diff options
Diffstat (limited to 'crypto/src/math/ec/custom/sec/SecP192R1Field.cs')
| -rw-r--r-- | crypto/src/math/ec/custom/sec/SecP192R1Field.cs | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecP192R1Field.cs b/crypto/src/math/ec/custom/sec/SecP192R1Field.cs new file mode 100644 index 000000000..5f3ecacc4 --- /dev/null +++ b/crypto/src/math/ec/custom/sec/SecP192R1Field.cs @@ -0,0 +1,172 @@ +using System; +using System.Diagnostics; + +namespace Org.BouncyCastle.Math.EC.Custom.Sec +{ + internal class SecP192R1Field + { + // 2^192 - 2^64 - 1 + internal static readonly uint[] P = new uint[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + private const uint P5 = 0xFFFFFFFF; + private static readonly uint[] PExt = new uint[]{ 0x00000001, 0x00000000, 0x00000002, 0x00000000, 0x00000001, + 0x00000000, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + private const uint PExt11 = 0xFFFFFFFF; + + public static void Add(uint[] x, uint[] y, uint[] z) + { + uint c = Nat192.Add(x, y, z); + if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P))) + { + Nat192.Sub(z, P, z); + } + } + + public static void AddExt(uint[] xx, uint[] yy, uint[] zz) + { + uint c = Nat192.AddExt(xx, yy, zz); + if (c != 0 || (zz[11] == PExt11 && Nat192.GteExt(zz, PExt))) + { + Nat192.SubExt(zz, PExt, zz); + } + } + + public static void AddOne(uint[] x, uint[] z) + { + Array.Copy(x, 0, z, 0, 6); + uint c = Nat192.Inc(z, 0); + if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P))) + { + Nat192.Sub(z, P, z); + } + } + + public static uint[] FromBigInteger(BigInteger x) + { + uint[] z = Nat192.FromBigInteger(x); + if (z[5] == P5 && Nat192.Gte(z, P)) + { + Nat192.Sub(z, P, z); + } + return z; + } + + public static void Half(uint[] x, uint[] z) + { + if ((x[0] & 1) == 0) + { + Nat192.ShiftDownBit(x, 0, z); + } + else + { + uint c = Nat192.Add(x, P, z); + Nat192.ShiftDownBit(z, c, z); + } + } + + public static void Multiply(uint[] x, uint[] y, uint[] z) + { + uint[] tt = Nat192.CreateExt(); + Nat192.Mul(x, y, tt); + Reduce(tt, z); + } + + public static void Negate(uint[] x, uint[] z) + { + if (Nat192.IsZero(x)) + { + Nat192.Zero(z); + } + else + { + Nat192.Sub(P, x, z); + } + } + + public static void Reduce(uint[] tt, uint[] z) + { + long t06 = tt[6], t07 = tt[7], t08 = tt[8]; + long t09 = tt[9], t10 = tt[10], t11 = tt[11]; + + long cc = 0; + cc += (long)tt[0] + t06 + t10; + z[0] = (uint)cc; + cc >>= 32; + cc += (long)tt[1] + t07 + t11; + z[1] = (uint)cc; + cc >>= 32; + cc += (long)tt[2] + t06 + t08 + t10; + z[2] = (uint)cc; + cc >>= 32; + cc += (long)tt[3] + t07 + t09 + t11; + z[3] = (uint)cc; + cc >>= 32; + cc += (long)tt[4] + t08 + t10; + z[4] = (uint)cc; + cc >>= 32; + cc += (long)tt[5] + t09 + t11; + z[5] = (uint)cc; + cc >>= 32; + + int c = (int)cc; + Debug.Assert(c >= 0); + while (c > 0) + { + c += Nat192.Sub(z, P, z); + } + + if (z[5] == P5 && Nat192.Gte(z, P)) + { + Nat192.Sub(z, P, z); + } + } + + public static void Square(uint[] x, uint[] z) + { + uint[] tt = Nat192.CreateExt(); + Nat192.Square(x, tt); + Reduce(tt, z); + } + + public static void SquareN(uint[] x, int n, uint[] z) + { + Debug.Assert(n > 0); + + uint[] tt = Nat192.CreateExt(); + Nat192.Square(x, tt); + Reduce(tt, z); + + while (--n > 0) + { + Nat192.Square(z, tt); + Reduce(tt, z); + } + } + + public static void Subtract(uint[] x, uint[] y, uint[] z) + { + int c = Nat192.Sub(x, y, z); + if (c != 0) + { + Nat192.Add(z, P, z); + } + } + + public static void SubtractExt(uint[] xx, uint[] yy, uint[] zz) + { + int c = Nat192.SubExt(xx, yy, zz); + if (c != 0) + { + Nat192.AddExt(zz, PExt, zz); + } + } + + public static void Twice(uint[] x, uint[] z) + { + uint c = Nat192.ShiftUpBit(x, 0, z); + if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P))) + { + Nat192.Sub(z, P, z); + } + } + } +} |