void RC5::Base::UncheckedSetKey(const byte *k, unsigned int keylen, const NameValuePairs ¶ms) { AssertValidKeyLength(keylen); r = GetRoundsAndThrowIfInvalid(params, this); sTable.New(2*(r+1)); static const RC5_WORD MAGIC_P = 0xb7e15163L; // magic constant P for wordsize static const RC5_WORD MAGIC_Q = 0x9e3779b9L; // magic constant Q for wordsize static const int U=sizeof(RC5_WORD); const unsigned int c = STDMAX((keylen+U-1)/U, 1U); // RC6 paper says c=1 if keylen==0 SecBlock<RC5_WORD> l(c); GetUserKey(LITTLE_ENDIAN_ORDER, l.begin(), c, k, keylen); sTable[0] = MAGIC_P; for (unsigned j=1; j<sTable.size(); j++) sTable[j] = sTable[j-1] + MAGIC_Q; RC5_WORD a=0, b=0; const unsigned n = 3*STDMAX((unsigned int)sTable.size(), c); for (unsigned h=0; h < n; h++) { a = sTable[h % sTable.size()] = rotlFixed((sTable[h % sTable.size()] + a + b), 3); b = l[h % c] = rotlMod((l[h % c] + a + b), (a+b)); } }
void SHARK::Base::UncheckedSetKey(const byte *key, unsigned int keyLen, const NameValuePairs ¶ms) { AssertValidKeyLength(keyLen); m_rounds = GetRoundsAndThrowIfInvalid(params, this); m_roundKeys.New(m_rounds+1); // concatenate key enought times to fill a for (unsigned int i=0; i<(m_rounds+1)*8; i++) ((byte *)m_roundKeys.begin())[i] = key[i%keyLen]; SHARK::Encryption e; e.InitForKeySetup(); byte IV[8] = {0,0,0,0,0,0,0,0}; CFB_Mode_ExternalCipher::Encryption cfb(e, IV); cfb.ProcessString((byte *)m_roundKeys.begin(), (m_rounds+1)*8); ConditionalByteReverse(BIG_ENDIAN_ORDER, m_roundKeys.begin(), m_roundKeys.begin(), (m_rounds+1)*8); m_roundKeys[m_rounds] = SHARKTransform(m_roundKeys[m_rounds]); if (!IsForwardTransformation()) { unsigned int i; // transform encryption round keys into decryption round keys for (i=0; i<m_rounds/2; i++) std::swap(m_roundKeys[i], m_roundKeys[m_rounds-i]); for (i=1; i<m_rounds; i++) m_roundKeys[i] = SHARKTransform(m_roundKeys[i]); } #ifdef IS_LITTLE_ENDIAN m_roundKeys[0] = ByteReverse(m_roundKeys[0]); m_roundKeys[m_rounds] = ByteReverse(m_roundKeys[m_rounds]); #endif }