How to use the ecdsa.ecdsa function in ecdsa

key_len = 48
                digest_len = 48
            else:
                # shouldn't happen
                raise ValidationFailure, 'unknown ECDSA curve'
            keyptr = candidate_key.key
            x = Crypto.Util.number.bytes_to_long(keyptr[0:key_len])
            y = Crypto.Util.number.bytes_to_long(keyptr[key_len:key_len * 2])
            assert ecdsa.ecdsa.point_is_valid(curve.generator, x, y)
            point = ecdsa.ellipticcurve.Point(curve.curve, x, y, curve.order)
            verifying_key = ecdsa.keys.VerifyingKey.from_public_point(point,
                                                                      curve)
            pubkey = ECKeyWrapper(verifying_key, key_len)
            r = rrsig.signature[:key_len]
            s = rrsig.signature[key_len:]
            sig = ecdsa.ecdsa.Signature(Crypto.Util.number.bytes_to_long(r),
                                        Crypto.Util.number.bytes_to_long(s))
        else:
            raise ValidationFailure, 'unknown algorithm %u' % rrsig.algorithm

        hash.update(_to_rdata(rrsig, origin)[:18])
        hash.update(rrsig.signer.to_digestable(origin))

        if rrsig.labels < len(rrname) - 1:
            suffix = rrname.split(rrsig.labels + 1)[1]
            rrname = name.from_text('*', suffix)
        rrnamebuf = rrname.to_digestable(origin)
        rrfixed = struct.pack('!HHI', rdataset.rdtype, rdataset.rdclass,
                              rrsig.original_ttl)
        rrlist = sorted(rdataset);
        for rr in rrlist:
            hash.update(rrnamebuf)

def __init__(self, privkey_bytes: bytes):
        assert_bytes(privkey_bytes)
        if len(privkey_bytes) != 32:
            raise Exception('unexpected size for secret. should be 32 bytes, not {}'.format(len(privkey_bytes)))
        secret = string_to_number(privkey_bytes)
        if not is_secret_within_curve_range(secret):
            raise InvalidECPointException('Invalid secret scalar (not within curve order)')
        self.secret_scalar = secret

        point = generator_secp256k1 * secret
        super().__init__(point_to_ser(point))
        self._privkey = ecdsa.ecdsa.Private_key(self._pubkey, secret)

def __init__( self, k ):
        secret = string_to_number(k)
        self.pubkey = ecdsa.ecdsa.Public_key( generator_secp256k1, generator_secp256k1 * secret )
        self.privkey = ecdsa.ecdsa.Private_key( self.pubkey, secret )
        self.secret = secret

"""Convert a public key in sec binary format to a public pair."""
    x = string_to_number(pubkey[1:33])
    sec0 = pubkey[:1]
    if sec0 not in (b'\2', b'\3'):
        raise Exception("Compressed pubkey expected")

    def public_pair_for_x(generator, x, is_even):
        curve = generator.curve()
        p = curve.p()
        alpha = (pow(x, 3, p) + curve.a() * x + curve.b()) % p
        beta = ecdsa.numbertheory.square_root_mod_prime(alpha, p)
        if is_even == bool(beta & 1):
            return (x, p - beta)
        return (x, beta)

    return public_pair_for_x(ecdsa.ecdsa.generator_secp256k1, x, is_even=(sec0 == b'\2'))

def undo_monkey_patching_of_python_ecdsa_internals_with_libsecp256k1():
    if not _libsecp256k1:
        return
    if not _patched_functions.prepared_to_patch:
        raise Exception("can't patch python-ecdsa without preparations")
    ecdsa.ecdsa.Private_key.sign      = _patched_functions.orig_sign
    ecdsa.ecdsa.Public_key.verifies   = _patched_functions.orig_verify
    ecdsa.ellipticcurve.Point.__mul__ = _patched_functions.orig_mul
    ecdsa.ellipticcurve.Point.__add__ = _patched_functions.orig_add

    _patched_functions.monkey_patching_active = False

sig = rrsig.signature[1:]
        elif _is_ecdsa(rrsig.algorithm):
            # use ecdsa for NIST-384p -- not currently supported by pycryptodome

            keyptr = candidate_key.key

            if rrsig.algorithm == ECDSAP256SHA256:
                curve = ecdsa.curves.NIST256p
                key_len = 32
            elif rrsig.algorithm == ECDSAP384SHA384:
                curve = ecdsa.curves.NIST384p
                key_len = 48

            x = number.bytes_to_long(keyptr[0:key_len])
            y = number.bytes_to_long(keyptr[key_len:key_len * 2])
            if not ecdsa.ecdsa.point_is_valid(curve.generator, x, y):
                raise ValidationFailure('invalid ECDSA key')
            point = ecdsa.ellipticcurve.Point(curve.curve, x, y, curve.order)
            verifying_key = ecdsa.keys.VerifyingKey.from_public_point(point,
                                                                      curve)
            pubkey = ECKeyWrapper(verifying_key, key_len)
            r = rrsig.signature[:key_len]
            s = rrsig.signature[key_len:]
            sig = ecdsa.ecdsa.Signature(number.bytes_to_long(r),
                                        number.bytes_to_long(s))

        else:
            raise ValidationFailure('unknown algorithm %u' % rrsig.algorithm)

        hash.update(_to_rdata(rrsig, origin)[:18])
        hash.update(rrsig.signer.to_digestable(origin))

def __init__(self, secret):
        self.pubkey = ecdsa.ecdsa.Public_key(generator_secp256k1,
                                             generator_secp256k1 * secret)
        self.privkey = ecdsa.ecdsa.Private_key(self.pubkey, secret)
        self.secret = secret

def decrypt_message(self, encrypted: Tuple[str, bytes], magic: bytes=b'BIE1') -> bytes:
        encrypted = base64.b64decode(encrypted)
        if len(encrypted) < 85:
            raise Exception('invalid ciphertext: length')
        magic_found = encrypted[:4]
        ephemeral_pubkey_bytes = encrypted[4:37]
        ciphertext = encrypted[37:-32]
        mac = encrypted[-32:]
        if magic_found != magic:
            raise Exception('invalid ciphertext: invalid magic bytes')
        try:
            ecdsa_point = _ser_to_python_ecdsa_point(ephemeral_pubkey_bytes)
        except AssertionError as e:
            raise Exception('invalid ciphertext: invalid ephemeral pubkey') from e
        if not ecdsa.ecdsa.point_is_valid(generator_secp256k1, ecdsa_point.x(), ecdsa_point.y()):
            raise Exception('invalid ciphertext: invalid ephemeral pubkey')
        ephemeral_pubkey = ECPubkey.from_point(ecdsa_point)
        ecdh_key = (ephemeral_pubkey * self.secret_scalar).get_public_key_bytes(compressed=True)
        key = hashlib.sha512(ecdh_key).digest()
        iv, key_e, key_m = key[0:16], key[16:32], key[32:]
        if mac != hmac_oneshot(key_m, encrypted[:-32], hashlib.sha256):
            raise InvalidPassword()
        return aes_decrypt_with_iv(key_e, iv, ciphertext)

def from_secret_exponent(klass, secexp, curve=NIST192p, hashfunc=sha1):
        self = klass(_error__please_use_generate=True)
        self.curve = curve
        self.default_hashfunc = hashfunc
        self.baselen = curve.baselen
        n = curve.order
        assert 1 <= secexp < n
        pubkey_point = curve.generator*secexp
        pubkey = ecdsa.Public_key(curve.generator, pubkey_point)
        pubkey.order = n
        self.verifying_key = VerifyingKey.from_public_point(pubkey_point, curve,
                                                            hashfunc)
        self.privkey = ecdsa.Private_key(pubkey, secexp)
        self.privkey.order = n
        return self