1#!/usr/bin/env python3
2"""Generate library/psa_crypto_driver_wrappers.h
3            library/psa_crypto_driver_wrappers_no_static.c
4
5   This module is invoked by the build scripts to auto generate the
6   psa_crypto_driver_wrappers.h and psa_crypto_driver_wrappers_no_static
7   based on template files in script/data_files/driver_templates/.
8"""
9# Copyright The Mbed TLS Contributors
10# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
11
12import sys
13import os
14import json
15from typing import NewType, Dict, Any
16from traceback import format_tb
17import argparse
18import jsonschema
19import jinja2
20
21import framework_scripts_path # pylint: disable=unused-import
22from mbedtls_framework import build_tree
23
24JSONSchema = NewType('JSONSchema', object)
25# The Driver is an Object, but practically it's indexable and can called a dictionary to
26# keep MyPy happy till MyPy comes with a more composite type for JsonObjects.
27Driver = NewType('Driver', dict)
28
29
30class JsonValidationException(Exception):
31    def __init__(self, message="Json Validation Failed"):
32        self.message = message
33        super().__init__(self.message)
34
35
36class DriverReaderException(Exception):
37    def __init__(self, message="Driver Reader Failed"):
38        self.message = message
39        super().__init__(self.message)
40
41
42def render(template_path: str, driver_jsoncontext: list) -> str:
43    """
44    Render template from the input file and driver JSON.
45    """
46    environment = jinja2.Environment(
47        loader=jinja2.FileSystemLoader(os.path.dirname(template_path)),
48        keep_trailing_newline=True)
49    template = environment.get_template(os.path.basename(template_path))
50
51    return template.render(drivers=driver_jsoncontext)
52
53def generate_driver_wrapper_file(template_dir: str,
54                                 output_dir: str,
55                                 template_file_name: str,
56                                 driver_jsoncontext: list) -> None:
57    """
58    Generate the file psa_crypto_driver_wrapper.c.
59    """
60    driver_wrapper_template_filename = \
61        os.path.join(template_dir, template_file_name)
62
63    result = render(driver_wrapper_template_filename, driver_jsoncontext)
64
65    with open(file=os.path.join(output_dir, os.path.splitext(template_file_name)[0]),
66              mode='w',
67              encoding='UTF-8') as out_file:
68        out_file.write(result)
69
70
71def validate_json(driverjson_data: Driver, driverschema_list: dict) -> None:
72    """
73    Validate the Driver JSON against an appropriate schema
74    the schema passed could be that matching an opaque/ transparent driver.
75    """
76    driver_type = driverjson_data["type"]
77    driver_prefix = driverjson_data["prefix"]
78    try:
79        _schema = driverschema_list[driver_type]
80        jsonschema.validate(instance=driverjson_data, schema=_schema)
81    except KeyError as err:
82        # This could happen if the driverjson_data.type does not exist in the provided schema list
83        # schemas = {'transparent': transparent_driver_schema, 'opaque': opaque_driver_schema}
84        # Print onto stdout and stderr.
85        print("Unknown Driver type " + driver_type +
86              " for driver " + driver_prefix, str(err))
87        print("Unknown Driver type " + driver_type +
88              " for driver " + driver_prefix, str(err), file=sys.stderr)
89        raise JsonValidationException() from err
90
91    except jsonschema.exceptions.ValidationError as err:
92        # Print onto stdout and stderr.
93        print("Error: Failed to validate data file: {} using schema: {}."
94              "\n Exception Message: \"{}\""
95              " ".format(driverjson_data, _schema, str(err)))
96        print("Error: Failed to validate data file: {} using schema: {}."
97              "\n Exception Message: \"{}\""
98              " ".format(driverjson_data, _schema, str(err)), file=sys.stderr)
99        raise JsonValidationException() from err
100
101
102def load_driver(schemas: Dict[str, Any], driver_file: str) -> Any:
103    """loads validated json driver"""
104    with open(file=driver_file, mode='r', encoding='UTF-8') as f:
105        json_data = json.load(f)
106        try:
107            validate_json(json_data, schemas)
108        except JsonValidationException as e:
109            raise DriverReaderException from e
110        return json_data
111
112
113def load_schemas(project_root: str) -> Dict[str, Any]:
114    """
115    Load schemas map
116    """
117    schema_file_paths = {
118        'transparent': os.path.join(project_root,
119                                    'scripts',
120                                    'data_files',
121                                    'driver_jsons',
122                                    'driver_transparent_schema.json'),
123        'opaque': os.path.join(project_root,
124                               'scripts',
125                               'data_files',
126                               'driver_jsons',
127                               'driver_opaque_schema.json')
128    }
129    driver_schema = {}
130    for key, file_path in schema_file_paths.items():
131        with open(file=file_path, mode='r', encoding='UTF-8') as file:
132            driver_schema[key] = json.load(file)
133    return driver_schema
134
135
136def read_driver_descriptions(project_root: str,
137                             json_directory: str,
138                             jsondriver_list: str) -> list:
139    """
140    Merge driver JSON files into a single ordered JSON after validation.
141    """
142    driver_schema = load_schemas(project_root)
143
144    with open(file=os.path.join(json_directory, jsondriver_list),
145              mode='r',
146              encoding='UTF-8') as driver_list_file:
147        driver_list = json.load(driver_list_file)
148
149    return [load_driver(schemas=driver_schema,
150                        driver_file=os.path.join(json_directory, driver_file_name))
151            for driver_file_name in driver_list]
152
153
154def trace_exception(e: Exception, file=sys.stderr) -> None:
155    """Prints exception trace to the given TextIO handle"""
156    print("Exception: type: %s, message: %s, trace: %s" % (
157        e.__class__, str(e), format_tb(e.__traceback__)
158    ), file)
159
160
161TEMPLATE_FILENAMES = ["psa_crypto_driver_wrappers.h.jinja",
162                      "psa_crypto_driver_wrappers_no_static.c.jinja"]
163
164def main() -> int:
165    """
166    Main with command line arguments.
167    """
168    def_arg_project_root = build_tree.guess_project_root()
169
170    parser = argparse.ArgumentParser()
171    parser.add_argument('--project-root', default=def_arg_project_root,
172                        help='root directory of repo source code')
173    parser.add_argument('--template-dir',
174                        help='directory holding the driver templates')
175    parser.add_argument('--json-dir',
176                        help='directory holding the driver JSONs')
177    parser.add_argument('output_directory', nargs='?',
178                        help='output file\'s location')
179    args = parser.parse_args()
180
181    project_root = os.path.abspath(args.project_root)
182
183    crypto_core_directory = build_tree.crypto_core_directory(project_root)
184
185    output_directory = args.output_directory if args.output_directory is not None else \
186        crypto_core_directory
187
188    template_directory = args.template_dir if args.template_dir is not None else \
189        os.path.join(project_root,
190                     'scripts',
191                     'data_files',
192                     'driver_templates')
193    json_directory = args.json_dir if args.json_dir is not None else \
194        os.path.join(project_root,
195                     'scripts',
196                     'data_files',
197                     'driver_jsons')
198
199    try:
200        # Read and validate list of driver jsons from driverlist.json
201        merged_driver_json = read_driver_descriptions(project_root,
202                                                      json_directory,
203                                                      'driverlist.json')
204    except DriverReaderException as e:
205        trace_exception(e)
206        return 1
207    for template_filename in TEMPLATE_FILENAMES:
208        generate_driver_wrapper_file(template_directory, output_directory,
209                                     template_filename, merged_driver_json)
210    return 0
211
212
213if __name__ == '__main__':
214    sys.exit(main())
215