#!/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
def read_file(self, header_file):
for line in header_file:
while line.endswith('\\\n'):
cont = next(header_file)
line = line[:-2] + cont
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) 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')