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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><html><head><meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"><title>Crypto++: pssr.h Source File</title><link href="doxygen.css" rel="stylesheet" type="text/css"></head><body><!-- Generated by Doxygen 1.3.2 --><div class="qindex"><a class="qindex" href="index.html">Main Page</a> | <a class="qindex" href="namespaces.html">Namespace List</a> | <a class="qindex" href="hierarchy.html">Class Hierarchy</a> | <a class="qindex" href="classes.html">Alphabetical List</a> | <a class="qindex" href="annotated.html">Compound List</a> | <a class="qindex" href="files.html">File List</a> | <a class="qindex" href="namespacemembers.html">Namespace Members</a> | <a class="qindex" href="functions.html">Compound Members</a> | <a class="qindex" href="globals.html">File Members</a></div><h1>pssr.h</h1><div class="fragment"><pre>00001 <span class="preprocessor">#ifndef CRYPTOPP_PSSR_H</span>00002 <span class="preprocessor"></span><span class="preprocessor">#define CRYPTOPP_PSSR_H</span>00003 <span class="preprocessor"></span>00004 <span class="preprocessor">#include "<a class="code" href="pubkey_8h.html">pubkey.h</a>"</span>00005 <span class="preprocessor">#include <functional></span>00006 00007 NAMESPACE_BEGIN(CryptoPP)00008 00009 <span class="comment">// TODO: implement standard variant of PSSR</span>00010 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF=P1363_MGF1<H> >00011 <span class="keyword">class </span>PSSR : <span class="keyword">public</span> <a class="code" href="class_signature_encoding_method_with_recovery.html">SignatureEncodingMethodWithRecovery</a>00012 {00013 <span class="keyword">public</span>:00014 PSSR(<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> representativeBitLen);00015 PSSR(<span class="keyword">const</span> byte *representative, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> representativeBitLen);00016 ~PSSR() {}00017 <span class="keywordtype">void</span> Update(<span class="keyword">const</span> byte *input, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> length);00018 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> DigestSize()<span class="keyword"> const </span>{<span class="keywordflow">return</span> BitsToBytes(representativeBitLen);}00019 <span class="keywordtype">void</span> Restart() {h.Restart();}00020 <span class="keywordtype">void</span> Encode(<a class="code" href="class_random_number_generator.html">RandomNumberGenerator</a> &rng, byte *representative);00021 <span class="keywordtype">bool</span> Verify(<span class="keyword">const</span> byte *representative);00022 <a class="code" href="struct_decoding_result.html">DecodingResult</a> Decode(byte *message);00023 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> MaximumRecoverableLength()<span class="keyword"> const </span>{<span class="keywordflow">return</span> MaximumRecoverableLength(representativeBitLen);}00024 <span class="keyword">static</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> MaximumRecoverableLength(<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> representativeBitLen);00025 <span class="keyword">static</span> <span class="keywordtype">bool</span> AllowLeftoverMessage() {<span class="keywordflow">return</span> <span class="keyword">true</span>;}00026 00027 <span class="keyword">protected</span>:00028 <span class="keyword">static</span> <span class="keywordtype">void</span> EncodeRepresentative(byte *representative, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> representativeBitLen, <span class="keyword">const</span> byte *w, <span class="keyword">const</span> byte *seed, <span class="keyword">const</span> byte *m1, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> m1Len);00029 <span class="keyword">static</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> DecodeRepresentative(<span class="keyword">const</span> byte *representative, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> representativeBitLen, byte *w, byte *seed, byte *m1);00030 00031 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> representativeBitLen, m1Len;00032 H h;00033 <a class="code" href="class_sec_block.html">SecByteBlock</a> m1, w, seed;00034 };00035 00036 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF>00037 PSSR<H,MGF>::PSSR(<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> representativeBitLen)00038 : representativeBitLen(representativeBitLen), m1Len(0)00039 , m1(MaximumRecoverableLength()), w(H::DIGESTSIZE), seed(H::DIGESTSIZE)00040 {00041 }00042 00043 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF>00044 PSSR<H,MGF>::PSSR(<span class="keyword">const</span> byte *representative, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> representativeBitLen)00045 : representativeBitLen(representativeBitLen), m1Len(0)00046 , m1(MaximumRecoverableLength()), w(H::DIGESTSIZE), seed(H::DIGESTSIZE)00047 {00048 m1Len = DecodeRepresentative(representative, representativeBitLen, w, seed, m1);00049 h.Update(m1, m1Len);00050 }00051 00052 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF>00053 <span class="keywordtype">void</span> PSSR<H,MGF>::Update(<span class="keyword">const</span> byte *input, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> length)00054 {00055 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> m1LenInc = STDMIN(length, MaximumRecoverableLength() - m1Len);00056 memcpy(m1+m1Len, input, m1LenInc);00057 m1Len += m1LenInc;00058 h.Update(input, length);00059 }00060 00061 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF>00062 <span class="keywordtype">void</span> PSSR<H,MGF>::Encode(<a class="code" href="class_random_number_generator.html">RandomNumberGenerator</a> &rng, byte *representative)00063 {00064 rng.<a class="code" href="class_random_number_generator.html#_x917_r_n_ga4">GenerateBlock</a>(seed, seed.size());00065 h.Update(seed, seed.size());00066 h.Final(w);00067 EncodeRepresentative(representative, representativeBitLen, w, seed, m1, m1Len);00068 }00069 00070 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF>00071 <span class="keywordtype">bool</span> PSSR<H,MGF>::Verify(<span class="keyword">const</span> byte *representative)00072 {00073 <a class="code" href="class_sec_block.html">SecByteBlock</a> m1r(MaximumRecoverableLength()), wr(H::DIGESTSIZE);00074 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> m1rLen = DecodeRepresentative(representative, representativeBitLen, wr, seed, m1r);00075 h.Update(seed, seed.size());00076 h.Final(w);00077 <span class="keywordflow">return</span> m1Len==m1rLen && memcmp(m1, m1r, m1Len)==0 && w==wr;00078 }00079 00080 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF>00081 <a class="code" href="struct_decoding_result.html">DecodingResult</a> PSSR<H,MGF>::Decode(byte *message)00082 {00083 <a class="code" href="class_sec_block.html">SecByteBlock</a> wh(H::DIGESTSIZE);00084 h.Update(seed, seed.size());00085 h.Final(wh);00086 <span class="keywordflow">if</span> (wh == w)00087 {00088 memcpy(message, m1, m1Len);00089 <span class="keywordflow">return</span> <a class="code" href="struct_decoding_result.html">DecodingResult</a>(m1Len);00090 }00091 <span class="keywordflow">else</span>00092 <span class="keywordflow">return</span> <a class="code" href="struct_decoding_result.html">DecodingResult</a>();00093 }00094 00095 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF>00096 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> PSSR<H,MGF>::MaximumRecoverableLength(<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> paddedLength)00097 {00098 <span class="keywordflow">return</span> paddedLength/8 > 1+2*H::DIGESTSIZE ? paddedLength/8-1-2*H::DIGESTSIZE : 0;00099 }00100 00101 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF>00102 <span class="keywordtype">void</span> PSSR<H,MGF>::EncodeRepresentative(byte *pssrBlock, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> pssrBlockLen, <span class="keyword">const</span> byte *w, <span class="keyword">const</span> byte *seed, <span class="keyword">const</span> byte *m1, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> m1Len)00103 {00104 assert (m1Len <= MaximumRecoverableLength(pssrBlockLen));00105 00106 <span class="comment">// convert from bit length to byte length</span>00107 <span class="keywordflow">if</span> (pssrBlockLen % 8 != 0)00108 {00109 pssrBlock[0] = 0;00110 pssrBlock++;00111 }00112 pssrBlockLen /= 8;00113 00114 <span class="keyword">const</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> hLen = H::DIGESTSIZE;00115 <span class="keyword">const</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> wLen = hLen, seedLen = hLen, dbLen = pssrBlockLen-wLen-seedLen;00116 byte *<span class="keyword">const</span> maskedSeed = pssrBlock+wLen;00117 byte *<span class="keyword">const</span> maskedDB = pssrBlock+wLen+seedLen;00118 00119 memcpy(pssrBlock, w, wLen);00120 memcpy(maskedSeed, seed, seedLen);00121 memset(maskedDB, 0, dbLen-m1Len-1);00122 maskedDB[dbLen-m1Len-1] = 0x01;00123 memcpy(maskedDB+dbLen-m1Len, m1, m1Len);00124 00125 MGF::GenerateAndMask(maskedSeed, seedLen+dbLen, w, wLen);00126 }00127 00128 <span class="keyword">template</span> <<span class="keyword">class</span> H, <span class="keyword">class</span> MGF>00129 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> PSSR<H,MGF>::DecodeRepresentative(<span class="keyword">const</span> byte *pssrBlock, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> pssrBlockLen, byte *w, byte *seed, byte *m1)00130 {00131 <span class="comment">// convert from bit length to byte length</span>00132 <span class="keywordflow">if</span> (pssrBlockLen % 8 != 0)00133 {00134 <span class="keywordflow">if</span> (pssrBlock[0] != 0)00135 <span class="keywordflow">return</span> 0;00136 pssrBlock++;00137 }00138 pssrBlockLen /= 8;00139 00140 <span class="keyword">const</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> hLen = H::DIGESTSIZE;00141 <span class="keyword">const</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> wLen = hLen, seedLen = hLen, dbLen = pssrBlockLen-wLen-seedLen;00142 00143 <span class="keywordflow">if</span> (pssrBlockLen < 2*hLen+1)00144 <span class="keywordflow">return</span> 0;00145 00146 memcpy(w, pssrBlock, wLen);00147 <a class="code" href="class_sec_block.html">SecByteBlock</a> t(pssrBlock+wLen, pssrBlockLen-wLen);00148 byte *<span class="keyword">const</span> maskedSeed = t;00149 byte *<span class="keyword">const</span> maskedDB = t+seedLen;00150 00151 MGF::GenerateAndMask(maskedSeed, seedLen+dbLen, w, wLen);00152 memcpy(seed, maskedSeed, seedLen);00153 00154 <span class="comment">// DB = 00 ... || 01 || M</span>00155 00156 byte *M = std::find_if(maskedDB, maskedDB+dbLen, std::bind2nd(std::not_equal_to<byte>(), 0));00157 <span class="keywordflow">if</span> (M!=maskedDB+dbLen && *M == 0x01)00158 {00159 M++;00160 memcpy(m1, M, maskedDB+dbLen-M);00161 <span class="keywordflow">return</span> maskedDB+dbLen-M;00162 }00163 <span class="keywordflow">else</span>00164 <span class="keywordflow">return</span> 0;00165 }00166 00167 NAMESPACE_END00168 00169 <span class="preprocessor">#endif</span></pre></div><hr size="1"><address style="align: right;"><small>Generated on Tue Jul 8 23:34:22 2003 for Crypto++ by<a href="http://www.doxygen.org/index.html"><img src="doxygen.png" alt="doxygen" align="middle" border=0 > </a>1.3.2 </small></address></body></html>⌨️ 快捷键说明
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