Move PSA information and dependency automation into their own module
This will let us use these features from other modules (yet to be created).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Signed-off-by: Tomás González <tomasagustin.gonzalezorlando@arm.com>
diff --git a/scripts/mbedtls_dev/psa_information.py b/scripts/mbedtls_dev/psa_information.py
new file mode 100644
index 0000000..0d3b246
--- /dev/null
+++ b/scripts/mbedtls_dev/psa_information.py
@@ -0,0 +1,117 @@
+"""Collect information about PSA cryptographic mechanisms.
+"""
+
+# 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 re
+from typing import Dict, FrozenSet, List, Optional
+
+from . import macro_collector
+
+
+def psa_want_symbol(name: str) -> str:
+ """Return the PSA_WANT_xxx symbol associated with a PSA crypto feature."""
+ if name.startswith('PSA_'):
+ return name[:4] + 'WANT_' + name[4:]
+ else:
+ raise ValueError('Unable to determine the PSA_WANT_ symbol for ' + name)
+
+def finish_family_dependency(dep: str, bits: int) -> str:
+ """Finish dep if it's a family dependency symbol prefix.
+ A family dependency symbol prefix is a PSA_WANT_ symbol that needs to be
+ qualified by the key size. If dep is such a symbol, finish it by adjusting
+ the prefix and appending the key size. Other symbols are left unchanged.
+ """
+ return re.sub(r'_FAMILY_(.*)', r'_\1_' + str(bits), dep)
+
+def finish_family_dependencies(dependencies: List[str], bits: int) -> List[str]:
+ """Finish any family dependency symbol prefixes.
+ Apply `finish_family_dependency` to each element of `dependencies`.
+ """
+ return [finish_family_dependency(dep, bits) for dep in dependencies]
+
+SYMBOLS_WITHOUT_DEPENDENCY = frozenset([
+ 'PSA_ALG_AEAD_WITH_AT_LEAST_THIS_LENGTH_TAG', # modifier, only in policies
+ 'PSA_ALG_AEAD_WITH_SHORTENED_TAG', # modifier
+ 'PSA_ALG_ANY_HASH', # only in policies
+ 'PSA_ALG_AT_LEAST_THIS_LENGTH_MAC', # modifier, only in policies
+ 'PSA_ALG_KEY_AGREEMENT', # chaining
+ 'PSA_ALG_TRUNCATED_MAC', # modifier
+])
+
+def automatic_dependencies(*expressions: str) -> List[str]:
+ """Infer dependencies of a test case by looking for PSA_xxx symbols.
+ The arguments are strings which should be C expressions. Do not use
+ string literals or comments as this function is not smart enough to
+ skip them.
+ """
+ used = set()
+ for expr in expressions:
+ used.update(re.findall(r'PSA_(?:ALG|ECC_FAMILY|KEY_TYPE)_\w+', expr))
+ used.difference_update(SYMBOLS_WITHOUT_DEPENDENCY)
+ return sorted(psa_want_symbol(name) for name in used)
+
+# A temporary hack: at the time of writing, not all dependency symbols
+# are implemented yet. Skip test cases for which the dependency symbols are
+# not available. Once all dependency symbols are available, this hack must
+# be removed so that a bug in the dependency symbols properly leads to a test
+# failure.
+def read_implemented_dependencies(filename: str) -> FrozenSet[str]:
+ return frozenset(symbol
+ for line in open(filename)
+ for symbol in re.findall(r'\bPSA_WANT_\w+\b', line))
+_implemented_dependencies = None #type: Optional[FrozenSet[str]] #pylint: disable=invalid-name
+
+def hack_dependencies_not_implemented(dependencies: List[str]) -> None:
+ global _implemented_dependencies #pylint: disable=global-statement,invalid-name
+ if _implemented_dependencies is None:
+ _implemented_dependencies = \
+ read_implemented_dependencies('include/psa/crypto_config.h')
+ if not all((dep.lstrip('!') in _implemented_dependencies or
+ not dep.lstrip('!').startswith('PSA_WANT'))
+ for dep in dependencies):
+ dependencies.append('DEPENDENCY_NOT_IMPLEMENTED_YET')
+
+class Information:
+ """Gather information about PSA constructors."""
+
+ def __init__(self) -> None:
+ self.constructors = self.read_psa_interface()
+
+ @staticmethod
+ def remove_unwanted_macros(
+ constructors: macro_collector.PSAMacroEnumerator
+ ) -> None:
+ # Mbed TLS doesn't support finite-field DH yet and will not support
+ # finite-field DSA. Don't attempt to generate any related test case.
+ constructors.key_types.discard('PSA_KEY_TYPE_DH_KEY_PAIR')
+ constructors.key_types.discard('PSA_KEY_TYPE_DH_PUBLIC_KEY')
+ constructors.key_types.discard('PSA_KEY_TYPE_DSA_KEY_PAIR')
+ constructors.key_types.discard('PSA_KEY_TYPE_DSA_PUBLIC_KEY')
+
+ def read_psa_interface(self) -> macro_collector.PSAMacroEnumerator:
+ """Return the list of known key types, algorithms, etc."""
+ constructors = macro_collector.InputsForTest()
+ header_file_names = ['include/psa/crypto_values.h',
+ 'include/psa/crypto_extra.h']
+ test_suites = ['tests/suites/test_suite_psa_crypto_metadata.data']
+ for header_file_name in header_file_names:
+ constructors.parse_header(header_file_name)
+ for test_cases in test_suites:
+ constructors.parse_test_cases(test_cases)
+ self.remove_unwanted_macros(constructors)
+ constructors.gather_arguments()
+ return constructors