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<div class="title">iterhash.cpp</div> </div>
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<div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">// iterhash.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">#ifndef __GNUC__</span>
<a name="l00004"></a>00004 <span class="preprocessor"></span><span class="preprocessor">#define CRYPTOPP_MANUALLY_INSTANTIATE_TEMPLATES</span>
<a name="l00005"></a>00005 <span class="preprocessor"></span><span class="preprocessor">#endif</span>
<a name="l00006"></a>00006 <span class="preprocessor"></span>
<a name="l00007"></a>00007 <span class="preprocessor">#include "iterhash.h"</span>
<a name="l00008"></a>00008 <span class="preprocessor">#include "misc.h"</span>
<a name="l00009"></a>00009
<a name="l00010"></a>00010 NAMESPACE_BEGIN(CryptoPP)
<a name="l00011"></a>00011
<a name="l00012"></a>00012 template <class T, class <a class="code" href="class_b_a_s_e.html">BASE</a>> <span class="keywordtype">void</span> <a class="code" href="class_iterated_hash_base.html" title="_">IteratedHashBase</a><T, <a class="code" href="class_b_a_s_e.html">BASE</a>>::Update(const byte *input, <span class="keywordtype">size_t</span> len)
<a name="l00013"></a>00013 {
<a name="l00014"></a>00014 HashWordType oldCountLo = m_countLo, oldCountHi = m_countHi;
<a name="l00015"></a>00015 <span class="keywordflow">if</span> ((m_countLo = oldCountLo + HashWordType(len)) < oldCountLo)
<a name="l00016"></a>00016 m_countHi++; <span class="comment">// carry from low to high</span>
<a name="l00017"></a>00017 m_countHi += (HashWordType)SafeRightShift<8*<span class="keyword">sizeof</span>(HashWordType)>(len);
<a name="l00018"></a>00018 <span class="keywordflow">if</span> (m_countHi < oldCountHi || SafeRightShift<2*8*<span class="keyword">sizeof</span>(HashWordType)>(len) != 0)
<a name="l00019"></a>00019 <span class="keywordflow">throw</span> <a class="code" href="class_hash_input_too_long.html" title="exception thrown when trying to hash more data than is allowed by a hash function">HashInputTooLong</a>(this->AlgorithmName());
<a name="l00020"></a>00020
<a name="l00021"></a>00021 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> blockSize = this-><a class="code" href="namespace_name.html#aa93e40d0259a59959d270e6c82a9f1eb" title="int, in bytes">BlockSize</a>();
<a name="l00022"></a>00022 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> num = ModPowerOf2(oldCountLo, blockSize);
<a name="l00023"></a>00023 T* dataBuf = this->DataBuf();
<a name="l00024"></a>00024 byte* data = (byte *)dataBuf;
<a name="l00025"></a>00025
<a name="l00026"></a>00026 <span class="keywordflow">if</span> (num != 0) <span class="comment">// process left over data</span>
<a name="l00027"></a>00027 {
<a name="l00028"></a>00028 <span class="keywordflow">if</span> (num+len >= blockSize)
<a name="l00029"></a>00029 {
<a name="l00030"></a>00030 memcpy(data+num, input, blockSize-num);
<a name="l00031"></a>00031 HashBlock(dataBuf);
<a name="l00032"></a>00032 input += (blockSize-num);
<a name="l00033"></a>00033 len -= (blockSize-num);
<a name="l00034"></a>00034 num = 0;
<a name="l00035"></a>00035 <span class="comment">// drop through and do the rest</span>
<a name="l00036"></a>00036 }
<a name="l00037"></a>00037 <span class="keywordflow">else</span>
<a name="l00038"></a>00038 {
<a name="l00039"></a>00039 memcpy(data+num, input, len);
<a name="l00040"></a>00040 <span class="keywordflow">return</span>;
<a name="l00041"></a>00041 }
<a name="l00042"></a>00042 }
<a name="l00043"></a>00043
<a name="l00044"></a>00044 <span class="comment">// now process the input data in blocks of blockSize bytes and save the leftovers to m_data</span>
<a name="l00045"></a>00045 <span class="keywordflow">if</span> (len >= blockSize)
<a name="l00046"></a>00046 {
<a name="l00047"></a>00047 <span class="keywordflow">if</span> (input == data)
<a name="l00048"></a>00048 {
<a name="l00049"></a>00049 assert(len == blockSize);
<a name="l00050"></a>00050 HashBlock(dataBuf);
<a name="l00051"></a>00051 <span class="keywordflow">return</span>;
<a name="l00052"></a>00052 }
<a name="l00053"></a>00053 <span class="keywordflow">else</span> <span class="keywordflow">if</span> (IsAligned<T>(input))
<a name="l00054"></a>00054 {
<a name="l00055"></a>00055 <span class="keywordtype">size_t</span> leftOver = HashMultipleBlocks((T *)input, len);
<a name="l00056"></a>00056 input += (len - leftOver);
<a name="l00057"></a>00057 len = leftOver;
<a name="l00058"></a>00058 }
<a name="l00059"></a>00059 <span class="keywordflow">else</span>
<a name="l00060"></a>00060 <span class="keywordflow">do</span>
<a name="l00061"></a>00061 { <span class="comment">// copy input first if it's not aligned correctly</span>
<a name="l00062"></a>00062 memcpy(data, input, blockSize);
<a name="l00063"></a>00063 HashBlock(dataBuf);
<a name="l00064"></a>00064 input+=blockSize;
<a name="l00065"></a>00065 len-=blockSize;
<a name="l00066"></a>00066 } <span class="keywordflow">while</span> (len >= blockSize);
<a name="l00067"></a>00067 }
<a name="l00068"></a>00068
<a name="l00069"></a>00069 <span class="keywordflow">if</span> (len && data != input)
<a name="l00070"></a>00070 memcpy(data, input, len);
<a name="l00071"></a>00071 }
<a name="l00072"></a>00072
<a name="l00073"></a>00073 <span class="keyword">template</span> <<span class="keyword">class</span> T, <span class="keyword">class</span> BASE> byte * <a class="code" href="class_iterated_hash_base.html" title="_">IteratedHashBase<T, BASE>::CreateUpdateSpace</a>(<span class="keywordtype">size_t</span> &size)
<a name="l00074"></a>00074 {
<a name="l00075"></a>00075 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> blockSize = this-><a class="code" href="namespace_name.html#aa93e40d0259a59959d270e6c82a9f1eb" title="int, in bytes">BlockSize</a>();
<a name="l00076"></a>00076 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> num = ModPowerOf2(m_countLo, blockSize);
<a name="l00077"></a>00077 size = blockSize - num;
<a name="l00078"></a>00078 <span class="keywordflow">return</span> (byte *)DataBuf() + num;
<a name="l00079"></a>00079 }
<a name="l00080"></a>00080
<a name="l00081"></a>00081 <span class="keyword">template</span> <<span class="keyword">class</span> T, <span class="keyword">class</span> BASE> <span class="keywordtype">size_t</span> <a class="code" href="class_iterated_hash_base.html" title="_">IteratedHashBase<T, BASE>::HashMultipleBlocks</a>(<span class="keyword">const</span> T *input, <span class="keywordtype">size_t</span> length)
<a name="l00082"></a>00082 {
<a name="l00083"></a>00083 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> blockSize = this-><a class="code" href="namespace_name.html#aa93e40d0259a59959d270e6c82a9f1eb" title="int, in bytes">BlockSize</a>();
<a name="l00084"></a>00084 <span class="keywordtype">bool</span> noReverse = NativeByteOrderIs(this->GetByteOrder());
<a name="l00085"></a>00085 T* dataBuf = this->DataBuf();
<a name="l00086"></a>00086 <span class="keywordflow">do</span>
<a name="l00087"></a>00087 {
<a name="l00088"></a>00088 <span class="keywordflow">if</span> (noReverse)
<a name="l00089"></a>00089 this->HashEndianCorrectedBlock(input);
<a name="l00090"></a>00090 <span class="keywordflow">else</span>
<a name="l00091"></a>00091 {
<a name="l00092"></a>00092 ByteReverse(dataBuf, input, this-><a class="code" href="namespace_name.html#aa93e40d0259a59959d270e6c82a9f1eb" title="int, in bytes">BlockSize</a>());
<a name="l00093"></a>00093 this->HashEndianCorrectedBlock(dataBuf);
<a name="l00094"></a>00094 }
<a name="l00095"></a>00095
<a name="l00096"></a>00096 input += blockSize/<span class="keyword">sizeof</span>(T);
<a name="l00097"></a>00097 length -= blockSize;
<a name="l00098"></a>00098 }
<a name="l00099"></a>00099 <span class="keywordflow">while</span> (length >= blockSize);
<a name="l00100"></a>00100 <span class="keywordflow">return</span> length;
<a name="l00101"></a>00101 }
<a name="l00102"></a>00102
<a name="l00103"></a>00103 <span class="keyword">template</span> <<span class="keyword">class</span> T, <span class="keyword">class</span> BASE> <span class="keywordtype">void</span> <a class="code" href="class_iterated_hash_base.html" title="_">IteratedHashBase<T, BASE>::PadLastBlock</a>(<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> lastBlockSize, byte padFirst)
<a name="l00104"></a>00104 {
<a name="l00105"></a>00105 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> blockSize = this-><a class="code" href="namespace_name.html#aa93e40d0259a59959d270e6c82a9f1eb" title="int, in bytes">BlockSize</a>();
<a name="l00106"></a>00106 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> num = ModPowerOf2(m_countLo, blockSize);
<a name="l00107"></a>00107 T* dataBuf = this->DataBuf();
<a name="l00108"></a>00108 byte* data = (byte *)dataBuf;
<a name="l00109"></a>00109 data[num++] = padFirst;
<a name="l00110"></a>00110 <span class="keywordflow">if</span> (num <= lastBlockSize)
<a name="l00111"></a>00111 memset(data+num, 0, lastBlockSize-num);
<a name="l00112"></a>00112 <span class="keywordflow">else</span>
<a name="l00113"></a>00113 {
<a name="l00114"></a>00114 memset(data+num, 0, blockSize-num);
<a name="l00115"></a>00115 HashBlock(dataBuf);
<a name="l00116"></a>00116 memset(data, 0, lastBlockSize);
<a name="l00117"></a>00117 }
<a name="l00118"></a>00118 }
<a name="l00119"></a>00119
<a name="l00120"></a>00120 <span class="keyword">template</span> <<span class="keyword">class</span> T, <span class="keyword">class</span> BASE> <span class="keywordtype">void</span> <a class="code" href="class_iterated_hash_base.html" title="_">IteratedHashBase<T, BASE>::Restart</a>()
<a name="l00121"></a>00121 {
<a name="l00122"></a>00122 m_countLo = m_countHi = 0;
<a name="l00123"></a>00123 Init();
<a name="l00124"></a>00124 }
<a name="l00125"></a>00125
<a name="l00126"></a>00126 <span class="keyword">template</span> <<span class="keyword">class</span> T, <span class="keyword">class</span> BASE> <span class="keywordtype">void</span> <a class="code" href="class_iterated_hash_base.html" title="_">IteratedHashBase<T, BASE>::TruncatedFinal</a>(byte *digest, <span class="keywordtype">size_t</span> size)
<a name="l00127"></a>00127 {
<a name="l00128"></a>00128 this->ThrowIfInvalidTruncatedSize(size);
<a name="l00129"></a>00129
<a name="l00130"></a>00130 T* dataBuf = this->DataBuf();
<a name="l00131"></a>00131 T* stateBuf = this->StateBuf();
<a name="l00132"></a>00132 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> blockSize = this-><a class="code" href="namespace_name.html#aa93e40d0259a59959d270e6c82a9f1eb" title="int, in bytes">BlockSize</a>();
<a name="l00133"></a>00133 ByteOrder order = this->GetByteOrder();
<a name="l00134"></a>00134
<a name="l00135"></a>00135 PadLastBlock(blockSize - 2*<span class="keyword">sizeof</span>(HashWordType));
<a name="l00136"></a>00136 dataBuf[blockSize/<span class="keyword">sizeof</span>(T)-2+order] = ConditionalByteReverse(order, this->GetBitCountLo());
<a name="l00137"></a>00137 dataBuf[blockSize/<span class="keyword">sizeof</span>(T)-1-order] = ConditionalByteReverse(order, this->GetBitCountHi());
<a name="l00138"></a>00138
<a name="l00139"></a>00139 HashBlock(dataBuf);
<a name="l00140"></a>00140
<a name="l00141"></a>00141 <span class="keywordflow">if</span> (IsAligned<HashWordType>(digest) && size%<span class="keyword">sizeof</span>(HashWordType)==0)
<a name="l00142"></a>00142 ConditionalByteReverse<HashWordType>(order, (HashWordType *)digest, stateBuf, size);
<a name="l00143"></a>00143 <span class="keywordflow">else</span>
<a name="l00144"></a>00144 {
<a name="l00145"></a>00145 ConditionalByteReverse<HashWordType>(order, stateBuf, stateBuf, this-><a class="code" href="namespace_name.html#ae065e5d1d16c399ad5404659e649bfec" title="int, in bytes">DigestSize</a>());
<a name="l00146"></a>00146 memcpy(digest, stateBuf, size);
<a name="l00147"></a>00147 }
<a name="l00148"></a>00148
<a name="l00149"></a>00149 this->Restart(); <span class="comment">// reinit for next use</span>
<a name="l00150"></a>00150 }
<a name="l00151"></a>00151
<a name="l00152"></a>00152 <span class="preprocessor">#ifdef __GNUC__</span>
<a name="l00153"></a>00153 <span class="preprocessor"></span> <span class="keyword">template</span> <span class="keyword">class </span><a class="code" href="class_iterated_hash_base.html">IteratedHashBase<word64, HashTransformation></a>;
<a name="l00154"></a>00154 <span class="keyword">template</span> <span class="keyword">class </span><a class="code" href="class_iterated_hash_base.html">IteratedHashBase<word64, MessageAuthenticationCode></a>;
<a name="l00155"></a>00155
<a name="l00156"></a>00156 <span class="keyword">template</span> <span class="keyword">class </span><a class="code" href="class_iterated_hash_base.html">IteratedHashBase<word32, HashTransformation></a>;
<a name="l00157"></a>00157 <span class="keyword">template</span> <span class="keyword">class </span><a class="code" href="class_iterated_hash_base.html">IteratedHashBase<word32, MessageAuthenticationCode></a>;
<a name="l00158"></a>00158 <span class="preprocessor">#endif</span>
<a name="l00159"></a>00159 <span class="preprocessor"></span>
<a name="l00160"></a>00160 NAMESPACE_END
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