#!/usr/bin/env python3 """Generate library/psa_crypto_driver_wrappers.c This module is invoked by the build scripts to auto generate the psa_crypto_driver_wrappers.c based on template files in script/data_files/driver_templates/. """ # Copyright The Mbed TLS Contributors # SPDX-License-Identifier: Apache-2.0 # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import sys import os import json from typing import NewType, Dict, Any from traceback import format_tb import argparse import jsonschema import jinja2 from mbedtls_dev import build_tree JSONSchema = NewType('JSONSchema', object) # The Driver is an Object, but practically it's indexable and can called a dictionary to # keep MyPy happy till MyPy comes with a more composite type for JsonObjects. Driver = NewType('Driver', dict) class JsonValidationException(Exception): def __init__(self, message="Json Validation Failed"): self.message = message super().__init__(self.message) class DriverReaderException(Exception): def __init__(self, message="Driver Reader Failed"): self.message = message super().__init__(self.message) def render(template_path: str, driver_jsoncontext: list) -> str: """ Render template from the input file and driver JSON. """ environment = jinja2.Environment( loader=jinja2.FileSystemLoader(os.path.dirname(template_path)), keep_trailing_newline=True) template = environment.get_template(os.path.basename(template_path)) return template.render(drivers=driver_jsoncontext) def generate_driver_wrapper_file(template_dir: str, output_dir: str, driver_jsoncontext: list) -> None: """ Generate the file psa_crypto_driver_wrapper.c. """ driver_wrapper_template_filename = \ os.path.join(template_dir, "psa_crypto_driver_wrappers.c.jinja") result = render(driver_wrapper_template_filename, driver_jsoncontext) with open(file=os.path.join(output_dir, "psa_crypto_driver_wrappers.c"), mode='w', encoding='UTF-8') as out_file: out_file.write(result) def validate_json(driverjson_data: Driver, driverschema_list: dict) -> None: """ Validate the Driver JSON against an appropriate schema the schema passed could be that matching an opaque/ transparent driver. """ driver_type = driverjson_data["type"] driver_prefix = driverjson_data["prefix"] try: _schema = driverschema_list[driver_type] jsonschema.validate(instance=driverjson_data, schema=_schema) except KeyError as err: # This could happen if the driverjson_data.type does not exist in the provided schema list # schemas = {'transparent': transparent_driver_schema, 'opaque': opaque_driver_schema} # Print onto stdout and stderr. print("Unknown Driver type " + driver_type + " for driver " + driver_prefix, str(err)) print("Unknown Driver type " + driver_type + " for driver " + driver_prefix, str(err), file=sys.stderr) raise JsonValidationException() from err except jsonschema.exceptions.ValidationError as err: # Print onto stdout and stderr. print("Error: Failed to validate data file: {} using schema: {}." "\n Exception Message: \"{}\"" " ".format(driverjson_data, _schema, str(err))) print("Error: Failed to validate data file: {} using schema: {}." "\n Exception Message: \"{}\"" " ".format(driverjson_data, _schema, str(err)), file=sys.stderr) raise JsonValidationException() from err def load_driver(schemas: Dict[str, Any], driver_file: str) -> Any: """loads validated json driver""" with open(file=driver_file, mode='r', encoding='UTF-8') as f: json_data = json.load(f) try: validate_json(json_data, schemas) except JsonValidationException as e: raise DriverReaderException from e return json_data def load_schemas(mbedtls_root: str) -> Dict[str, Any]: """ Load schemas map """ schema_file_paths = { 'transparent': os.path.join(mbedtls_root, 'scripts', 'data_files', 'driver_jsons', 'driver_transparent_schema.json'), 'opaque': os.path.join(mbedtls_root, 'scripts', 'data_files', 'driver_jsons', 'driver_opaque_schema.json') } driver_schema = {} for key, file_path in schema_file_paths.items(): with open(file=file_path, mode='r', encoding='UTF-8') as file: driver_schema[key] = json.load(file) return driver_schema def read_driver_descriptions(mbedtls_root: str, json_directory: str, jsondriver_list: str) -> list: """ Merge driver JSON files into a single ordered JSON after validation. """ driver_schema = load_schemas(mbedtls_root) with open(file=os.path.join(json_directory, jsondriver_list), mode='r', encoding='UTF-8') as driver_list_file: driver_list = json.load(driver_list_file) return [load_driver(schemas=driver_schema, driver_file=os.path.join(json_directory, driver_file_name)) for driver_file_name in driver_list] def trace_exception(e: Exception, file=sys.stderr) -> None: """Prints exception trace to the given TextIO handle""" print("Exception: type: %s, message: %s, trace: %s" % ( e.__class__, str(e), format_tb(e.__traceback__) ), file) def main() -> int: """ Main with command line arguments. """ def_arg_mbedtls_root = build_tree.guess_mbedtls_root() parser = argparse.ArgumentParser() parser.add_argument('--mbedtls-root', default=def_arg_mbedtls_root, help='root directory of mbedtls source code') parser.add_argument('--template-dir', help='directory holding the driver templates') parser.add_argument('--json-dir', help='directory holding the driver JSONs') parser.add_argument('output_directory', nargs='?', help='output file\'s location') args = parser.parse_args() mbedtls_root = os.path.abspath(args.mbedtls_root) output_directory = args.output_directory if args.output_directory is not None else \ os.path.join(mbedtls_root, 'library') template_directory = args.template_dir if args.template_dir is not None else \ os.path.join(mbedtls_root, 'scripts', 'data_files', 'driver_templates') json_directory = args.json_dir if args.json_dir is not None else \ os.path.join(mbedtls_root, 'scripts', 'data_files', 'driver_jsons') try: # Read and validate list of driver jsons from driverlist.json merged_driver_json = read_driver_descriptions(mbedtls_root, json_directory, 'driverlist.json') except DriverReaderException as e: trace_exception(e) return 1 generate_driver_wrapper_file(template_directory, output_directory, merged_driver_json) return 0 if __name__ == '__main__': sys.exit(main())