You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
480 lines
17 KiB
480 lines
17 KiB
from typing import Tuple
|
|
|
|
from asn1crypto.keys import ECDomainParameters, ECPointBitString, ECPrivateKey, PrivateKeyAlgorithm, PrivateKeyInfo
|
|
|
|
from coincurve.context import GLOBAL_CONTEXT, Context
|
|
from coincurve.ecdsa import cdata_to_der, der_to_cdata, deserialize_recoverable, recover, serialize_recoverable
|
|
from coincurve.flags import EC_COMPRESSED, EC_UNCOMPRESSED
|
|
from coincurve.types import Hasher, Nonce
|
|
from coincurve.utils import (
|
|
DEFAULT_NONCE,
|
|
bytes_to_int,
|
|
der_to_pem,
|
|
get_valid_secret,
|
|
hex_to_bytes,
|
|
int_to_bytes_padded,
|
|
pad_scalar,
|
|
pem_to_der,
|
|
sha256,
|
|
validate_secret,
|
|
)
|
|
|
|
from ._libsecp256k1 import ffi, lib
|
|
|
|
|
|
class PrivateKey:
|
|
def __init__(self, secret: bytes = None, context: Context = GLOBAL_CONTEXT):
|
|
"""
|
|
:param secret: The secret used to initialize the private key.
|
|
If not provided or `None`, a new key will be generated.
|
|
"""
|
|
self.secret: bytes = validate_secret(secret) if secret is not None else get_valid_secret()
|
|
self.context = context
|
|
self.public_key: PublicKey = PublicKey.from_valid_secret(self.secret, self.context)
|
|
|
|
def sign(self, message: bytes, hasher: Hasher = sha256, custom_nonce: Nonce = DEFAULT_NONCE) -> bytes:
|
|
"""
|
|
Create an ECDSA signature.
|
|
|
|
:param message: The message to sign.
|
|
:param hasher: The hash function to use, which must return 32 bytes. By default,
|
|
the `sha256` algorithm is used. If `None`, no hashing occurs.
|
|
:param custom_nonce: Custom nonce data in the form `(nonce_function, input_data)`.
|
|
:return: The ECDSA signature.
|
|
:raises ValueError: If the message hash was not 32 bytes long, the nonce generation
|
|
function failed, or the private key was invalid.
|
|
"""
|
|
msg_hash = hasher(message) if hasher is not None else message
|
|
if len(msg_hash) != 32:
|
|
raise ValueError('Message hash must be 32 bytes long.')
|
|
|
|
signature = ffi.new('secp256k1_ecdsa_signature *')
|
|
nonce_fn, nonce_data = custom_nonce
|
|
|
|
signed = lib.secp256k1_ecdsa_sign(self.context.ctx, signature, msg_hash, self.secret, nonce_fn, nonce_data)
|
|
|
|
if not signed:
|
|
raise ValueError('The nonce generation function failed, or the private key was invalid.')
|
|
|
|
return cdata_to_der(signature, self.context)
|
|
|
|
def sign_recoverable(self, message: bytes, hasher: Hasher = sha256, custom_nonce: Nonce = DEFAULT_NONCE) -> bytes:
|
|
"""
|
|
Create a recoverable ECDSA signature.
|
|
|
|
:param message: The message to sign.
|
|
:param hasher: The hash function to use, which must return 32 bytes. By default,
|
|
the `sha256` algorithm is used. If `None`, no hashing occurs.
|
|
:param custom_nonce: Custom nonce data in the form `(nonce_function, input_data)`.
|
|
:return: The recoverable ECDSA signature.
|
|
:raises ValueError: If the message hash was not 32 bytes long, the nonce generation
|
|
function failed, or the private key was invalid.
|
|
"""
|
|
msg_hash = hasher(message) if hasher is not None else message
|
|
if len(msg_hash) != 32:
|
|
raise ValueError('Message hash must be 32 bytes long.')
|
|
|
|
signature = ffi.new('secp256k1_ecdsa_recoverable_signature *')
|
|
nonce_fn, nonce_data = custom_nonce
|
|
|
|
signed = lib.secp256k1_ecdsa_sign_recoverable(
|
|
self.context.ctx, signature, msg_hash, self.secret, nonce_fn, nonce_data
|
|
)
|
|
|
|
if not signed:
|
|
raise ValueError('The nonce generation function failed, or the private key was invalid.')
|
|
|
|
return serialize_recoverable(signature, self.context)
|
|
|
|
def ecdh(self, public_key: bytes) -> bytes:
|
|
"""
|
|
Compute an EC Diffie-Hellman secret in constant time.
|
|
|
|
:param public_key: The formatted public key.
|
|
:return: The 32 byte shared secret.
|
|
:raises ValueError: If the public key could not be parsed or was invalid.
|
|
"""
|
|
secret = ffi.new('unsigned char [32]')
|
|
|
|
lib.secp256k1_ecdh(self.context.ctx, secret, PublicKey(public_key).public_key, self.secret, ffi.NULL, ffi.NULL)
|
|
|
|
return bytes(ffi.buffer(secret, 32))
|
|
|
|
def add(self, scalar: bytes, update: bool = False):
|
|
"""
|
|
Add a scalar to the private key.
|
|
|
|
:param scalar: The scalar with which to add.
|
|
:param update: Whether or not to update and return the private key in-place.
|
|
:return: The new private key, or the modified private key if `update` is `True`.
|
|
:rtype: PrivateKey
|
|
:raises ValueError: If the tweak was out of range or the resulting private key was invalid.
|
|
"""
|
|
scalar = pad_scalar(scalar)
|
|
|
|
secret = ffi.new('unsigned char [32]', self.secret)
|
|
|
|
success = lib.secp256k1_ec_privkey_tweak_add(self.context.ctx, secret, scalar)
|
|
|
|
if not success:
|
|
raise ValueError('The tweak was out of range, or the resulting private key is invalid.')
|
|
|
|
secret = bytes(ffi.buffer(secret, 32))
|
|
|
|
if update:
|
|
self.secret = secret
|
|
self._update_public_key()
|
|
return self
|
|
|
|
return PrivateKey(secret, self.context)
|
|
|
|
def multiply(self, scalar: bytes, update: bool = False):
|
|
"""
|
|
Multiply the private key by a scalar.
|
|
|
|
:param scalar: The scalar with which to multiply.
|
|
:param update: Whether or not to update and return the private key in-place.
|
|
:return: The new private key, or the modified private key if `update` is `True`.
|
|
:rtype: PrivateKey
|
|
"""
|
|
scalar = validate_secret(scalar)
|
|
|
|
secret = ffi.new('unsigned char [32]', self.secret)
|
|
|
|
lib.secp256k1_ec_privkey_tweak_mul(self.context.ctx, secret, scalar)
|
|
|
|
secret = bytes(ffi.buffer(secret, 32))
|
|
|
|
if update:
|
|
self.secret = secret
|
|
self._update_public_key()
|
|
return self
|
|
|
|
return PrivateKey(secret, self.context)
|
|
|
|
def to_hex(self) -> str:
|
|
"""
|
|
:return: The private key encoded as a hex string.
|
|
"""
|
|
return self.secret.hex()
|
|
|
|
def to_int(self) -> int:
|
|
"""
|
|
:return: The private key as an integer.
|
|
"""
|
|
return bytes_to_int(self.secret)
|
|
|
|
def to_pem(self) -> bytes:
|
|
"""
|
|
:return: The private key encoded in PEM format.
|
|
"""
|
|
return der_to_pem(self.to_der())
|
|
|
|
def to_der(self) -> bytes:
|
|
"""
|
|
:return: The private key encoded in DER format.
|
|
"""
|
|
pk = ECPrivateKey(
|
|
{
|
|
'version': 'ecPrivkeyVer1',
|
|
'private_key': self.to_int(),
|
|
'public_key': ECPointBitString(self.public_key.format(compressed=False)),
|
|
}
|
|
)
|
|
|
|
return PrivateKeyInfo(
|
|
{
|
|
'version': 0,
|
|
'private_key_algorithm': PrivateKeyAlgorithm(
|
|
{
|
|
'algorithm': 'ec',
|
|
'parameters': ECDomainParameters(name='named', value='1.3.132.0.10'),
|
|
}
|
|
),
|
|
'private_key': pk,
|
|
}
|
|
).dump()
|
|
|
|
@classmethod
|
|
def from_hex(cls, hexed: str, context: Context = GLOBAL_CONTEXT):
|
|
"""
|
|
:param hexed: The private key encoded as a hex string.
|
|
:param context:
|
|
:return: The private key.
|
|
:rtype: PrivateKey
|
|
"""
|
|
return PrivateKey(hex_to_bytes(hexed), context)
|
|
|
|
@classmethod
|
|
def from_int(cls, num: int, context: Context = GLOBAL_CONTEXT):
|
|
"""
|
|
:param num: The private key as an integer.
|
|
:param context:
|
|
:return: The private key.
|
|
:rtype: PrivateKey
|
|
"""
|
|
return PrivateKey(int_to_bytes_padded(num), context)
|
|
|
|
@classmethod
|
|
def from_pem(cls, pem: bytes, context: Context = GLOBAL_CONTEXT):
|
|
"""
|
|
:param pem: The private key encoded in PEM format.
|
|
:param context:
|
|
:return: The private key.
|
|
:rtype: PrivateKey
|
|
"""
|
|
return PrivateKey(
|
|
int_to_bytes_padded(PrivateKeyInfo.load(pem_to_der(pem)).native['private_key']['private_key']), context
|
|
)
|
|
|
|
@classmethod
|
|
def from_der(cls, der: bytes, context: Context = GLOBAL_CONTEXT):
|
|
"""
|
|
:param der: The private key encoded in DER format.
|
|
:param context:
|
|
:return: The private key.
|
|
:rtype: PrivateKey
|
|
"""
|
|
return PrivateKey(int_to_bytes_padded(PrivateKeyInfo.load(der).native['private_key']['private_key']), context)
|
|
|
|
def _update_public_key(self):
|
|
created = lib.secp256k1_ec_pubkey_create(self.context.ctx, self.public_key.public_key, self.secret)
|
|
|
|
if not created:
|
|
raise ValueError('Invalid secret.')
|
|
|
|
def __eq__(self, other) -> bool:
|
|
return self.secret == other.secret
|
|
|
|
|
|
class PublicKey:
|
|
def __init__(self, data, context: Context = GLOBAL_CONTEXT):
|
|
"""
|
|
:param data: The formatted public key. This class supports parsing
|
|
compressed (33 bytes, header byte `0x02` or `0x03`),
|
|
uncompressed (65 bytes, header byte `0x04`), or
|
|
hybrid (65 bytes, header byte `0x06` or `0x07`) format public keys.
|
|
:type data: bytes
|
|
:param context:
|
|
:raises ValueError: If the public key could not be parsed or was invalid.
|
|
"""
|
|
if not isinstance(data, bytes):
|
|
self.public_key = data
|
|
else:
|
|
public_key = ffi.new('secp256k1_pubkey *')
|
|
|
|
parsed = lib.secp256k1_ec_pubkey_parse(context.ctx, public_key, data, len(data))
|
|
|
|
if not parsed:
|
|
raise ValueError('The public key could not be parsed or is invalid.')
|
|
|
|
self.public_key = public_key
|
|
|
|
self.context = context
|
|
|
|
@classmethod
|
|
def from_secret(cls, secret: bytes, context: Context = GLOBAL_CONTEXT):
|
|
"""
|
|
Derive a public key from a private key secret.
|
|
|
|
:param secret: The private key secret.
|
|
:param context:
|
|
:return: The public key.
|
|
:rtype: PublicKey
|
|
"""
|
|
public_key = ffi.new('secp256k1_pubkey *')
|
|
|
|
created = lib.secp256k1_ec_pubkey_create(context.ctx, public_key, validate_secret(secret))
|
|
|
|
if not created: # no cov
|
|
raise ValueError(
|
|
'Somehow an invalid secret was used. Please '
|
|
'submit this as an issue here: '
|
|
'https://github.com/ofek/coincurve/issues/new'
|
|
)
|
|
|
|
return PublicKey(public_key, context)
|
|
|
|
@classmethod
|
|
def from_valid_secret(cls, secret: bytes, context: Context = GLOBAL_CONTEXT):
|
|
public_key = ffi.new('secp256k1_pubkey *')
|
|
|
|
created = lib.secp256k1_ec_pubkey_create(context.ctx, public_key, secret)
|
|
|
|
if not created:
|
|
raise ValueError('Invalid secret.')
|
|
|
|
return PublicKey(public_key, context)
|
|
|
|
@classmethod
|
|
def from_point(cls, x: int, y: int, context: Context = GLOBAL_CONTEXT):
|
|
"""
|
|
Derive a public key from a coordinate point in the form `(x, y)`.
|
|
|
|
:param x:
|
|
:param y:
|
|
:param context:
|
|
:return: The public key.
|
|
:rtype: PublicKey
|
|
"""
|
|
return PublicKey(b'\x04' + int_to_bytes_padded(x) + int_to_bytes_padded(y), context)
|
|
|
|
@classmethod
|
|
def from_signature_and_message(
|
|
cls, signature: bytes, message: bytes, hasher: Hasher = sha256, context: Context = GLOBAL_CONTEXT
|
|
):
|
|
"""
|
|
Recover an ECDSA public key from a recoverable signature.
|
|
|
|
:param signature: The recoverable ECDSA signature.
|
|
:param message: The message that was supposedly signed.
|
|
:param hasher: The hash function to use, which must return 32 bytes. By default,
|
|
the `sha256` algorithm is used. If `None`, no hashing occurs.
|
|
:param context:
|
|
:return: The public key that signed the message.
|
|
:rtype: PublicKey
|
|
:raises ValueError: If the message hash was not 32 bytes long or recovery of the ECDSA public key failed.
|
|
"""
|
|
return PublicKey(
|
|
recover(message, deserialize_recoverable(signature, context=context), hasher=hasher, context=context)
|
|
)
|
|
|
|
@classmethod
|
|
def combine_keys(cls, public_keys, context: Context = GLOBAL_CONTEXT):
|
|
"""
|
|
Add a number of public keys together.
|
|
|
|
:param public_keys: A sequence of public keys.
|
|
:type public_keys: List[PublicKey]
|
|
:param context:
|
|
:return: The combined public key.
|
|
:rtype: PublicKey
|
|
:raises ValueError: If the sum of the public keys was invalid.
|
|
"""
|
|
public_key = ffi.new('secp256k1_pubkey *')
|
|
|
|
combined = lib.secp256k1_ec_pubkey_combine(
|
|
context.ctx, public_key, [pk.public_key for pk in public_keys], len(public_keys)
|
|
)
|
|
|
|
if not combined:
|
|
raise ValueError('The sum of the public keys is invalid.')
|
|
|
|
return PublicKey(public_key, context)
|
|
|
|
def format(self, compressed: bool = True) -> bytes:
|
|
"""
|
|
Format the public key.
|
|
|
|
:param compressed: Whether or to use the compressed format.
|
|
:return: The 33 byte formatted public key, or the 65 byte formatted public key if `compressed` is `False`.
|
|
"""
|
|
length = 33 if compressed else 65
|
|
serialized = ffi.new('unsigned char [%d]' % length)
|
|
output_len = ffi.new('size_t *', length)
|
|
|
|
lib.secp256k1_ec_pubkey_serialize(
|
|
self.context.ctx, serialized, output_len, self.public_key, EC_COMPRESSED if compressed else EC_UNCOMPRESSED
|
|
)
|
|
|
|
return bytes(ffi.buffer(serialized, length))
|
|
|
|
def point(self) -> Tuple[int, int]:
|
|
"""
|
|
:return: The public key as a coordinate point.
|
|
"""
|
|
public_key = self.format(compressed=False)
|
|
return bytes_to_int(public_key[1:33]), bytes_to_int(public_key[33:])
|
|
|
|
def verify(self, signature: bytes, message: bytes, hasher: Hasher = sha256) -> bool:
|
|
"""
|
|
:param signature: The ECDSA signature.
|
|
:param message: The message that was supposedly signed.
|
|
:param hasher: The hash function to use, which must return 32 bytes. By default,
|
|
the `sha256` algorithm is used. If `None`, no hashing occurs.
|
|
:return: A boolean indicating whether or not the signature is correct.
|
|
:raises ValueError: If the message hash was not 32 bytes long or the DER-encoded signature could not be parsed.
|
|
"""
|
|
msg_hash = hasher(message) if hasher is not None else message
|
|
if len(msg_hash) != 32:
|
|
raise ValueError('Message hash must be 32 bytes long.')
|
|
|
|
verified = lib.secp256k1_ecdsa_verify(self.context.ctx, der_to_cdata(signature), msg_hash, self.public_key)
|
|
|
|
# A performance hack to avoid global bool() lookup.
|
|
return not not verified
|
|
|
|
def add(self, scalar: bytes, update: bool = False):
|
|
"""
|
|
Add a scalar to the public key.
|
|
|
|
:param scalar: The scalar with which to add.
|
|
:param update: Whether or not to update and return the public key in-place.
|
|
:return: The new public key, or the modified public key if `update` is `True`.
|
|
:rtype: PublicKey
|
|
:raises ValueError: If the tweak was out of range or the resulting public key was invalid.
|
|
"""
|
|
scalar = pad_scalar(scalar)
|
|
|
|
new_key = ffi.new('secp256k1_pubkey *', self.public_key[0])
|
|
|
|
success = lib.secp256k1_ec_pubkey_tweak_add(self.context.ctx, new_key, scalar)
|
|
|
|
if not success:
|
|
raise ValueError('The tweak was out of range, or the resulting public key is invalid.')
|
|
|
|
if update:
|
|
self.public_key = new_key
|
|
return self
|
|
|
|
return PublicKey(new_key, self.context)
|
|
|
|
def multiply(self, scalar: bytes, update: bool = False):
|
|
"""
|
|
Multiply the public key by a scalar.
|
|
|
|
:param scalar: The scalar with which to multiply.
|
|
:param update: Whether or not to update and return the public key in-place.
|
|
:return: The new public key, or the modified public key if `update` is `True`.
|
|
:rtype: PublicKey
|
|
"""
|
|
scalar = validate_secret(scalar)
|
|
|
|
new_key = ffi.new('secp256k1_pubkey *', self.public_key[0])
|
|
|
|
lib.secp256k1_ec_pubkey_tweak_mul(self.context.ctx, new_key, scalar)
|
|
|
|
if update:
|
|
self.public_key = new_key
|
|
return self
|
|
|
|
return PublicKey(new_key, self.context)
|
|
|
|
def combine(self, public_keys, update: bool = False):
|
|
"""
|
|
Add a number of public keys together.
|
|
|
|
:param public_keys: A sequence of public keys.
|
|
:type public_keys: List[PublicKey]
|
|
:param update: Whether or not to update and return the public key in-place.
|
|
:return: The combined public key, or the modified public key if `update` is `True`.
|
|
:rtype: PublicKey
|
|
:raises ValueError: If the sum of the public keys was invalid.
|
|
"""
|
|
new_key = ffi.new('secp256k1_pubkey *')
|
|
|
|
combined = lib.secp256k1_ec_pubkey_combine(
|
|
self.context.ctx, new_key, [pk.public_key for pk in public_keys], len(public_keys)
|
|
)
|
|
|
|
if not combined:
|
|
raise ValueError('The sum of the public keys is invalid.')
|
|
|
|
if update:
|
|
self.public_key = new_key
|
|
return self
|
|
|
|
return PublicKey(new_key, self.context)
|
|
|
|
def __eq__(self, other) -> bool:
|
|
return self.format(compressed=False) == other.format(compressed=False)
|
|
|