diff options
Diffstat (limited to 'crypto/src/math/raw')
| -rw-r--r-- | crypto/src/math/raw/Bits.cs | 29 | ||||
| -rw-r--r-- | crypto/src/math/raw/Interleave.cs | 101 |
2 files changed, 71 insertions, 59 deletions
diff --git a/crypto/src/math/raw/Bits.cs b/crypto/src/math/raw/Bits.cs new file mode 100644 index 000000000..d344e1672 --- /dev/null +++ b/crypto/src/math/raw/Bits.cs @@ -0,0 +1,29 @@ +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); + } + } +} diff --git a/crypto/src/math/raw/Interleave.cs b/crypto/src/math/raw/Interleave.cs index 49d3768d7..8e98eac32 100644 --- a/crypto/src/math/raw/Interleave.cs +++ b/crypto/src/math/raw/Interleave.cs @@ -70,11 +70,10 @@ namespace Org.BouncyCastle.Math.Raw internal static ulong Expand32to64(uint x) { // "shuffle" low half to even bits and high half to odd bits - uint t; - t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8)); - t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 2)) & 0x0C0C0C0CU; x ^= (t ^ (t << 2)); - t = (x ^ (x >> 1)) & 0x22222222U; x ^= (t ^ (t << 1)); + x = Bits.BitPermuteStep(x, 0x0000FF00U, 8); + x = Bits.BitPermuteStep(x, 0x00F000F0U, 4); + x = Bits.BitPermuteStep(x, 0x0C0C0C0CU, 2); + x = Bits.BitPermuteStep(x, 0x22222222U, 1); return ((x >> 1) & M32) << 32 | (x & M32); } @@ -82,12 +81,11 @@ namespace Org.BouncyCastle.Math.Raw internal static void Expand64To128(ulong x, ulong[] z, int zOff) { // "shuffle" low half to even bits and high half to odd bits - ulong t; - t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16)); - t = (x ^ (x >> 8)) & 0x0000FF000000FF00UL; x ^= (t ^ (t << 8)); - t = (x ^ (x >> 4)) & 0x00F000F000F000F0UL; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 2)) & 0x0C0C0C0C0C0C0C0CUL; x ^= (t ^ (t << 2)); - t = (x ^ (x >> 1)) & 0x2222222222222222UL; x ^= (t ^ (t << 1)); + x = Bits.BitPermuteStep(x, 0x00000000FFFF0000UL, 16); + x = Bits.BitPermuteStep(x, 0x0000FF000000FF00UL, 8); + x = Bits.BitPermuteStep(x, 0x00F000F000F000F0UL, 4); + x = Bits.BitPermuteStep(x, 0x0C0C0C0C0C0C0C0CUL, 2); + x = Bits.BitPermuteStep(x, 0x2222222222222222UL, 1); z[zOff ] = (x ) & M64; z[zOff + 1] = (x >> 1) & M64; @@ -97,28 +95,19 @@ namespace Org.BouncyCastle.Math.Raw { for (int i = 0; i < xsLen; ++i) { - // "shuffle" low half to even bits and high half to odd bits - ulong x = xs[xsOff + i], t; - t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16)); - t = (x ^ (x >> 8)) & 0x0000FF000000FF00UL; x ^= (t ^ (t << 8)); - t = (x ^ (x >> 4)) & 0x00F000F000F000F0UL; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 2)) & 0x0C0C0C0C0C0C0C0CUL; x ^= (t ^ (t << 2)); - t = (x ^ (x >> 1)) & 0x2222222222222222UL; x ^= (t ^ (t << 1)); - - zs[zsOff++] = (x ) & M64; - zs[zsOff++] = (x >> 1) & M64; + Expand64To128(xs[xsOff + i], zs, zsOff); + zsOff += 2; } } internal static void Expand64To128Rev(ulong x, ulong[] z, int zOff) { // "shuffle" low half to even bits and high half to odd bits - ulong t; - t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16)); - t = (x ^ (x >> 8)) & 0x0000FF000000FF00UL; x ^= (t ^ (t << 8)); - t = (x ^ (x >> 4)) & 0x00F000F000F000F0UL; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 2)) & 0x0C0C0C0C0C0C0C0CUL; x ^= (t ^ (t << 2)); - t = (x ^ (x >> 1)) & 0x2222222222222222UL; x ^= (t ^ (t << 1)); + x = Bits.BitPermuteStep(x, 0x00000000FFFF0000UL, 16); + x = Bits.BitPermuteStep(x, 0x0000FF000000FF00UL, 8); + x = Bits.BitPermuteStep(x, 0x00F000F000F000F0UL, 4); + x = Bits.BitPermuteStep(x, 0x0C0C0C0C0C0C0C0CUL, 2); + x = Bits.BitPermuteStep(x, 0x2222222222222222UL, 1); z[zOff] = (x ) & M64R; z[zOff + 1] = (x << 1) & M64R; @@ -127,68 +116,62 @@ namespace Org.BouncyCastle.Math.Raw internal static uint Shuffle(uint x) { // "shuffle" low half to even bits and high half to odd bits - uint t; - t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8)); - t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 2)) & 0x0C0C0C0CU; x ^= (t ^ (t << 2)); - t = (x ^ (x >> 1)) & 0x22222222U; x ^= (t ^ (t << 1)); + x = Bits.BitPermuteStep(x, 0x0000FF00U, 8); + x = Bits.BitPermuteStep(x, 0x00F000F0U, 4); + x = Bits.BitPermuteStep(x, 0x0C0C0C0CU, 2); + x = Bits.BitPermuteStep(x, 0x22222222U, 1); return x; } internal static ulong Shuffle(ulong x) { // "shuffle" low half to even bits and high half to odd bits - ulong t; - t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16)); - t = (x ^ (x >> 8)) & 0x0000FF000000FF00UL; x ^= (t ^ (t << 8)); - t = (x ^ (x >> 4)) & 0x00F000F000F000F0UL; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 2)) & 0x0C0C0C0C0C0C0C0CUL; x ^= (t ^ (t << 2)); - t = (x ^ (x >> 1)) & 0x2222222222222222UL; x ^= (t ^ (t << 1)); + x = Bits.BitPermuteStep(x, 0x00000000FFFF0000UL, 16); + x = Bits.BitPermuteStep(x, 0x0000FF000000FF00UL, 8); + x = Bits.BitPermuteStep(x, 0x00F000F000F000F0UL, 4); + x = Bits.BitPermuteStep(x, 0x0C0C0C0C0C0C0C0CUL, 2); + x = Bits.BitPermuteStep(x, 0x2222222222222222UL, 1); return x; } internal static uint Shuffle2(uint x) { // "shuffle" (twice) low half to even bits and high half to odd bits - uint t; - t = (x ^ (x >> 7)) & 0x00AA00AAU; x ^= (t ^ (t << 7)); - t = (x ^ (x >> 14)) & 0x0000CCCCU; x ^= (t ^ (t << 14)); - t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8)); + x = Bits.BitPermuteStep(x, 0x00AA00AAU, 7); + x = Bits.BitPermuteStep(x, 0x0000CCCCU, 14); + x = Bits.BitPermuteStep(x, 0x00F000F0U, 4); + x = Bits.BitPermuteStep(x, 0x0000FF00U, 8); return x; } internal static uint Unshuffle(uint x) { // "unshuffle" even bits to low half and odd bits to high half - uint t; - t = (x ^ (x >> 1)) & 0x22222222U; x ^= (t ^ (t << 1)); - t = (x ^ (x >> 2)) & 0x0C0C0C0CU; x ^= (t ^ (t << 2)); - t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8)); + x = Bits.BitPermuteStep(x, 0x22222222U, 1); + x = Bits.BitPermuteStep(x, 0x0C0C0C0CU, 2); + x = Bits.BitPermuteStep(x, 0x00F000F0U, 4); + x = Bits.BitPermuteStep(x, 0x0000FF00U, 8); return x; } internal static ulong Unshuffle(ulong x) { // "unshuffle" even bits to low half and odd bits to high half - ulong t; - t = (x ^ (x >> 1)) & 0x2222222222222222UL; x ^= (t ^ (t << 1)); - t = (x ^ (x >> 2)) & 0x0C0C0C0C0C0C0C0CUL; x ^= (t ^ (t << 2)); - t = (x ^ (x >> 4)) & 0x00F000F000F000F0UL; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 8)) & 0x0000FF000000FF00UL; x ^= (t ^ (t << 8)); - t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16)); + x = Bits.BitPermuteStep(x, 0x2222222222222222UL, 1); + x = Bits.BitPermuteStep(x, 0x0C0C0C0C0C0C0C0CUL, 2); + x = Bits.BitPermuteStep(x, 0x00F000F000F000F0UL, 4); + x = Bits.BitPermuteStep(x, 0x0000FF000000FF00UL, 8); + x = Bits.BitPermuteStep(x, 0x00000000FFFF0000UL, 16); return x; } internal static uint Unshuffle2(uint x) { // "unshuffle" (twice) even bits to low half and odd bits to high half - uint t; - t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8)); - t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4)); - t = (x ^ (x >> 14)) & 0x0000CCCCU; x ^= (t ^ (t << 14)); - t = (x ^ (x >> 7)) & 0x00AA00AAU; x ^= (t ^ (t << 7)); + x = Bits.BitPermuteStep(x, 0x0000FF00U, 8); + x = Bits.BitPermuteStep(x, 0x00F000F0U, 4); + x = Bits.BitPermuteStep(x, 0x0000CCCCU, 14); + x = Bits.BitPermuteStep(x, 0x00AA00AAU, 7); return x; } } |