Prefix internal components with _

Some of our code, namely the nrf52_upload module, is only intended for
use within the SDK but not part of the public API.  This patch adds an
underscore to those components to indicate the visibility.

Author: robin-nitrokey

.flake8

@@ -4,4 +4,4 @@
 # E501 (line length) disabled as this is handled by black which takes better care of edge cases
 extend-ignore = E203,E501,E701
 max-complexity = 18
-extend-exclude = src/nitrokey/trussed/bootloader/nrf52_upload
+extend-exclude = src/nitrokey/trussed/bootloader/_nrf52_upload

pyproject.toml

@@ -55,7 +55,7 @@ strict = true
 
 # nrf52_upload is only temporary in this package
 [[tool.mypy.overrides]]
-module = "nitrokey.trussed.bootloader.nrf52_upload.*"
+module = "nitrokey.trussed.bootloader._nrf52_upload.*"
 ignore_errors = true
 
 # nrf52 has to use the untyped nrf52_upload module

src/nitrokey/helpers.py src/nitrokey/_helpers.pysrc/nitrokey/helpers.py renamed to src/nitrokey/_helpers.py

@@ -348,7 +348,7 @@ def _send_receive(
     ) -> bytes:
         encoded_structure = self._custom_encode(structure)
         ins_b, p1, p2 = self._encode_command(ins)
-        bytes_data = iso7816_compose(ins_b, p1, p2, data=encoded_structure)
+        bytes_data = _iso7816_compose(ins_b, p1, p2, data=encoded_structure)
         if self.write_corpus_fn:
             self.write_corpus_fn(ins, bytes_data)
         return self._send_receive_inner(bytes_data, log_info=f"{ins}")
@@ -373,7 +373,7 @@ def _send_receive_inner(self, data: bytes, log_info: str = "") -> bytes:
                 self.logfn(f"Got RemainingData status: [{status_bytes.hex()}]")
             log_multipacket = True
             ins_b, p1, p2 = self._encode_command(Instruction.SendRemaining)
-            bytes_data = iso7816_compose(ins_b, p1, p2)
+            bytes_data = _iso7816_compose(ins_b, p1, p2)
             try:
                 result = self.dev._call_app(App.SECRETS, data=bytes_data)
             except Exception as e:
@@ -863,7 +863,7 @@ def _semver_equal_or_newer(self, required_version: str) -> bool:
         return current >= semver_req_version
 
 
-def iso7816_compose(
+def _iso7816_compose(
     ins: int,
     p1: int,
     p2: int,

src/nitrokey/nk3/secrets_app.py

@@ -16,7 +16,7 @@
 
 from spsdk.mboot.exceptions import McuBootConnectionError
 
-from nitrokey.helpers import Retries
+from nitrokey._helpers import Retries
 from nitrokey.nk3 import NK3_DATA
 from nitrokey.nk3.bootloader import Nitrokey3Bootloader
 from nitrokey.nk3.device import Nitrokey3Device