1 #region Copyright notice and license
2 
3 // Copyright 2015 gRPC authors.
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 //     http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 
17 #endregion
18 
19 using System.Collections.Generic;
20 using System.Collections.ObjectModel;
21 
22 using Grpc.Core.Internal;
23 using Grpc.Core.Utils;
24 
25 namespace Grpc.Core
26 {
27     /// <summary>
28     /// Client-side call credentials. Provide authorization with per-call granularity.
29     /// </summary>
30     public abstract class CallCredentials
31     {
32         /// <summary>
33         /// Composes multiple <c>CallCredentials</c> objects into
34         /// a single <c>CallCredentials</c> object.
35         /// </summary>
36         /// <param name="credentials">credentials to compose</param>
37         /// <returns>The new <c>CompositeCallCredentials</c></returns>
Compose(params CallCredentials[] credentials)38         public static CallCredentials Compose(params CallCredentials[] credentials)
39         {
40             return new CompositeCallCredentials(credentials);
41         }
42 
43         /// <summary>
44         /// Creates a new instance of <c>CallCredentials</c> class from an
45         /// interceptor that can attach metadata to outgoing calls.
46         /// </summary>
47         /// <param name="interceptor">authentication interceptor</param>
FromInterceptor(AsyncAuthInterceptor interceptor)48         public static CallCredentials FromInterceptor(AsyncAuthInterceptor interceptor)
49         {
50             return new AsyncAuthInterceptorCredentials(interceptor);
51         }
52 
53         /// <summary>
54         /// Populates call credentials configurator with this instance's configuration.
55         /// End users never need to invoke this method as it is part of internal implementation.
56         /// </summary>
InternalPopulateConfiguration(CallCredentialsConfiguratorBase configurator, object state)57         public abstract void InternalPopulateConfiguration(CallCredentialsConfiguratorBase configurator, object state);
58 
59         private class CompositeCallCredentials : CallCredentials
60         {
61             readonly IReadOnlyList<CallCredentials> credentials;
62 
CompositeCallCredentials(CallCredentials[] credentials)63             public CompositeCallCredentials(CallCredentials[] credentials)
64             {
65                 GrpcPreconditions.CheckArgument(credentials.Length >= 2, "Composite credentials object can only be created from 2 or more credentials.");
66                 this.credentials = new List<CallCredentials>(credentials).AsReadOnly();
67             }
68 
InternalPopulateConfiguration(CallCredentialsConfiguratorBase configurator, object state)69             public override void InternalPopulateConfiguration(CallCredentialsConfiguratorBase configurator, object state)
70             {
71                 configurator.SetCompositeCredentials(state, credentials);
72             }
73         }
74 
75         private class AsyncAuthInterceptorCredentials : CallCredentials
76         {
77             readonly AsyncAuthInterceptor interceptor;
78 
AsyncAuthInterceptorCredentials(AsyncAuthInterceptor interceptor)79             public AsyncAuthInterceptorCredentials(AsyncAuthInterceptor interceptor)
80             {
81                 this.interceptor = GrpcPreconditions.CheckNotNull(interceptor);
82             }
83 
InternalPopulateConfiguration(CallCredentialsConfiguratorBase configurator, object state)84             public override void InternalPopulateConfiguration(CallCredentialsConfiguratorBase configurator, object state)
85             {
86                 configurator.SetAsyncAuthInterceptorCredentials(state, interceptor);
87             }
88         }
89     }
90 }
91