diff options
Diffstat (limited to 'crypto/src/math/ec/custom/sec/SecP192R1Field.cs')
| -rw-r--r-- | crypto/src/math/ec/custom/sec/SecP192R1Field.cs | 71 |
1 files changed, 59 insertions, 12 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecP192R1Field.cs b/crypto/src/math/ec/custom/sec/SecP192R1Field.cs index 71ccfc4b7..8e2aad5af 100644 --- a/crypto/src/math/ec/custom/sec/SecP192R1Field.cs +++ b/crypto/src/math/ec/custom/sec/SecP192R1Field.cs @@ -9,6 +9,8 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec internal static readonly uint[] P = new uint[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; internal static readonly uint[] PExt = new uint[]{ 0x00000001, 0x00000000, 0x00000002, 0x00000000, 0x00000001, 0x00000000, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + private static readonly uint[] PExtInv = new uint[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFE, + 0xFFFFFFFF, 0x00000001, 0x00000000, 0x00000002 }; private const uint P5 = 0xFFFFFFFF; private const uint PExt11 = 0xFFFFFFFF; @@ -17,26 +19,28 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec uint c = Nat192.Add(x, y, z); if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P))) { - Nat192.SubFrom(P, z); + AddPInvTo(z); } } public static void AddExt(uint[] xx, uint[] yy, uint[] zz) { - uint c = Nat192.AddExt(xx, yy, zz); + uint c = Nat.Add(12, xx, yy, zz); if (c != 0 || (zz[11] == PExt11 && Nat192.GteExt(zz, PExt))) { - Nat192.SubExt(zz, PExt, zz); + if (Nat.AddTo(PExtInv.Length, PExtInv, zz) != 0) + { + Nat.IncAt(12, zz, PExtInv.Length); + } } } public static void AddOne(uint[] x, uint[] z) { - Nat192.Copy(x, z); - uint c = Nat192.Inc(z, 0); + uint c = Nat.Inc(6, x, z); if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P))) { - Nat192.SubFrom(P, z); + AddPInvTo(z); } } @@ -123,10 +127,10 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec public static void Reduce32(uint x, uint[] z) { - if ((x != 0 && (Nat192.AddWord(x, z, 0) + Nat192.AddWord(x, z, 2) != 0)) + if ((x != 0 && (Nat.AddWordTo(6, x, z) + Nat.AddWordAt(6, x, z, 2) != 0)) || (z[5] == P5 && Nat192.Gte(z, P))) { - Nat192.SubFrom(P, z); + AddPInvTo(z); } } @@ -157,16 +161,19 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec int c = Nat192.Sub(x, y, z); if (c != 0) { - Nat192.AddTo(P, z); + SubPInvFrom(z); } } public static void SubtractExt(uint[] xx, uint[] yy, uint[] zz) { - int c = Nat192.SubExt(xx, yy, zz); + int c = Nat.Sub(12, xx, yy, zz); if (c != 0) { - Nat192.AddExt(zz, PExt, zz); + if (Nat.SubFrom(PExtInv.Length, PExtInv, zz) != 0) + { + Nat.DecAt(12, zz, PExtInv.Length); + } } } @@ -175,7 +182,47 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec uint c = Nat.ShiftUpBit(6, x, 0, z); if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P))) { - Nat192.SubFrom(P, z); + AddPInvTo(z); + } + } + + private static void AddPInvTo(uint[] z) + { + long c = (long)z[0] + 1; + z[0] = (uint)c; + c >>= 32; + if (c != 0) + { + c += (long)z[1]; + z[1] = (uint)c; + c >>= 32; + } + c += (long)z[2] + 1; + z[2] = (uint)c; + c >>= 32; + if (c != 0) + { + Nat.IncAt(6, z, 3); + } + } + + private static void SubPInvFrom(uint[] z) + { + long c = (long)z[0] - 1; + z[0] = (uint)c; + c >>= 32; + if (c != 0) + { + c += (long)z[1]; + z[1] = (uint)c; + c >>= 32; + } + c += (long)z[2] - 1; + z[2] = (uint)c; + c >>= 32; + if (c != 0) + { + Nat.DecAt(6, z, 3); } } } |