV"</span>);
<a name="l00116"></a>00116 <span class="keywordflow">case</span> State_AuthFooter:
<a name="l00117"></a>00117 <span class="keywordflow">throw</span> <a class="code" href="class_authenticated_symmetric_cipher_1_1_bad_state.html" title="this indicates that a member function was called in the wrong state, for example trying to encrypt a ...">BadState</a>(<a class="code" href="class_authenticated_symmetric_cipher.html#aae9cc715b7640cfc1f5fcad980ea34a2" title="returns name of this algorithm, not universally implemented yet">AlgorithmName</a>(), <span class="stringliteral">"ProcessData was called after footer input has started"</span>);
<a name="l00118"></a>00118 <span class="keywordflow">case</span> State_IVSet:
<a name="l00119"></a>00119 AuthenticateLastHeaderBlock();
<a name="l00120"></a>00120 m_bufferedDataLength = 0;
<a name="l00121"></a>00121 m_state = AuthenticationIsOnPlaintext()==<a class="code" href="class_stream_transformation.html#a3244f76963a12a5ab6112326c7af9724" title="returns whether this is an encryption object">IsForwardTransformation</a>() ? State_AuthUntransformed : State_AuthTransformed;
<a name="l00122"></a>00122 <span class="keywordflow">goto</span> reswitch;
<a name="l00123"></a>00123 <span class="keywordflow">case</span> State_AuthUntransformed:
<a name="l00124"></a>00124 AuthenticateData(inString, length);
<a name="l00125"></a>00125 AccessSymmetricCipher().<a class="code" href="class_stream_transformation.html#a26feabde21bc4d1783195969733e3bb0" title="encrypt or decrypt an array of bytes of specified length">ProcessData</a>(outString, inString, length);
<a name="l00126"></a>00126 <span class="keywordflow">break</span>;
<a name="l00127"></a>00127 <span class="keywordflow">case</span> State_AuthTransformed:
<a name="l00128"></a>00128 AccessSymmetricCipher().<a class="code" href="class_stream_transformation.html#a26feabde21bc4d1783195969733e3bb0" title="encrypt or decrypt an array of bytes of specified length">ProcessData</a>(outString, inString, length);
<a name="l00129"></a>00129 AuthenticateData(outString, length);
<a name="l00130"></a>00130 <span class="keywordflow">break</span>;
<a name="l00131"></a>00131 <span class="keywordflow">default</span>:
<a name="l00132"></a>00132 assert(<span class="keyword">false</span>);
<a name="l00133"></a>00133 }
<a name="l00134"></a>00134 }
<a name="l00135"></a>00135
<a name="l00136"></a><a class="code" href="class_authenticated_symmetric_cipher_base.html#acd833963b6abcfabc9ada275fbea8625">00136</a> <span class="keywordtype">void</span> <a class="code" href="class_authenticated_symmetric_cipher_base.html#acd833963b6abcfabc9ada275fbea8625" title="truncated version of Final()">AuthenticatedSymmetricCipherBase::TruncatedFinal</a>(byte *mac, <span class="keywordtype">size_t</span> macSize)
<a name="l00137"></a>00137 {
<a name="l00138"></a>00138 <span class="keywordflow">if</span> (m_totalHeaderLength > <a class="code" href="class_authenticated_symmetric_cipher.html#a2f15306daa15eebe988df98a9c7386b0" title="the maximum length of AAD that can be input before the encrypted data">MaxHeaderLength</a>())
<a name="l00139"></a>00139 <span class="keywordflow">throw</span> <a class="code" href="class_invalid_argument.html" title="exception thrown when an invalid argument is detected">InvalidArgument</a>(<a class="code" href="class_authenticated_symmetric_cipher.html#aae9cc715b7640cfc1f5fcad980ea34a2" title="returns name of this algorithm, not universally implemented yet">AlgorithmName</a>() + <span class="stringliteral">": header length of "</span> + IntToString(m_totalHeaderLength) + <span class="stringliteral">" exceeds the maximum of "</span> + IntToString(<a class="code" href="class_authenticated_symmetric_cipher.html#a2f15306daa15eebe988df98a9c7386b0" title="the maximum length of AAD that can be input before the encrypted data">MaxHeaderLength</a>()));
<a name="l00140"></a>00140
<a name="l00141"></a>00141 <span class="keywordflow">if</span> (m_totalFooterLength > <a class="code" href="class_authenticated_symmetric_cipher.html#a2307840ae74d2c4a1cc028d4aff903b3" title="the maximum length of AAD that can be input after the encrypted data">MaxFooterLength</a>())
<a name="l00142"></a>00142 {
<a name="l00143"></a>00143 <span class="keywordflow">if</span> (<a class="code" href="class_authenticated_symmetric_cipher.html#a2307840ae74d2c4a1cc028d4aff903b3" title="the maximum length of AAD that can be input after the encrypted data">MaxFooterLength</a>() == 0)
<a name="l00144"></a>00144 <span class="keywordflow">throw</span> <a class="code" href="class_invalid_argument.html" title="exception thrown when an invalid argument is detected">InvalidArgument</a>(<a class="code" href="class_authenticated_symmetric_cipher.html#aae9cc715b7640cfc1f5fcad980ea34a2" title="returns name of this algorithm, not universally implemented yet">AlgorithmName</a>() + <span class="stringliteral">": additional authenticated data (AAD) cannot be input after data to be encrypted or decrypted"</span>);
<a name="l00145"></a>00145 <span class="keywordflow">else</span>
<a name="l00146"></a>00146 <span class="keywordflow">throw</span> <a class="code" href="class_invalid_argument.html" title="exception thrown when an invalid argument is detected">InvalidArgument</a>(<a class="code" href="class_authenticated_symmetric_cipher.html#aae9cc715b7640cfc1f5fcad980ea34a2" title="returns name of this algorithm, not universally implemented yet">AlgorithmName</a>() + <span class="stringliteral">": footer length of "</span> + IntToString(m_totalFooterLength) + <span class="stringliteral">" exceeds the maximum of "</span> + IntToString(<a class="code" href="class_authenticated_symmetric_cipher.html#a2307840ae74d2c4a1cc028d4aff903b3" title="the maximum length of AAD that can be input after the encrypted data">MaxFooterLength</a>()));
<a name="l00147"></a>00147 }
<a name="l00148"></a>00148
<a name="l00149"></a>00149 <span class="keywordflow">switch</span> (m_state)
<a name="l00150"></a>00150 {
<a name="l00151"></a>00151 <span class="keywordflow">case</span> State_Start:
<a name="l00152"></a>00152 <span class="keywordflow">case</span> State_KeySet:
<a name="l00153"></a>00153 <span class="keywordflow">throw</span> <a class="code" href="class_authenticated_symmetric_cipher_1_1_bad_state.html" title="this indicates that a member function was called in the wrong state, for example trying to encrypt a ...">BadState</a>(<a class="code" href="class_authenticated_symmetric_cipher.html#aae9cc715b7640cfc1f5fcad980ea34a2" title="returns name of this algorithm, not universally implemented yet">AlgorithmName</a>(), <span class="stringliteral">"TruncatedFinal"</span>, <span class="stringliteral">"setting key and IV"</span>);
<a name="l00154"></a>00154
<a name="l00155"></a>00155 <span class="keywordflow">case</span> State_IVSet:
<a name="l00156"></a>00156 AuthenticateLastHeaderBlock();
<a name="l00157"></a>00157 m_bufferedDataLength = 0;
<a name="l00158"></a>00158 <span class="comment">// fall through</span>
<a name="l00159"></a>00159
<a name="l00160"></a>00160 <span class="keywordflow">case</span> State_AuthUntransformed:
<a name="l00161"></a>00161 <span class="keywordflow">case</span> State_AuthTransformed:
<a name="l00162"></a>00162 AuthenticateLastConfidentialBlock();
<a name="l00163"></a>00163 m_bufferedDataLength = 0;
<a name="l00164"></a>00164 <span class="comment">// fall through</span>
<a name="l00165"></a>00165
<a name="l00166"></a>00166 <span class="keywordflow">case</span> State_AuthFooter:
<a name="l00167"></a>00167 AuthenticateLastFooterBlock(mac, macSize);
<a name="l00168"></a>00168 m_bufferedDataLength = 0;
<a name="l00169"></a>00169 <span class="keywordflow">break</span>;
<a name="l00170"></a>00170
<a name="l00171"></a>00171 <span class="keywordflow">default</span>:
<a name="l00172"></a>00172 assert(<span class="keyword">false</span>);
<a name="l00173"></a>00173 }
<a name="l00174"></a>00174
<a name="l00175"></a>00175 m_state = State_KeySet;
<a name="l00176"></a>00176 }
<a name="l00177"></a>00177
<a name="l00178"></a>00178 NAMESPACE_END
<a name="l00179"></a>00179
<a name="l00180"></a>00180 <span class="preprocessor">#endif</span>
</pre></div></div>
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