cleaner invitation step messages

client/invitation/messages/step3.go

@@ -8,39 +8,55 @@ import (
 	"google.golang.org/protobuf/proto"
 )
 
-// Step3InitiatorFinalizesInviteeAndCreatesContactCard is called by the initiator when a
-// step-2 answer (invitee's encrypted ContactCard) arrives. It decrypts the card, upgrades
-// the invitee's peer entry with the real keys, and returns the initiator's own ContactCard
-// ready to be sent to the invitee via any transport.
-func Step3InitiatorFinalizesInviteeAndCreatesContactCard(invitation *meowlib.Invitation) (*client.Peer, *meowlib.ContactCard, error) {
+// Step3InitiatorFinalizesInviteeAndCreatesContactCard is called by the initiator when the
+// step-2 answer (serialized Invitation bytes) arrives. It decrypts the invitee's ContactCard,
+// upgrades the pending peer with the invitee's real keys, and returns a serialized Invitation
+// (step=3) whose Payload is the initiator's ContactCard, ready to be consumed directly by
+// Step4InviteeFinalizesInitiator on the invitee side.
+func Step3InitiatorFinalizesInviteeAndCreatesContactCard(invitationBytes []byte) ([]byte, error) {
+	var invitation meowlib.Invitation
+	if err := proto.Unmarshal(invitationBytes, &invitation); err != nil {
+		return nil, err
+	}
+
 	var invitationAnswer meowlib.PackedUserMessage
 	if err := proto.Unmarshal(invitation.Payload, &invitationAnswer); err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 
 	peer := client.GetConfig().GetIdentity().Peers.GetFromInvitationId(invitation.Uuid)
 	if peer == nil {
-		return nil, nil, errors.New("no peer for invitation uuid " + invitation.Uuid)
+		return nil, errors.New("no peer for invitation uuid " + invitation.Uuid)
 	}
 	// Guard against duplicate delivery (e.g., same answer from multiple servers).
 	if peer.InvitationKp == nil {
-		return nil, nil, nil
+		return nil, nil
 	}
 
 	usermsg, err := peer.ProcessInboundStep2UserMessage(&invitationAnswer, invitation.From)
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 
 	var inviteeCC meowlib.ContactCard
 	if err := proto.Unmarshal(usermsg.Invitation.Payload, &inviteeCC); err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 
-	myCC, peer, err := client.GetConfig().GetIdentity().InvitationStep3(&inviteeCC)
+	myCC, _, err := client.GetConfig().GetIdentity().InvitationStep3(&inviteeCC)
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	client.GetConfig().GetIdentity().Save()
-	return peer, myCC, nil
+
+	ccBytes, err := proto.Marshal(myCC)
+	if err != nil {
+		return nil, err
+	}
+	inv := &meowlib.Invitation{
+		Uuid:    myCC.InvitationId,
+		Step:    3,
+		Payload: ccBytes,
+	}
+	return proto.Marshal(inv)
 }