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| author | Peter Dettman <peter.dettman@bouncycastle.org> | 2022-10-20 17:41:10 +0700 |
|---|---|---|
| committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2022-10-20 17:41:10 +0700 |
| commit | cd1564f37a3af1a7abc5092eb55040d337e79ae2 (patch) | |
| tree | e75c0812208876eccfa3f15cf8fda10ecf3fb4e8 /crypto/src/math | |
| parent | Microsoft.NET.Test.Sdk 17.3.2 (diff) | |
| download | BouncyCastle.NET-ed25519-cd1564f37a3af1a7abc5092eb55040d337e79ae2.tar.xz | |
Add Inverse64 method
Diffstat (limited to 'crypto/src/math')
| -rw-r--r-- | crypto/src/math/raw/Mod.cs | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/crypto/src/math/raw/Mod.cs b/crypto/src/math/raw/Mod.cs index ea61bdd83..acbb1d91f 100644 --- a/crypto/src/math/raw/Mod.cs +++ b/crypto/src/math/raw/Mod.cs @@ -41,7 +41,7 @@ namespace Org.BouncyCastle.Math.Raw public static uint Inverse32(uint d) { - Debug.Assert((d & 1) == 1); + Debug.Assert((d & 1U) == 1U); //int x = d + (((d + 1) & 4) << 1); // d.x == 1 mod 2**4 uint x = d; // d.x == 1 mod 2**3 @@ -53,6 +53,21 @@ namespace Org.BouncyCastle.Math.Raw return x; } + public static ulong Inverse64(ulong d) + { + Debug.Assert((d & 1UL) == 1UL); + + //ulong x = d + (((d + 1) & 4) << 1); // d.x == 1 mod 2**4 + ulong x = d; // d.x == 1 mod 2**3 + x *= 2 - d * x; // d.x == 1 mod 2**6 + x *= 2 - d * x; // d.x == 1 mod 2**12 + x *= 2 - d * x; // d.x == 1 mod 2**24 + x *= 2 - d * x; // d.x == 1 mod 2**48 + x *= 2 - d * x; // d.x == 1 mod 2**96 + Debug.Assert(d * x == 1UL); + return x; + } + public static uint ModOddInverse(uint[] m, uint[] x, uint[] z) { #if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER |