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Diffstat (limited to 'scripts/generate_psa_constants.py')
| -rwxr-xr-x | scripts/generate_psa_constants.py | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/scripts/generate_psa_constants.py b/scripts/generate_psa_constants.py new file mode 100755 index 000000000..960a07986 --- /dev/null +++ b/scripts/generate_psa_constants.py @@ -0,0 +1,344 @@ +#!/usr/bin/env python3 + +"""Generate psa_constant_names_generated.c +which is included by programs/psa/psa_constant_names.c. +The code generated by this module is only meant to be used in the context +of that program. + +An argument passed to this script will modify the output directory where the +file is written: +* by default (no arguments passed): writes to programs/psa/ +* OUTPUT_FILE_DIR passed: writes to OUTPUT_FILE_DIR/ +""" + +# 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 sys + +from mbedtls_dev import build_tree +from mbedtls_dev import macro_collector + +OUTPUT_TEMPLATE = '''\ +/* Automatically generated by generate_psa_constant.py. DO NOT EDIT. */ + +static const char *psa_strerror(psa_status_t status) +{ + switch (status) { + %(status_cases)s + default: return NULL; + } +} + +static const char *psa_ecc_family_name(psa_ecc_family_t curve) +{ + switch (curve) { + %(ecc_curve_cases)s + default: return NULL; + } +} + +static const char *psa_dh_family_name(psa_dh_family_t group) +{ + switch (group) { + %(dh_group_cases)s + default: return NULL; + } +} + +static const char *psa_hash_algorithm_name(psa_algorithm_t hash_alg) +{ + switch (hash_alg) { + %(hash_algorithm_cases)s + default: return NULL; + } +} + +static const char *psa_ka_algorithm_name(psa_algorithm_t ka_alg) +{ + switch (ka_alg) { + %(ka_algorithm_cases)s + default: return NULL; + } +} + +static int psa_snprint_key_type(char *buffer, size_t buffer_size, + psa_key_type_t type) +{ + size_t required_size = 0; + switch (type) { + %(key_type_cases)s + default: + %(key_type_code)s{ + return snprintf(buffer, buffer_size, + "0x%%04x", (unsigned) type); + } + break; + } + buffer[0] = 0; + return (int) required_size; +} + +#define NO_LENGTH_MODIFIER 0xfffffffflu +static int psa_snprint_algorithm(char *buffer, size_t buffer_size, + psa_algorithm_t alg) +{ + size_t required_size = 0; + psa_algorithm_t core_alg = alg; + unsigned long length_modifier = NO_LENGTH_MODIFIER; + if (PSA_ALG_IS_MAC(alg)) { + core_alg = PSA_ALG_TRUNCATED_MAC(alg, 0); + if (alg & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) { + append(&buffer, buffer_size, &required_size, + "PSA_ALG_AT_LEAST_THIS_LENGTH_MAC(", 33); + length_modifier = PSA_MAC_TRUNCATED_LENGTH(alg); + } else if (core_alg != alg) { + append(&buffer, buffer_size, &required_size, + "PSA_ALG_TRUNCATED_MAC(", 22); + length_modifier = PSA_MAC_TRUNCATED_LENGTH(alg); + } + } else if (PSA_ALG_IS_AEAD(alg)) { + core_alg = PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG(alg); + if (core_alg == 0) { + /* For unknown AEAD algorithms, there is no "default tag length". */ + core_alg = alg; + } else if (alg & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) { + append(&buffer, buffer_size, &required_size, + "PSA_ALG_AEAD_WITH_AT_LEAST_THIS_LENGTH_TAG(", 43); + length_modifier = PSA_ALG_AEAD_GET_TAG_LENGTH(alg); + } else if (core_alg != alg) { + append(&buffer, buffer_size, &required_size, + "PSA_ALG_AEAD_WITH_SHORTENED_TAG(", 32); + length_modifier = PSA_ALG_AEAD_GET_TAG_LENGTH(alg); + } + } else if (PSA_ALG_IS_KEY_AGREEMENT(alg) && + !PSA_ALG_IS_RAW_KEY_AGREEMENT(alg)) { + core_alg = PSA_ALG_KEY_AGREEMENT_GET_KDF(alg); + append(&buffer, buffer_size, &required_size, + "PSA_ALG_KEY_AGREEMENT(", 22); + append_with_alg(&buffer, buffer_size, &required_size, + psa_ka_algorithm_name, + PSA_ALG_KEY_AGREEMENT_GET_BASE(alg)); + append(&buffer, buffer_size, &required_size, ", ", 2); + } + switch (core_alg) { + %(algorithm_cases)s + default: + %(algorithm_code)s{ + append_integer(&buffer, buffer_size, &required_size, + "0x%%08lx", (unsigned long) core_alg); + } + break; + } + if (core_alg != alg) { + if (length_modifier != NO_LENGTH_MODIFIER) { + append(&buffer, buffer_size, &required_size, ", ", 2); + append_integer(&buffer, buffer_size, &required_size, + "%%lu", length_modifier); + } + append(&buffer, buffer_size, &required_size, ")", 1); + } + buffer[0] = 0; + return (int) required_size; +} + +static int psa_snprint_key_usage(char *buffer, size_t buffer_size, + psa_key_usage_t usage) +{ + size_t required_size = 0; + if (usage == 0) { + if (buffer_size > 1) { + buffer[0] = '0'; + buffer[1] = 0; + } else if (buffer_size == 1) { + buffer[0] = 0; + } + return 1; + } +%(key_usage_code)s + if (usage != 0) { + if (required_size != 0) { + append(&buffer, buffer_size, &required_size, " | ", 3); + } + append_integer(&buffer, buffer_size, &required_size, + "0x%%08lx", (unsigned long) usage); + } else { + buffer[0] = 0; + } + return (int) required_size; +} + +/* End of automatically generated file. */ +''' + +KEY_TYPE_FROM_CURVE_TEMPLATE = '''if (%(tester)s(type)) { + append_with_curve(&buffer, buffer_size, &required_size, + "%(builder)s", %(builder_length)s, + PSA_KEY_TYPE_ECC_GET_FAMILY(type)); + } else ''' + +KEY_TYPE_FROM_GROUP_TEMPLATE = '''if (%(tester)s(type)) { + append_with_group(&buffer, buffer_size, &required_size, + "%(builder)s", %(builder_length)s, + PSA_KEY_TYPE_DH_GET_FAMILY(type)); + } else ''' + +ALGORITHM_FROM_HASH_TEMPLATE = '''if (%(tester)s(core_alg)) { + append(&buffer, buffer_size, &required_size, + "%(builder)s(", %(builder_length)s + 1); + append_with_alg(&buffer, buffer_size, &required_size, + psa_hash_algorithm_name, + PSA_ALG_GET_HASH(core_alg)); + append(&buffer, buffer_size, &required_size, ")", 1); + } else ''' + +BIT_TEST_TEMPLATE = '''\ + if (%(var)s & %(flag)s) { + if (required_size != 0) { + append(&buffer, buffer_size, &required_size, " | ", 3); + } + append(&buffer, buffer_size, &required_size, "%(flag)s", %(length)d); + %(var)s ^= %(flag)s; + }\ +''' + +class CaseBuilder(macro_collector.PSAMacroCollector): + """Collect PSA crypto macro definitions and write value recognition functions. + + 1. Call `read_file` on the input header file(s). + 2. Call `write_file` to write ``psa_constant_names_generated.c``. + """ + + def __init__(self): + super().__init__(include_intermediate=True) + + @staticmethod + def _make_return_case(name): + return 'case %(name)s: return "%(name)s";' % {'name': name} + + @staticmethod + def _make_append_case(name): + template = ('case %(name)s: ' + 'append(&buffer, buffer_size, &required_size, "%(name)s", %(length)d); ' + 'break;') + return template % {'name': name, 'length': len(name)} + + @staticmethod + def _make_bit_test(var, flag): + return BIT_TEST_TEMPLATE % {'var': var, + 'flag': flag, + 'length': len(flag)} + + def _make_status_cases(self): + return '\n '.join(map(self._make_return_case, + sorted(self.statuses))) + + def _make_ecc_curve_cases(self): + return '\n '.join(map(self._make_return_case, + sorted(self.ecc_curves))) + + def _make_dh_group_cases(self): + return '\n '.join(map(self._make_return_case, + sorted(self.dh_groups))) + + def _make_key_type_cases(self): + return '\n '.join(map(self._make_append_case, + sorted(self.key_types))) + + @staticmethod + def _make_key_type_from_curve_code(builder, tester): + return KEY_TYPE_FROM_CURVE_TEMPLATE % {'builder': builder, + 'builder_length': len(builder), + 'tester': tester} + + @staticmethod + def _make_key_type_from_group_code(builder, tester): + return KEY_TYPE_FROM_GROUP_TEMPLATE % {'builder': builder, + 'builder_length': len(builder), + 'tester': tester} + + def _make_ecc_key_type_code(self): + d = self.key_types_from_curve + make = self._make_key_type_from_curve_code + return ''.join([make(k, d[k]) for k in sorted(d.keys())]) + + def _make_dh_key_type_code(self): + d = self.key_types_from_group + make = self._make_key_type_from_group_code + return ''.join([make(k, d[k]) for k in sorted(d.keys())]) + + def _make_hash_algorithm_cases(self): + return '\n '.join(map(self._make_return_case, + sorted(self.hash_algorithms))) + + def _make_ka_algorithm_cases(self): + return '\n '.join(map(self._make_return_case, + sorted(self.ka_algorithms))) + + def _make_algorithm_cases(self): + return '\n '.join(map(self._make_append_case, + sorted(self.algorithms))) + + @staticmethod + def _make_algorithm_from_hash_code(builder, tester): + return ALGORITHM_FROM_HASH_TEMPLATE % {'builder': builder, + 'builder_length': len(builder), + 'tester': tester} + + def _make_algorithm_code(self): + d = self.algorithms_from_hash + make = self._make_algorithm_from_hash_code + return ''.join([make(k, d[k]) for k in sorted(d.keys())]) + + def _make_key_usage_code(self): + return '\n'.join([self._make_bit_test('usage', bit) + for bit in sorted(self.key_usage_flags)]) + + def write_file(self, output_file): + """Generate the pretty-printer function code from the gathered + constant definitions. + """ + data = {} + data['status_cases'] = self._make_status_cases() + data['ecc_curve_cases'] = self._make_ecc_curve_cases() + data['dh_group_cases'] = self._make_dh_group_cases() + data['key_type_cases'] = self._make_key_type_cases() + data['key_type_code'] = (self._make_ecc_key_type_code() + + self._make_dh_key_type_code()) + data['hash_algorithm_cases'] = self._make_hash_algorithm_cases() + data['ka_algorithm_cases'] = self._make_ka_algorithm_cases() + data['algorithm_cases'] = self._make_algorithm_cases() + data['algorithm_code'] = self._make_algorithm_code() + data['key_usage_code'] = self._make_key_usage_code() + output_file.write(OUTPUT_TEMPLATE % data) + +def generate_psa_constants(header_file_names, output_file_name): + collector = CaseBuilder() + for header_file_name in header_file_names: + with open(header_file_name, 'rb') as header_file: + collector.read_file(header_file) + temp_file_name = output_file_name + '.tmp' + with open(temp_file_name, 'w') as output_file: + collector.write_file(output_file) + os.replace(temp_file_name, output_file_name) + +if __name__ == '__main__': + build_tree.chdir_to_root() + # Allow to change the directory where psa_constant_names_generated.c is written to. + OUTPUT_FILE_DIR = sys.argv[1] if len(sys.argv) == 2 else "programs/psa" + generate_psa_constants(['include/psa/crypto_values.h', + 'include/psa/crypto_extra.h'], + OUTPUT_FILE_DIR + '/psa_constant_names_generated.c') |