void RC6::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
const RC6_WORD *sptr = sTable.end();
RC6_WORD a, b, c, d, t, u;
Block::Get(inBlock)(a)(b)(c)(d);
sptr -= 2;
c -= sptr[1];
a -= sptr[0];
for (unsigned i=0; i < r; i++)
{
sptr -= 2;
t = a; a = d; d = c; c = b; b = t;
u = rotlFixed(d*(2*d+1), 5);
t = rotlFixed(b*(2*b+1), 5);
c = rotrMod(c-sptr[1], t) ^ u;
a = rotrMod(a-sptr[0], u) ^ t;
}
sptr -= 2;
d -= sTable[1];
b -= sTable[0];
Block::Put(xorBlock, outBlock)(a)(b)(c)(d);
}
void RC6Decryption::ProcessBlock(const byte *in, byte *out) const
{
const RC6_WORD *sptr = sTable+sTable.size;
RC6_WORD a, b, c, d, t, u;
GetBlockLittleEndian(in, a, b, c, d);
sptr -= 2;
c -= sptr[1];
a -= sptr[0];
for (unsigned i=0; i < r; i++)
{
sptr -= 2;
t = a; a = d; d = c; c = b; b = t;
u = rotlFixed(d*(2*d+1), 5);
t = rotlFixed(b*(2*b+1), 5);
c = rotrMod(c-sptr[1], t) ^ u;
a = rotrMod(a-sptr[0], u) ^ t;
}
sptr -= 2;
d -= sTable[1];
b -= sTable[0];
PutBlockLittleEndian(out, a, b, c, d);
}
void RC5::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
const RC5_WORD *sptr = sTable.end();
RC5_WORD a, b;
Block::Get(inBlock)(a)(b);
for (unsigned i=0; i<r; i++)
{
sptr-=2;
b = rotrMod(b-sptr[1], a) ^ a;
a = rotrMod(a-sptr[0], b) ^ b;
}
b -= sTable[1];
a -= sTable[0];
Block::Put(xorBlock, outBlock)(a)(b);
}
