gf2n_8cpp-source.html

Crypto++是一个非常强大的密码学库,主要是功能全

00694                                 temp ^= ((temp >> j) & 1) << (t1 + j);
00695                 <span class="keywordflow">else</span>
00696                         b[t1/WORD_BITS-1] ^= temp &lt;&lt; t1%WORD_BITS;
00697 
00698                 <span class="keywordflow">if</span> (t1 % WORD_BITS)
00699                         b[t1/WORD_BITS] ^= temp &gt;&gt; (WORD_BITS - t1%WORD_BITS);
00700 
00701                 <span class="keywordflow">if</span> (t0%WORD_BITS)
00702                 {
00703                         b[t0/WORD_BITS-1] ^= temp &lt;&lt; t0%WORD_BITS;
00704                         b[t0/WORD_BITS] ^= temp &gt;&gt; (WORD_BITS - t0%WORD_BITS);
00705                 }
00706                 <span class="keywordflow">else</span>
00707                         b[t0/WORD_BITS-1] ^= temp;
00708         }
00709 
00710         CopyWords(result.<a class="code" href="class_polynomial_mod2.html#_polynomial_mod2r0">reg</a>.<a class="code" href="class_sec_block.html#_sec_block_with_hinta7">begin</a>(), b, result.<a class="code" href="class_polynomial_mod2.html#_polynomial_mod2r0">reg</a>.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>());
00711         <span class="keywordflow">return</span> result;
00712 }
00713 
00714 <span class="keyword">const</span> GF2NT::Element&amp; GF2NT::Multiply(<span class="keyword">const</span> Element &amp;a, <span class="keyword">const</span> Element &amp;b)<span class="keyword"> const</span>
00715 <span class="keyword"></span>{
00716         <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> aSize = STDMIN(a.reg.size(), result.<a class="code" href="class_polynomial_mod2.html#_polynomial_mod2r0">reg</a>.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>());
00717         Element r((word)0, m);
00718 
00719         <span class="keywordflow">for</span> (<span class="keywordtype">int</span> i=m-1; i&gt;=0; i--)
00720         {
00721                 <span class="keywordflow">if</span> (r[m-1])
00722                 {
00723                         ShiftWordsLeftByBits(r.reg.begin(), r.reg.size(), 1);
00724                         XorWords(r.reg.begin(), m_modulus.reg, r.reg.size());
00725                 }
00726                 <span class="keywordflow">else</span>
00727                         ShiftWordsLeftByBits(r.reg.begin(), r.reg.size(), 1);
00728 
00729                 <span class="keywordflow">if</span> (b[i])
00730                         XorWords(r.reg.begin(), a.reg, aSize);
00731         }
00732 
00733         <span class="keywordflow">if</span> (m%WORD_BITS)
00734                 r.reg.begin()[r.reg.size()-1] = (word)Crop(r.reg[r.reg.size()-1], m%WORD_BITS);
00735 
00736         CopyWords(result.<a class="code" href="class_polynomial_mod2.html#_polynomial_mod2r0">reg</a>.<a class="code" href="class_sec_block.html#_sec_block_with_hinta7">begin</a>(), r.reg.begin(), result.<a class="code" href="class_polynomial_mod2.html#_polynomial_mod2r0">reg</a>.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>());
00737         <span class="keywordflow">return</span> result;
00738 }
00739 
00740 <span class="keyword">const</span> GF2NT::Element&amp; GF2NT::Reduced(<span class="keyword">const</span> Element &amp;a)<span class="keyword"> const</span>
00741 <span class="keyword"></span>{
00742         <span class="keywordflow">if</span> (t0-t1 &lt; WORD_BITS)
00743                 <span class="keywordflow">return</span> m_domain.Mod(a, m_modulus);
00744 
00745         <a class="code" href="class_sec_block.html">SecWordBlock</a> b(a.reg);
00746 
00747         <span class="keywordtype">unsigned</span> i;
00748         <span class="keywordflow">for</span> (i=b.size()-1; i&gt;=BitsToWords(t0); i--)
00749         {
00750                 word temp = b[i];
00751 
00752                 <span class="keywordflow">if</span> (t0%WORD_BITS)
00753                 {
00754                         b[i-t0/WORD_BITS] ^= temp &gt;&gt; t0%WORD_BITS;
00755                         b[i-t0/WORD_BITS-1] ^= temp &lt;&lt; (WORD_BITS - t0%WORD_BITS);
00756                 }
00757                 <span class="keywordflow">else</span>
00758                         b[i-t0/WORD_BITS] ^= temp;
00759 
00760                 <span class="keywordflow">if</span> ((t0-t1)%WORD_BITS)
00761                 {
00762                         b[i-(t0-t1)/WORD_BITS] ^= temp &gt;&gt; (t0-t1)%WORD_BITS;
00763                         b[i-(t0-t1)/WORD_BITS-1] ^= temp &lt;&lt; (WORD_BITS - (t0-t1)%WORD_BITS);
00764                 }
00765                 <span class="keywordflow">else</span>
00766                         b[i-(t0-t1)/WORD_BITS] ^= temp;
00767         }
00768 
00769         <span class="keywordflow">if</span> (i==BitsToWords(t0)-1 &amp;&amp; t0%WORD_BITS)
00770         {
00771                 word mask = ((word)1&lt;&lt;(t0%WORD_BITS))-1;
00772                 word temp = b[i] &amp; ~mask;
00773                 b[i] &amp;= mask;
00774 
00775                 b[i-t0/WORD_BITS] ^= temp &gt;&gt; t0%WORD_BITS;
00776 
00777                 <span class="keywordflow">if</span> ((t0-t1)%WORD_BITS)
00778                 {
00779                         b[i-(t0-t1)/WORD_BITS] ^= temp &gt;&gt; (t0-t1)%WORD_BITS;
00780                         <span class="keywordflow">if</span> ((t0-t1)%WORD_BITS &gt; t0%WORD_BITS)
00781                                 b[i-(t0-t1)/WORD_BITS-1] ^= temp &lt;&lt; (WORD_BITS - (t0-t1)%WORD_BITS);
00782                         <span class="keywordflow">else</span>
00783                                 assert(temp &lt;&lt; (WORD_BITS - (t0-t1)%WORD_BITS) == 0);
00784                 }
00785                 <span class="keywordflow">else</span>
00786                         b[i-(t0-t1)/WORD_BITS] ^= temp;
00787         }
00788 
00789         SetWords(result.<a class="code" href="class_polynomial_mod2.html#_polynomial_mod2r0">reg</a>.<a class="code" href="class_sec_block.html#_sec_block_with_hinta7">begin</a>(), 0, result.<a class="code" href="class_polynomial_mod2.html#_polynomial_mod2r0">reg</a>.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>());
00790         CopyWords(result.<a class="code" href="class_polynomial_mod2.html#_polynomial_mod2r0">reg</a>.<a class="code" href="class_sec_block.html#_sec_block_with_hinta7">begin</a>(), b, STDMIN(b.size(), result.<a class="code" href="class_polynomial_mod2.html#_polynomial_mod2r0">reg</a>.<a class="code" href="class_sec_block.html#_sec_block_with_hinta13">size</a>()));
00791         <span class="keywordflow">return</span> result;
00792 }
00793 
00794 <span class="keywordtype">void</span> GF2NP::DEREncodeElement(<a class="code" href="class_buffered_transformation.html">BufferedTransformation</a> &amp;out, <span class="keyword">const</span> Element &amp;a)<span class="keyword"> const</span>
00795 <span class="keyword"></span>{
00796         a.DEREncodeAsOctetString(out, MaxElementByteLength());
00797 }
00798 
00799 <span class="keywordtype">void</span> GF2NP::BERDecodeElement(<a class="code" href="class_buffered_transformation.html">BufferedTransformation</a> &amp;in, Element &amp;a)<span class="keyword"> const</span>
00800 <span class="keyword"></span>{
00801         a.BERDecodeAsOctetString(in, MaxElementByteLength());
00802 }
00803 
00804 <span class="keywordtype">void</span> GF2NT::DEREncode(<a class="code" href="class_buffered_transformation.html">BufferedTransformation</a> &amp;bt)<span class="keyword"> const</span>
00805 <span class="keyword"></span>{
00806         <a class="code" href="class_d_e_r_sequence_encoder.html">DERSequenceEncoder</a> seq(bt);
00807                 ASN1::characteristic_two_field().DEREncode(seq);
00808                 <a class="code" href="class_d_e_r_sequence_encoder.html">DERSequenceEncoder</a> parameters(seq);
00809                         DEREncodeUnsigned(parameters, m);
00810                         ASN1::tpBasis().DEREncode(parameters);
00811                         DEREncodeUnsigned(parameters, t1);
00812                 parameters.<a class="code" href="class_d_e_r_general_encoder.html#_d_e_r_set_encodera2">MessageEnd</a>();
00813         seq.<a class="code" href="class_d_e_r_general_encoder.html#_d_e_r_set_encodera2">MessageEnd</a>();
00814 }
00815 
00816 <span class="keywordtype">void</span> GF2NPP::DEREncode(<a class="code" href="class_buffered_transformation.html">BufferedTransformation</a> &amp;bt)<span class="keyword"> const</span>
00817 <span class="keyword"></span>{
00818         <a class="code" href="class_d_e_r_sequence_encoder.html">DERSequenceEncoder</a> seq(bt);
00819                 ASN1::characteristic_two_field().DEREncode(seq);
00820                 <a class="code" href="class_d_e_r_sequence_encoder.html">DERSequenceEncoder</a> parameters(seq);
00821                         DEREncodeUnsigned(parameters, m);
00822                         ASN1::ppBasis().DEREncode(parameters);
00823                         <a class="code" href="class_d_e_r_sequence_encoder.html">DERSequenceEncoder</a> pentanomial(parameters);
00824                                 DEREncodeUnsigned(pentanomial, t3);
00825                                 DEREncodeUnsigned(pentanomial, t2);
00826                                 DEREncodeUnsigned(pentanomial, t1);
00827                         pentanomial.<a class="code" href="class_d_e_r_general_encoder.html#_d_e_r_set_encodera2">MessageEnd</a>();
00828                 parameters.<a class="code" href="class_d_e_r_general_encoder.html#_d_e_r_set_encodera2">MessageEnd</a>();
00829         seq.<a class="code" href="class_d_e_r_general_encoder.html#_d_e_r_set_encodera2">MessageEnd</a>();
00830 }
00831 
00832 <a class="code" href="class_g_f2_n_p.html">GF2NP</a> * BERDecodeGF2NP(<a class="code" href="class_buffered_transformation.html">BufferedTransformation</a> &amp;bt)
00833 {
00834         <span class="comment">// VC60 workaround: auto_ptr lacks reset()</span>
00835         member_ptr&lt;GF2NP&gt; result;
00836 
00837         <a class="code" href="class_b_e_r_sequence_decoder.html">BERSequenceDecoder</a> seq(bt);
00838                 <span class="keywordflow">if</span> (<a class="code" href="class_o_i_d.html">OID</a>(seq) != ASN1::characteristic_two_field())
00839                         BERDecodeError();
00840                 <a class="code" href="class_b_e_r_sequence_decoder.html">BERSequenceDecoder</a> parameters(seq);
00841                         <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> m;
00842                         BERDecodeUnsigned(parameters, m);
00843                         <a class="code" href="class_o_i_d.html">OID</a> oid(parameters);
00844                         <span class="keywordflow">if</span> (oid == ASN1::tpBasis())
00845                         {
00846                                 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> t1;
00847                                 BERDecodeUnsigned(parameters, t1);
00848                                 result.reset(<span class="keyword">new</span> <a class="code" href="class_g_f2_n_t.html">GF2NT</a>(m, t1, 0));
00849                         }
00850                         <span class="keywordflow">else</span> <span class="keywordflow">if</span> (oid == ASN1::ppBasis())
00851                         {
00852                                 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> t1, t2, t3;
00853                                 <a class="code" href="class_b_e_r_sequence_decoder.html">BERSequenceDecoder</a> pentanomial(parameters);
00854                                 BERDecodeUnsigned(pentanomial, t3);
00855                                 BERDecodeUnsigned(pentanomial, t2);
00856                                 BERDecodeUnsigned(pentanomial, t1);
00857                                 pentanomial.<a class="code" href="class_b_e_r_general_decoder.html#_b_e_r_set_decodera9">MessageEnd</a>();
00858                                 result.reset(<span class="keyword">new</span> <a class="code" href="class_g_f2_n_p_p.html">GF2NPP</a>(m, t3, t2, t1, 0));
00859                         }
00860                         <span class="keywordflow">else</span>
00861                         {
00862                                 BERDecodeError();
00863                                 <span class="keywordflow">return</span> NULL;
00864                         }
00865