def ec_generate_pair(curve):
"""
Generates a EC public/private key pair
:param curve:
A unicode string. Valid values include "secp256r1", "secp384r1" and
"secp521r1".
:raises:
ValueError - when any of the parameters contain an invalid value
TypeError - when any of the parameters are of the wrong type
:return:
A 2-element tuple of (asn1crypto.keys.PublicKeyInfo,
asn1crypto.keys.PrivateKeyInfo)
"""
if curve not in set(['secp256r1', 'secp384r1', 'secp521r1']):
raise ValueError(
pretty_message(
'''
curve must be one of "secp256r1", "secp384r1", "secp521r1", not %s
''', repr(curve)))
curve_num_bytes = CURVE_BYTES[curve]
curve_base_point = {
'secp256r1': SECP256R1_BASE_POINT,
'secp384r1': SECP384R1_BASE_POINT,
'secp521r1': SECP521R1_BASE_POINT,
}[curve]
while True:
private_key_bytes = rand_bytes(curve_num_bytes)
private_key_int = int_from_bytes(private_key_bytes, signed=False)
if private_key_int > 0 and private_key_int < curve_base_point.order:
break
private_key_info = keys.PrivateKeyInfo({
'version':
0,
'private_key_algorithm':
keys.PrivateKeyAlgorithm({
'algorithm':
'ec',
'parameters':
keys.ECDomainParameters(name='named', value=curve)
}),
'private_key':
keys.ECPrivateKey({
'version': 'ecPrivkeyVer1',
'private_key': private_key_int
}),
})
ec_point = ec_compute_public_key_point(private_key_info)
private_key_info['private_key'].parsed['public_key'] = ec_point.copy()
return (ec_public_key_info(ec_point, curve), private_key_info)
def test_ec_private_key_width_dotted(self):
k = keys.ECPrivateKey({
'version': 1,
'private_key': 1,
'parameters': keys.ECDomainParameters(('named', '1.3.132.0.10')),
})
self.assertEqual('ecPrivkeyVer1', k['version'].native)
self.assertEqual(1, k['private_key'].native)
self.assertEqual('secp256k1', k['parameters'].native)
self.assertEqual(
b'\x04\x20\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01',
k['private_key'].dump()
)
def test_named_curve_register(self):
keys.NamedCurve.register('customcurve', '1.2.3.4.5.6.7.8', 16)
k = keys.NamedCurve('customcurve')
self.assertEqual('customcurve', k.native)
self.assertEqual('1.2.3.4.5.6.7.8', k.dotted)
k = keys.ECPrivateKey({
'version': 1,
'private_key': 1,
'parameters': keys.ECDomainParameters(('named', 'customcurve')),
})
self.assertEqual('ecPrivkeyVer1', k['version'].native)
self.assertEqual(1, k['private_key'].native)
self.assertEqual('customcurve', k['parameters'].native)
self.assertEqual(
b'\x04\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01',
k['private_key'].dump()
)
