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Crypto++是一个非常强大的密码学库,主要是功能全

00115                 <span class="keywordflow">else</span>
00116                 {
00117                         memcpy(outString, inString, length);
00118                         ProcessBlocks(outString, outString, length / s);
00119                 }
00120         }
00121         <span class="keywordflow">else</span>
00122         {
00123                 <span class="keywordflow">while</span> (length)
00124                 {
00125                         <span class="keywordflow">if</span> (!requireAlignedInput || IsAlignedOn(inString, alignment))
00126                                 ProcessBlocks(m_buffer, inString, 1);
00127                         <span class="keywordflow">else</span>
00128                         {
00129                                 memcpy(m_buffer, inString, s);
00130                                 ProcessBlocks(m_buffer, m_buffer, 1);
00131                         }
00132                         memcpy(outString, m_buffer, s);
00133                         length -= s;
00134                 }
00135         }
00136 }
00137 
00138 <span class="keywordtype">void</span> CBC_Encryption::ProcessBlocks(byte *outString, <span class="keyword">const</span> byte *inString, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> numberOfBlocks)
00139 {
00140         <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> blockSize = <a class="code" href="namespace_name.html#a9">BlockSize</a>();
00141         <span class="keywordflow">while</span> (numberOfBlocks--)
00142         {
00143                 xorbuf(m_register, inString, blockSize);
00144                 m_cipher-&gt;ProcessBlock(m_register);
00145                 memcpy(outString, m_register, blockSize);
00146                 inString += blockSize;
00147                 outString += blockSize;
00148         }
00149 }
00150 
00151 <span class="keywordtype">void</span> CBC_CTS_Encryption::ProcessLastBlock(byte *outString, <span class="keyword">const</span> byte *inString, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> length)
00152 {
00153         <span class="keywordflow">if</span> (length &lt;= <a class="code" href="namespace_name.html#a9">BlockSize</a>())
00154         {
00155                 <span class="keywordflow">if</span> (!m_stolenIV)
00156                         <span class="keywordflow">throw</span> <a class="code" href="class_invalid_argument.html">InvalidArgument</a>(<span class="stringliteral">"CBC_Encryption: message is too short for ciphertext stealing"</span>);
00157 
00158                 <span class="comment">// steal from IV</span>
00159                 memcpy(outString, m_register, length);
00160                 outString = m_stolenIV;
00161         }
00162         <span class="keywordflow">else</span>
00163         {
00164                 <span class="comment">// steal from next to last block</span>
00165                 xorbuf(m_register, inString, <a class="code" href="namespace_name.html#a9">BlockSize</a>());
00166                 m_cipher-&gt;ProcessBlock(m_register);
00167                 inString += <a class="code" href="namespace_name.html#a9">BlockSize</a>();
00168                 length -= <a class="code" href="namespace_name.html#a9">BlockSize</a>();
00169                 memcpy(outString+<a class="code" href="namespace_name.html#a9">BlockSize</a>(), m_register, length);
00170         }
00171 
00172         <span class="comment">// output last full ciphertext block</span>
00173         xorbuf(m_register, inString, length);
00174         m_cipher-&gt;ProcessBlock(m_register);
00175         memcpy(outString, m_register, <a class="code" href="namespace_name.html#a9">BlockSize</a>());
00176 }
00177 
00178 <span class="keywordtype">void</span> CBC_Decryption::ProcessBlocks(byte *outString, <span class="keyword">const</span> byte *inString, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> numberOfBlocks)
00179 {
00180         <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> blockSize = <a class="code" href="namespace_name.html#a9">BlockSize</a>();
00181         <span class="keywordflow">while</span> (numberOfBlocks--)
00182         {
00183                 memcpy(m_temp, inString, blockSize);
00184                 m_cipher-&gt;ProcessBlock(m_temp, outString);
00185                 xorbuf(outString, m_register, blockSize);
00186                 m_register.swap(m_temp);
00187                 inString += blockSize;
00188                 outString += blockSize;
00189         }
00190 }
00191 
00192 <span class="keywordtype">void</span> CBC_CTS_Decryption::ProcessLastBlock(byte *outString, <span class="keyword">const</span> byte *inString, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> length)
00193 {
00194         <span class="keyword">const</span> byte *pn, *pn1;
00195         <span class="keywordtype">bool</span> stealIV = length &lt;= <a class="code" href="namespace_name.html#a9">BlockSize</a>();
00196 
00197         <span class="keywordflow">if</span> (stealIV)
00198         {
00199                 pn = inString;
00200                 pn1 = m_register;
00201         }
00202         <span class="keywordflow">else</span>
00203         {
00204                 pn = inString + <a class="code" href="namespace_name.html#a9">BlockSize</a>();
00205                 pn1 = inString;
00206                 length -= <a class="code" href="namespace_name.html#a9">BlockSize</a>();
00207         }
00208 
00209         <span class="comment">// decrypt last partial plaintext block</span>
00210         memcpy(m_temp, pn1, <a class="code" href="namespace_name.html#a9">BlockSize</a>());
00211         m_cipher-&gt;ProcessBlock(m_temp);
00212         xorbuf(m_temp, pn, length);
00213 
00214         <span class="keywordflow">if</span> (stealIV)
00215                 memcpy(outString, m_temp, length);
00216         <span class="keywordflow">else</span>
00217         {
00218                 memcpy(outString+<a class="code" href="namespace_name.html#a9">BlockSize</a>(), m_temp, length);
00219                 <span class="comment">// decrypt next to last plaintext block</span>
00220                 memcpy(m_temp, pn, length);
00221                 m_cipher-&gt;ProcessBlock(m_temp);
00222                 xorbuf(outString, m_temp, m_register, <a class="code" href="namespace_name.html#a9">BlockSize</a>());
00223         }
00224 }
00225 
00226 NAMESPACE_END
00227 
00228 <span class="preprocessor">#endif</span>
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