Initial checkin of gRPC to third_party/

third_party/grpc/src/csharp/Grpc.Core/ChannelCredentials.cs

Index: third_party/grpc/src/csharp/Grpc.Core/ChannelCredentials.cs
diff --git a/third_party/grpc/src/csharp/Grpc.Core/ChannelCredentials.cs b/third_party/grpc/src/csharp/Grpc.Core/ChannelCredentials.cs
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index 0000000000000000000000000000000000000000..03cda284008a93d163cfa396e5664052be26356c
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+#region Copyright notice and license
+
+// Copyright 2015-2016, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+using Grpc.Core.Internal;
+using Grpc.Core.Utils;
+
+namespace Grpc.Core
+{
+    /// <summary>
+    /// Client-side channel credentials. Used for creation of a secure channel.
+    /// </summary>
+    public abstract class ChannelCredentials
+    {
+        static readonly ChannelCredentials InsecureInstance = new InsecureCredentialsImpl();
+
+        /// <summary>
+        /// Returns instance of credentials that provides no security and 
+        /// will result in creating an unsecure channel with no encryption whatsoever.
+        /// </summary>
+        public static ChannelCredentials Insecure
+        {
+            get
+            {
+                return InsecureInstance;
+            }
+        }
+
+        /// <summary>
+        /// Creates a new instance of <c>ChannelCredentials</c> class by composing
+        /// given channel credentials with call credentials.
+        /// </summary>
+        /// <param name="channelCredentials">Channel credentials.</param>
+        /// <param name="callCredentials">Call credentials.</param>
+        /// <returns>The new composite <c>ChannelCredentials</c></returns>
+        public static ChannelCredentials Create(ChannelCredentials channelCredentials, CallCredentials callCredentials)
+        {
+            return new CompositeChannelCredentials(channelCredentials, callCredentials);
+        }
+
+        /// <summary>
+        /// Creates native object for the credentials. May return null if insecure channel
+        /// should be created.
+        /// </summary>
+        /// <returns>The native credentials.</returns>
+        internal abstract ChannelCredentialsSafeHandle ToNativeCredentials();
+
+        /// <summary>
+        /// Returns <c>true</c> if this credential type allows being composed by <c>CompositeCredentials</c>.
+        /// </summary>
+        internal virtual bool IsComposable
+        {
+            get { return false; }
+        }
+
+        private sealed class InsecureCredentialsImpl : ChannelCredentials
+        {
+            internal override ChannelCredentialsSafeHandle ToNativeCredentials()
+            {
+                return null;
+            }
+        }
+    }
+
+    /// <summary>
+    /// Client-side SSL credentials.
+    /// </summary>
+    public sealed class SslCredentials : ChannelCredentials
+    {
+        readonly string rootCertificates;
+        readonly KeyCertificatePair keyCertificatePair;
+
+        /// <summary>
+        /// Creates client-side SSL credentials loaded from
+        /// disk file pointed to by the GRPC_DEFAULT_SSL_ROOTS_FILE_PATH environment variable.
+        /// If that fails, gets the roots certificates from a well known place on disk.
+        /// </summary>
+        public SslCredentials() : this(null, null)
+        {
+        }
+
+        /// <summary>
+        /// Creates client-side SSL credentials from
+        /// a string containing PEM encoded root certificates.
+        /// </summary>
+        public SslCredentials(string rootCertificates) : this(rootCertificates, null)
+        {
+        }
+            
+        /// <summary>
+        /// Creates client-side SSL credentials.
+        /// </summary>
+        /// <param name="rootCertificates">string containing PEM encoded server root certificates.</param>
+        /// <param name="keyCertificatePair">a key certificate pair.</param>
+        public SslCredentials(string rootCertificates, KeyCertificatePair keyCertificatePair)
+        {
+            this.rootCertificates = rootCertificates;
+            this.keyCertificatePair = keyCertificatePair;
+        }
+
+        /// <summary>
+        /// PEM encoding of the server root certificates.
+        /// </summary>
+        public string RootCertificates
+        {
+            get
+            {
+                return this.rootCertificates;
+            }
+        }
+
+        /// <summary>
+        /// Client side key and certificate pair.
+        /// If null, client will not use key and certificate pair.
+        /// </summary>
+        public KeyCertificatePair KeyCertificatePair
+        {
+            get
+            {
+                return this.keyCertificatePair;
+            }
+        }
+
+        // Composing composite makes no sense.
+        internal override bool IsComposable
+        {
+            get { return true; }
+        }
+
+        internal override ChannelCredentialsSafeHandle ToNativeCredentials()
+        {
+            return ChannelCredentialsSafeHandle.CreateSslCredentials(rootCertificates, keyCertificatePair);
+        }
+    }
+
+    /// <summary>
+    /// Credentials that allow composing one <see cref="ChannelCredentials"/> object and 
+    /// one or more <see cref="CallCredentials"/> objects into a single <see cref="ChannelCredentials"/>.
+    /// </summary>
+    internal sealed class CompositeChannelCredentials : ChannelCredentials
+    {
+        readonly ChannelCredentials channelCredentials;
+        readonly CallCredentials callCredentials;
+
+        /// <summary>
+        /// Initializes a new instance of <c>CompositeChannelCredentials</c> class.
+        /// The resulting credentials object will be composite of all the credentials specified as parameters.
+        /// </summary>
+        /// <param name="channelCredentials">channelCredentials to compose</param>
+        /// <param name="callCredentials">channelCredentials to compose</param>
+        public CompositeChannelCredentials(ChannelCredentials channelCredentials, CallCredentials callCredentials)
+        {
+            this.channelCredentials = GrpcPreconditions.CheckNotNull(channelCredentials);
+            this.callCredentials = GrpcPreconditions.CheckNotNull(callCredentials);
+            GrpcPreconditions.CheckArgument(channelCredentials.IsComposable, "Supplied channel credentials do not allow composition.");
+        }
+
+        internal override ChannelCredentialsSafeHandle ToNativeCredentials()
+        {
+            using (var channelCreds = channelCredentials.ToNativeCredentials())
+            using (var callCreds = callCredentials.ToNativeCredentials())
+            {
+                var nativeComposite = ChannelCredentialsSafeHandle.CreateComposite(channelCreds, callCreds);
+                if (nativeComposite.IsInvalid)
+                {
+                    throw new ArgumentException("Error creating native composite credentials. Likely, this is because you are trying to compose incompatible credentials.");
+                }
+                return nativeComposite;
+            }
+        }
+    }
+}