diff options
Diffstat (limited to 'crypto/src/math/ec/rfc7748/X448Field.cs')
| -rw-r--r-- | crypto/src/math/ec/rfc7748/X448Field.cs | 80 |
1 files changed, 74 insertions, 6 deletions
diff --git a/crypto/src/math/ec/rfc7748/X448Field.cs b/crypto/src/math/ec/rfc7748/X448Field.cs index 240518cde..4d3be5cda 100644 --- a/crypto/src/math/ec/rfc7748/X448Field.cs +++ b/crypto/src/math/ec/rfc7748/X448Field.cs @@ -1,6 +1,8 @@ using System; using System.Diagnostics; +using Org.BouncyCastle.Math.Raw; + namespace Org.BouncyCastle.Math.EC.Rfc7748 { [CLSCompliantAttribute(false)] @@ -10,6 +12,10 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748 private const uint M28 = 0x0FFFFFFFU; + private static readonly uint[] P32 = new uint[]{ 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, + 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFEU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, + 0xFFFFFFFFU, 0xFFFFFFFFU }; + protected X448Field() {} public static void Add(uint[] x, uint[] y, uint[] z) @@ -129,6 +135,12 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748 } } + public static void Decode(uint[] x, int xOff, uint[] z) + { + Decode224(x, xOff, z, 0); + Decode224(x, xOff + 7, z, 8); + } + public static void Decode(byte[] x, int xOff, uint[] z) { Decode56(x, xOff, z, 0); @@ -141,6 +153,21 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748 Decode56(x, xOff + 49, z, 14); } + private static void Decode224(uint[] x, int xOff, uint[] z, int zOff) + { + uint x0 = x[xOff + 0], x1 = x[xOff + 1], x2 = x[xOff + 2], x3 = x[xOff + 3]; + uint x4 = x[xOff + 4], x5 = x[xOff + 5], x6 = x[xOff + 6]; + + z[zOff + 0] = x0 & M28; + z[zOff + 1] = (x0 >> 28 | x1 << 4) & M28; + z[zOff + 2] = (x1 >> 24 | x2 << 8) & M28; + z[zOff + 3] = (x2 >> 20 | x3 << 12) & M28; + z[zOff + 4] = (x3 >> 16 | x4 << 16) & M28; + z[zOff + 5] = (x4 >> 12 | x5 << 20) & M28; + z[zOff + 6] = (x5 >> 8 | x6 << 24) & M28; + z[zOff + 7] = x6 >> 4; + } + private static uint Decode24(byte[] bs, int off) { uint n = bs[off]; @@ -166,6 +193,12 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748 z[zOff + 1] = (lo >> 28) | (hi << 4); } + public static void Encode(uint[] x, uint[] z, int zOff) + { + Encode224(x, 0, z, zOff); + Encode224(x, 8, z, zOff + 7); + } + public static void Encode(uint[] x, byte[] z, int zOff) { Encode56(x, 0, z, zOff); @@ -178,6 +211,20 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748 Encode56(x, 14, z, zOff + 49); } + private static void Encode224(uint[] x, int xOff, uint[] z, int zOff) + { + uint x0 = x[xOff + 0], x1 = x[xOff + 1], x2 = x[xOff + 2], x3 = x[xOff + 3]; + uint x4 = x[xOff + 4], x5 = x[xOff + 5], x6 = x[xOff + 6], x7 = x[xOff + 7]; + + z[zOff + 0] = x0 | (x1 << 28); + z[zOff + 1] = (x1 >> 4) | (x2 << 24); + z[zOff + 2] = (x2 >> 8) | (x3 << 20); + z[zOff + 3] = (x3 >> 12) | (x4 << 16); + z[zOff + 4] = (x4 >> 16) | (x5 << 12); + z[zOff + 5] = (x5 >> 20) | (x6 << 8); + z[zOff + 6] = (x6 >> 24) | (x7 << 4); + } + private static void Encode24(uint n, byte[] bs, int off) { bs[ off] = (byte)(n ); @@ -202,14 +249,35 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748 public static void Inv(uint[] x, uint[] z) { - // z = x^(p-2) = x^(2^448 - 2^224 - 3) - // (223 1s) (1 0s) (222 1s) (1 0s) (1 1s) - // Addition chain: [1] 2 3 6 9 18 19 37 74 111 [222] [223] + //uint[] t = Create(); + //PowPm3d4(x, t); + //Sqr(t, 2, t); + //Mul(t, x, z); uint[] t = Create(); - PowPm3d4(x, t); - Sqr(t, 2, t); - Mul(t, x, z); + uint[] u = new uint[14]; + + Copy(x, 0, t, 0); + Normalize(t); + Encode(t, u, 0); + + Mod.ModOddInverse(P32, u, u); + + Decode(u, 0, z); + } + + public static void InvVar(uint[] x, uint[] z) + { + uint[] t = Create(); + uint[] u = new uint[14]; + + Copy(x, 0, t, 0); + Normalize(t); + Encode(t, u, 0); + + Mod.ModOddInverseVar(P32, u, u); + + Decode(u, 0, z); } public static int IsZero(uint[] x) |