diff options
Diffstat (limited to 'crypto/src/math/ec/custom/sec/SecP384R1Field.cs')
| -rw-r--r-- | crypto/src/math/ec/custom/sec/SecP384R1Field.cs | 105 |
1 files changed, 101 insertions, 4 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecP384R1Field.cs b/crypto/src/math/ec/custom/sec/SecP384R1Field.cs index 0780df3f0..f15678497 100644 --- a/crypto/src/math/ec/custom/sec/SecP384R1Field.cs +++ b/crypto/src/math/ec/custom/sec/SecP384R1Field.cs @@ -1,16 +1,18 @@ 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 SecP384R1Field { // 2^384 - 2^128 - 2^96 + 2^32 - 1 - internal static readonly uint[] P = new uint[]{ 0xFFFFFFFF, 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFE, 0xFFFFFFFF, + private static readonly uint[] P = new uint[]{ 0xFFFFFFFF, 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; - internal static readonly uint[] PExt = new uint[]{ 0x00000001, 0xFFFFFFFE, 0x00000000, 0x00000002, 0x00000000, 0xFFFFFFFE, + private static readonly uint[] PExt = new uint[]{ 0x00000001, 0xFFFFFFFE, 0x00000000, 0x00000002, 0x00000000, 0xFFFFFFFE, 0x00000000, 0x00000002, 0x00000001, 0x00000000, 0x00000000, 0x00000000, 0xFFFFFFFE, 0x00000001, 0x00000000, 0xFFFFFFFE, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; private static readonly uint[] PExtInv = new uint[]{ 0xFFFFFFFF, 0x00000001, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0x00000001, @@ -72,6 +74,81 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec } } + public static void Inv(uint[] x, uint[] z) + { + /* + * Raise this element to the exponent 2^384 - 2^128 - 2^96 + 2^32 - 3 + * + * Breaking up the exponent's binary representation into "repunits", we get: + * { 255 1s } { 1 0s } { 32 1s } { 64 0s } { 30 1s } { 1 0s} { 1 1s} + * + * Therefore we need an addition chain containing 1, 30, 32, 255 (the lengths of the repunits) + * We use: [1], 2, 3, 6, 12, 24, [30], [32], 62, 124, 248, 254, [255] + */ + + if (0 != IsZero(x)) + throw new ArgumentException("cannot be 0", "x"); + + uint[] x1 = x; + uint[] x2 = Nat.Create(12); + Square(x1, x2); + Multiply(x2, x1, x2); + uint[] x3 = Nat.Create(12); + Square(x2, x3); + Multiply(x3, x1, x3); + uint[] x6 = Nat.Create(12); + SquareN(x3, 3, x6); + Multiply(x6, x3, x6); + uint[] x12 = x3; + SquareN(x6, 6, x12); + Multiply(x12, x6, x12); + uint[] x24 = Nat.Create(12); + SquareN(x12, 12, x24); + Multiply(x24, x12, x24); + uint[] x30 = x12; + SquareN(x24, 6, x30); + Multiply(x30, x6, x30); + uint[] x32 = x24; + SquareN(x30, 2, x32); + Multiply(x32, x2, x32); + uint[] x62 = x2; + SquareN(x32, 30, x62); + Multiply(x62, x30, x62); + uint[] x124 = Nat.Create(12); + SquareN(x62, 62, x124); + Multiply(x124, x62, x124); + uint[] x248 = x62; + SquareN(x124, 124, x248); + Multiply(x248, x124, x248); + uint[] x254 = x124; + SquareN(x248, 6, x254); + Multiply(x254, x6, x254); + uint[] x255 = x6; + Square(x254, x255); + Multiply(x255, x1, x255); + + uint[] t = x255; + SquareN(t, 33, t); + Multiply(t, x32, t); + SquareN(t, 94, t); + Multiply(t, x30, t); + SquareN(t, 2, t); + + // NOTE that x1 and z could be the same array + Multiply(x1, t, z); + } + + public static int IsZero(uint[] x) + { + uint d = 0; + for (int i = 0; i < 12; ++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 = Nat.Create(24); @@ -81,9 +158,9 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec public static void Negate(uint[] x, uint[] z) { - if (Nat.IsZero(12, x)) + if (0 != IsZero(x)) { - Nat.Zero(12, z); + Nat.Sub(12, P, P, z); } else { @@ -91,6 +168,26 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec } } + public static void Random(SecureRandom r, uint[] z) + { + byte[] bb = new byte[12 * 4]; + do + { + r.NextBytes(bb); + Pack.LE_To_UInt32(bb, 0, z, 0, 12); + } + while (0 == Nat.LessThan(12, 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) { long xx16 = xx[16], xx17 = xx[17], xx18 = xx[18], xx19 = xx[19]; |