void EmitCore(CipherGenContext context)
{
Expression a = context.GetDataExpression(DataIndexes[0]);
Expression b = context.GetDataExpression(DataIndexes[1]);
VariableExpression tmp;
if (Mask == 0xffffffff)
{
/* t = a * k;
* a = b;
* b = t * k^-1;
*/
using (context.AcquireTempVar(out tmp))
{
context.Emit(new AssignmentStatement
{
Value = a * (LiteralExpression)Key,
Target = tmp
}).Emit(new AssignmentStatement
{
Value = b,
Target = a
}).Emit(new AssignmentStatement
{
Value = tmp * (LiteralExpression)MathsUtils.modInv(Key),
Target = b
});
}
}
else
{
var mask = (LiteralExpression)Mask;
var notMask = (LiteralExpression) ~Mask;
/* t = (a & mask) * k;
* a = a & (~mask) | (b & mask);
* b = b & (~mask) | (t * k^-1);
*/
using (context.AcquireTempVar(out tmp))
{
context.Emit(new AssignmentStatement
{
Value = (a & mask) * (LiteralExpression)Key,
Target = tmp
}).Emit(new AssignmentStatement
{
Value = (a & notMask) | (b & mask),
Target = a
}).Emit(new AssignmentStatement
{
Value = (b & notMask) | (tmp * (LiteralExpression)MathsUtils.modInv(Key)),
Target = b
});
}
}
}
public override void EmitInverse(CipherGenContext context)
{
Expression val = context.GetDataExpression(DataIndexes[0]);
VariableExpression tmp;
using (context.AcquireTempVar(out tmp)) {
if (IsAlternate)
{
context.Emit(new AssignmentStatement {
Value = (val << (32 - Bits)),
Target = tmp
}).Emit(new AssignmentStatement {
Value = (val >> Bits) | tmp,
Target = val
});
}
else
{
context.Emit(new AssignmentStatement {
Value = (val >> (32 - Bits)),
Target = tmp
}).Emit(new AssignmentStatement {
Value = (val << Bits) | tmp,
Target = val
});
}
}
}
void EmitCore(CipherGenContext context, uint[,] k)
{
Expression a = context.GetDataExpression(DataIndexes[0]);
Expression b = context.GetDataExpression(DataIndexes[1]);
Expression c = context.GetDataExpression(DataIndexes[2]);
Expression d = context.GetDataExpression(DataIndexes[3]);
VariableExpression ta, tb, tc, td;
Func <uint, LiteralExpression> l = v => (LiteralExpression)v;
using (context.AcquireTempVar(out ta))
using (context.AcquireTempVar(out tb))
using (context.AcquireTempVar(out tc))
using (context.AcquireTempVar(out td))
{
context.Emit(new AssignmentStatement
{
Value = a * l(k[0, 0]) + b * l(k[0, 1]) + c * l(k[0, 2]) + d * l(k[0, 3]),
Target = ta
}).Emit(new AssignmentStatement
{
Value = a * l(k[1, 0]) + b * l(k[1, 1]) + c * l(k[1, 2]) + d * l(k[1, 3]),
Target = tb
}).Emit(new AssignmentStatement
{
Value = a * l(k[2, 0]) + b * l(k[2, 1]) + c * l(k[2, 2]) + d * l(k[2, 3]),
Target = tc
}).Emit(new AssignmentStatement
{
Value = a * l(k[3, 0]) + b * l(k[3, 1]) + c * l(k[3, 2]) + d * l(k[3, 3]),
Target = td
})
.Emit(new AssignmentStatement {
Value = ta, Target = a
})
.Emit(new AssignmentStatement {
Value = tb, Target = b
})
.Emit(new AssignmentStatement {
Value = tc, Target = c
})
.Emit(new AssignmentStatement {
Value = td, Target = d
});
}
}