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Diffstat (limited to 'CryptoPP/gost.cpp')
| -rw-r--r-- | CryptoPP/gost.cpp | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/CryptoPP/gost.cpp b/CryptoPP/gost.cpp new file mode 100644 index 000000000..bbd829752 --- /dev/null +++ b/CryptoPP/gost.cpp @@ -0,0 +1,123 @@ +#include "pch.h" +#include "gost.h" +#include "misc.h" + +NAMESPACE_BEGIN(CryptoPP) + +// these are the S-boxes given in Applied Cryptography 2nd Ed., p. 333 +const byte GOST::Base::sBox[8][16]={ + {4, 10, 9, 2, 13, 8, 0, 14, 6, 11, 1, 12, 7, 15, 5, 3}, + {14, 11, 4, 12, 6, 13, 15, 10, 2, 3, 8, 1, 0, 7, 5, 9}, + {5, 8, 1, 13, 10, 3, 4, 2, 14, 15, 12, 7, 6, 0, 9, 11}, + {7, 13, 10, 1, 0, 8, 9, 15, 14, 4, 6, 12, 11, 2, 5, 3}, + {6, 12, 7, 1, 5, 15, 13, 8, 4, 10, 9, 14, 0, 3, 11, 2}, + {4, 11, 10, 0, 7, 2, 1, 13, 3, 6, 8, 5, 9, 12, 15, 14}, + {13, 11, 4, 1, 3, 15, 5, 9, 0, 10, 14, 7, 6, 8, 2, 12}, + {1, 15, 13, 0, 5, 7, 10, 4, 9, 2, 3, 14, 6, 11, 8, 12}}; + +/* // these are the S-boxes given in the GOST source code listing in Applied + // Cryptography 2nd Ed., p. 644. they appear to be from the DES S-boxes + {13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7 }, + { 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1 }, + {12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11 }, + { 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9 }, + { 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15 }, + {10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8 }, + {15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10 }, + {14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7 }}; +*/ + +volatile bool GOST::Base::sTableCalculated = false; +word32 GOST::Base::sTable[4][256]; + +void GOST::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &) +{ + AssertValidKeyLength(length); + + PrecalculateSTable(); + + GetUserKey(LITTLE_ENDIAN_ORDER, key.begin(), 8, userKey, KEYLENGTH); +} + +void GOST::Base::PrecalculateSTable() +{ + if (!sTableCalculated) + { + for (unsigned i = 0; i < 4; i++) + for (unsigned j = 0; j < 256; j++) + { + word32 temp = sBox[2*i][j%16] | (sBox[2*i+1][j/16] << 4); + sTable[i][j] = rotlMod(temp, 11+8*i); + } + + sTableCalculated=true; + } +} + +#define f(x) ( t=x, \ + sTable[3][GETBYTE(t, 3)] ^ sTable[2][GETBYTE(t, 2)] \ + ^ sTable[1][GETBYTE(t, 1)] ^ sTable[0][GETBYTE(t, 0)] ) + +typedef BlockGetAndPut<word32, LittleEndian> Block; + +void GOST::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const +{ + word32 n1, n2, t; + + Block::Get(inBlock)(n1)(n2); + + for (unsigned int i=0; i<3; i++) + { + n2 ^= f(n1+key[0]); + n1 ^= f(n2+key[1]); + n2 ^= f(n1+key[2]); + n1 ^= f(n2+key[3]); + n2 ^= f(n1+key[4]); + n1 ^= f(n2+key[5]); + n2 ^= f(n1+key[6]); + n1 ^= f(n2+key[7]); + } + + n2 ^= f(n1+key[7]); + n1 ^= f(n2+key[6]); + n2 ^= f(n1+key[5]); + n1 ^= f(n2+key[4]); + n2 ^= f(n1+key[3]); + n1 ^= f(n2+key[2]); + n2 ^= f(n1+key[1]); + n1 ^= f(n2+key[0]); + + Block::Put(xorBlock, outBlock)(n2)(n1); +} + +void GOST::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const +{ + word32 n1, n2, t; + + Block::Get(inBlock)(n1)(n2); + + n2 ^= f(n1+key[0]); + n1 ^= f(n2+key[1]); + n2 ^= f(n1+key[2]); + n1 ^= f(n2+key[3]); + n2 ^= f(n1+key[4]); + n1 ^= f(n2+key[5]); + n2 ^= f(n1+key[6]); + n1 ^= f(n2+key[7]); + + for (unsigned int i=0; i<3; i++) + { + n2 ^= f(n1+key[7]); + n1 ^= f(n2+key[6]); + n2 ^= f(n1+key[5]); + n1 ^= f(n2+key[4]); + n2 ^= f(n1+key[3]); + n1 ^= f(n2+key[2]); + n2 ^= f(n1+key[1]); + n1 ^= f(n2+key[0]); + } + + Block::Put(xorBlock, outBlock)(n2)(n1); +} + +NAMESPACE_END |