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78 lines
2.9 KiB
78 lines
2.9 KiB
#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; |
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using BestHTTP.SecureProtocol.Org.BouncyCastle.Math.EC; |
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using BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto; |
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using BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Parameters; |
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namespace BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Agreement |
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{ |
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/** |
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* P1363 7.2.1 ECSVDP-DH |
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* |
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* ECSVDP-DH is Elliptic Curve Secret Value Derivation Primitive, |
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* Diffie-Hellman version. It is based on the work of [DH76], [Mil86], |
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* and [Kob87]. This primitive derives a shared secret value from one |
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* party's private key and another party's public key, where both have |
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* the same set of EC domain parameters. If two parties correctly |
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* execute this primitive, they will produce the same output. This |
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* primitive can be invoked by a scheme to derive a shared secret key; |
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* specifically, it may be used with the schemes ECKAS-DH1 and |
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* DL/ECKAS-DH2. It assumes that the input keys are valid (see also |
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* Section 7.2.2). |
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*/ |
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public class ECDHBasicAgreement |
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: IBasicAgreement |
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{ |
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protected internal ECPrivateKeyParameters privKey; |
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public virtual void Init( |
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ICipherParameters parameters) |
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{ |
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if (parameters is ParametersWithRandom) |
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{ |
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parameters = ((ParametersWithRandom)parameters).Parameters; |
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} |
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this.privKey = (ECPrivateKeyParameters)parameters; |
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} |
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public virtual int GetFieldSize() |
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{ |
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return (privKey.Parameters.Curve.FieldSize + 7) / 8; |
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} |
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public virtual BigInteger CalculateAgreement( |
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ICipherParameters pubKey) |
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{ |
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ECPublicKeyParameters pub = (ECPublicKeyParameters)pubKey; |
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ECDomainParameters dp = privKey.Parameters; |
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if (!dp.Equals(pub.Parameters)) |
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throw new InvalidOperationException("ECDH public key has wrong domain parameters"); |
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BigInteger d = privKey.D; |
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// Always perform calculations on the exact curve specified by our private key's parameters |
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ECPoint Q = ECAlgorithms.CleanPoint(dp.Curve, pub.Q); |
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if (Q.IsInfinity) |
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throw new InvalidOperationException("Infinity is not a valid public key for ECDH"); |
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BigInteger h = dp.H; |
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if (!h.Equals(BigInteger.One)) |
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{ |
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d = dp.HInv.Multiply(d).Mod(dp.N); |
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Q = ECAlgorithms.ReferenceMultiply(Q, h); |
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} |
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ECPoint P = Q.Multiply(d).Normalize(); |
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if (P.IsInfinity) |
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throw new InvalidOperationException("Infinity is not a valid agreement value for ECDH"); |
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return P.AffineXCoord.ToBigInteger(); |
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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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