Clean message format and improve validation a bit.

ma.go

@@ -1,7 +1,5 @@
 package ma
 
-import "time"
-
 const (
 
 	// Just our name
@@ -16,27 +14,19 @@ const (
 	// The rendezvous string used for peer discovery in libp2p.
 	RENDEZVOUS = "/" + NAME + "/" + VERSION
 
-	// The topic prefix used in pubsub. It is the same as the rendezvous string.
-	// But we keep it separate for future flexibility.
-	TOPIC_PREFIX = RENDEZVOUS
-
 	// BLAKE3 label for symmetric key generation.
 	HASH_ALGORITHM_MULTICODEC_STRING = "blake3"
 	BLAKE3_LABEL                     = NAME
 	BLAKE3_SUM_SIZE                  = 32 // 256 bits
 
-	// MIME types
-
-	// A MIME type for a message. Just to implement it for future proofing.
-	MESSAGE_MIME_TYPE  = "application/x-ma-message; version=" + VERSION
-	ENVELOPE_MIME_TYPE = "application/x-ma-envelope; version=" + VERSION
+	// Message constants
+	MESSAGE_TYPE           = "/ma/message/" + VERSION
+	ENVELOPE_MESSAGE_TYPE  = "/ma/message/envelope/" + VERSION
+	BROADCAST_MESSAGE_TYPE = "/ma/message/broadcast/" + VERSION
 
-	// Broadcasts
-	BROADCAST_MIME_TYPE = "application/x-ma-broadcast; version=" + VERSION
-	BROADCAST_TOPIC     = "/" + NAME + "/broadcast/" + VERSION
+	BROADCAST_TOPIC = BROADCAST_MESSAGE_TYPE
 
 	MESSAGE_DEFAULT_CONTENT_TYPE = "text/plain"
-	MESSAGE_DEFAULT_TTL          = time.Hour * 24
 
 	// API
 	DEFAULT_IPFS_API_MULTIADDR = "/ip4/127.0.0.1/tcp/45005" // Default to Brave browser, Kubo is /ip4/127.0.0.1/tcp/5001

msg/broadcast.go

@@ -26,15 +26,13 @@ func NewBroadcast(
 
 	m := &Message{
 		// Message meta data
-		ID:       id,
-		MimeType: ma.BROADCAST_MIME_TYPE,
-		Version:  ma.VERSION,
+		Id:   id,
+		Type: ma.BROADCAST_MESSAGE_TYPE,
 		// Recipients
 		From: from,
 		// Body
 		ContentType: contentType,
-		// The content is not signed as such, but the hash is.
-		Content: content,
+		Content:     content,
 	}
 
 	err = m.Sign(priv_key)
@@ -72,7 +70,7 @@ func (m *Message) Broadcast(ctx context.Context, t *pubsub.Topic) error {
 }
 
 func (m *Message) verifyBroadcast(t *pubsub.Topic) error {
-	if m.MimeType != ma.BROADCAST_MIME_TYPE {
+	if m.Type != ma.BROADCAST_MESSAGE_TYPE {
 		return ErrMessageInvalidType
 	}
 

msg/errors.go

@@ -10,14 +10,15 @@ import (
 var (
 	ErrBroadcastHasRecipient = errors.New("broadcast message must not have a recipient")
 	ErrBroadcastInvalidTopic = fmt.Errorf("broadcast topic must be %s", ma.BROADCAST_TOPIC)
-	ErrBroadcastInvalidType  = fmt.Errorf("broadcast message must not %s", ma.BROADCAST_MIME_TYPE)
+	ErrBroadcastInvalidType  = fmt.Errorf("broadcast message must not %s", ma.BROADCAST_MESSAGE_TYPE)
 	ErrEmptyID               = errors.New("id must be non-empty")
 	ErrInvalidID             = errors.New("invalid message id")
 	ErrFetchDoc              = errors.New("failed to fetch entity document")
 	ErrMessageInvalidType    = errors.New("invalid Message type")
 	ErrInvalidSender         = errors.New("invalid sender")
 	ErrInvalidRecipient      = errors.New("invalid recipient")
 	ErrMissingContentType    = errors.New("empty ContentType")
+	ErrMissingContent        = errors.New("empty ContentType")
 	ErrMissingFrom           = errors.New("mmissing From sender")
 	ErrMissinSignature       = errors.New("mmissing signature")
 	ErrNilMessage            = errors.New("nil Message provided")

msg/headers.go

@@ -1,7 +1,6 @@
 package msg
 
 import (
-	semver "github.com/blang/semver/v4"
 	cbor "github.com/fxamacker/cbor/v2"
 )
 
@@ -10,11 +9,9 @@ import (
 // NB! Content is *not* a part of the headers
 type Headers struct {
 	// Version of the message format
-	Version string
-	// Unique identifier of the message
-	ID string `cbor:"id"`
+	Id string `cbor:"id"`
 	// MIME type of the message
-	MimeType string `cbor:"mimeType"`
+	Type string `cbor:"type"`
 	// Sender of the message
 	From string `cbor:"from"`
 	// Recipient of the message
@@ -29,9 +26,8 @@ func (m *Message) unsignedHeaders() Headers {
 
 	return Headers{
 		// Message Headers
-		ID:          m.ID,
-		MimeType:    m.MimeType,
-		Version:     m.Version,
+		Id:          m.Id,
+		Type:        m.Type,
 		From:        m.From,
 		To:          m.To,
 		ContentType: m.ContentType,
@@ -54,7 +50,3 @@ func (m *Message) Headers() Headers {
 func (m *Message) marshalHeadersToCBOR() ([]byte, error) {
 	return cbor.Marshal(m.Headers())
 }
-
-func (h *Headers) semVersion() (semver.Version, error) {
-	return semver.Make(h.Version)
-}

msg/message.go

@@ -11,21 +11,13 @@ import (
 	nanoid "github.com/matoous/go-nanoid/v2"
 )
 
-const (
-
-	// Messages which are older than a day should be ignored
-	MESSAGE_TTL = ma.MESSAGE_DEFAULT_TTL
-)
-
 // This struct mimicks the Message format, but it's *not* Message.
 // It should enable using Message later, if that's a good idea.
 type Message struct {
-	// Version of the message format
-	Version string `cbor:"version"`
 	// Unique identifier of the message
-	ID string `cbor:"id"`
+	Id string `cbor:"id"`
 	// MIME type of the message
-	MimeType string `cbor:"mimeType"`
+	Type string `cbor:"mimeType"`
 	// Sender of the message
 	From string `cbor:"from"`
 	// Recipient of the message
@@ -54,16 +46,19 @@ func New(
 
 	m := &Message{
 		// Message meta data
-		ID:       id,
-		MimeType: ma.MESSAGE_MIME_TYPE,
-		Version:  ma.VERSION,
+		Id:   id,
+		Type: ma.MESSAGE_TYPE,
 		// Recipient
 		From: from,
 		To:   to,
 		// Body
 		ContentType: contentType,
-		// The content is not signed as such, but the hash is.
-		Content: content,
+		Content:     content,
+	}
+
+	err = verifyContent(content)
+	if err != nil {
+		return nil, err
 	}
 
 	err = m.Sign(priv_key)
@@ -81,14 +76,13 @@ func newFromHeaders(h *Headers) (*Message, error) {
 
 	err := h.validate()
 	if err != nil {
-		return nil, fmt.Errorf("msg_new_from_headers: failed to validate headers: %w", err)
+		return nil, fmt.Errorf("newFromHeaders: %w", err)
 	}
 
 	m := &Message{
 		// Message meta data
-		ID:       h.ID,
-		MimeType: h.MimeType,
-		Version:  h.Version,
+		Id:   h.Id,
+		Type: h.Type,
 		// Recipient
 		From: h.From,
 		To:   h.To,
@@ -97,6 +91,7 @@ func newFromHeaders(h *Headers) (*Message, error) {
 		// Signature
 		Signature: h.Signature,
 	}
+
 	return m, nil
 }
 

msg/validate.go

@@ -2,6 +2,7 @@ package msg
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/bahner/go-ma"
 	"github.com/bahner/go-ma/did"
@@ -18,29 +19,30 @@ func (h *Headers) validate() error {
 		return ErrNilMessage
 	}
 
-	if h.MimeType != ma.MESSAGE_MIME_TYPE && h.MimeType != ma.BROADCAST_MIME_TYPE {
-		return ErrMessageInvalidType
+	// Verify ID
+	err = verifyID(h.Id)
+	if err != nil {
+		return err
 	}
 
-	// Check that message body headers are valid
-	if h.ContentType == "" {
-		return ErrMissingContentType
+	err = verifyType(h.Type)
+	if err != nil {
+		return err
 	}
 
-	// Verify ID
-	err = h.verifyID()
+	// Message version check. Check the type first
+	err = verifyMessageVersion(h.Type)
 	if err != nil {
 		return err
 	}
 
-	// Verify actors
-	err = h.verifyActors()
+	err = verifyContentType(h.ContentType)
 	if err != nil {
 		return err
 	}
 
-	// Message version check
-	err = h.verifyMessageVersion()
+	// Verify actors
+	err = h.verifyActors()
 	if err != nil {
 		return err
 	}
@@ -49,9 +51,14 @@ func (h *Headers) validate() error {
 }
 
 // Compare messageVersion.  Return nil if ok else an error
-func (h *Headers) verifyMessageVersion() error {
+// Takes the type string as input
+func verifyMessageVersion(t string) error {
+
+	// Split the string on "/"
+	parts := strings.Split(t, "/")
 
-	messageSemver, err := h.semVersion()
+	// Make a semver version from the last element
+	messageSemver, err := semver.Make(parts[len(parts)-1])
 	if err != nil {
 		return err
 	}
@@ -89,7 +96,7 @@ func (h *Headers) verifyActors() error {
 		return err
 	}
 
-	if h.ContentType == ma.BROADCAST_MIME_TYPE {
+	if h.ContentType == ma.BROADCAST_MESSAGE_TYPE {
 		if h.To != "" {
 			return ErrBroadcastHasRecipient
 		}
@@ -110,14 +117,46 @@ func (h *Headers) verifyActors() error {
 }
 
 // Check that ID is valid
-func (h *Headers) verifyID() error {
-	if h.ID == "" {
+func verifyID(id string) error {
+	if id == "" {
 		return ErrEmptyID
 	}
 
-	if !internal.IsValidNanoID(h.ID) {
+	if !internal.IsValidNanoID(id) {
 		return ErrInvalidID
 	}
 
 	return nil
 }
+
+func verifyType(t string) error {
+
+	if t == ma.MESSAGE_TYPE || t == ma.BROADCAST_MESSAGE_TYPE {
+		return nil
+	}
+
+	return ErrMessageInvalidType
+
+}
+
+// We don't want to parse this. That's up to the receiver
+// But we do want to check that it is there.
+func verifyContentType(ct string) error {
+
+	if ct == "" {
+		return ErrMissingContentType
+	}
+
+	return nil
+}
+
+// We don't want to parse this. That's up to the receiver
+// But we do want to check that it is there.
+func verifyContent(c []byte) error {
+
+	if c == nil {
+		return ErrMissingContent
+	}
+
+	return nil
+}