Add support for validating a token

Author: Alan Quillin

src/corelib/Providers/Rackspace/CloudIdentityProvider.cs

@@ -737,6 +737,28 @@ public UserAccess Impersonate(RackspaceImpersonationIdentity identity, bool forc
             return impToken;
         }
 
+        /// <inheritdoc/>
+        public UserAccess ValidateToken(string token, string tenantId = null, CloudIdentity identity = null)
+        {
+            if (token == null)
+                throw new ArgumentNullException("token");
+            if (string.IsNullOrEmpty(token))
+                throw new ArgumentException("token cannot be empty");
+
+            var queryStringParameters = BuildOptionalParameterList(new Dictionary<string, string>
+                {
+                    {"belongsTo", tenantId}
+                });
+            
+            var response = ExecuteRESTRequest<AuthenticationResponse>(identity, new Uri(_urlBase, string.Format("/v2.0/tokens/{0}", token)), HttpMethod.GET, queryStringParameter: queryStringParameters);
+
+
+            if (response == null || response.Data == null || response.Data.UserAccess == null || response.Data.UserAccess.Token == null)
+                return null;
+
+            return response.Data.UserAccess;
+        }
+
         private JObject BuildImpersonationRequestJson(string path, string userName, int expirationInSeconds)
         {
             var request = new JObject();

src/corelib/Providers/Rackspace/IExtendedCloudIdentityProvider.cs

@@ -349,5 +349,19 @@ public interface IExtendedCloudIdentityProvider : IIdentityProvider
         /// <exception cref="ResponseException">If the REST API request failed.</exception>
         /// <seealso href="http://docs.openstack.org/api/openstack-identity-service/2.0/content/POST_updateUserCredential_v2.0_users__userId__OS-KSADM_credentials__credential-type__.html">Update User Credentials (OpenStack Identity Service API v2.0 Reference)</seealso>
         UserCredential UpdateUserCredentials(string userId, string username, string apiKey, CloudIdentity identity = null);
+
+        /// <summary>
+        /// Validates a given token.
+        /// </summary>
+        /// <param name="token">The token to be authenticated.</param>
+        /// <param name="tenantId">The Id of the Tenant to vaidate in scope.</param>
+        /// <param name="identity">The cloud identity to use for this request. If not specified, the default identity for the current provider instance will be used.</param>
+        /// <returns>A <see cref="UserAccess"/> object containing the authentication token and user data.</returns>
+        /// <exception cref="ArgumentNullException">If <paramref name="token"/> is <c>null</c>.</exception>
+        /// <exception cref="ArgumentException">If <paramref name="token"/> is empty.</exception>
+        /// <exception cref="NotSupportedException">If the provider does not support the given <paramref name="identity"/> type.</exception>
+        /// <exception cref="InvalidOperationException">If <paramref name="identity"/> is <c>null</c> and no default identity is available for the provider.</exception>
+        /// <exception cref="ResponseException">If the authentication request failed or the token does not exist.</exception>
+        UserAccess ValidateToken(string token, string tenantId = null, CloudIdentity identity = null);
     }
 }