mbedtls/scripts/mbedtls_dev/macro_collector.py
Gilles Peskine d6d2d6a7d7 Use InputsForTest in generate_psa_tests
In generate_psa_tests, use InputsForTest rather than PSAMacroCollector
to gather values. This way, the enumeration of values to test includes
values used in metadata tests in addition to constructors parsed from
header files. This allows greater coverage of values built from
constructors with arguments. This doesn't make a difference yet, but
it will once algorithm constructors with arguments are supported in
generate_psa_tests.

Make the injection of numerical values optional. They are useful for
test_psa_constant_names, so keep them there. Don't use them for
not-supported tests: they might make sense, but the current code
wouldn't work since it doesn't know how to make up fake key material
or what dependencies to generate. Don't use them for storage tests:
they only make sense for supported values.

Don't inject 'PSA_SUCCESS': that's superfluous.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
2021-05-25 19:31:21 +02:00

468 lines
20 KiB
Python

"""Collect macro definitions from header files.
"""
# 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 itertools
import re
from typing import Dict, Iterable, Iterator, List, Optional, Pattern, Set, Tuple, Union
class ReadFileLineException(Exception):
def __init__(self, filename: str, line_number: Union[int, str]) -> None:
message = 'in {} at {}'.format(filename, line_number)
super(ReadFileLineException, self).__init__(message)
self.filename = filename
self.line_number = line_number
class read_file_lines:
# Dear Pylint, conventionally, a context manager class name is lowercase.
# pylint: disable=invalid-name,too-few-public-methods
"""Context manager to read a text file line by line.
```
with read_file_lines(filename) as lines:
for line in lines:
process(line)
```
is equivalent to
```
with open(filename, 'r') as input_file:
for line in input_file:
process(line)
```
except that if process(line) raises an exception, then the read_file_lines
snippet annotates the exception with the file name and line number.
"""
def __init__(self, filename: str, binary: bool = False) -> None:
self.filename = filename
self.line_number = 'entry' #type: Union[int, str]
self.generator = None #type: Optional[Iterable[Tuple[int, str]]]
self.binary = binary
def __enter__(self) -> 'read_file_lines':
self.generator = enumerate(open(self.filename,
'rb' if self.binary else 'r'))
return self
def __iter__(self) -> Iterator[str]:
assert self.generator is not None
for line_number, content in self.generator:
self.line_number = line_number
yield content
self.line_number = 'exit'
def __exit__(self, exc_type, exc_value, exc_traceback) -> None:
if exc_type is not None:
raise ReadFileLineException(self.filename, self.line_number) \
from exc_value
class PSAMacroEnumerator:
"""Information about constructors of various PSA Crypto types.
This includes macro names as well as information about their arguments
when applicable.
This class only provides ways to enumerate expressions that evaluate to
values of the covered types. Derived classes are expected to populate
the set of known constructors of each kind, as well as populate
`self.arguments_for` for arguments that are not of a kind that is
enumerated here.
"""
def __init__(self) -> None:
"""Set up an empty set of known constructor macros.
"""
self.statuses = set() #type: Set[str]
self.algorithms = set() #type: Set[str]
self.ecc_curves = set() #type: Set[str]
self.dh_groups = set() #type: Set[str]
self.key_types = set() #type: Set[str]
self.key_usage_flags = set() #type: Set[str]
self.hash_algorithms = set() #type: Set[str]
self.mac_algorithms = set() #type: Set[str]
self.ka_algorithms = set() #type: Set[str]
self.kdf_algorithms = set() #type: Set[str]
self.aead_algorithms = set() #type: Set[str]
# macro name -> list of argument names
self.argspecs = {} #type: Dict[str, List[str]]
# argument name -> list of values
self.arguments_for = {
'mac_length': [],
'min_mac_length': [],
'tag_length': [],
'min_tag_length': [],
} #type: Dict[str, List[str]]
def gather_arguments(self) -> None:
"""Populate the list of values for macro arguments.
Call this after parsing all the inputs.
"""
self.arguments_for['hash_alg'] = sorted(self.hash_algorithms)
self.arguments_for['mac_alg'] = sorted(self.mac_algorithms)
self.arguments_for['ka_alg'] = sorted(self.ka_algorithms)
self.arguments_for['kdf_alg'] = sorted(self.kdf_algorithms)
self.arguments_for['aead_alg'] = sorted(self.aead_algorithms)
self.arguments_for['curve'] = sorted(self.ecc_curves)
self.arguments_for['group'] = sorted(self.dh_groups)
@staticmethod
def _format_arguments(name: str, arguments: Iterable[str]) -> str:
"""Format a macro call with arguments.."""
return name + '(' + ', '.join(arguments) + ')'
_argument_split_re = re.compile(r' *, *')
@classmethod
def _argument_split(cls, arguments: str) -> List[str]:
return re.split(cls._argument_split_re, arguments)
def distribute_arguments(self, name: str) -> Iterator[str]:
"""Generate macro calls with each tested argument set.
If name is a macro without arguments, just yield "name".
If name is a macro with arguments, yield a series of
"name(arg1,...,argN)" where each argument takes each possible
value at least once.
"""
try:
if name not in self.argspecs:
yield name
return
argspec = self.argspecs[name]
if argspec == []:
yield name + '()'
return
argument_lists = [self.arguments_for[arg] for arg in argspec]
arguments = [values[0] for values in argument_lists]
yield self._format_arguments(name, arguments)
# Dear Pylint, enumerate won't work here since we're modifying
# the array.
# pylint: disable=consider-using-enumerate
for i in range(len(arguments)):
for value in argument_lists[i][1:]:
arguments[i] = value
yield self._format_arguments(name, arguments)
arguments[i] = argument_lists[0][0]
except BaseException as e:
raise Exception('distribute_arguments({})'.format(name)) from e
def generate_expressions(self, names: Iterable[str]) -> Iterator[str]:
"""Generate expressions covering values constructed from the given names.
`names` can be any iterable collection of macro names.
For example:
* ``generate_expressions(['PSA_ALG_CMAC', 'PSA_ALG_HMAC'])``
generates ``'PSA_ALG_CMAC'`` as well as ``'PSA_ALG_HMAC(h)'`` for
every known hash algorithm ``h``.
* ``macros.generate_expressions(macros.key_types)`` generates all
key types.
"""
return itertools.chain(*map(self.distribute_arguments, names))
class PSAMacroCollector(PSAMacroEnumerator):
"""Collect PSA crypto macro definitions from C header files.
"""
def __init__(self, include_intermediate: bool = False) -> None:
"""Set up an object to collect PSA macro definitions.
Call the read_file method of the constructed object on each header file.
* include_intermediate: if true, include intermediate macros such as
PSA_XXX_BASE that do not designate semantic values.
"""
super().__init__()
self.include_intermediate = include_intermediate
self.key_types_from_curve = {} #type: Dict[str, str]
self.key_types_from_group = {} #type: Dict[str, str]
self.algorithms_from_hash = {} #type: Dict[str, str]
def is_internal_name(self, name: str) -> bool:
"""Whether this is an internal macro. Internal macros will be skipped."""
if not self.include_intermediate:
if name.endswith('_BASE') or name.endswith('_NONE'):
return True
if '_CATEGORY_' in name:
return True
return name.endswith('_FLAG') or name.endswith('_MASK')
def record_algorithm_subtype(self, name: str, expansion: str) -> None:
"""Record the subtype of an algorithm constructor.
Given a ``PSA_ALG_xxx`` macro name and its expansion, if the algorithm
is of a subtype that is tracked in its own set, add it to the relevant
set.
"""
# This code is very ad hoc and fragile. It should be replaced by
# something more robust.
if re.match(r'MAC(?:_|\Z)', name):
self.mac_algorithms.add(name)
elif re.match(r'KDF(?:_|\Z)', name):
self.kdf_algorithms.add(name)
elif re.search(r'0x020000[0-9A-Fa-f]{2}', expansion):
self.hash_algorithms.add(name)
elif re.search(r'0x03[0-9A-Fa-f]{6}', expansion):
self.mac_algorithms.add(name)
elif re.search(r'0x05[0-9A-Fa-f]{6}', expansion):
self.aead_algorithms.add(name)
elif re.search(r'0x09[0-9A-Fa-f]{2}0000', expansion):
self.ka_algorithms.add(name)
elif re.search(r'0x08[0-9A-Fa-f]{6}', expansion):
self.kdf_algorithms.add(name)
# "#define" followed by a macro name with either no parameters
# or a single parameter and a non-empty expansion.
# Grab the macro name in group 1, the parameter name if any in group 2
# and the expansion in group 3.
_define_directive_re = re.compile(r'\s*#\s*define\s+(\w+)' +
r'(?:\s+|\((\w+)\)\s*)' +
r'(.+)')
_deprecated_definition_re = re.compile(r'\s*MBEDTLS_DEPRECATED')
def read_line(self, line):
"""Parse a C header line and record the PSA identifier it defines if any.
This function analyzes lines that start with "#define PSA_"
(up to non-significant whitespace) and skips all non-matching lines.
"""
# pylint: disable=too-many-branches
m = re.match(self._define_directive_re, line)
if not m:
return
name, parameter, expansion = m.groups()
expansion = re.sub(r'/\*.*?\*/|//.*', r' ', expansion)
if parameter:
self.argspecs[name] = [parameter]
if re.match(self._deprecated_definition_re, expansion):
# Skip deprecated values, which are assumed to be
# backward compatibility aliases that share
# numerical values with non-deprecated values.
return
if self.is_internal_name(name):
# Macro only to build actual values
return
elif (name.startswith('PSA_ERROR_') or name == 'PSA_SUCCESS') \
and not parameter:
self.statuses.add(name)
elif name.startswith('PSA_KEY_TYPE_') and not parameter:
self.key_types.add(name)
elif name.startswith('PSA_KEY_TYPE_') and parameter == 'curve':
self.key_types_from_curve[name] = name[:13] + 'IS_' + name[13:]
elif name.startswith('PSA_KEY_TYPE_') and parameter == 'group':
self.key_types_from_group[name] = name[:13] + 'IS_' + name[13:]
elif name.startswith('PSA_ECC_FAMILY_') and not parameter:
self.ecc_curves.add(name)
elif name.startswith('PSA_DH_FAMILY_') and not parameter:
self.dh_groups.add(name)
elif name.startswith('PSA_ALG_') and not parameter:
if name in ['PSA_ALG_ECDSA_BASE',
'PSA_ALG_RSA_PKCS1V15_SIGN_BASE']:
# Ad hoc skipping of duplicate names for some numerical values
return
self.algorithms.add(name)
self.record_algorithm_subtype(name, expansion)
elif name.startswith('PSA_ALG_') and parameter == 'hash_alg':
if name in ['PSA_ALG_DSA', 'PSA_ALG_ECDSA']:
# A naming irregularity
tester = name[:8] + 'IS_RANDOMIZED_' + name[8:]
else:
tester = name[:8] + 'IS_' + name[8:]
self.algorithms_from_hash[name] = tester
elif name.startswith('PSA_KEY_USAGE_') and not parameter:
self.key_usage_flags.add(name)
else:
# Other macro without parameter
return
_nonascii_re = re.compile(rb'[^\x00-\x7f]+')
_continued_line_re = re.compile(rb'\\\r?\n\Z')
def read_file(self, header_file):
for line in header_file:
m = re.search(self._continued_line_re, line)
while m:
cont = next(header_file)
line = line[:m.start(0)] + cont
m = re.search(self._continued_line_re, line)
line = re.sub(self._nonascii_re, rb'', line).decode('ascii')
self.read_line(line)
class InputsForTest(PSAMacroCollector):
# pylint: disable=too-many-instance-attributes
"""Accumulate information about macros to test.
enumerate
This includes macro names as well as information about their arguments
when applicable.
"""
def __init__(self) -> None:
super().__init__()
self.all_declared = set() #type: Set[str]
# Identifier prefixes
self.table_by_prefix = {
'ERROR': self.statuses,
'ALG': self.algorithms,
'ECC_CURVE': self.ecc_curves,
'DH_GROUP': self.dh_groups,
'KEY_TYPE': self.key_types,
'KEY_USAGE': self.key_usage_flags,
} #type: Dict[str, Set[str]]
# Test functions
self.table_by_test_function = {
# Any function ending in _algorithm also gets added to
# self.algorithms.
'key_type': [self.key_types],
'block_cipher_key_type': [self.key_types],
'stream_cipher_key_type': [self.key_types],
'ecc_key_family': [self.ecc_curves],
'ecc_key_types': [self.ecc_curves],
'dh_key_family': [self.dh_groups],
'dh_key_types': [self.dh_groups],
'hash_algorithm': [self.hash_algorithms],
'mac_algorithm': [self.mac_algorithms],
'cipher_algorithm': [],
'hmac_algorithm': [self.mac_algorithms],
'aead_algorithm': [self.aead_algorithms],
'key_derivation_algorithm': [self.kdf_algorithms],
'key_agreement_algorithm': [self.ka_algorithms],
'asymmetric_signature_algorithm': [],
'asymmetric_signature_wildcard': [self.algorithms],
'asymmetric_encryption_algorithm': [],
'other_algorithm': [],
} #type: Dict[str, List[Set[str]]]
self.arguments_for['mac_length'] += ['1', '63']
self.arguments_for['min_mac_length'] += ['1', '63']
self.arguments_for['tag_length'] += ['1', '63']
self.arguments_for['min_tag_length'] += ['1', '63']
def add_numerical_values(self) -> None:
"""Add numerical values that are not supported to the known identifiers."""
# Sets of names per type
self.algorithms.add('0xffffffff')
self.ecc_curves.add('0xff')
self.dh_groups.add('0xff')
self.key_types.add('0xffff')
self.key_usage_flags.add('0x80000000')
# Hard-coded values for unknown algorithms
#
# These have to have values that are correct for their respective
# PSA_ALG_IS_xxx macros, but are also not currently assigned and are
# not likely to be assigned in the near future.
self.hash_algorithms.add('0x020000fe') # 0x020000ff is PSA_ALG_ANY_HASH
self.mac_algorithms.add('0x03007fff')
self.ka_algorithms.add('0x09fc0000')
self.kdf_algorithms.add('0x080000ff')
# For AEAD algorithms, the only variability is over the tag length,
# and this only applies to known algorithms, so don't test an
# unknown algorithm.
def get_names(self, type_word: str) -> Set[str]:
"""Return the set of known names of values of the given type."""
return {
'status': self.statuses,
'algorithm': self.algorithms,
'ecc_curve': self.ecc_curves,
'dh_group': self.dh_groups,
'key_type': self.key_types,
'key_usage': self.key_usage_flags,
}[type_word]
# Regex for interesting header lines.
# Groups: 1=macro name, 2=type, 3=argument list (optional).
_header_line_re = \
re.compile(r'#define +' +
r'(PSA_((?:(?:DH|ECC|KEY)_)?[A-Z]+)_\w+)' +
r'(?:\(([^\n()]*)\))?')
# Regex of macro names to exclude.
_excluded_name_re = re.compile(r'_(?:GET|IS|OF)_|_(?:BASE|FLAG|MASK)\Z')
# Additional excluded macros.
_excluded_names = set([
# Macros that provide an alternative way to build the same
# algorithm as another macro.
'PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG',
'PSA_ALG_FULL_LENGTH_MAC',
# Auxiliary macro whose name doesn't fit the usual patterns for
# auxiliary macros.
'PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG_CASE',
])
def parse_header_line(self, line: str) -> None:
"""Parse a C header line, looking for "#define PSA_xxx"."""
m = re.match(self._header_line_re, line)
if not m:
return
name = m.group(1)
self.all_declared.add(name)
if re.search(self._excluded_name_re, name) or \
name in self._excluded_names:
return
dest = self.table_by_prefix.get(m.group(2))
if dest is None:
return
dest.add(name)
if m.group(3):
self.argspecs[name] = self._argument_split(m.group(3))
_nonascii_re = re.compile(rb'[^\x00-\x7f]+') #type: Pattern
def parse_header(self, filename: str) -> None:
"""Parse a C header file, looking for "#define PSA_xxx"."""
with read_file_lines(filename, binary=True) as lines:
for line in lines:
line = re.sub(self._nonascii_re, rb'', line).decode('ascii')
self.parse_header_line(line)
_macro_identifier_re = re.compile(r'[A-Z]\w+')
def generate_undeclared_names(self, expr: str) -> Iterable[str]:
for name in re.findall(self._macro_identifier_re, expr):
if name not in self.all_declared:
yield name
def accept_test_case_line(self, function: str, argument: str) -> bool:
#pylint: disable=unused-argument
undeclared = list(self.generate_undeclared_names(argument))
if undeclared:
raise Exception('Undeclared names in test case', undeclared)
return True
def add_test_case_line(self, function: str, argument: str) -> None:
"""Parse a test case data line, looking for algorithm metadata tests."""
sets = []
if function.endswith('_algorithm'):
sets.append(self.algorithms)
if function == 'key_agreement_algorithm' and \
argument.startswith('PSA_ALG_KEY_AGREEMENT('):
# We only want *raw* key agreement algorithms as such, so
# exclude ones that are already chained with a KDF.
# Keep the expression as one to test as an algorithm.
function = 'other_algorithm'
sets += self.table_by_test_function[function]
if self.accept_test_case_line(function, argument):
for s in sets:
s.add(argument)
# Regex matching a *.data line containing a test function call and
# its arguments. The actual definition is partly positional, but this
# regex is good enough in practice.
_test_case_line_re = re.compile(r'(?!depends_on:)(\w+):([^\n :][^:\n]*)')
def parse_test_cases(self, filename: str) -> None:
"""Parse a test case file (*.data), looking for algorithm metadata tests."""
with read_file_lines(filename) as lines:
for line in lines:
m = re.match(self._test_case_line_re, line)
if m:
self.add_test_case_line(m.group(1), m.group(2))