[Cast Channel] Add support for nonce challenge to Cast channel authentication.

extensions/browser/api/cast_channel/cast_socket.h

Index: extensions/browser/api/cast_channel/cast_socket.h
diff --git a/extensions/browser/api/cast_channel/cast_socket.h b/extensions/browser/api/cast_channel/cast_socket.h
index 2fa1821d7ca054fa369b02f37c06ae6c7036707f..6e5e4c4603bc4b03310010ed67029e8d1e058b48 100644
--- a/extensions/browser/api/cast_channel/cast_socket.h
+++ b/extensions/browser/api/cast_channel/cast_socket.h
@@ -43,6 +43,7 @@ class X509Certificate;
 namespace extensions {
 namespace api {
 namespace cast_channel {
+class AuthContext;
 class CastMessage;
 class Logger;
 struct LastErrors;
@@ -154,6 +155,18 @@ class CastSocketImpl : public CastSocket {
                  const scoped_refptr<Logger>& logger,
                  uint64_t device_capabilities);
 
+  // For test-only.
+  // This constructor allows for setting a custom AuthContext.
+  CastSocketImpl(const std::string& owner_extension_id,
+                 const net::IPEndPoint& ip_endpoint,
+                 ChannelAuthType channel_auth,
+                 net::NetLog* net_log,
+                 const base::TimeDelta& connect_timeout,
+                 bool keep_alive,
+                 const scoped_refptr<Logger>& logger,
+                 uint64_t device_capabilities,
+                 std::unique_ptr<AuthContext> auth_context);

[mark a. foltz, 2017/03/10 00:47:23]

const AuthContext&

[ryanchung, 2017/03/10 02:10:27]

Done.

+
   // Ensures that the socket is closed.
   ~CastSocketImpl() override;
 
@@ -320,6 +333,9 @@ class CastSocketImpl : public CastSocket {
   // certificate is not yet fetched.
   scoped_refptr<net::X509Certificate> peer_cert_;
 
+  // The challenge context for the current connection.
+  std::unique_ptr<AuthContext> auth_context_;

[mark a. foltz, 2017/03/10 00:47:23]

const AuthContext

GUID is a short string and not worth passing ownership of IMO.

[ryanchung, 2017/03/10 02:10:27]

Done.

+
   // Reply received from the receiver to a challenge request.
   std::unique_ptr<CastMessage> challenge_reply_;