diff options
Diffstat (limited to 'crypto/src/math/ec/custom/sec/SecP224K1Field.cs')
| -rw-r--r-- | crypto/src/math/ec/custom/sec/SecP224K1Field.cs | 115 |
1 files changed, 107 insertions, 8 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecP224K1Field.cs b/crypto/src/math/ec/custom/sec/SecP224K1Field.cs index 98cf777a5..d20ac63f3 100644 --- a/crypto/src/math/ec/custom/sec/SecP224K1Field.cs +++ b/crypto/src/math/ec/custom/sec/SecP224K1Field.cs @@ -1,19 +1,22 @@ 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.Sec { internal class SecP224K1Field { // 2^224 - 2^32 - 2^12 - 2^11 - 2^9 - 2^7 - 2^4 - 2 - 1 - internal static readonly uint[] P = new uint[]{ 0xFFFFE56D, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, - 0xFFFFFFFF }; - internal static readonly uint[] PExt = new uint[]{ 0x02C23069, 0x00003526, 0x00000001, 0x00000000, 0x00000000, - 0x00000000, 0x00000000, 0xFFFFCADA, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; - private static readonly uint[] PExtInv = new uint[]{ 0xFD3DCF97, 0xFFFFCAD9, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, - 0xFFFFFFFF, 0xFFFFFFFF, 0x00003525, 0x00000002 }; + internal static readonly uint[] P = new uint[]{ 0xFFFFE56D, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, + 0xFFFFFFFF, 0xFFFFFFFF }; + private static readonly uint[] PExt = new uint[]{ 0x02C23069, 0x00003526, 0x00000001, 0x00000000, 0x00000000, + 0x00000000, 0x00000000, 0xFFFFCADA, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF + }; + private static readonly uint[] PExtInv = new uint[]{ 0xFD3DCF97, 0xFFFFCAD9, 0xFFFFFFFE, 0xFFFFFFFF, + 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0x00003525, 0x00000002 }; private const uint P6 = 0xFFFFFFFF; private const uint PExt13 = 0xFFFFFFFF; private const uint PInv33 = 0x1A93; @@ -71,6 +74,82 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec } } + public static void Inv(uint[] x, uint[] z) + { + /* + * Raise this element to the exponent 2^224 - 2^32 - 2^12 - 2^11 - 2^9 - 2^7 - 2^4 - 5 + * + * Breaking up the exponent's binary representation into "repunits", we get: + * { 191 1s } { 1 0s } { 19 1s } "0010101101011" + * + * Therefore we need an addition chain containing 1, 2, 19, 191 (the lengths of the repunits) + * We use: [1], [2], 4, 5, 9, 10, [19], 38, 76, 152, 190 [191] + */ + + if (0 != IsZero(x)) + throw new ArgumentException("cannot be 0", "x"); + + uint[] x1 = x; + uint[] x2 = Nat224.Create(); + Square(x1, x2); + Multiply(x2, x1, x2); + uint[] x4 = Nat224.Create(); + SquareN(x2, 2, x4); + Multiply(x4, x2, x4); + uint[] x5 = Nat224.Create(); + Square(x4, x5); + Multiply(x5, x1, x5); + uint[] x9 = x5; + SquareN(x5, 4, x9); + Multiply(x9, x4, x9); + uint[] x10 = x4; + Square(x9, x10); + Multiply(x10, x1, x10); + uint[] x19 = x10; + SquareN(x10, 9, x19); + Multiply(x19, x9, x19); + uint[] x38 = x9; + SquareN(x19, 19, x38); + Multiply(x38, x19, x38); + uint[] x76 = Nat224.Create(); + SquareN(x38, 38, x76); + Multiply(x76, x38, x76); + uint[] x152 = Nat224.Create(); + SquareN(x76, 76, x152); + Multiply(x152, x76, x152); + uint[] x190 = x76; + SquareN(x152, 38, x190); + Multiply(x190, x38, x190); + uint[] x191 = x38; + Square(x190, x191); + Multiply(x191, x1, x191); + + uint[] t = x191; + SquareN(t, 20, t); + Multiply(t, x19, t); + SquareN(t, 3, t); + Multiply(t, x1, t); + SquareN(t, 2, t); + Multiply(t, x1, t); + SquareN(t, 3, t); + Multiply(t, x2, t); + SquareN(t, 2, t); + Multiply(t, x1, t); + SquareN(t, 3, t); + Multiply(t, x2, z); + } + + public static int IsZero(uint[] x) + { + uint d = 0; + for (int i = 0; i < 7; ++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 = Nat224.CreateExt(); @@ -92,9 +171,9 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec public static void Negate(uint[] x, uint[] z) { - if (Nat224.IsZero(x)) + if (0 != IsZero(x)) { - Nat224.Zero(z); + Nat224.Sub(P, P, z); } else { @@ -102,6 +181,26 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec } } + public static void Random(SecureRandom r, uint[] z) + { + byte[] bb = new byte[7 * 4]; + do + { + r.NextBytes(bb); + Pack.LE_To_UInt32(bb, 0, z, 0, 7); + } + while (0 == Nat.LessThan(7, 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) { ulong cc = Nat224.Mul33Add(PInv33, xx, 7, xx, 0, z, 0); |