537 lines
22 KiB
Python
Executable File
537 lines
22 KiB
Python
Executable File
#!/usr/bin/env python3
|
|
|
|
"""Mbed TLS configuration file manipulation library and tool
|
|
|
|
Basic usage, to read the Mbed TLS or Mbed Crypto configuration:
|
|
config = ConfigFile()
|
|
if 'MBEDTLS_RSA_C' in config: print('RSA is enabled')
|
|
"""
|
|
|
|
## 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 os
|
|
import re
|
|
|
|
class Setting:
|
|
"""Representation of one Mbed TLS config.h setting.
|
|
|
|
Fields:
|
|
* name: the symbol name ('MBEDTLS_xxx').
|
|
* value: the value of the macro. The empty string for a plain #define
|
|
with no value.
|
|
* active: True if name is defined, False if a #define for name is
|
|
present in config.h but commented out.
|
|
* section: the name of the section that contains this symbol.
|
|
"""
|
|
# pylint: disable=too-few-public-methods
|
|
def __init__(self, active, name, value='', section=None):
|
|
self.active = active
|
|
self.name = name
|
|
self.value = value
|
|
self.section = section
|
|
|
|
class Config:
|
|
"""Representation of the Mbed TLS configuration.
|
|
|
|
In the documentation of this class, a symbol is said to be *active*
|
|
if there is a #define for it that is not commented out, and *known*
|
|
if there is a #define for it whether commented out or not.
|
|
|
|
This class supports the following protocols:
|
|
* `name in config` is `True` if the symbol `name` is active, `False`
|
|
otherwise (whether `name` is inactive or not known).
|
|
* `config[name]` is the value of the macro `name`. If `name` is inactive,
|
|
raise `KeyError` (even if `name` is known).
|
|
* `config[name] = value` sets the value associated to `name`. `name`
|
|
must be known, but does not need to be set. This does not cause
|
|
name to become set.
|
|
"""
|
|
|
|
def __init__(self):
|
|
self.settings = {}
|
|
|
|
def __contains__(self, name):
|
|
"""True if the given symbol is active (i.e. set).
|
|
|
|
False if the given symbol is not set, even if a definition
|
|
is present but commented out.
|
|
"""
|
|
return name in self.settings and self.settings[name].active
|
|
|
|
def all(self, *names):
|
|
"""True if all the elements of names are active (i.e. set)."""
|
|
return all(self.__contains__(name) for name in names)
|
|
|
|
def any(self, *names):
|
|
"""True if at least one symbol in names are active (i.e. set)."""
|
|
return any(self.__contains__(name) for name in names)
|
|
|
|
def known(self, name):
|
|
"""True if a #define for name is present, whether it's commented out or not."""
|
|
return name in self.settings
|
|
|
|
def __getitem__(self, name):
|
|
"""Get the value of name, i.e. what the preprocessor symbol expands to.
|
|
|
|
If name is not known, raise KeyError. name does not need to be active.
|
|
"""
|
|
return self.settings[name].value
|
|
|
|
def get(self, name, default=None):
|
|
"""Get the value of name. If name is inactive (not set), return default.
|
|
|
|
If a #define for name is present and not commented out, return
|
|
its expansion, even if this is the empty string.
|
|
|
|
If a #define for name is present but commented out, return default.
|
|
"""
|
|
if name in self.settings:
|
|
return self.settings[name].value
|
|
else:
|
|
return default
|
|
|
|
def __setitem__(self, name, value):
|
|
"""If name is known, set its value.
|
|
|
|
If name is not known, raise KeyError.
|
|
"""
|
|
self.settings[name].value = value
|
|
|
|
def set(self, name, value=None):
|
|
"""Set name to the given value and make it active.
|
|
|
|
If value is None and name is already known, don't change its value.
|
|
If value is None and name is not known, set its value to the empty
|
|
string.
|
|
"""
|
|
if name in self.settings:
|
|
if value is not None:
|
|
self.settings[name].value = value
|
|
self.settings[name].active = True
|
|
else:
|
|
self.settings[name] = Setting(True, name, value=value)
|
|
|
|
def unset(self, name):
|
|
"""Make name unset (inactive).
|
|
|
|
name remains known if it was known before.
|
|
"""
|
|
if name not in self.settings:
|
|
return
|
|
self.settings[name].active = False
|
|
|
|
def adapt(self, adapter):
|
|
"""Run adapter on each known symbol and (de)activate it accordingly.
|
|
|
|
`adapter` must be a function that returns a boolean. It is called as
|
|
`adapter(name, active, section)` for each setting, where `active` is
|
|
`True` if `name` is set and `False` if `name` is known but unset,
|
|
and `section` is the name of the section containing `name`. If
|
|
`adapter` returns `True`, then set `name` (i.e. make it active),
|
|
otherwise unset `name` (i.e. make it known but inactive).
|
|
"""
|
|
for setting in self.settings.values():
|
|
setting.active = adapter(setting.name, setting.active,
|
|
setting.section)
|
|
|
|
def is_full_section(section):
|
|
"""Is this section affected by "config.py full" and friends?"""
|
|
return section.endswith('support') or section.endswith('modules')
|
|
|
|
def realfull_adapter(_name, active, section):
|
|
"""Activate all symbols found in the system and feature sections."""
|
|
if not is_full_section(section):
|
|
return active
|
|
return True
|
|
|
|
# The goal of the full configuration is to have everything that can be tested
|
|
# together. This includes deprecated or insecure options. It excludes:
|
|
# * Options that require additional build dependencies or unusual hardware.
|
|
# * Options that make testing less effective.
|
|
# * Options that are incompatible with other options, or more generally that
|
|
# interact with other parts of the code in such a way that a bulk enabling
|
|
# is not a good way to test them.
|
|
# * Options that remove features.
|
|
EXCLUDE_FROM_FULL = frozenset([
|
|
#pylint: disable=line-too-long
|
|
'MBEDTLS_CTR_DRBG_USE_128_BIT_KEY', # interacts with ENTROPY_FORCE_SHA256
|
|
'MBEDTLS_DEPRECATED_REMOVED', # conflicts with deprecated options
|
|
'MBEDTLS_DEPRECATED_WARNING', # conflicts with deprecated options
|
|
'MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED', # influences the use of ECDH in TLS
|
|
'MBEDTLS_ECP_NO_FALLBACK', # removes internal ECP implementation
|
|
'MBEDTLS_ECP_NO_INTERNAL_RNG', # removes a feature
|
|
'MBEDTLS_ECP_RESTARTABLE', # incompatible with USE_PSA_CRYPTO
|
|
'MBEDTLS_ENTROPY_FORCE_SHA256', # interacts with CTR_DRBG_128_BIT_KEY
|
|
'MBEDTLS_HAVE_SSE2', # hardware dependency
|
|
'MBEDTLS_MEMORY_BACKTRACE', # depends on MEMORY_BUFFER_ALLOC_C
|
|
'MBEDTLS_MEMORY_BUFFER_ALLOC_C', # makes sanitizers (e.g. ASan) less effective
|
|
'MBEDTLS_MEMORY_DEBUG', # depends on MEMORY_BUFFER_ALLOC_C
|
|
'MBEDTLS_NO_64BIT_MULTIPLICATION', # influences anything that uses bignum
|
|
'MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES', # removes a feature
|
|
'MBEDTLS_NO_PLATFORM_ENTROPY', # removes a feature
|
|
'MBEDTLS_NO_UDBL_DIVISION', # influences anything that uses bignum
|
|
'MBEDTLS_PKCS11_C', # build dependency (libpkcs11-helper)
|
|
'MBEDTLS_PLATFORM_NO_STD_FUNCTIONS', # removes a feature
|
|
'MBEDTLS_PSA_CRYPTO_CONFIG', # toggles old/new style PSA config
|
|
'MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG', # behavior change + build dependency
|
|
'MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER', # incompatible with USE_PSA_CRYPTO
|
|
'MBEDTLS_PSA_CRYPTO_SPM', # platform dependency (PSA SPM)
|
|
'MBEDTLS_PSA_INJECT_ENTROPY', # build dependency (hook functions)
|
|
'MBEDTLS_REMOVE_3DES_CIPHERSUITES', # removes a feature
|
|
'MBEDTLS_REMOVE_ARC4_CIPHERSUITES', # removes a feature
|
|
'MBEDTLS_RSA_NO_CRT', # influences the use of RSA in X.509 and TLS
|
|
'MBEDTLS_SHA512_NO_SHA384', # removes a feature
|
|
'MBEDTLS_SSL_HW_RECORD_ACCEL', # build dependency (hook functions)
|
|
'MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN', # build dependency (clang+memsan)
|
|
'MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND', # build dependency (valgrind headers)
|
|
'MBEDTLS_TEST_NULL_ENTROPY', # removes a feature
|
|
'MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION', # influences the use of X.509 in TLS
|
|
'MBEDTLS_ZLIB_SUPPORT', # build dependency (libz)
|
|
])
|
|
|
|
def is_seamless_alt(name):
|
|
"""Whether the xxx_ALT symbol should be included in the full configuration.
|
|
|
|
Include alternative implementations of platform functions, which are
|
|
configurable function pointers that default to the built-in function.
|
|
This way we test that the function pointers exist and build correctly
|
|
without changing the behavior, and tests can verify that the function
|
|
pointers are used by modifying those pointers.
|
|
|
|
Exclude alternative implementations of library functions since they require
|
|
an implementation of the relevant functions and an xxx_alt.h header.
|
|
"""
|
|
if name == 'MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT':
|
|
# Similar to non-platform xxx_ALT, requires platform_alt.h
|
|
return False
|
|
return name.startswith('MBEDTLS_PLATFORM_')
|
|
|
|
def include_in_full(name):
|
|
"""Rules for symbols in the "full" configuration."""
|
|
if name in EXCLUDE_FROM_FULL:
|
|
return False
|
|
if name.endswith('_ALT'):
|
|
return is_seamless_alt(name)
|
|
return True
|
|
|
|
def full_adapter(name, active, section):
|
|
"""Config adapter for "full"."""
|
|
if not is_full_section(section):
|
|
return active
|
|
return include_in_full(name)
|
|
|
|
# The baremetal configuration excludes options that require a library or
|
|
# operating system feature that is typically not present on bare metal
|
|
# systems. Features that are excluded from "full" won't be in "baremetal"
|
|
# either (unless explicitly turned on in baremetal_adapter) so they don't
|
|
# need to be repeated here.
|
|
EXCLUDE_FROM_BAREMETAL = frozenset([
|
|
#pylint: disable=line-too-long
|
|
'MBEDTLS_ENTROPY_NV_SEED', # requires a filesystem and FS_IO or alternate NV seed hooks
|
|
'MBEDTLS_FS_IO', # requires a filesystem
|
|
'MBEDTLS_HAVEGE_C', # requires a clock
|
|
'MBEDTLS_HAVE_TIME', # requires a clock
|
|
'MBEDTLS_HAVE_TIME_DATE', # requires a clock
|
|
'MBEDTLS_NET_C', # requires POSIX-like networking
|
|
'MBEDTLS_PLATFORM_FPRINTF_ALT', # requires FILE* from stdio.h
|
|
'MBEDTLS_PLATFORM_NV_SEED_ALT', # requires a filesystem and ENTROPY_NV_SEED
|
|
'MBEDTLS_PLATFORM_TIME_ALT', # requires a clock and HAVE_TIME
|
|
'MBEDTLS_PSA_CRYPTO_SE_C', # requires a filesystem and PSA_CRYPTO_STORAGE_C
|
|
'MBEDTLS_PSA_CRYPTO_STORAGE_C', # requires a filesystem
|
|
'MBEDTLS_PSA_ITS_FILE_C', # requires a filesystem
|
|
'MBEDTLS_THREADING_C', # requires a threading interface
|
|
'MBEDTLS_THREADING_PTHREAD', # requires pthread
|
|
'MBEDTLS_TIMING_C', # requires a clock
|
|
])
|
|
|
|
def keep_in_baremetal(name):
|
|
"""Rules for symbols in the "baremetal" configuration."""
|
|
if name in EXCLUDE_FROM_BAREMETAL:
|
|
return False
|
|
return True
|
|
|
|
def baremetal_adapter(name, active, section):
|
|
"""Config adapter for "baremetal"."""
|
|
if not is_full_section(section):
|
|
return active
|
|
if name == 'MBEDTLS_NO_PLATFORM_ENTROPY':
|
|
# No OS-provided entropy source
|
|
return True
|
|
return include_in_full(name) and keep_in_baremetal(name)
|
|
|
|
def include_in_crypto(name):
|
|
"""Rules for symbols in a crypto configuration."""
|
|
if name.startswith('MBEDTLS_X509_') or \
|
|
name.startswith('MBEDTLS_SSL_') or \
|
|
name.startswith('MBEDTLS_KEY_EXCHANGE_'):
|
|
return False
|
|
if name in [
|
|
'MBEDTLS_CERTS_C', # part of libmbedx509
|
|
'MBEDTLS_DEBUG_C', # part of libmbedtls
|
|
'MBEDTLS_NET_C', # part of libmbedtls
|
|
'MBEDTLS_PKCS11_C', # part of libmbedx509
|
|
]:
|
|
return False
|
|
return True
|
|
|
|
def crypto_adapter(adapter):
|
|
"""Modify an adapter to disable non-crypto symbols.
|
|
|
|
``crypto_adapter(adapter)(name, active, section)`` is like
|
|
``adapter(name, active, section)``, but unsets all X.509 and TLS symbols.
|
|
"""
|
|
def continuation(name, active, section):
|
|
if not include_in_crypto(name):
|
|
return False
|
|
if adapter is None:
|
|
return active
|
|
return adapter(name, active, section)
|
|
return continuation
|
|
|
|
DEPRECATED = frozenset([
|
|
'MBEDTLS_SSL_PROTO_SSL3',
|
|
'MBEDTLS_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO',
|
|
])
|
|
|
|
def no_deprecated_adapter(adapter):
|
|
"""Modify an adapter to disable deprecated symbols.
|
|
|
|
``no_deprecated_adapter(adapter)(name, active, section)`` is like
|
|
``adapter(name, active, section)``, but unsets all deprecated symbols
|
|
and sets ``MBEDTLS_DEPRECATED_REMOVED``.
|
|
"""
|
|
def continuation(name, active, section):
|
|
if name == 'MBEDTLS_DEPRECATED_REMOVED':
|
|
return True
|
|
if name in DEPRECATED:
|
|
return False
|
|
if adapter is None:
|
|
return active
|
|
return adapter(name, active, section)
|
|
return continuation
|
|
|
|
class ConfigFile(Config):
|
|
"""Representation of the Mbed TLS configuration read for a file.
|
|
|
|
See the documentation of the `Config` class for methods to query
|
|
and modify the configuration.
|
|
"""
|
|
|
|
_path_in_tree = 'include/mbedtls/config.h'
|
|
default_path = [_path_in_tree,
|
|
os.path.join(os.path.dirname(__file__),
|
|
os.pardir,
|
|
_path_in_tree),
|
|
os.path.join(os.path.dirname(os.path.abspath(os.path.dirname(__file__))),
|
|
_path_in_tree)]
|
|
|
|
def __init__(self, filename=None):
|
|
"""Read the Mbed TLS configuration file."""
|
|
if filename is None:
|
|
for candidate in self.default_path:
|
|
if os.path.lexists(candidate):
|
|
filename = candidate
|
|
break
|
|
else:
|
|
raise Exception('Mbed TLS configuration file not found',
|
|
self.default_path)
|
|
super().__init__()
|
|
self.filename = filename
|
|
self.current_section = 'header'
|
|
with open(filename, 'r', encoding='utf-8') as file:
|
|
self.templates = [self._parse_line(line) for line in file]
|
|
self.current_section = None
|
|
|
|
def set(self, name, value=None):
|
|
if name not in self.settings:
|
|
self.templates.append((name, '', '#define ' + name + ' '))
|
|
super().set(name, value)
|
|
|
|
_define_line_regexp = (r'(?P<indentation>\s*)' +
|
|
r'(?P<commented_out>(//\s*)?)' +
|
|
r'(?P<define>#\s*define\s+)' +
|
|
r'(?P<name>\w+)' +
|
|
r'(?P<arguments>(?:\((?:\w|\s|,)*\))?)' +
|
|
r'(?P<separator>\s*)' +
|
|
r'(?P<value>.*)')
|
|
_section_line_regexp = (r'\s*/?\*+\s*[\\@]name\s+SECTION:\s*' +
|
|
r'(?P<section>.*)[ */]*')
|
|
_config_line_regexp = re.compile(r'|'.join([_define_line_regexp,
|
|
_section_line_regexp]))
|
|
def _parse_line(self, line):
|
|
"""Parse a line in config.h and return the corresponding template."""
|
|
line = line.rstrip('\r\n')
|
|
m = re.match(self._config_line_regexp, line)
|
|
if m is None:
|
|
return line
|
|
elif m.group('section'):
|
|
self.current_section = m.group('section')
|
|
return line
|
|
else:
|
|
active = not m.group('commented_out')
|
|
name = m.group('name')
|
|
value = m.group('value')
|
|
template = (name,
|
|
m.group('indentation'),
|
|
m.group('define') + name +
|
|
m.group('arguments') + m.group('separator'))
|
|
self.settings[name] = Setting(active, name, value,
|
|
self.current_section)
|
|
return template
|
|
|
|
def _format_template(self, name, indent, middle):
|
|
"""Build a line for config.h for the given setting.
|
|
|
|
The line has the form "<indent>#define <name> <value>"
|
|
where <middle> is "#define <name> ".
|
|
"""
|
|
setting = self.settings[name]
|
|
value = setting.value
|
|
if value is None:
|
|
value = ''
|
|
# Normally the whitespace to separte the symbol name from the
|
|
# value is part of middle, and there's no whitespace for a symbol
|
|
# with no value. But if a symbol has been changed from having a
|
|
# value to not having one, the whitespace is wrong, so fix it.
|
|
if value:
|
|
if middle[-1] not in '\t ':
|
|
middle += ' '
|
|
else:
|
|
middle = middle.rstrip()
|
|
return ''.join([indent,
|
|
'' if setting.active else '//',
|
|
middle,
|
|
value]).rstrip()
|
|
|
|
def write_to_stream(self, output):
|
|
"""Write the whole configuration to output."""
|
|
for template in self.templates:
|
|
if isinstance(template, str):
|
|
line = template
|
|
else:
|
|
line = self._format_template(*template)
|
|
output.write(line + '\n')
|
|
|
|
def write(self, filename=None):
|
|
"""Write the whole configuration to the file it was read from.
|
|
|
|
If filename is specified, write to this file instead.
|
|
"""
|
|
if filename is None:
|
|
filename = self.filename
|
|
with open(filename, 'w', encoding='utf-8') as output:
|
|
self.write_to_stream(output)
|
|
|
|
if __name__ == '__main__':
|
|
def main():
|
|
"""Command line config.h manipulation tool."""
|
|
parser = argparse.ArgumentParser(description="""
|
|
Mbed TLS and Mbed Crypto configuration file manipulation tool.
|
|
""")
|
|
parser.add_argument('--file', '-f',
|
|
help="""File to read (and modify if requested).
|
|
Default: {}.
|
|
""".format(ConfigFile.default_path))
|
|
parser.add_argument('--force', '-o',
|
|
action='store_true',
|
|
help="""For the set command, if SYMBOL is not
|
|
present, add a definition for it.""")
|
|
parser.add_argument('--write', '-w', metavar='FILE',
|
|
help="""File to write to instead of the input file.""")
|
|
subparsers = parser.add_subparsers(dest='command',
|
|
title='Commands')
|
|
parser_get = subparsers.add_parser('get',
|
|
help="""Find the value of SYMBOL
|
|
and print it. Exit with
|
|
status 0 if a #define for SYMBOL is
|
|
found, 1 otherwise.
|
|
""")
|
|
parser_get.add_argument('symbol', metavar='SYMBOL')
|
|
parser_set = subparsers.add_parser('set',
|
|
help="""Set SYMBOL to VALUE.
|
|
If VALUE is omitted, just uncomment
|
|
the #define for SYMBOL.
|
|
Error out of a line defining
|
|
SYMBOL (commented or not) is not
|
|
found, unless --force is passed.
|
|
""")
|
|
parser_set.add_argument('symbol', metavar='SYMBOL')
|
|
parser_set.add_argument('value', metavar='VALUE', nargs='?',
|
|
default='')
|
|
parser_unset = subparsers.add_parser('unset',
|
|
help="""Comment out the #define
|
|
for SYMBOL. Do nothing if none
|
|
is present.""")
|
|
parser_unset.add_argument('symbol', metavar='SYMBOL')
|
|
|
|
def add_adapter(name, function, description):
|
|
subparser = subparsers.add_parser(name, help=description)
|
|
subparser.set_defaults(adapter=function)
|
|
add_adapter('baremetal', baremetal_adapter,
|
|
"""Like full, but exclude features that require platform
|
|
features such as file input-output.""")
|
|
add_adapter('full', full_adapter,
|
|
"""Uncomment most features.
|
|
Exclude alternative implementations and platform support
|
|
options, as well as some options that are awkward to test.
|
|
""")
|
|
add_adapter('full_no_deprecated', no_deprecated_adapter(full_adapter),
|
|
"""Uncomment most non-deprecated features.
|
|
Like "full", but without deprecated features.
|
|
""")
|
|
add_adapter('realfull', realfull_adapter,
|
|
"""Uncomment all boolean #defines.
|
|
Suitable for generating documentation, but not for building.""")
|
|
add_adapter('crypto', crypto_adapter(None),
|
|
"""Only include crypto features. Exclude X.509 and TLS.""")
|
|
add_adapter('crypto_baremetal', crypto_adapter(baremetal_adapter),
|
|
"""Like baremetal, but with only crypto features,
|
|
excluding X.509 and TLS.""")
|
|
add_adapter('crypto_full', crypto_adapter(full_adapter),
|
|
"""Like full, but with only crypto features,
|
|
excluding X.509 and TLS.""")
|
|
|
|
args = parser.parse_args()
|
|
config = ConfigFile(args.file)
|
|
if args.command is None:
|
|
parser.print_help()
|
|
return 1
|
|
elif args.command == 'get':
|
|
if args.symbol in config:
|
|
value = config[args.symbol]
|
|
if value:
|
|
sys.stdout.write(value + '\n')
|
|
return 0 if args.symbol in config else 1
|
|
elif args.command == 'set':
|
|
if not args.force and args.symbol not in config.settings:
|
|
sys.stderr.write("A #define for the symbol {} "
|
|
"was not found in {}\n"
|
|
.format(args.symbol, config.filename))
|
|
return 1
|
|
config.set(args.symbol, value=args.value)
|
|
elif args.command == 'unset':
|
|
config.unset(args.symbol)
|
|
else:
|
|
config.adapt(args.adapter)
|
|
config.write(args.write)
|
|
return 0
|
|
|
|
# Import modules only used by main only if main is defined and called.
|
|
# pylint: disable=wrong-import-position
|
|
import argparse
|
|
import sys
|
|
sys.exit(main())
|