python/trezorctl: send raw bytes to device (fixes #116)

python/src/trezorlib/cli/debug.py

@@ -16,7 +16,7 @@
 
 import click
 
-from .. import debuglink
+from .. import debuglink, mapping, messages, protobuf
 from ..messages import DebugLinkShowTextStyle as S
 
 
@@ -71,3 +71,48 @@ def show_text(connect, icon, color, header, body):
     return debuglink.show_text(
         connect(), header, body_text, icon=icon, icon_color=color
     )
+
+
+@cli.command()
+@click.argument("message_name_or_type")
+@click.argument("hex_data")
+@click.pass_obj
+def send_bytes(connect, message_name_or_type, hex_data):
+    """Send raw bytes to Trezor.
+
+    Message type and message data must be specified separately, due to how message
+    chunking works on the transport level. Message length is calculated and sent
+    automatically, and it is currently impossible to explicitly specify invalid length.
+
+    MESSAGE_NAME_OR_TYPE can either be a number, or a name from the MessageType enum,
+    in which case the value of that enum is used.
+    """
+    if message_name_or_type.isdigit():
+        message_type = int(message_name_or_type)
+    else:
+        message_type = getattr(messages.MessageType, message_name_or_type)
+
+    if not isinstance(message_type, int):
+        raise click.ClickException("Invalid message type.")
+
+    try:
+        message_data = bytes.fromhex(hex_data)
+    except Exception as e:
+        raise click.ClickException("Invalid hex data.") from e
+
+    transport = connect(return_transport=True)
+    transport.begin_session()
+    transport.write(message_type, message_data)
+
+    response_type, response_data = transport.read()
+    transport.end_session()
+
+    click.echo("Response type: {}".format(response_type))
+    click.echo("Response data: {}".format(response_data.hex()))
+
+    try:
+        msg = mapping.decode(response_type, response_data)
+        click.echo("Parsed message:")
+        click.echo(protobuf.format_message(msg))
+    except Exception as e:
+        click.echo("Could not parse response: {}".format(e))

python/src/trezorlib/cli/trezorctl.py

@@ -157,19 +157,21 @@ def cli(ctx, path, verbose, is_json, passphrase_on_host, session_id):
         except ValueError:
             raise click.ClickException("Not a valid session id: {}".format(session_id))
 
-    def get_device():
+    def get_device(return_transport=False):
         try:
-            device = get_transport(path, prefix_search=False)
+            transport = get_transport(path, prefix_search=False)
         except Exception:
             try:
-                device = get_transport(path, prefix_search=True)
+                transport = get_transport(path, prefix_search=True)
             except Exception:
                 click.echo("Failed to find a Trezor device.")
                 if path is not None:
                     click.echo("Using path: {}".format(path))
                 sys.exit(1)
+        if return_transport:
+            return transport
         return TrezorClient(
-            transport=device,
+            transport=transport,
             ui=ui.ClickUI(passphrase_on_host=passphrase_on_host),
             session_id=session_id,
         )