- Initial commit

Runtime/3rdParty/BouncyCastle/crypto/agreement/ECDHCBasicAgreement.cs

@@ -0,0 +1,76 @@
+#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.Security;
+using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto;
+using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Parameters;
+
+namespace Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Agreement
+{
+    /**
+     * P1363 7.2.2 ECSVDP-DHC
+     *
+     * ECSVDP-DHC is Elliptic Curve Secret Value Derivation Primitive,
+     * Diffie-Hellman version with cofactor multiplication. It is based on
+     * the work of [DH76], [Mil86], [Kob87], [LMQ98] and [Kal98a]. 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 does not assume the
+     * validity of the input public key (see also Section 7.2.1).
+     * <p>
+     * Note: As stated P1363 compatibility mode with ECDH can be preset, and
+     * in this case the implementation doesn't have a ECDH compatibility mode
+     * (if you want that just use ECDHBasicAgreement and note they both implement
+     * BasicAgreement!).</p>
+     */
+    public class ECDHCBasicAgreement
+        : IBasicAgreement
+    {
+        private 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("ECDHC public key has wrong domain parameters");
+
+            BigInteger hd = dp.H.Multiply(privKey.D).Mod(dp.N);
+
+            // Always perform calculations on the exact curve specified by our private key's parameters
+            ECPoint pubPoint = ECAlgorithms.CleanPoint(dp.Curve, pub.Q);
+            if (pubPoint.IsInfinity)
+                throw new InvalidOperationException("Infinity is not a valid public key for ECDHC");
+
+            ECPoint P = pubPoint.Multiply(hd).Normalize();
+            if (P.IsInfinity)
+                throw new InvalidOperationException("Infinity is not a valid agreement value for ECDHC");
+
+            return P.AffineXCoord.ToBigInteger();
+        }
+    }
+}
+#pragma warning restore
+#endif