Sketch out mechanism for configuring WebSocket authentication from au…

…th strategy

#108
#136

src/KubeClient.Extensions.WebSockets/K8sWebSocketOptions.cs

@@ -12,6 +12,7 @@ namespace KubeClient.Extensions.WebSockets
     ///     Options for connecting to Kubernetes web sockets.
     /// </summary>
     public class K8sWebSocketOptions
+        : IClientAuthenticationConfig
     {
         /// <summary>
         ///     The default size (in bytes) for WebSocket send / receive buffers.
@@ -68,6 +69,40 @@ public K8sWebSocketOptions()
         /// </summary>
         public TimeSpan KeepAliveInterval { get; set; } = TimeSpan.FromSeconds(5);
 
+        /// <summary>
+        ///     Add a client certificate for authentication to the Kubernetes API.
+        /// </summary>
+        /// <param name="certificate">
+        ///     An <see cref="X509Certificate2"/> representing the client certificate to use.
+        /// </param>
+        void IClientAuthenticationConfig.AddClientCertificate(X509Certificate2 certificate)
+        {
+            if (certificate == null)
+                throw new ArgumentNullException(nameof(certificate));
+
+            ClientCertificates.Add(certificate);
+        }
+
+        /// <summary>
+        ///     Configure the HTTP "Authorization" header for authentication to the Kubernetes API.
+        /// </summary>
+        /// <param name="scheme">
+        ///     The authentication scheme (e.g. "Basic", "Bearer", etc).
+        /// </param>
+        /// <param name="value">
+        ///     The authentication value.
+        /// </param>
+        void IClientAuthenticationConfig.SetAuthorizationHeader(string scheme, string value)
+        {
+            if (String.IsNullOrWhiteSpace(scheme))
+                throw new ArgumentException($"Argument cannot be null, empty, or entirely composed of whitespace: {nameof(scheme)}.", nameof(scheme));
+
+            if (value == null)
+                throw new ArgumentNullException(nameof(value));
+
+            RequestHeaders[HttpKnownHeaderNames.Authorization] = $"{scheme} ${value}";
+        }
+
         /// <summary>
         ///     Create <see cref="K8sWebSocketOptions"/> using the client's authentication settings.
         /// </summary>
@@ -103,7 +138,9 @@ public static K8sWebSocketOptions FromClientOptions(KubeClientOptions clientOpti
 
             var socketOptions = new K8sWebSocketOptions();
 
-            // TODO: Expose functionality for obtaining access token via KubeAuthStrategy and call it from here, rather than using the special-case credential configuration logic below.
+            // NOTE: Not all authentication strategies are supported yet.
+            if (clientOptions.AuthStrategy != null)
+                clientOptions.AuthStrategy.Configure(socketOptions);
 
             switch (clientOptions.AuthStrategy)
             {

src/KubeClient/Authentication/BasicAuthStrategy.cs

@@ -65,6 +65,23 @@ public override ClientBuilder Configure(ClientBuilder clientBuilder)
             );
         }
 
+        /// <summary>
+        ///     Configure client authentication.
+        /// </summary>
+        /// <param name="clientAuthenticationConfig">
+        ///     The client authentication configuration.
+        /// </param>
+        public override void Configure(IClientAuthenticationConfig clientAuthenticationConfig)
+        {
+            if (clientAuthenticationConfig == null)
+                throw new ArgumentNullException(nameof(clientAuthenticationConfig));
+
+            clientAuthenticationConfig.SetAuthorizationHeader(
+                scheme: "Basic",
+                value: BasicAuthenticationHandler.EncodeHeaderValue(UserName, Password)
+            );
+        }
+
         /// <summary>
         ///     Create a deep clone of the authentication strategy.
         /// </summary>

src/KubeClient/Authentication/BearerTokenAuthStrategy.cs

@@ -57,6 +57,25 @@ public override ClientBuilder Configure(ClientBuilder clientBuilder)
             );
         }
 
+        /// <summary>
+        ///     Configure client authentication.
+        /// </summary>
+        /// <param name="clientAuthenticationConfig">
+        ///     The client authentication configuration.
+        /// </param>
+        public override void Configure(IClientAuthenticationConfig clientAuthenticationConfig)
+        {
+            if (clientAuthenticationConfig == null)
+                throw new ArgumentNullException(nameof(clientAuthenticationConfig));
+
+            Validate();
+
+            clientAuthenticationConfig.SetAuthorizationHeader(
+                scheme: "Bearer",
+                value: Token
+            );
+        }
+
         /// <summary>
         ///     Create a deep clone of the authentication strategy.
         /// </summary>

src/KubeClient/Authentication/BearerTokenProviderAuthStrategy.cs

@@ -88,6 +88,20 @@ public override ClientBuilder Configure(ClientBuilder clientBuilder)
             );
         }
 
+        /// <summary>
+        ///     Configure client authentication.
+        /// </summary>
+        /// <param name="clientAuthenticationConfig">
+        ///     The client authentication configuration.
+        /// </param>
+        public override void Configure(IClientAuthenticationConfig clientAuthenticationConfig)
+        {
+            if (clientAuthenticationConfig == null)
+                throw new ArgumentNullException(nameof(clientAuthenticationConfig));
+
+            throw new NotImplementedException(); // TODO: Figure out how to implement this (especially given that we would need to do it synchronously).
+        }
+
         /// <summary>
         ///     Create a deep clone of the authentication strategy.
         /// </summary>

src/KubeClient/Authentication/CertificateAuthStrategy.cs

@@ -57,6 +57,22 @@ public override ClientBuilder Configure(ClientBuilder clientBuilder)
             return clientBuilder.WithClientCertificate(Certificate);
         }
 
+        /// <summary>
+        ///     Configure client authentication.
+        /// </summary>
+        /// <param name="clientAuthenticationConfig">
+        ///     The client authentication configuration.
+        /// </param>
+        public override void Configure(IClientAuthenticationConfig clientAuthenticationConfig)
+        {
+            if (clientAuthenticationConfig == null)
+                throw new ArgumentNullException(nameof(clientAuthenticationConfig));
+
+            Validate();
+
+            clientAuthenticationConfig.AddClientCertificate(Certificate);
+        }
+
         /// <summary>
         ///     Create a deep clone of the authentication strategy.
         /// </summary>

src/KubeClient/Authentication/CredentialPluginAuthStrategy.cs

@@ -89,6 +89,20 @@ public override ClientBuilder Configure(ClientBuilder clientBuilder)
             );
         }
 
+        /// <summary>
+        ///     Configure client authentication.
+        /// </summary>
+        /// <param name="clientAuthenticationConfig">
+        ///     The client authentication configuration.
+        /// </param>
+        public override void Configure(IClientAuthenticationConfig clientAuthenticationConfig)
+        {
+            if (clientAuthenticationConfig == null)
+                throw new ArgumentNullException(nameof(clientAuthenticationConfig));
+
+            throw new NotImplementedException(); // TODO: Figure out how to implement this (especially given that we would need to do it synchronously).
+        }
+
         /// <summary>
         ///     Create a deep clone of the authentication strategy.
         /// </summary>

src/KubeClient/Authentication/IClientAuthenticationConfig.cs

@@ -0,0 +1,31 @@
+using System.Security.Cryptography.X509Certificates;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace KubeClient.Authentication
+{
+    /// <summary>
+    ///     Represents configuration for client authentication to the Kubernetes API.
+    /// </summary>
+    public interface IClientAuthenticationConfig
+    {
+        /// <summary>
+        ///     Add a client certificate for authentication to the Kubernetes API.
+        /// </summary>
+        /// <param name="certificate">
+        ///     An <see cref="X509Certificate2"/> representing the client certificate to use.
+        /// </param>
+        void AddClientCertificate(X509Certificate2 certificate);
+
+        /// <summary>
+        ///     Configure the HTTP "Authorization" header for authentication to the Kubernetes API.
+        /// </summary>
+        /// <param name="scheme">
+        ///     The authentication scheme (e.g. "Basic", "Bearer", etc).
+        /// </param>
+        /// <param name="value">
+        ///     The authentication value.
+        /// </param>
+        void SetAuthorizationHeader(string scheme, string value);
+    }
+}

src/KubeClient/Authentication/NoneAuthStrategy.cs

@@ -1,4 +1,5 @@
 using HTTPlease;
+using System;
 using System.Net.Http;
 
 namespace KubeClient.Authentication
@@ -41,7 +42,29 @@ public override void Validate()
         /// <returns>
         ///     The configured <see cref="ClientBuilder"/>.
         /// </returns>
-        public override ClientBuilder Configure(ClientBuilder clientBuilder) => clientBuilder;
+        public override ClientBuilder Configure(ClientBuilder clientBuilder)
+        {
+            if (clientBuilder == null)
+                throw new ArgumentNullException(nameof(clientBuilder));
+
+            Validate();
+
+            return clientBuilder;
+        }
+
+        /// <summary>
+        ///     Configure client authentication.
+        /// </summary>
+        /// <param name="clientAuthenticationConfig">
+        ///     The client authentication configuration.
+        /// </param>
+        public override void Configure(IClientAuthenticationConfig clientAuthenticationConfig)
+        {
+            if (clientAuthenticationConfig == null)
+                throw new ArgumentNullException(nameof(clientAuthenticationConfig));
+
+            Validate();
+        }
 
         /// <summary>
         ///     Create a deep clone of the authentication strategy.

src/KubeClient/KubeAuthStrategy.cs

@@ -32,6 +32,14 @@ public abstract class KubeAuthStrategy
         /// </returns>
         public abstract ClientBuilder Configure(ClientBuilder clientBuilder);
 
+        /// <summary>
+        ///     Configure client authentication.
+        /// </summary>
+        /// <param name="clientAuthenticationConfig">
+        ///     The client authentication configuration.
+        /// </param>
+        public abstract void Configure(IClientAuthenticationConfig clientAuthenticationConfig);
+
         /// <summary>
         ///     Create a deep clone of the authentication strategy.
         /// </summary>

src/KubeClient/MessageHandlers/BasicAuthenticationHandler.cs

@@ -22,12 +22,12 @@ public class BasicAuthenticationHandler : DelegatingHandler
         /// <param name="password">The password to use</param>
         public BasicAuthenticationHandler(string username, string password)
         {
-            if(String.IsNullOrEmpty(username))
+            if (String.IsNullOrEmpty(username))
                 throw new ArgumentNullException(nameof(username));
-            if(String.IsNullOrEmpty(password))
+            if (String.IsNullOrEmpty(password))
                 throw new ArgumentNullException(nameof(password));
 
-            _encoded = Convert.ToBase64String(Encoding.ASCII.GetBytes(username + ":" + password));
+            _encoded = EncodeHeaderValue(username, password);
         }
 
         /// <inheritdoc />
@@ -36,5 +36,27 @@ protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage reques
             request.Headers.Authorization = new AuthenticationHeaderValue("Basic", _encoded);
             return base.SendAsync(request, cancellationToken);
         }
+
+        /// <summary>
+        ///     Encode a username and password to use as a Basic authentication header value.
+        /// </summary>
+        /// <param name="username">
+        ///     The username to use.
+        /// </param>
+        /// <param name="password">
+        ///     The password to use.
+        /// </param>
+        /// <returns>
+        ///     The encoded header value.
+        /// </returns>
+        public static string EncodeHeaderValue(string username, string password)
+        {
+            if (String.IsNullOrEmpty(username))
+                throw new ArgumentNullException(nameof(username));
+            if (String.IsNullOrEmpty(password))
+                throw new ArgumentNullException(nameof(password));
+
+            return Convert.ToBase64String(Encoding.ASCII.GetBytes(username + ":" + password));
+        }
     }
 }