GUI pairing working as it should

hexnoise.py

@@ -28,8 +28,9 @@ class ReportType(enum.Enum):
     KEYBOARD = 1
     MOUSE = 2
     PAIRING_INPUT = 3
-    PAIRING_SUCESS = 4
+    PAIRING_SUCCESS = 4
     PAIRING_ERROR = 5
+    PAIRING_START = 6
 
 class ProtocolError(Exception):
     pass
@@ -205,6 +206,8 @@ class NoiseEngine:
         self.proto.set_as_initiator()
         self.proto.set_keypair_from_private_bytes(Keypair.STATIC, self.static_local)
         self.proto.start_handshake()
+        self.paired = False
+        self.connected = False
         self.packetizer.send_packet(PacketType.INITIATE_HANDSHAKE, b'')
         self.debug_print('Handshake started')
 
@@ -226,6 +229,17 @@ class NoiseEngine:
                 self.proto.read_message(payload)
             else:
                 raise ProtocolError(f'Incorrect packet type {pkt_type}. Ignoring since this is only test code.')
+
+        msg_type, payload = self.packetizer.receive_packet()
+        rtype, data = self._decrypt(payload)
+        if rtype is ReportType.PAIRING_SUCCESS:
+            self.connected, self.paired = True, True
+        elif rtype is ReportType.PAIRING_START:
+            self.connected, self.paired = True, False
+        else:
+            self.connected, self.paired = True, False
+            raise UserWarning(f'Unexpected record type {rtype} in {msg_type} packet. Ignoring.')
+
         if self.debug:
             print('Handshake finished, handshake hash:')
             hexdump(print, self.proto.get_handshake_hash())
@@ -282,7 +296,7 @@ class NoiseEngine:
     def pairing_messages(self):
         user_input = ''
         for msg_type, payload in self.receive_loop():
-            if msg_type == ReportType.PAIRING_INPUT:
+            if msg_type is ReportType.PAIRING_INPUT:
                 ch = chr(payload[0])
                 if ch == '\b':
                     user_input = user_input[:-1]
@@ -290,10 +304,10 @@ class NoiseEngine:
                     user_input += ch
                 yield user_input
 
-            elif msg_type == ReportType.PAIRING_SUCESS:
+            elif msg_type is ReportType.PAIRING_SUCCESS:
                 break
 
-            elif msg_type == ReportType.PAIRING_ERROR:
+            elif msg_type is ReportType.PAIRING_ERROR:
                 raise ProtocolError('Device-side pairing error') # FIXME find better exception subclass here
 
             else:
@@ -313,7 +327,6 @@ class NoiseEngine:
                     keys = { *KeyMapper.map_modifiers(modbyte), *KeyMapper.map_regulars(keycodes) }
                     if self.debug:
                         print('Emitting:', keys)
-                    print('payload:', binascii.hexlify(payload), 'emitting:', keys)
 
                     for key in keys - old_kcs:
                         ui.emit(key, 1, syn=False)

pairing.py

@@ -49,27 +49,29 @@ class PairingWindow(Gtk.Window):
     def run_handshake(self):
         self.noise.perform_handshake()
 
-        binding_incantation = self.noise.channel_binding_incantation()
+        if not self.noise.paired:
-        self.label.set_markup(f'<b>Step 2</b>\n\nPerform channel binding ritual.\n'
+            binding_incantation = self.noise.channel_binding_incantation()
-                              f'Enter the following incantation, then press enter.\n'
+            GLib.idle_add(self.label.set_markup,
-                              f'<b>{binding_incantation}</b>')
+                    f'<b>Step 2</b>\n\nPerform channel binding ritual.\n'
-        
+                    f'Enter the following incantation, then press enter.\n'
-        def update_text(text):
+                    f'<b>{binding_incantation}</b>')
-            self.entry.set_text(text)
+            
-            self.entry.set_position(len(text))
+            def update_text(text):
+                self.entry.set_text(text)
+                self.entry.set_position(len(text))
 
-            clean = lambda s: re.sub('[^a-z0-9-]', '', s.lower())
+                clean = lambda s: re.sub('[^a-z0-9-]', '', s.lower())
-            if clean(binding_incantation).startswith(clean(text)):
+                if clean(binding_incantation).startswith(clean(text)):
-                color = 0.9, 1.0, 0.9 # light red
+                    color = 0.9, 1.0, 0.9 # light red
-            else:
+                else:
-                color = 1.0, 0.9, 0.9 # light green
+                    color = 1.0, 0.9, 0.9 # light green
-            self.entry.override_background_color(Gtk.StateType.NORMAL, Gdk.RGBA(*color, 1.0))
+                self.entry.override_background_color(Gtk.StateType.NORMAL, Gdk.RGBA(*color, 1.0))
 
-        for user_input in self.noise.pairing_messages():
+            for user_input in self.noise.pairing_messages():
-            print(f'User input: "{user_input}"')
+                print(f'User input: "{user_input}"')
-            GLib.idle_add(update_text, user_input)
+                GLib.idle_add(update_text, user_input)
 
-        self.label.set_markup(f'<b>Done!</b>')
+        GLib.idle_add(self.label.set_markup, f'<b>Done!</b>')
 
         # FIXME demo
         self.noise.uinput_passthrough()

src/demo.c

@@ -61,8 +61,8 @@ static uint8_t remote_key_reference[CURVE25519_KEY_LEN];
 
 void _fini(void);
 
-static inline void delay_ms_busy_loop(uint32_t ms) {
+static inline void delay(uint32_t n) {
-	for (volatile uint32_t i = 0; i < 14903*ms; i++);
+	for (volatile uint32_t i = 0; i < 1490*n; i++);
 }
 
 
@@ -414,10 +414,16 @@ int main(void)
     if (generate_identity_key(&noise_state))
         LOG_PRINTF("Error generating identiy key\n");
 
+    int poll_ctr = 0;
 	while (23) {
-        TRACING_SET(TR_USBH_POLL);
+        delay(1);
-		usbh_poll(tim6_get_time_us());
+
-        TRACING_CLEAR(TR_USBH_POLL);
+        if (++poll_ctr == 10) {
+            poll_ctr = 0;
+            TRACING_SET(TR_USBH_POLL);
+            usbh_poll(tim6_get_time_us());
+            TRACING_CLEAR(TR_USBH_POLL);
+        }
 
         TRACING_SET(TR_HOST_PKT_HANDLER);
         if (host_packet_length > 0) {

src/noise.c

@@ -147,9 +147,18 @@ int try_continue_noise_handshake(struct NoiseState *st, uint8_t *buf, size_t len
         HANDLE_NOISE_ERROR(noise_dhstate_get_public_key(remote_dh, st->remote_key, sizeof(st->remote_key)), "getting remote pubkey");
 
         if (!memcmp(st->remote_key, st->remote_key_reference, sizeof(st->remote_key))) { /* keys match */
+            uint8_t response = REPORT_PAIRING_SUCCESS;
+            if (send_encrypted_message(st, &response, sizeof(response)))
+                LOG_PRINTF("Error sending pairing response packet\n");
+
             uninit_handshake(st, HANDSHAKE_DONE_KNOWN_HOST);
             st->failed_handshakes = 0;
+
         } else { /* keys don't match */
+            uint8_t response = REPORT_PAIRING_START;
+            if (send_encrypted_message(st, &response, sizeof(response)))
+                LOG_PRINTF("Error sending pairing response packet\n");
+
             uninit_handshake(st, HANDSHAKE_DONE_UNKNOWN_HOST);
             st->failed_handshakes++;
         }

src/packet_interface.h

@@ -23,6 +23,7 @@ enum packet_types {
     REPORT_PAIRING_INPUT = 3,
     REPORT_PAIRING_SUCCESS = 4,
     REPORT_PAIRING_ERROR = 5,
+    REPORT_PAIRING_START = 6,
 };
 
 struct hid_report_packet {