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著名的密码库Crypto++的文档 C++语言的杰作。程序员必备。

<a name="l00071"></a>00071                 time_t tstamp1 = time(0);
<a name="l00072"></a>00072                 xorbuf(dtbuf, (byte *)&amp;tstamp1, UnsignedMin(<span class="keyword">sizeof</span>(tstamp1), S));
<a name="l00073"></a>00073                 cipher-&gt;ProcessBlock(dtbuf);
<a name="l00074"></a>00074                 clock_t tstamp2 = clock();
<a name="l00075"></a>00075                 xorbuf(dtbuf, (byte *)&amp;tstamp2, UnsignedMin(<span class="keyword">sizeof</span>(tstamp2), S));
<a name="l00076"></a>00076                 cipher-&gt;ProcessBlock(dtbuf);
<a name="l00077"></a>00077         }
<a name="l00078"></a>00078 
<a name="l00079"></a>00079         <span class="comment">// for FIPS 140-2</span>
<a name="l00080"></a>00080         <a class="code" href="class_random_number_generator.html#497145546d24e6d4abaf10b7e0f1ba17" title="generate random array of bytes">GenerateBlock</a>(m_lastBlock, S);
<a name="l00081"></a>00081 }
<a name="l00082"></a>00082 
<a name="l00083"></a><a class="code" href="class_x917_r_n_g.html#5b84223763a1f90ddc55e87769df7bf9">00083</a> <span class="keywordtype">void</span> <a class="code" href="class_x917_r_n_g.html#5b84223763a1f90ddc55e87769df7bf9" title="generate random bytes as input to a BufferedTransformation">X917RNG::GenerateIntoBufferedTransformation</a>(<a class="code" href="class_buffered_transformation.html" title="interface for buffered transformations">BufferedTransformation</a> &amp;target, <span class="keyword">const</span> std::string &amp;channel, lword size)
<a name="l00084"></a>00084 {
<a name="l00085"></a>00085         <span class="keywordflow">while</span> (size &gt; 0)
<a name="l00086"></a>00086         {
<a name="l00087"></a>00087                 <span class="comment">// calculate new enciphered timestamp</span>
<a name="l00088"></a>00088                 <span class="keywordflow">if</span> (m_deterministicTimeVector.<a class="code" href="class_sec_block.html#f5999bffe3193e62719cc0792b0282a7">size</a>())
<a name="l00089"></a>00089                 {
<a name="l00090"></a>00090                         cipher-&gt;ProcessBlock(m_deterministicTimeVector, dtbuf);
<a name="l00091"></a>00091                         IncrementCounterByOne(m_deterministicTimeVector, S);
<a name="l00092"></a>00092                 }
<a name="l00093"></a>00093                 <span class="keywordflow">else</span>
<a name="l00094"></a>00094                 {
<a name="l00095"></a>00095                         clock_t c = clock();
<a name="l00096"></a>00096                         xorbuf(dtbuf, (byte *)&amp;c, UnsignedMin(<span class="keyword">sizeof</span>(c), S));
<a name="l00097"></a>00097                         time_t t = time(NULL);
<a name="l00098"></a>00098                         xorbuf(dtbuf+S-UnsignedMin(<span class="keyword">sizeof</span>(t), S), (byte *)&amp;t, UnsignedMin(<span class="keyword">sizeof</span>(t), S));
<a name="l00099"></a>00099                         cipher-&gt;ProcessBlock(dtbuf);
<a name="l00100"></a>00100                 }
<a name="l00101"></a>00101 
<a name="l00102"></a>00102                 <span class="comment">// combine enciphered timestamp with seed</span>
<a name="l00103"></a>00103                 xorbuf(randseed, dtbuf, S);
<a name="l00104"></a>00104 
<a name="l00105"></a>00105                 <span class="comment">// generate a new block of random bytes</span>
<a name="l00106"></a>00106                 cipher-&gt;ProcessBlock(randseed);
<a name="l00107"></a>00107                 <span class="keywordflow">if</span> (memcmp(m_lastBlock, randseed, S) == 0)
<a name="l00108"></a>00108                         <span class="keywordflow">throw</span> <a class="code" href="class_self_test_failure.html" title="exception thrown when a crypto algorithm is used after a self test fails">SelfTestFailure</a>(<span class="stringliteral">"X917RNG: Continuous random number generator test failed."</span>);
<a name="l00109"></a>00109 
<a name="l00110"></a>00110                 <span class="comment">// output random bytes</span>
<a name="l00111"></a>00111                 <span class="keywordtype">size_t</span> len = UnsignedMin(S, size);
<a name="l00112"></a>00112                 target.<a class="code" href="class_buffered_transformation.html#97a60b54fafdb3df59e1457ef629fc5f">ChannelPut</a>(channel, randseed, len);
<a name="l00113"></a>00113                 size -= len;
<a name="l00114"></a>00114 
<a name="l00115"></a>00115                 <span class="comment">// compute new seed vector</span>
<a name="l00116"></a>00116                 memcpy(m_lastBlock, randseed, S);
<a name="l00117"></a>00117                 xorbuf(randseed, dtbuf, S);
<a name="l00118"></a>00118                 cipher-&gt;ProcessBlock(randseed);
<a name="l00119"></a>00119         }
<a name="l00120"></a>00120 }
<a name="l00121"></a>00121 
<a name="l00122"></a>00122 <span class="preprocessor">#endif</span>
<a name="l00123"></a>00123 <span class="preprocessor"></span>
<a name="l00124"></a><a class="code" href="class_maurer_randomness_test.html#b7e148c7e8d213b8f77d1336e47857c2">00124</a> <a class="code" href="class_maurer_randomness_test.html#b7e148c7e8d213b8f77d1336e47857c2">MaurerRandomnessTest::MaurerRandomnessTest</a>()
<a name="l00125"></a>00125         : sum(0.0), n(0)
<a name="l00126"></a>00126 {
<a name="l00127"></a>00127         <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> i=0; i&lt;V; i++)
<a name="l00128"></a>00128                 tab[i] = 0;
<a name="l00129"></a>00129 }
<a name="l00130"></a>00130 
<a name="l00131"></a><a class="code" href="class_maurer_randomness_test.html#e2629df58de48eafc8b8d9f0b060ff98">00131</a> <span class="keywordtype">size_t</span> <a class="code" href="class_maurer_randomness_test.html#e2629df58de48eafc8b8d9f0b060ff98" title="input multiple bytes for blocking or non-blocking processing">MaurerRandomnessTest::Put2</a>(<span class="keyword">const</span> byte *inString, <span class="keywordtype">size_t</span> length, <span class="keywordtype">int</span> messageEnd, <span class="keywordtype">bool</span> blocking)
<a name="l00132"></a>00132 {
<a name="l00133"></a>00133         <span class="keywordflow">while</span> (length--)
<a name="l00134"></a>00134         {
<a name="l00135"></a>00135                 byte inByte = *inString++;
<a name="l00136"></a>00136                 <span class="keywordflow">if</span> (n &gt;= Q)
<a name="l00137"></a>00137                         sum += log(<span class="keywordtype">double</span>(n - tab[inByte]));
<a name="l00138"></a>00138                 tab[inByte] = n;
<a name="l00139"></a>00139                 n++;
<a name="l00140"></a>00140         }
<a name="l00141"></a>00141         <span class="keywordflow">return</span> 0;
<a name="l00142"></a>00142 }
<a name="l00143"></a>00143 
<a name="l00144"></a><a class="code" href="class_maurer_randomness_test.html#16395898502d71b76b9419868031b2d7">00144</a> <span class="keywordtype">double</span> <a class="code" href="class_maurer_randomness_test.html#16395898502d71b76b9419868031b2d7">MaurerRandomnessTest::GetTestValue</a>()<span class="keyword"> const</span>
<a name="l00145"></a>00145 <span class="keyword"></span>{
<a name="l00146"></a>00146         <span class="keywordflow">if</span> (<a class="code" href="class_maurer_randomness_test.html#e243c50c1b8f918b0719b207b699ea58">BytesNeeded</a>() &gt; 0)
<a name="l00147"></a>00147                 <span class="keywordflow">throw</span> <a class="code" href="class_exception.html" title="base class for all exceptions thrown by Crypto++">Exception</a>(<a class="code" href="class_exception.html#8e53909d979479380e0274807c074c0a27d9ee7704100a88e4ae4adcc4072015" title="some error not belong to any of the above categories">Exception::OTHER_ERROR</a>, <span class="stringliteral">"MaurerRandomnessTest: "</span> + IntToString(<a class="code" href="class_maurer_randomness_test.html#e243c50c1b8f918b0719b207b699ea58">BytesNeeded</a>()) + <span class="stringliteral">" more bytes of input needed"</span>);
<a name="l00148"></a>00148 
<a name="l00149"></a>00149         <span class="keywordtype">double</span> fTu = (sum/(n-Q))/log(2.0);      <span class="comment">// this is the test value defined by Maurer</span>
<a name="l00150"></a>00150 
<a name="l00151"></a>00151         <span class="keywordtype">double</span> value = fTu * 0.1392;            <span class="comment">// arbitrarily normalize it to</span>
<a name="l00152"></a>00152         <span class="keywordflow">return</span> value &gt; 1.0 ? 1.0 : value;       <span class="comment">// a number between 0 and 1</span>
<a name="l00153"></a>00153 }
<a name="l00154"></a>00154 
<a name="l00155"></a>00155 NAMESPACE_END
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