00001
00002
00003 #include "pch.h"
00004
00005 #ifndef CRYPTOPP_IMPORTS
00006
00007 #include "modes.h"
00008
00009 #ifndef NDEBUG
00010 #include "des.h"
00011 #endif
00012
00013 NAMESPACE_BEGIN(CryptoPP)
00014
00015 #ifndef NDEBUG
00016 void Modes_TestInstantiations()
00017 {
00018 CFB_Mode<DES>::Encryption m0;
00019 CFB_Mode<DES>::Decryption m1;
00020 OFB_Mode<DES>::Encryption m2;
00021 CTR_Mode<DES>::Encryption m3;
00022 ECB_Mode<DES>::Encryption m4;
00023 CBC_Mode<DES>::Encryption m5;
00024 }
00025 #endif
00026
00027 void CipherModeBase::SetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms)
00028 {
00029 UncheckedSetKey(params, key, length, GetIVAndThrowIfInvalid(params));
00030 }
00031
00032 void CipherModeBase::GetNextIV(byte *IV)
00033 {
00034 if (!IsForwardTransformation())
00035 throw NotImplemented("CipherModeBase: GetNextIV() must be called on an encryption object");
00036
00037 m_cipher->ProcessBlock(m_register);
00038 memcpy(IV, m_register, BlockSize());
00039 }
00040
00041 void CTR_ModePolicy::SeekToIteration(lword iterationCount)
00042 {
00043 int carry=0;
00044 for (int i=BlockSize()-1; i>=0; i--)
00045 {
00046 unsigned int sum = m_register[i] + byte(iterationCount) + carry;
00047 m_counterArray[i] = (byte) sum;
00048 carry = sum >> 8;
00049 iterationCount >>= 8;
00050 }
00051 }
00052
00053 static inline void IncrementCounterByOne(byte *inout, unsigned int s)
00054 {
00055 for (int i=s-1, carry=1; i>=0 && carry; i--)
00056 carry = !++inout[i];
00057 }
00058
00059 static inline void IncrementCounterByOne(byte *output, const byte *input, unsigned int s)
00060 {
00061 int i, carry;
00062 for (i=s-1, carry=1; i>=0 && carry; i--)
00063 carry = !(output[i] = input[i]+1);
00064 memcpy(output, input, i+1);
00065 }
00066
00067 void CTR_ModePolicy::GetNextIV(byte *IV)
00068 {
00069 IncrementCounterByOne(IV, m_counterArray, BlockSize());
00070 }
00071
00072 inline void CTR_ModePolicy::ProcessMultipleBlocks(byte *output, const byte *input, unsigned int n)
00073 {
00074 unsigned int s = BlockSize(), j = 0;
00075 for (unsigned int i=1; i<n; i++, j+=s)
00076 IncrementCounterByOne(m_counterArray + j + s, m_counterArray + j, s);
00077 m_cipher->ProcessAndXorMultipleBlocks(m_counterArray, input, output, n);
00078 IncrementCounterByOne(m_counterArray, m_counterArray + s*(n-1), s);
00079 }
00080
00081 void CTR_ModePolicy::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, unsigned int iterationCount)
00082 {
00083 unsigned int maxBlocks = m_cipher->OptimalNumberOfParallelBlocks();
00084 if (maxBlocks == 1)
00085 {
00086 unsigned int sizeIncrement = BlockSize();
00087 while (iterationCount)
00088 {
00089 m_cipher->ProcessAndXorBlock(m_counterArray, input, output);
00090 IncrementCounterByOne(m_counterArray, sizeIncrement);
00091 output += sizeIncrement;
00092 input += sizeIncrement;
00093 iterationCount -= 1;
00094 }
00095 }
00096 else
00097 {
00098 unsigned int sizeIncrement = maxBlocks * BlockSize();
00099 while (iterationCount >= maxBlocks)
00100 {
00101 ProcessMultipleBlocks(output, input, maxBlocks);
00102 output += sizeIncrement;
00103 input += sizeIncrement;
00104 iterationCount -= maxBlocks;
00105 }
00106 if (iterationCount > 0)
00107 ProcessMultipleBlocks(output, input, iterationCount);
00108 }
00109 }
00110
00111 void CTR_ModePolicy::CipherResynchronize(byte *keystreamBuffer, const byte *iv)
00112 {
00113 unsigned int s = BlockSize();
00114 CopyOrZero(m_register, iv, s);
00115 m_counterArray.New(s * m_cipher->OptimalNumberOfParallelBlocks());
00116 CopyOrZero(m_counterArray, iv, s);
00117 }
00118
00119 void BlockOrientedCipherModeBase::UncheckedSetKey(const NameValuePairs ¶ms, const byte *key, unsigned int length, const byte *iv)
00120 {
00121 m_cipher->SetKey(key, length, params);
00122 ResizeBuffers();
00123 if (IsResynchronizable())
00124 Resynchronize(iv);
00125 }
00126
00127 void BlockOrientedCipherModeBase::ProcessData(byte *outString, const byte *inString, unsigned int length)
00128 {
00129 unsigned int s = BlockSize();
00130 assert(length % s == 0);
00131 unsigned int alignment = m_cipher->BlockAlignment();
00132 bool inputAlignmentOk = !RequireAlignedInput() || IsAlignedOn(inString, alignment);
00133
00134 if (IsAlignedOn(outString, alignment))
00135 {
00136 if (inputAlignmentOk)
00137 ProcessBlocks(outString, inString, length / s);
00138 else
00139 {
00140 memcpy(outString, inString, length);
00141 ProcessBlocks(outString, outString, length / s);
00142 }
00143 }
00144 else
00145 {
00146 while (length)
00147 {
00148 if (inputAlignmentOk)
00149 ProcessBlocks(m_buffer, inString, 1);
00150 else
00151 {
00152 memcpy(m_buffer, inString, s);
00153 ProcessBlocks(m_buffer, m_buffer, 1);
00154 }
00155 memcpy(outString, m_buffer, s);
00156 inString += s;
00157 outString += s;
00158 length -= s;
00159 }
00160 }
00161 }
00162
00163 void CBC_Encryption::ProcessBlocks(byte *outString, const byte *inString, unsigned int numberOfBlocks)
00164 {
00165 unsigned int blockSize = BlockSize();
00166 while (numberOfBlocks--)
00167 {
00168 xorbuf(m_register, inString, blockSize);
00169 m_cipher->ProcessBlock(m_register);
00170 memcpy(outString, m_register, blockSize);
00171 inString += blockSize;
00172 outString += blockSize;
00173 }
00174 }
00175
00176 void CBC_CTS_Encryption::ProcessLastBlock(byte *outString, const byte *inString, unsigned int length)
00177 {
00178 if (length <= BlockSize())
00179 {
00180 if (!m_stolenIV)
00181 throw InvalidArgument("CBC_Encryption: message is too short for ciphertext stealing");
00182
00183
00184 memcpy(outString, m_register, length);
00185 outString = m_stolenIV;
00186 }
00187 else
00188 {
00189
00190 xorbuf(m_register, inString, BlockSize());
00191 m_cipher->ProcessBlock(m_register);
00192 inString += BlockSize();
00193 length -= BlockSize();
00194 memcpy(outString+BlockSize(), m_register, length);
00195 }
00196
00197
00198 xorbuf(m_register, inString, length);
00199 m_cipher->ProcessBlock(m_register);
00200 memcpy(outString, m_register, BlockSize());
00201 }
00202
00203 void CBC_Decryption::ProcessBlocks(byte *outString, const byte *inString, unsigned int numberOfBlocks)
00204 {
00205 unsigned int blockSize = BlockSize();
00206 while (numberOfBlocks--)
00207 {
00208 memcpy(m_temp, inString, blockSize);
00209 m_cipher->ProcessBlock(m_temp, outString);
00210 xorbuf(outString, m_register, blockSize);
00211 m_register.swap(m_temp);
00212 inString += blockSize;
00213 outString += blockSize;
00214 }
00215 }
00216
00217 void CBC_CTS_Decryption::ProcessLastBlock(byte *outString, const byte *inString, unsigned int length)
00218 {
00219 const byte *pn, *pn1;
00220 bool stealIV = length <= BlockSize();
00221
00222 if (stealIV)
00223 {
00224 pn = inString;
00225 pn1 = m_register;
00226 }
00227 else
00228 {
00229 pn = inString + BlockSize();
00230 pn1 = inString;
00231 length -= BlockSize();
00232 }
00233
00234
00235 memcpy(m_temp, pn1, BlockSize());
00236 m_cipher->ProcessBlock(m_temp);
00237 xorbuf(m_temp, pn, length);
00238
00239 if (stealIV)
00240 memcpy(outString, m_temp, length);
00241 else
00242 {
00243 memcpy(outString+BlockSize(), m_temp, length);
00244
00245 memcpy(m_temp, pn, length);
00246 m_cipher->ProcessBlock(m_temp);
00247 xorbuf(outString, m_temp, m_register, BlockSize());
00248 }
00249 }
00250
00251 NAMESPACE_END
00252
00253 #endif