Hook up Chrome Cast sender to Cast CRL.

extensions/common/api/cast_channel/cast_channel.proto

Index: extensions/common/api/cast_channel/cast_channel.proto
diff --git a/extensions/common/api/cast_channel/cast_channel.proto b/extensions/common/api/cast_channel/cast_channel.proto
index 1bd2877bdbe9057bb18f59d55abfe455bd9f654a..098ecb74dacbaaa5c4f8016ad627acb5a2a278b7 100644
--- a/extensions/common/api/cast_channel/cast_channel.proto
+++ b/extensions/common/api/cast_channel/cast_channel.proto
@@ -59,10 +59,17 @@ enum SignatureAlgorithm {
   RSASSA_PSS = 2;
 }
 
+enum HashAlgorithm {
+  SHA1 = 0;
+  SHA256 = 1;
+}
+
 // Messages for authentication protocol between a sender and a receiver.
 message AuthChallenge {
   optional SignatureAlgorithm signature_algorithm = 1
       [default = RSASSA_PKCS1v15];
+  optional bytes sender_nonce = 2;
+  optional HashAlgorithm hash_algorithm = 3 [default = SHA1];
 }
 
 message AuthResponse {
@@ -71,6 +78,9 @@ message AuthResponse {
   repeated bytes intermediate_certificate = 3;
   optional SignatureAlgorithm signature_algorithm = 4
       [default = RSASSA_PKCS1v15];
+  optional bytes sender_nonce = 5;
+  optional HashAlgorithm hash_algorithm = 6 [default = SHA1];
+  optional bytes crl = 7;
 }
 
 message AuthError {