diff options
Diffstat (limited to 'crypto/src/math/ec/custom/djb/Curve25519Field.cs')
| -rw-r--r-- | crypto/src/math/ec/custom/djb/Curve25519Field.cs | 292 |
1 files changed, 0 insertions, 292 deletions
diff --git a/crypto/src/math/ec/custom/djb/Curve25519Field.cs b/crypto/src/math/ec/custom/djb/Curve25519Field.cs deleted file mode 100644 index 31416249d..000000000 --- a/crypto/src/math/ec/custom/djb/Curve25519Field.cs +++ /dev/null @@ -1,292 +0,0 @@ -using System; -using System.Diagnostics; - -using Org.BouncyCastle.Crypto.Utilities; -using Org.BouncyCastle.Math.Raw; -using Org.BouncyCastle.Security; - -namespace Org.BouncyCastle.Math.EC.Custom.Djb -{ - internal class Curve25519Field - { - // 2^255 - 19 - internal static readonly uint[] P = new uint[]{ 0xFFFFFFED, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, - 0xFFFFFFFF, 0xFFFFFFFF, 0x7FFFFFFF }; - private const uint P7 = 0x7FFFFFFF; - private static readonly uint[] PExt = new uint[]{ 0x00000169, 0x00000000, 0x00000000, 0x00000000, 0x00000000, - 0x00000000, 0x00000000, 0x00000000, 0xFFFFFFED, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, - 0xFFFFFFFF, 0x3FFFFFFF }; - private const uint PInv = 0x13; - - public static void Add(uint[] x, uint[] y, uint[] z) - { - Nat256.Add(x, y, z); - if (Nat256.Gte(z, P)) - { - SubPFrom(z); - } - } - - public static void AddExt(uint[] xx, uint[] yy, uint[] zz) - { - Nat.Add(16, xx, yy, zz); - if (Nat.Gte(16, zz, PExt)) - { - SubPExtFrom(zz); - } - } - - public static void AddOne(uint[] x, uint[] z) - { - Nat.Inc(8, x, z); - if (Nat256.Gte(z, P)) - { - SubPFrom(z); - } - } - - public static uint[] FromBigInteger(BigInteger x) - { - uint[] z = Nat.FromBigInteger(256, x); - while (Nat256.Gte(z, P)) - { - Nat256.SubFrom(P, z); - } - return z; - } - - public static void Half(uint[] x, uint[] z) - { - if ((x[0] & 1) == 0) - { - Nat.ShiftDownBit(8, x, 0, z); - } - else - { - Nat256.Add(x, P, z); - Nat.ShiftDownBit(8, z, 0); - } - } - - public static void Inv(uint[] x, uint[] z) - { - Mod.CheckedModOddInverse(P, x, z); - } - - public static int IsZero(uint[] x) - { - uint d = 0; - for (int i = 0; i < 8; ++i) - { - d |= x[i]; - } - d = (d >> 1) | (d & 1); - return ((int)d - 1) >> 31; - } - - public static void Multiply(uint[] x, uint[] y, uint[] z) - { - uint[] tt = Nat256.CreateExt(); - Nat256.Mul(x, y, tt); - Reduce(tt, z); - } - - public static void MultiplyAddToExt(uint[] x, uint[] y, uint[] zz) - { - Nat256.MulAddTo(x, y, zz); - if (Nat.Gte(16, zz, PExt)) - { - SubPExtFrom(zz); - } - } - - public static void Negate(uint[] x, uint[] z) - { - if (0 != IsZero(x)) - { - Nat256.Sub(P, P, z); - } - else - { - Nat256.Sub(P, x, z); - } - } - - public static void Random(SecureRandom r, uint[] z) - { - byte[] bb = new byte[8 * 4]; - do - { - r.NextBytes(bb); - Pack.LE_To_UInt32(bb, 0, z, 0, 8); - z[7] &= P7; - } - while (0 == Nat.LessThan(8, z, P)); - } - - public static void RandomMult(SecureRandom r, uint[] z) - { - do - { - Random(r, z); - } - while (0 != IsZero(z)); - } - - public static void Reduce(uint[] xx, uint[] z) - { - Debug.Assert(xx[15] >> 30 == 0); - - uint xx07 = xx[7]; - Nat.ShiftUpBit(8, xx, 8, xx07, z, 0); - uint c = Nat256.MulByWordAddTo(PInv, xx, z) << 1; - uint z7 = z[7]; - c += (z7 >> 31) - (xx07 >> 31); - z7 &= P7; - z7 += Nat.AddWordTo(7, c * PInv, z); - z[7] = z7; - if (z7 >= P7 && Nat256.Gte(z, P)) - { - SubPFrom(z); - } - } - - public static void Reduce27(uint x, uint[] z) - { - Debug.Assert(x >> 26 == 0); - - uint z7 = z[7]; - uint c = (x << 1 | z7 >> 31); - z7 &= P7; - z7 += Nat.AddWordTo(7, c * PInv, z); - z[7] = z7; - if (z7 >= P7 && Nat256.Gte(z, P)) - { - SubPFrom(z); - } - } - - public static void Square(uint[] x, uint[] z) - { - uint[] tt = Nat256.CreateExt(); - Nat256.Square(x, tt); - Reduce(tt, z); - } - - public static void SquareN(uint[] x, int n, uint[] z) - { - Debug.Assert(n > 0); - - uint[] tt = Nat256.CreateExt(); - Nat256.Square(x, tt); - Reduce(tt, z); - - while (--n > 0) - { - Nat256.Square(z, tt); - Reduce(tt, z); - } - } - - public static void Subtract(uint[] x, uint[] y, uint[] z) - { - int c = Nat256.Sub(x, y, z); - if (c != 0) - { - AddPTo(z); - } - } - - public static void SubtractExt(uint[] xx, uint[] yy, uint[] zz) - { - int c = Nat.Sub(16, xx, yy, zz); - if (c != 0) - { - AddPExtTo(zz); - } - } - - public static void Twice(uint[] x, uint[] z) - { - Nat.ShiftUpBit(8, x, 0, z); - if (Nat256.Gte(z, P)) - { - SubPFrom(z); - } - } - - private static uint AddPTo(uint[] z) - { - long c = (long)z[0] - PInv; - z[0] = (uint)c; - c >>= 32; - if (c != 0) - { - c = Nat.DecAt(7, z, 1); - } - c += (long)z[7] + (P7 + 1); - z[7] = (uint)c; - c >>= 32; - return (uint)c; - } - - private static uint AddPExtTo(uint[] zz) - { - long c = (long)zz[0] + PExt[0]; - zz[0] = (uint)c; - c >>= 32; - if (c != 0) - { - c = Nat.IncAt(8, zz, 1); - } - c += (long)zz[8] - PInv; - zz[8] = (uint)c; - c >>= 32; - if (c != 0) - { - c = Nat.DecAt(15, zz, 9); - } - c += (long)zz[15] + (PExt[15] + 1); - zz[15] = (uint)c; - c >>= 32; - return (uint)c; - } - - private static int SubPFrom(uint[] z) - { - long c = (long)z[0] + PInv; - z[0] = (uint)c; - c >>= 32; - if (c != 0) - { - c = Nat.IncAt(7, z, 1); - } - c += (long)z[7] - (P7 + 1); - z[7] = (uint)c; - c >>= 32; - return (int)c; - } - - private static int SubPExtFrom(uint[] zz) - { - long c = (long)zz[0] - PExt[0]; - zz[0] = (uint)c; - c >>= 32; - if (c != 0) - { - c = Nat.DecAt(8, zz, 1); - } - c += (long)zz[8] + PInv; - zz[8] = (uint)c; - c >>= 32; - if (c != 0) - { - c = Nat.IncAt(15, zz, 9); - } - c += (long)zz[15] - (PExt[15] + 1); - zz[15] = (uint)c; - c >>= 32; - return (int)c; - } - } -} |