Updating D2D protocol to v1 to support separate sequence numbers.

components/cryptauth/device_to_device_authenticator.cc

Index: components/cryptauth/device_to_device_authenticator.cc
diff --git a/components/cryptauth/device_to_device_authenticator.cc b/components/cryptauth/device_to_device_authenticator.cc
index d80449ffaa05d80d216e5663cea571e3bde28616..caf601cc12034050f782beb91248378553a879e8 100644
--- a/components/cryptauth/device_to_device_authenticator.cc
+++ b/components/cryptauth/device_to_device_authenticator.cc
@@ -15,6 +15,7 @@
 #include "components/cryptauth/device_to_device_secure_context.h"
 #include "components/cryptauth/secure_context.h"
 #include "components/cryptauth/secure_message_delegate.h"
+#include "components/cryptauth/session_keys.h"
 #include "components/cryptauth/wire_message.h"
 #include "components/proximity_auth/logging/logging.h"
 
@@ -154,7 +155,7 @@ void DeviceToDeviceAuthenticator::OnResponderAuthTimedOut() {
 
 void DeviceToDeviceAuthenticator::OnResponderAuthValidated(
     bool validated,
-    const std::string& session_symmetric_key) {
+    std::unique_ptr<SessionKeys> session_keys) {
   if (!validated) {
     Fail("Unable to validated [Responder Auth]");
     return;
@@ -163,11 +164,11 @@ void DeviceToDeviceAuthenticator::OnResponderAuthValidated(
   PA_LOG(INFO) << "Successfully validated [Responder Auth]! "
                << "Sending [Initiator Auth]...";
   state_ = State::VALIDATED_RESPONDER_AUTH;
-  session_symmetric_key_ = session_symmetric_key;
+  session_keys_ = std::move(session_keys);
 
   // Create the [Initiator Auth] message to send to the remote device.
   DeviceToDeviceInitiatorOperations::CreateInitiatorAuthMessage(
-      session_symmetric_key,
+      session_keys_.get(),
       connection_->remote_device().persistent_symmetric_key,
       responder_auth_message_, secure_message_delegate_.get(),
       base::Bind(&DeviceToDeviceAuthenticator::OnInitiatorAuthCreated,
@@ -204,7 +205,7 @@ void DeviceToDeviceAuthenticator::Fail(const std::string& error_message,
 
 void DeviceToDeviceAuthenticator::Succeed() {
   DCHECK(state_ == State::SENT_INITIATOR_AUTH);
-  DCHECK(!session_symmetric_key_.empty());
+  DCHECK(session_keys_);
   PA_LOG(INFO) << "Authentication succeeded!";
 
   state_ = State::AUTHENTICATION_SUCCESS;
@@ -212,7 +213,7 @@ void DeviceToDeviceAuthenticator::Succeed() {
   callback_.Run(
       Result::SUCCESS,
       base::MakeUnique<DeviceToDeviceSecureContext>(
-          std::move(secure_message_delegate_), session_symmetric_key_,
+          std::move(secure_message_delegate_), std::move(session_keys_),
           responder_auth_message_, SecureContext::PROTOCOL_VERSION_THREE_ONE));
 }