#!/usr/bin/env python3 """Generate programs/psa/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. """ import os import re 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_curve_name(psa_ecc_curve_t curve) { switch (curve) { %(ecc_curve_cases)s default: return NULL; } } static const char *psa_dh_group_name(psa_dh_group_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%%08lx", (unsigned long) 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 (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_TAG_LENGTH(alg); if (core_alg == 0) { /* For unknown AEAD algorithms, there is no "default tag length". */ core_alg = alg; } else if (core_alg != alg) { append(&buffer, buffer_size, &required_size, "PSA_ALG_AEAD_WITH_TAG_LENGTH(", 29); length_modifier = PSA_AEAD_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_GET_CURVE(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_GET_GROUP(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 MacroCollector: """Collect PSA crypto macro definitions from C header files. 1. Call `read_file` on the input header file(s). 2. Call `write_file` to write ``psa_constant_names_generated.c``. """ def __init__(self): self.statuses = set() self.key_types = set() self.key_types_from_curve = {} self.key_types_from_group = {} self.ecc_curves = set() self.dh_groups = set() self.algorithms = set() self.hash_algorithms = set() self.ka_algorithms = set() self.algorithms_from_hash = {} self.key_usages = set() # "#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 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 name.endswith('_FLAG') or name.endswith('MASK'): # 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_CURVE_') and not parameter: self.ecc_curves.add(name) elif name.startswith('PSA_DH_GROUP_') 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) # Ad hoc detection of hash algorithms if re.search(r'0x010000[0-9A-Fa-f]{2}', expansion): self.hash_algorithms.add(name) # Ad hoc detection of key agreement algorithms if re.search(r'0x30[0-9A-Fa-f]{2}0000', expansion): self.ka_algorithms.add(name) 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_usages.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) @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_usages)]) 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 = MacroCollector() 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.rename(temp_file_name, output_file_name) if __name__ == '__main__': if not os.path.isdir('programs') and os.path.isdir('../programs'): os.chdir('..') generate_psa_constants(['include/psa/crypto_values.h', 'include/psa/crypto_extra.h'], 'programs/psa/psa_constant_names_generated.c')