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

GMNamedCurves

public static class GMNamedCurves
Elliptic curve registry for GM.
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.GM { public static class GMNamedCurves { internal class SM2P256V1Holder : X9ECParametersHolder { internal static readonly X9ECParametersHolder Instance = new SM2P256V1Holder(); private SM2P256V1Holder() { } protected override ECCurve CreateCurve() { BigInteger q = FromHex("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF"); BigInteger a = FromHex("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC"); BigInteger b = FromHex("28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93"); BigInteger order = FromHex("FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123"); 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, "0432C4AE2C1F1981195F9904466A39C9948FE30BBFF2660BE1715A4589334C74C7BC3736A2F4F6779C59BDCEE36B692153D0A9877CC62A474002DF32E52139F0A0"); return new X9ECParameters(curve, g, curve.Order, curve.Cofactor, seed); } } internal class WapiP192V1Holder : X9ECParametersHolder { internal static readonly X9ECParametersHolder Instance = new WapiP192V1Holder(); private WapiP192V1Holder() { } protected override ECCurve CreateCurve() { BigInteger q = FromHex("BDB6F4FE3E8B1D9E0DA8C0D46F4C318CEFE4AFE3B6B8551F"); BigInteger a = FromHex("BB8E5E8FBC115E139FE6A814FE48AAA6F0ADA1AA5DF91985"); BigInteger b = FromHex("1854BEBDC31B21B7AEFC80AB0ECD10D5B1B3308E6DBF11C1"); BigInteger order = FromHex("BDB6F4FE3E8B1D9E0DA8C0D40FC962195DFAE76F56564677"); 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, "044AD5F7048DE709AD51236DE65E4D4B482C836DC6E410664002BB3A02D4AAADACAE24817A4CA3A1B014B5270432DB27D2"); 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 GMNamedCurves() { objIds = new Dictionary<string, DerObjectIdentifier>(StringComparer.OrdinalIgnoreCase); curves = new Dictionary<DerObjectIdentifier, X9ECParametersHolder>(); names = new Dictionary<DerObjectIdentifier, string>(); DefineCurve("wapip192v1", GMObjectIdentifiers.wapip192v1, WapiP192V1Holder.Instance); DefineCurve("wapi192v1", GMObjectIdentifiers.wapi192v1, WapiP192V1Holder.Instance); DefineCurve("sm2p256v1", GMObjectIdentifiers.sm2p256v1, SM2P256V1Holder.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); } } }