from typing import Dict, Optional, Tuple, Type, Union
import dns.name
from dns.dnssecalgs.base import GenericPrivateKey
from dns.dnssectypes import Algorithm
from dns.exception import UnsupportedAlgorithm
from dns.rdtypes.ANY.DNSKEY import DNSKEY
if dns._features.have("dnssec"):
from dns.dnssecalgs.dsa import PrivateDSA, PrivateDSANSEC3SHA1
from dns.dnssecalgs.ecdsa import PrivateECDSAP256SHA256, PrivateECDSAP384SHA384
from dns.dnssecalgs.eddsa import PrivateED448, PrivateED25519
from dns.dnssecalgs.rsa import (
PrivateRSAMD5,
PrivateRSASHA1,
PrivateRSASHA1NSEC3SHA1,
PrivateRSASHA256,
PrivateRSASHA512,
)
_have_cryptography = True
else:
_have_cryptography = False
AlgorithmPrefix = Optional[Union[bytes, dns.name.Name]]
algorithms: Dict[Tuple[Algorithm, AlgorithmPrefix], Type[GenericPrivateKey]] = {}
if _have_cryptography:
algorithms.update(
{
(Algorithm.RSAMD5, None): PrivateRSAMD5,
(Algorithm.DSA, None): PrivateDSA,
(Algorithm.RSASHA1, None): PrivateRSASHA1,
(Algorithm.DSANSEC3SHA1, None): PrivateDSANSEC3SHA1,
(Algorithm.RSASHA1NSEC3SHA1, None): PrivateRSASHA1NSEC3SHA1,
(Algorithm.RSASHA256, None): PrivateRSASHA256,
(Algorithm.RSASHA512, None): PrivateRSASHA512,
(Algorithm.ECDSAP256SHA256, None): PrivateECDSAP256SHA256,
(Algorithm.ECDSAP384SHA384, None): PrivateECDSAP384SHA384,
(Algorithm.ED25519, None): PrivateED25519,
(Algorithm.ED448, None): PrivateED448,
}
)
def get_algorithm_cls(
algorithm: Union[int, str], prefix: AlgorithmPrefix = None
) -> Type[GenericPrivateKey]:
"""Get Private Key class from Algorithm.
*algorithm*, a ``str`` or ``int`` specifying the DNSKEY algorithm.
Raises ``UnsupportedAlgorithm`` if the algorithm is unknown.
Returns a ``dns.dnssecalgs.GenericPrivateKey``
"""
algorithm = Algorithm.make(algorithm)
cls = algorithms.get((algorithm, prefix))
if cls:
return cls
raise UnsupportedAlgorithm(
'algorithm "%s" not supported by dnspython' % Algorithm.to_text(algorithm)
)
def get_algorithm_cls_from_dnskey(dnskey: DNSKEY) -> Type[GenericPrivateKey]:
"""Get Private Key class from DNSKEY.
*dnskey*, a ``DNSKEY`` to get Algorithm class for.
Raises ``UnsupportedAlgorithm`` if the algorithm is unknown.
Returns a ``dns.dnssecalgs.GenericPrivateKey``
"""
prefix: AlgorithmPrefix = None
if dnskey.algorithm == Algorithm.PRIVATEDNS:
prefix, _ = dns.name.from_wire(dnskey.key, 0)
elif dnskey.algorithm == Algorithm.PRIVATEOID:
length = int(dnskey.key[0])
prefix = dnskey.key[0 : length + 1]
return get_algorithm_cls(dnskey.algorithm, prefix)
def register_algorithm_cls(
algorithm: Union[int, str],
algorithm_cls: Type[GenericPrivateKey],
name: Optional[Union[dns.name.Name, str]] = None,
oid: Optional[bytes] = None,
) -> None:
"""Register Algorithm Private Key class.
*algorithm*, a ``str`` or ``int`` specifying the DNSKEY algorithm.
*algorithm_cls*: A `GenericPrivateKey` class.
*name*, an optional ``dns.name.Name`` or ``str``, for for PRIVATEDNS algorithms.
*oid*: an optional BER-encoded `bytes` for PRIVATEOID algorithms.
Raises ``ValueError`` if a name or oid is specified incorrectly.
"""
if not issubclass(algorithm_cls, GenericPrivateKey):
raise TypeError("Invalid algorithm class")
algorithm = Algorithm.make(algorithm)
prefix: AlgorithmPrefix = None
if algorithm == Algorithm.PRIVATEDNS:
if name is None:
raise ValueError("Name required for PRIVATEDNS algorithms")
if isinstance(name, str):
name = dns.name.from_text(name)
prefix = name
elif algorithm == Algorithm.PRIVATEOID:
if oid is None:
raise ValueError("OID required for PRIVATEOID algorithms")
prefix = bytes([len(oid)]) + oid
elif name:
raise ValueError("Name only supported for PRIVATEDNS algorithm")
elif oid:
raise ValueError("OID only supported for PRIVATEOID algorithm")
algorithms[(algorithm, prefix)] = algorithm_cls
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