84 lines
2.7 KiB
C#
84 lines
2.7 KiB
C#
#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
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#pragma warning disable
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using System;
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using BestHTTP.SecureProtocol.Org.BouncyCastle.Math.EC.Multiplier;
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namespace BestHTTP.SecureProtocol.Org.BouncyCastle.Math.EC.Endo
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{
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public abstract class EndoUtilities
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{
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public static readonly string PRECOMP_NAME = "bc_endo";
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public static BigInteger[] DecomposeScalar(ScalarSplitParameters p, BigInteger k)
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{
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int bits = p.Bits;
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BigInteger b1 = CalculateB(k, p.G1, bits);
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BigInteger b2 = CalculateB(k, p.G2, bits);
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BigInteger a = k.Subtract((b1.Multiply(p.V1A)).Add(b2.Multiply(p.V2A)));
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BigInteger b = (b1.Multiply(p.V1B)).Add(b2.Multiply(p.V2B)).Negate();
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return new BigInteger[]{ a, b };
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}
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public static ECPoint MapPoint(ECEndomorphism endomorphism, ECPoint p)
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{
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EndoPreCompInfo precomp = (EndoPreCompInfo)p.Curve.Precompute(p, PRECOMP_NAME,
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new MapPointCallback(endomorphism, p));
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return precomp.MappedPoint;
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}
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private static BigInteger CalculateB(BigInteger k, BigInteger g, int t)
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{
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bool negative = (g.SignValue < 0);
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BigInteger b = k.Multiply(g.Abs());
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bool extra = b.TestBit(t - 1);
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b = b.ShiftRight(t);
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if (extra)
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{
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b = b.Add(BigInteger.One);
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}
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return negative ? b.Negate() : b;
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}
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private class MapPointCallback
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: IPreCompCallback
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{
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private readonly ECEndomorphism m_endomorphism;
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private readonly ECPoint m_point;
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internal MapPointCallback(ECEndomorphism endomorphism, ECPoint point)
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{
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this.m_endomorphism = endomorphism;
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this.m_point = point;
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}
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public PreCompInfo Precompute(PreCompInfo existing)
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{
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EndoPreCompInfo existingEndo = existing as EndoPreCompInfo;
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if (CheckExisting(existingEndo, m_endomorphism))
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return existingEndo;
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ECPoint mappedPoint = m_endomorphism.PointMap.Map(m_point);
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EndoPreCompInfo result = new EndoPreCompInfo();
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result.Endomorphism = m_endomorphism;
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result.MappedPoint = mappedPoint;
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return result;
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}
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private bool CheckExisting(EndoPreCompInfo existingEndo, ECEndomorphism endomorphism)
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{
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return null != existingEndo
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&& existingEndo.Endomorphism == endomorphism
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&& existingEndo.MappedPoint != null;
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}
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}
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}
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}
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#pragma warning restore
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#endif
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