add all

Packages/com.tivadar.best.http/Runtime/3rdParty/BouncyCastle/crypto/agreement/ECDHBasicAgreement.cs

@@ -0,0 +1,78 @@
+#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
+#pragma warning disable
+using System;
+
+using Best.HTTP.SecureProtocol.Org.BouncyCastle.Math;
+using Best.HTTP.SecureProtocol.Org.BouncyCastle.Math.EC;
+using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto;
+using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Parameters;
+
+namespace Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Agreement
+{
+    /**
+     * P1363 7.2.1 ECSVDP-DH
+     *
+     * ECSVDP-DH is Elliptic Curve Secret Value Derivation Primitive,
+     * Diffie-Hellman version. It is based on the work of [DH76], [Mil86],
+     * and [Kob87]. This primitive derives a shared secret value from one
+     * party's private key and another party's public key, where both have
+     * the same set of EC domain parameters. If two parties correctly
+     * execute this primitive, they will produce the same output. This
+     * primitive can be invoked by a scheme to derive a shared secret key;
+     * specifically, it may be used with the schemes ECKAS-DH1 and
+     * DL/ECKAS-DH2. It assumes that the input keys are valid (see also
+     * Section 7.2.2).
+     */
+    public class ECDHBasicAgreement
+        : IBasicAgreement
+    {
+        protected internal ECPrivateKeyParameters privKey;
+
+        public virtual void Init(
+            ICipherParameters parameters)
+        {
+            if (parameters is ParametersWithRandom)
+            {
+                parameters = ((ParametersWithRandom)parameters).Parameters;
+            }
+
+            this.privKey = (ECPrivateKeyParameters)parameters;
+        }
+
+        public virtual int GetFieldSize()
+        {
+            return (privKey.Parameters.Curve.FieldSize + 7) / 8;
+        }
+
+        public virtual BigInteger CalculateAgreement(
+            ICipherParameters pubKey)
+        {
+            ECPublicKeyParameters pub = (ECPublicKeyParameters)pubKey;
+            ECDomainParameters dp = privKey.Parameters;
+            if (!dp.Equals(pub.Parameters))
+                throw new InvalidOperationException("ECDH public key has wrong domain parameters");
+
+            BigInteger d = privKey.D;
+
+            // Always perform calculations on the exact curve specified by our private key's parameters
+            ECPoint Q = ECAlgorithms.CleanPoint(dp.Curve, pub.Q);
+            if (Q.IsInfinity)
+                throw new InvalidOperationException("Infinity is not a valid public key for ECDH");
+
+            BigInteger h = dp.H;
+            if (!h.Equals(BigInteger.One))
+            {
+                d = dp.HInv.Multiply(d).Mod(dp.N);
+                Q = ECAlgorithms.ReferenceMultiply(Q, h);
+            }
+
+            ECPoint P = Q.Multiply(d).Normalize();
+            if (P.IsInfinity)
+                throw new InvalidOperationException("Infinity is not a valid agreement value for ECDH");
+
+            return P.AffineXCoord.ToBigInteger();
+        }
+    }
+}
+#pragma warning restore
+#endif