Revert of Auth work to support new auth protocol

chrome/browser/extensions/api/cast_channel/cast_channel.proto

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
 package extensions.api.cast_channel;
 
@@ skipping 35 matching lines @@
     BINARY = 1;
   }
   required PayloadType payload_type = 5;
 
   // Depending on payload_type, exactly one of the following optional fields
   // will always be set.
   optional string payload_utf8 = 6;
   optional bytes payload_binary = 7;
 }
 
-enum SignatureAlgorithm {
-  UNSPECIFIED = 0;
-  RSASSA_PKCS1v15 = 1;
-  RSASSA_PSS = 2;
-}
-
 // Messages for authentication protocol between a sender and a receiver.
 message AuthChallenge {
-  optional SignatureAlgorithm signature_algorithm = 1
-      [default = RSASSA_PKCS1v15];
 }
 
 message AuthResponse {
   required bytes signature = 1;
   required bytes client_auth_certificate = 2;
-  repeated bytes intermediate_certificate = 3;
-  optional SignatureAlgorithm signature_algorithm = 4
-      [default = RSASSA_PKCS1v15];
 }
 
 message AuthError {
   enum ErrorType {
     INTERNAL_ERROR = 0;
     NO_TLS = 1;  // The underlying connection is not TLS
-    SIGNATURE_ALGORITHM_UNAVAILABLE = 2;
   }
   required ErrorType error_type = 1;
 }
 
 message DeviceAuthMessage {
   // Request fields
   optional AuthChallenge challenge = 1;
   // Response fields
   optional AuthResponse response = 2;
   optional AuthError error = 3;
 }