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Assets/BestHTTP/SecureProtocol/crypto/tls/TlsDheKeyExchange.cs

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+#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
+
+using System;
+using System.Collections;
+using System.IO;
+
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Math;
+using Org.BouncyCastle.Security;
+using Org.BouncyCastle.Utilities.IO;
+
+namespace Org.BouncyCastle.Crypto.Tls
+{
+    public class TlsDheKeyExchange
+        :   TlsDHKeyExchange
+    {
+        protected TlsSignerCredentials mServerCredentials = null;
+
+        public TlsDheKeyExchange(int keyExchange, IList supportedSignatureAlgorithms, DHParameters dhParameters)
+            :   base(keyExchange, supportedSignatureAlgorithms, dhParameters)
+        {
+        }
+
+        public override void ProcessServerCredentials(TlsCredentials serverCredentials)
+        {
+            if (!(serverCredentials is TlsSignerCredentials))
+                throw new TlsFatalAlert(AlertDescription.internal_error);
+
+            ProcessServerCertificate(serverCredentials.Certificate);
+
+            this.mServerCredentials = (TlsSignerCredentials)serverCredentials;
+        }
+
+        public override byte[] GenerateServerKeyExchange()
+        {
+            if (this.mDHParameters == null)
+                throw new TlsFatalAlert(AlertDescription.internal_error);
+
+            DigestInputBuffer buf = new DigestInputBuffer();
+
+            this.mDHAgreePrivateKey = TlsDHUtilities.GenerateEphemeralServerKeyExchange(mContext.SecureRandom,
+                this.mDHParameters, buf);
+
+            /*
+             * RFC 5246 4.7. digitally-signed element needs SignatureAndHashAlgorithm from TLS 1.2
+             */
+            SignatureAndHashAlgorithm signatureAndHashAlgorithm = TlsUtilities.GetSignatureAndHashAlgorithm(
+                mContext, mServerCredentials);
+
+            IDigest d = TlsUtilities.CreateHash(signatureAndHashAlgorithm);
+
+            SecurityParameters securityParameters = mContext.SecurityParameters;
+            d.BlockUpdate(securityParameters.clientRandom, 0, securityParameters.clientRandom.Length);
+            d.BlockUpdate(securityParameters.serverRandom, 0, securityParameters.serverRandom.Length);
+            buf.UpdateDigest(d);
+
+            byte[] hash = DigestUtilities.DoFinal(d);
+
+            byte[] signature = mServerCredentials.GenerateCertificateSignature(hash);
+
+            DigitallySigned signed_params = new DigitallySigned(signatureAndHashAlgorithm, signature);
+            signed_params.Encode(buf);
+
+            return buf.ToArray();
+        }
+
+        public override void ProcessServerKeyExchange(Stream input)
+        {
+            SecurityParameters securityParameters = mContext.SecurityParameters;
+
+            SignerInputBuffer buf = new SignerInputBuffer();
+            Stream teeIn = new TeeInputStream(input, buf);
+
+            ServerDHParams dhParams = ServerDHParams.Parse(teeIn);
+
+            DigitallySigned signed_params = ParseSignature(input);
+
+            ISigner signer = InitVerifyer(mTlsSigner, signed_params.Algorithm, securityParameters);
+            buf.UpdateSigner(signer);
+            if (!signer.VerifySignature(signed_params.Signature))
+                throw new TlsFatalAlert(AlertDescription.decrypt_error);
+
+            this.mDHAgreePublicKey = TlsDHUtilities.ValidateDHPublicKey(dhParams.PublicKey);
+            this.mDHParameters = ValidateDHParameters(mDHAgreePublicKey.Parameters);
+        }
+
+        protected virtual ISigner InitVerifyer(TlsSigner tlsSigner, SignatureAndHashAlgorithm algorithm,
+            SecurityParameters securityParameters)
+        {
+            ISigner signer = tlsSigner.CreateVerifyer(algorithm, this.mServerPublicKey);
+            signer.BlockUpdate(securityParameters.clientRandom, 0, securityParameters.clientRandom.Length);
+            signer.BlockUpdate(securityParameters.serverRandom, 0, securityParameters.serverRandom.Length);
+            return signer;
+        }
+    }
+}
+
+#endif