crypto/src/math/raw/Bits.cs


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29

using System;

namespace Org.BouncyCastle.Math.Raw
{
    internal abstract class Bits
    {
        internal static uint BitPermuteStep(uint x, uint m, int s)
        {
            uint t = (x ^ (x >> s)) & m;
            return (t ^ (t << s)) ^ x;
        }

        internal static ulong BitPermuteStep(ulong x, ulong m, int s)
        {
            ulong t = (x ^ (x >> s)) & m;
            return (t ^ (t << s)) ^ x;
        }

        internal static uint BitPermuteStepSimple(uint x, uint m, int s)
        {
            return ((x & m) << s) | ((x >> s) & m);
        }

        internal static ulong BitPermuteStepSimple(ulong x, ulong m, int s)
        {
            return ((x & m) << s) | ((x >> s) & m);
        }
    }
}