invitation process upgrade

client/peer.go

@@ -56,8 +56,10 @@ type Peer struct {
 	DbIds               []string `json:"db_ids,omitempty"`
 	Type                string   `json:"type,omitempty"`
 	PersonnaeDbId       string   `json:"personnae_db_id,omitempty"`
+	// Invitation temporary keypair (step 1 only — discarded after step 3)
+	InvitationKp *meowlib.KeyPair `json:"invitation_kp,omitempty"`
 	// Double Ratchet state
-	DrKpPublic         string `json:"dr_kp_public,omitempty"`
+	DrKpPublic string `json:"dr_kp_public,omitempty"`
 	DrKpPrivate        string `json:"dr_kp_private,omitempty"`
 	DrRootKey          string `json:"dr_root_key,omitempty"`
 	DrInitiator        bool   `json:"dr_initiator,omitempty"`
@@ -171,9 +173,28 @@ func (p *Peer) BuildSingleFileMessage(filename string, message []byte) ([]meowli
 	return msgs, nil
 }
 
-// Builds an invitation answer user message.
-// it takes as input a contactcard generated by Identity.AnswerInvitation
-func (p *Peer) BuildInvitationAnswerMessage(myContactCard *meowlib.ContactCard) (*meowlib.UserMessage, error) {
+// BuildInvitationStep2Message builds the invitee's answer UserMessage (STEP_2_SEND).
+// The ContactCard is encrypted with the initiator's temp public key via ProcessOutboundUserMessage.
+func (p *Peer) BuildInvitationStep2Message(myContactCard *meowlib.ContactCard) (*meowlib.UserMessage, error) {
+	var msg meowlib.UserMessage
+	var invitation meowlib.Invitation
+	invitation.Step = 2
+	out, err := proto.Marshal(myContactCard)
+	if err != nil {
+		return nil, err
+	}
+	invitation.Uuid = p.InvitationId
+	invitation.Payload = out
+	msg.Destination = p.ContactLookupKey
+	msg.Invitation = &invitation
+	msg.From = p.MyIdentity.Public
+	msg.Type = "1"
+	return &msg, nil
+}
+
+// BuildInvitationStep3Message builds the initiator's full ContactCard UserMessage (STEP_3_SEND).
+// Sent through the invitee's servers after the initiator has finalized their keypairs.
+func (p *Peer) BuildInvitationStep3Message(myContactCard *meowlib.ContactCard) (*meowlib.UserMessage, error) {
 	var msg meowlib.UserMessage
 	var invitation meowlib.Invitation
 	invitation.Step = 3
@@ -190,6 +211,42 @@ func (p *Peer) BuildInvitationAnswerMessage(myContactCard *meowlib.ContactCard)
 	return &msg, nil
 }
 
+// BuildInvitationStep4Message builds the invitee's confirmation UserMessage (STEP_4).
+// Sent through the initiator's servers to signal the invitation is complete.
+func (p *Peer) BuildInvitationStep4Message() (*meowlib.UserMessage, error) {
+	var msg meowlib.UserMessage
+	var invitation meowlib.Invitation
+	invitation.Step = 4
+	invitation.Uuid = p.InvitationId
+	msg.Destination = p.ContactLookupKey
+	msg.Invitation = &invitation
+	msg.From = p.MyIdentity.Public
+	msg.Type = "1"
+	return &msg, nil
+}
+
+// ProcessInboundStep2UserMessage decrypts the invitee's step-2 answer using the
+// initiator's temporary InvitationKp private key. inviteePublicKey is the sender's
+// identity public key (carried in Invitation.From by the server).
+func (p *Peer) ProcessInboundStep2UserMessage(packed *meowlib.PackedUserMessage, inviteePublicKey string) (*meowlib.UserMessage, error) {
+	dec, err := meowlib.AsymDecryptAndCheck(p.InvitationKp.Private, inviteePublicKey, packed.Payload, packed.Signature)
+	if err != nil {
+		return nil, err
+	}
+	return p.DeserializeUserMessage(dec)
+}
+
+// ProcessInboundStep3UserMessage decrypts the initiator's step-3 full ContactCard using
+// the invitee's MyEncryptionKp. Signature verification is skipped because the
+// initiator's identity key is not yet known — it is extracted from the decrypted payload.
+func (p *Peer) ProcessInboundStep3UserMessage(packed *meowlib.PackedUserMessage) (*meowlib.UserMessage, error) {
+	dec, err := meowlib.AsymDecrypt(p.MyEncryptionKp.Private, packed.Payload)
+	if err != nil {
+		return nil, err
+	}
+	return p.DeserializeUserMessage(dec)
+}
+
 //
 // Messages encryption and packaging
 //