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#!/usr/bin/env python3
"""
(C) 2021,2025 Jack Lloyd
Botan is released under the Simplified BSD License (see license.txt)
"""
import sys
import re
import datetime
def curve_info(src):
re_kv = re.compile('([A-Za-z]+) = ([0-9A-Za-z-_\\. ]+)')
current = {}
for line in src:
line = line.strip()
if line == '':
continue
kv = re_kv.match(line)
if kv is None:
raise Exception('Unknown line', line)
key = kv.group(1)
val = kv.group(2)
if key in ['Name']:
current[key] = val
elif key in ['OID', 'Impl']:
current[key] = val.split(' ')
elif key in ['A']:
if val == '-3':
current[key] = current['P'] - 3
else:
current[key] = int(val, 16)
elif key in ['P', 'B', 'X', 'Y', 'N']:
current[key] = int(val, 16)
if key == 'N':
yield current
current = {}
def format_int(x):
return hex(x).upper().replace('0X', '0x')
def print_curve(curve):
template_str = """ // %s
if(%s) {
return load_EC_group_info(
"%s",
"%s",
"%s",
"%s",
"%s",
"%s",
%s);
}
"""
name = curve['Name']
oids = ['OID{%s}' % (oid.replace('.', ', ')) for oid in curve['OID']]
p = format_int(curve['P'])
a = format_int(curve['A'])
b = format_int(curve['B'])
x = format_int(curve['X'])
y = format_int(curve['Y'])
n = format_int(curve['N'])
oid_match = ' || '.join(['oid == %s' % oid for oid in oids])
pref_oid = 'oid' if len(oids) == 1 else oids[0]
return template_str % (name, oid_match, p, a, b, x, y, n, pref_oid)
def format_names(names):
legacy = []
generic = []
pcurves = []
pcurves_no_generic = []
for (nm, impl) in names:
if 'pcurve' in impl:
pcurves.append(nm)
if 'generic' not in impl:
pcurves_no_generic.append(nm)
elif 'generic' in impl:
generic.append(nm)
else:
assert 'legacy' in impl
legacy.append(nm)
legacy_macro = "defined(BOTAN_HAS_LEGACY_EC_POINT)"
generic_macro = "defined(BOTAN_HAS_PCURVES_GENERIC)"
for nm in sorted(pcurves):
nm_macro = "BOTAN_HAS_PCURVES_%s" % (nm.upper())
if nm in pcurves_no_generic:
yield "#if defined(%s) || %s" % (nm_macro, legacy_macro)
yield " // Not supported by pcurves_generic"
else:
yield "#if defined(%s) || %s || %s" % (nm_macro, legacy_macro, generic_macro)
yield ' \"%s\",' % (nm)
yield "#endif\n"
yield "#if %s || %s" % (legacy_macro, generic_macro)
for nm in sorted(generic):
yield ' \"%s\",' % (nm)
yield "#endif\n"
yield "#if %s" % (legacy_macro)
for nm in sorted(legacy):
yield ' \"%s\",' % (nm)
yield "#endif\n"
def format_orders(orders):
template_str = """ if(low_bits == 0x%08X && order == BigInt("%s")) {\n return OID{%s};\n }\n""";
orders_seen = set([])
for (order,oid) in orders:
low_bits = order & 0xFFFFFFFF
order = format_int(order)
if order in orders_seen:
raise Exception("Duplicate EC group order %s" % (order))
orders_seen.add(order)
oid = oid[0].replace('.', ', ')
yield template_str % (low_bits, order, oid)
def main():
curves = [c for c in curve_info(open('./src/build-data/ec_groups.txt'))]
template_str = open('./src/build-data/ec_named.cpp.in').read()
names = "\n".join(format_names([(c['Name'], c['Impl']) for c in curves]))
orders = "\n".join(format_orders([(c['N'], c['OID']) for c in curves]))
curves = '\n'.join([print_curve(curve) for curve in curves])
this_script = sys.argv[0]
today = datetime.date.today().strftime("%Y-%m-%d")
print(template_str % (this_script, today, curves, orders, names.strip()), end='')
return 0
if __name__ == '__main__':
sys.exit(main())