1#!/usr/bin/env python3 2 3"""Generate psa_constant_names_generated.c 4which is included by programs/psa/psa_constant_names.c. 5The code generated by this module is only meant to be used in the context 6of that program. 7 8An argument passed to this script will modify the output directory where the 9file is written: 10* by default (no arguments passed): writes to programs/psa/ 11* OUTPUT_FILE_DIR passed: writes to OUTPUT_FILE_DIR/ 12""" 13 14# Copyright The Mbed TLS Contributors 15# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later 16 17import os 18import sys 19 20from mbedtls_dev import macro_collector 21 22OUTPUT_TEMPLATE = '''\ 23/* Automatically generated by generate_psa_constant.py. DO NOT EDIT. */ 24 25static const char *psa_strerror(psa_status_t status) 26{ 27 switch (status) { 28 %(status_cases)s 29 default: return NULL; 30 } 31} 32 33static const char *psa_ecc_family_name(psa_ecc_family_t curve) 34{ 35 switch (curve) { 36 %(ecc_curve_cases)s 37 default: return NULL; 38 } 39} 40 41static const char *psa_dh_family_name(psa_dh_family_t group) 42{ 43 switch (group) { 44 %(dh_group_cases)s 45 default: return NULL; 46 } 47} 48 49static const char *psa_hash_algorithm_name(psa_algorithm_t hash_alg) 50{ 51 switch (hash_alg) { 52 %(hash_algorithm_cases)s 53 default: return NULL; 54 } 55} 56 57static const char *psa_ka_algorithm_name(psa_algorithm_t ka_alg) 58{ 59 switch (ka_alg) { 60 %(ka_algorithm_cases)s 61 default: return NULL; 62 } 63} 64 65static int psa_snprint_key_type(char *buffer, size_t buffer_size, 66 psa_key_type_t type) 67{ 68 size_t required_size = 0; 69 switch (type) { 70 %(key_type_cases)s 71 default: 72 %(key_type_code)s{ 73 return snprintf(buffer, buffer_size, 74 "0x%%04x", (unsigned) type); 75 } 76 break; 77 } 78 buffer[0] = 0; 79 return (int) required_size; 80} 81 82#define NO_LENGTH_MODIFIER 0xfffffffflu 83static int psa_snprint_algorithm(char *buffer, size_t buffer_size, 84 psa_algorithm_t alg) 85{ 86 size_t required_size = 0; 87 psa_algorithm_t core_alg = alg; 88 unsigned long length_modifier = NO_LENGTH_MODIFIER; 89 if (PSA_ALG_IS_MAC(alg)) { 90 core_alg = PSA_ALG_TRUNCATED_MAC(alg, 0); 91 if (alg & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG) { 92 append(&buffer, buffer_size, &required_size, 93 "PSA_ALG_AT_LEAST_THIS_LENGTH_MAC(", 33); 94 length_modifier = PSA_MAC_TRUNCATED_LENGTH(alg); 95 } else if (core_alg != alg) { 96 append(&buffer, buffer_size, &required_size, 97 "PSA_ALG_TRUNCATED_MAC(", 22); 98 length_modifier = PSA_MAC_TRUNCATED_LENGTH(alg); 99 } 100 } else if (PSA_ALG_IS_AEAD(alg)) { 101 core_alg = PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG(alg); 102 if (core_alg == 0) { 103 /* For unknown AEAD algorithms, there is no "default tag length". */ 104 core_alg = alg; 105 } else if (alg & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG) { 106 append(&buffer, buffer_size, &required_size, 107 "PSA_ALG_AEAD_WITH_AT_LEAST_THIS_LENGTH_TAG(", 43); 108 length_modifier = PSA_ALG_AEAD_GET_TAG_LENGTH(alg); 109 } else if (core_alg != alg) { 110 append(&buffer, buffer_size, &required_size, 111 "PSA_ALG_AEAD_WITH_SHORTENED_TAG(", 32); 112 length_modifier = PSA_ALG_AEAD_GET_TAG_LENGTH(alg); 113 } 114 } else if (PSA_ALG_IS_KEY_AGREEMENT(alg) && 115 !PSA_ALG_IS_RAW_KEY_AGREEMENT(alg)) { 116 core_alg = PSA_ALG_KEY_AGREEMENT_GET_KDF(alg); 117 append(&buffer, buffer_size, &required_size, 118 "PSA_ALG_KEY_AGREEMENT(", 22); 119 append_with_alg(&buffer, buffer_size, &required_size, 120 psa_ka_algorithm_name, 121 PSA_ALG_KEY_AGREEMENT_GET_BASE(alg)); 122 append(&buffer, buffer_size, &required_size, ", ", 2); 123 } 124 switch (core_alg) { 125 %(algorithm_cases)s 126 default: 127 %(algorithm_code)s{ 128 append_integer(&buffer, buffer_size, &required_size, 129 "0x%%08lx", (unsigned long) core_alg); 130 } 131 break; 132 } 133 if (core_alg != alg) { 134 if (length_modifier != NO_LENGTH_MODIFIER) { 135 append(&buffer, buffer_size, &required_size, ", ", 2); 136 append_integer(&buffer, buffer_size, &required_size, 137 "%%lu", length_modifier); 138 } 139 append(&buffer, buffer_size, &required_size, ")", 1); 140 } 141 buffer[0] = 0; 142 return (int) required_size; 143} 144 145static int psa_snprint_key_usage(char *buffer, size_t buffer_size, 146 psa_key_usage_t usage) 147{ 148 size_t required_size = 0; 149 if (usage == 0) { 150 if (buffer_size > 1) { 151 buffer[0] = '0'; 152 buffer[1] = 0; 153 } else if (buffer_size == 1) { 154 buffer[0] = 0; 155 } 156 return 1; 157 } 158%(key_usage_code)s 159 if (usage != 0) { 160 if (required_size != 0) { 161 append(&buffer, buffer_size, &required_size, " | ", 3); 162 } 163 append_integer(&buffer, buffer_size, &required_size, 164 "0x%%08lx", (unsigned long) usage); 165 } else { 166 buffer[0] = 0; 167 } 168 return (int) required_size; 169} 170 171/* End of automatically generated file. */ 172''' 173 174KEY_TYPE_FROM_CURVE_TEMPLATE = '''if (%(tester)s(type)) { 175 append_with_curve(&buffer, buffer_size, &required_size, 176 "%(builder)s", %(builder_length)s, 177 PSA_KEY_TYPE_ECC_GET_FAMILY(type)); 178 } else ''' 179 180KEY_TYPE_FROM_GROUP_TEMPLATE = '''if (%(tester)s(type)) { 181 append_with_group(&buffer, buffer_size, &required_size, 182 "%(builder)s", %(builder_length)s, 183 PSA_KEY_TYPE_DH_GET_FAMILY(type)); 184 } else ''' 185 186ALGORITHM_FROM_HASH_TEMPLATE = '''if (%(tester)s(core_alg)) { 187 append(&buffer, buffer_size, &required_size, 188 "%(builder)s(", %(builder_length)s + 1); 189 append_with_alg(&buffer, buffer_size, &required_size, 190 psa_hash_algorithm_name, 191 PSA_ALG_GET_HASH(core_alg)); 192 append(&buffer, buffer_size, &required_size, ")", 1); 193 } else ''' 194 195BIT_TEST_TEMPLATE = '''\ 196 if (%(var)s & %(flag)s) { 197 if (required_size != 0) { 198 append(&buffer, buffer_size, &required_size, " | ", 3); 199 } 200 append(&buffer, buffer_size, &required_size, "%(flag)s", %(length)d); 201 %(var)s ^= %(flag)s; 202 }\ 203''' 204 205class CaseBuilder(macro_collector.PSAMacroCollector): 206 """Collect PSA crypto macro definitions and write value recognition functions. 207 208 1. Call `read_file` on the input header file(s). 209 2. Call `write_file` to write ``psa_constant_names_generated.c``. 210 """ 211 212 def __init__(self): 213 super().__init__(include_intermediate=True) 214 215 @staticmethod 216 def _make_return_case(name): 217 return 'case %(name)s: return "%(name)s";' % {'name': name} 218 219 @staticmethod 220 def _make_append_case(name): 221 template = ('case %(name)s: ' 222 'append(&buffer, buffer_size, &required_size, "%(name)s", %(length)d); ' 223 'break;') 224 return template % {'name': name, 'length': len(name)} 225 226 @staticmethod 227 def _make_bit_test(var, flag): 228 return BIT_TEST_TEMPLATE % {'var': var, 229 'flag': flag, 230 'length': len(flag)} 231 232 def _make_status_cases(self): 233 return '\n '.join(map(self._make_return_case, 234 sorted(self.statuses))) 235 236 def _make_ecc_curve_cases(self): 237 return '\n '.join(map(self._make_return_case, 238 sorted(self.ecc_curves))) 239 240 def _make_dh_group_cases(self): 241 return '\n '.join(map(self._make_return_case, 242 sorted(self.dh_groups))) 243 244 def _make_key_type_cases(self): 245 return '\n '.join(map(self._make_append_case, 246 sorted(self.key_types))) 247 248 @staticmethod 249 def _make_key_type_from_curve_code(builder, tester): 250 return KEY_TYPE_FROM_CURVE_TEMPLATE % {'builder': builder, 251 'builder_length': len(builder), 252 'tester': tester} 253 254 @staticmethod 255 def _make_key_type_from_group_code(builder, tester): 256 return KEY_TYPE_FROM_GROUP_TEMPLATE % {'builder': builder, 257 'builder_length': len(builder), 258 'tester': tester} 259 260 def _make_ecc_key_type_code(self): 261 d = self.key_types_from_curve 262 make = self._make_key_type_from_curve_code 263 return ''.join([make(k, d[k]) for k in sorted(d.keys())]) 264 265 def _make_dh_key_type_code(self): 266 d = self.key_types_from_group 267 make = self._make_key_type_from_group_code 268 return ''.join([make(k, d[k]) for k in sorted(d.keys())]) 269 270 def _make_hash_algorithm_cases(self): 271 return '\n '.join(map(self._make_return_case, 272 sorted(self.hash_algorithms))) 273 274 def _make_ka_algorithm_cases(self): 275 return '\n '.join(map(self._make_return_case, 276 sorted(self.ka_algorithms))) 277 278 def _make_algorithm_cases(self): 279 return '\n '.join(map(self._make_append_case, 280 sorted(self.algorithms))) 281 282 @staticmethod 283 def _make_algorithm_from_hash_code(builder, tester): 284 return ALGORITHM_FROM_HASH_TEMPLATE % {'builder': builder, 285 'builder_length': len(builder), 286 'tester': tester} 287 288 def _make_algorithm_code(self): 289 d = self.algorithms_from_hash 290 make = self._make_algorithm_from_hash_code 291 return ''.join([make(k, d[k]) for k in sorted(d.keys())]) 292 293 def _make_key_usage_code(self): 294 return '\n'.join([self._make_bit_test('usage', bit) 295 for bit in sorted(self.key_usage_flags)]) 296 297 def write_file(self, output_file): 298 """Generate the pretty-printer function code from the gathered 299 constant definitions. 300 """ 301 data = {} 302 data['status_cases'] = self._make_status_cases() 303 data['ecc_curve_cases'] = self._make_ecc_curve_cases() 304 data['dh_group_cases'] = self._make_dh_group_cases() 305 data['key_type_cases'] = self._make_key_type_cases() 306 data['key_type_code'] = (self._make_ecc_key_type_code() + 307 self._make_dh_key_type_code()) 308 data['hash_algorithm_cases'] = self._make_hash_algorithm_cases() 309 data['ka_algorithm_cases'] = self._make_ka_algorithm_cases() 310 data['algorithm_cases'] = self._make_algorithm_cases() 311 data['algorithm_code'] = self._make_algorithm_code() 312 data['key_usage_code'] = self._make_key_usage_code() 313 output_file.write(OUTPUT_TEMPLATE % data) 314 315def generate_psa_constants(header_file_names, output_file_name): 316 collector = CaseBuilder() 317 for header_file_name in header_file_names: 318 with open(header_file_name, 'rb') as header_file: 319 collector.read_file(header_file) 320 temp_file_name = output_file_name + '.tmp' 321 with open(temp_file_name, 'w') as output_file: 322 collector.write_file(output_file) 323 os.replace(temp_file_name, output_file_name) 324 325if __name__ == '__main__': 326 if not os.path.isdir('programs') and os.path.isdir('../programs'): 327 os.chdir('..') 328 # Allow to change the directory where psa_constant_names_generated.c is written to. 329 OUTPUT_FILE_DIR = sys.argv[1] if len(sys.argv) == 2 else "programs/psa" 330 generate_psa_constants(['include/psa/crypto_values.h', 331 'include/psa/crypto_extra.h'], 332 OUTPUT_FILE_DIR + '/psa_constant_names_generated.c') 333