<PackageReference Include="BouncyCastle.Cryptography" Version="2.6.2" />

AnssiNamedCurves

public static class AnssiNamedCurves
Elliptic curve registry for ANSSI.
using Org.BouncyCastle.Asn1.X9; using Org.BouncyCastle.Math; using Org.BouncyCastle.Math.EC; using Org.BouncyCastle.Math.EC.Multiplier; using Org.BouncyCastle.Utilities.Collections; using Org.BouncyCastle.Utilities.Encoders; using System; using System.Collections.Generic; namespace Org.BouncyCastle.Asn1.Anssi { public static class AnssiNamedCurves { internal class Frp256v1Holder : X9ECParametersHolder { internal static readonly X9ECParametersHolder Instance = new Frp256v1Holder(); private Frp256v1Holder() { } protected override ECCurve CreateCurve() { BigInteger q = FromHex("F1FD178C0B3AD58F10126DE8CE42435B3961ADBCABC8CA6DE8FCF353D86E9C03"); BigInteger a = FromHex("F1FD178C0B3AD58F10126DE8CE42435B3961ADBCABC8CA6DE8FCF353D86E9C00"); BigInteger b = FromHex("EE353FCA5428A9300D4ABA754A44C00FDFEC0C9AE4B1A1803075ED967B7BB73F"); BigInteger order = FromHex("F1FD178C0B3AD58F10126DE8CE42435B53DC67E140D2BF941FFDD459C6D655E1"); BigInteger one = BigInteger.One; return ConfigureCurve(new FpCurve(q, a, b, order, one, true)); } protected override X9ECParameters CreateParameters() { byte[] seed = null; ECCurve curve = base.Curve; X9ECPoint g = ConfigureBasepoint(curve, "04B6B3D4C356C139EB31183D4749D423958C27D2DCAF98B70164C97A2DD98F5CFF6142E0F7C8B204911F9271F0F3ECEF8C2701C307E8E4C9E183115A1554062CFB"); return new X9ECParameters(curve, g, curve.Order, curve.Cofactor, seed); } } private static readonly Dictionary<string, DerObjectIdentifier> objIds; private static readonly Dictionary<DerObjectIdentifier, X9ECParametersHolder> curves; private static readonly Dictionary<DerObjectIdentifier, string> names; public static IEnumerable<string> Names => CollectionUtilities.Proxy(objIds.Keys); private static X9ECPoint ConfigureBasepoint(ECCurve curve, string encoding) { X9ECPoint x9ECPoint = new X9ECPoint(curve, Hex.DecodeStrict(encoding)); WNafUtilities.ConfigureBasepoint(x9ECPoint.Point); return x9ECPoint; } private static ECCurve ConfigureCurve(ECCurve curve) { return curve; } private static BigInteger FromHex(string hex) { return new BigInteger(1, Hex.DecodeStrict(hex)); } private static void DefineCurve(string name, DerObjectIdentifier oid, X9ECParametersHolder holder) { objIds.Add(name, oid); names.Add(oid, name); curves.Add(oid, holder); } static AnssiNamedCurves() { objIds = new Dictionary<string, DerObjectIdentifier>(StringComparer.OrdinalIgnoreCase); curves = new Dictionary<DerObjectIdentifier, X9ECParametersHolder>(); names = new Dictionary<DerObjectIdentifier, string>(); DefineCurve("FRP256v1", AnssiObjectIdentifiers.FRP256v1, Frp256v1Holder.Instance); } public static X9ECParameters GetByName(string name) { DerObjectIdentifier oid = GetOid(name); if (oid != null) return GetByOid(oid); return null; } public static X9ECParametersHolder GetByNameLazy(string name) { DerObjectIdentifier oid = GetOid(name); if (oid != null) return GetByOidLazy(oid); return null; } public static X9ECParameters GetByOid(DerObjectIdentifier oid) { return GetByOidLazy(oid)?.Parameters; } public static X9ECParametersHolder GetByOidLazy(DerObjectIdentifier oid) { return CollectionUtilities.GetValueOrNull(curves, oid); } public static string GetName(DerObjectIdentifier oid) { return CollectionUtilities.GetValueOrNull(names, oid); } public static DerObjectIdentifier GetOid(string name) { return CollectionUtilities.GetValueOrNull(objIds, name); } } }