# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license # Copyright (C) 2003-2017 Nominum, Inc. # # Permission to use, copy, modify, and distribute this software and its # documentation for any purpose with or without fee is hereby granted, # provided that the above copyright notice and this permission notice # appear in all copies. # # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. """Common DNSSEC-related functions and constants.""" import base64 import contextlib import functools import hashlib import struct import time from datetime import datetime from typing import Callable, Dict, List, Optional, Set, Tuple, Union, cast import dns._features import dns.exception import dns.name import dns.node import dns.rdata import dns.rdataclass import dns.rdataset import dns.rdatatype import dns.rrset import dns.transaction import dns.zone from dns.dnssectypes import Algorithm, DSDigest, NSEC3Hash from dns.exception import ( # pylint: disable=W0611 AlgorithmKeyMismatch, DeniedByPolicy, UnsupportedAlgorithm, ValidationFailure, ) from dns.rdtypes.ANY.CDNSKEY import CDNSKEY from dns.rdtypes.ANY.CDS import CDS from dns.rdtypes.ANY.DNSKEY import DNSKEY from dns.rdtypes.ANY.DS import DS from dns.rdtypes.ANY.NSEC import NSEC, Bitmap from dns.rdtypes.ANY.NSEC3PARAM import NSEC3PARAM from dns.rdtypes.ANY.RRSIG import RRSIG, sigtime_to_posixtime from dns.rdtypes.dnskeybase import Flag PublicKey = Union[ "GenericPublicKey", "rsa.RSAPublicKey", "ec.EllipticCurvePublicKey", "ed25519.Ed25519PublicKey", "ed448.Ed448PublicKey", ] PrivateKey = Union[ "GenericPrivateKey", "rsa.RSAPrivateKey", "ec.EllipticCurvePrivateKey", "ed25519.Ed25519PrivateKey", "ed448.Ed448PrivateKey", ] RRsetSigner = Callable[[dns.transaction.Transaction, dns.rrset.RRset], None] def algorithm_from_text(text: str) -> Algorithm: """Convert text into a DNSSEC algorithm value. *text*, a ``str``, the text to convert to into an algorithm value. Returns an ``int``. """ return Algorithm.from_text(text) def algorithm_to_text(value: Union[Algorithm, int]) -> str: """Convert a DNSSEC algorithm value to text *value*, a ``dns.dnssec.Algorithm``. Returns a ``str``, the name of a DNSSEC algorithm. """ return Algorithm.to_text(value) def to_timestamp(value: Union[datetime, str, float, int]) -> int: """Convert various format to a timestamp""" if isinstance(value, datetime): return int(value.timestamp()) elif isinstance(value, str): return sigtime_to_posixtime(value) elif isinstance(value, float): return int(value) elif isinstance(value, int): return value else: raise TypeError("Unsupported timestamp type") def key_id(key: Union[DNSKEY, CDNSKEY]) -> int: """Return the key id (a 16-bit number) for the specified key. *key*, a ``dns.rdtypes.ANY.DNSKEY.DNSKEY`` Returns an ``int`` between 0 and 65535 """ rdata = key.to_wire() if key.algorithm == Algorithm.RSAMD5: return (rdata[-3] << 8) + rdata[-2] else: total = 0 for i in range(len(rdata) // 2): total += (rdata[2 * i] << 8) + rdata[2 * i + 1] if len(rdata) % 2 != 0: total += rdata[len(rdata) - 1] << 8 total += (total >> 16) & 0xFFFF return total & 0xFFFF class Policy: def __init__(self): pass def ok_to_sign(self, _: DNSKEY) -> bool: # pragma: no cover return False def ok_to_validate(self, _: DNSKEY) -> bool: # pragma: no cover return False def ok_to_create_ds(self, _: DSDigest) -> bool: # pragma: no cover return False def ok_to_validate_ds(self, _: DSDigest) -> bool: # pragma: no cover return False class SimpleDeny(Policy): def __init__(self, deny_sign, deny_validate, deny_create_ds, deny_validate_ds): super().__init__() self._deny_sign = deny_sign self._deny_validate = deny_validate self._deny_create_ds = deny_create_ds self._deny_validate_ds = deny_validate_ds def ok_to_sign(self, key: DNSKEY) -> bool: return key.algorithm not in self._deny_sign def ok_to_validate(self, key: DNSKEY) -> bool: return key.algorithm not in self._deny_validate def ok_to_create_ds(self, algorithm: DSDigest) -> bool: return algorithm not in self._deny_create_ds def ok_to_validate_ds(self, algorithm: DSDigest) -> bool: return algorithm not in self._deny_validate_ds rfc_8624_policy = SimpleDeny( {Algorithm.RSAMD5, Algorithm.DSA, Algorithm.DSANSEC3SHA1, Algorithm.ECCGOST}, {Algorithm.RSAMD5, Algorithm.DSA, Algorithm.DSANSEC3SHA1}, {DSDigest.NULL, DSDigest.SHA1, DSDigest.GOST}, {DSDigest.NULL}, ) allow_all_policy = SimpleDeny(set(), set(), set(), set()) default_policy = rfc_8624_policy def make_ds( name: Union[dns.name.Name, str], key: dns.rdata.Rdata, algorithm: Union[DSDigest, str], origin: Optional[dns.name.Name] = None, policy: Optional[Policy] = None, validating: bool = False, ) -> DS: """Create a DS record for a DNSSEC key. *name*, a ``dns.name.Name`` or ``str``, the owner name of the DS record. *key*, a ``dns.rdtypes.ANY.DNSKEY.DNSKEY`` or ``dns.rdtypes.ANY.DNSKEY.CDNSKEY``, the key the DS is about. *algorithm*, a ``str`` or ``int`` specifying the hash algorithm. The currently supported hashes are "SHA1", "SHA256", and "SHA384". Case does not matter for these strings. *origin*, a ``dns.name.Name`` or ``None``. If *key* is a relative name, then it will be made absolute using the specified origin. *policy*, a ``dns.dnssec.Policy`` or ``None``. If ``None``, the default policy, ``dns.dnssec.default_policy`` is used; this policy defaults to that of RFC 8624. *validating*, a ``bool``. If ``True``, then policy is checked in validating mode, i.e. "Is it ok to validate using this digest algorithm?". Otherwise the policy is checked in creating mode, i.e. "Is it ok to create a DS with this digest algorithm?". Raises ``UnsupportedAlgorithm`` if the algorithm is unknown. Raises ``DeniedByPolicy`` if the algorithm is denied by policy. Returns a ``dns.rdtypes.ANY.DS.DS`` """ if policy is None: policy = default_policy try: if isinstance(algorithm, str): algorithm = DSDigest[algorithm.upper()] except Exception: raise UnsupportedAlgorithm('unsupported algorithm "%s"' % algorithm) if validating: check = policy.ok_to_validate_ds else: check = policy.ok_to_create_ds if not check(algorithm): raise DeniedByPolicy if not isinstance(key, (DNSKEY, CDNSKEY)): raise ValueError("key is not a DNSKEY/CDNSKEY") if algorithm == DSDigest.SHA1: dshash = hashlib.sha1() elif algorithm == DSDigest.SHA256: dshash = hashlib.sha256() elif algorithm == DSDigest.SHA384: dshash = hashlib.sha384() else: raise UnsupportedAlgorithm('unsupported algorithm "%s"' % algorithm) if isinstance(name, str): name = dns.name.from_text(name, origin) wire = name.canonicalize().to_wire() assert wire is not None dshash.update(wire) dshash.update(key.to_wire(origin=origin)) digest = dshash.digest() dsrdata = struct.pack("!HBB", key_id(key), key.algorithm, algorithm) + digest ds = dns.rdata.from_wire( dns.rdataclass.IN, dns.rdatatype.DS, dsrdata, 0, len(dsrdata) ) return cast(DS, ds) def make_cds( name: Union[dns.name.Name, str], key: dns.rdata.Rdata, algorithm: Union[DSDigest, str], origin: Optional[dns.name.Name] = None, ) -> CDS: """Create a CDS record for a DNSSEC key. *name*, a ``dns.name.Name`` or ``str``, the owner name of the DS record. *key*, a ``dns.rdtypes.ANY.DNSKEY.DNSKEY`` or ``dns.rdtypes.ANY.DNSKEY.CDNSKEY``, the key the DS is about. *algorithm*, a ``str`` or ``int`` specifying the hash algorithm. The currently supported hashes are "SHA1", "SHA256", and "SHA384". Case does not matter for these strings. *origin*, a ``dns.name.Name`` or ``None``. If *key* is a relative name, then it will be made absolute using the specified origin. Raises ``UnsupportedAlgorithm`` if the algorithm is unknown. Returns a ``dns.rdtypes.ANY.DS.CDS`` """ ds = make_ds(name, key, algorithm, origin) return CDS( rdclass=ds.rdclass, rdtype=dns.rdatatype.CDS, key_tag=ds.key_tag, algorithm=ds.algorithm, digest_type=ds.digest_type, digest=ds.digest, ) def _find_candidate_keys( keys: Dict[dns.name.Name, Union[dns.rdataset.Rdataset, dns.node.Node]], rrsig: RRSIG ) -> Optional[List[DNSKEY]]: value = keys.get(rrsig.signer) if isinstance(value, dns.node.Node): rdataset = value.get_rdataset(dns.rdataclass.IN, dns.rdatatype.DNSKEY) else: rdataset = value if rdataset is None: return None return [ cast(DNSKEY, rd) for rd in rdataset if rd.algorithm == rrsig.algorithm and key_id(rd) == rrsig.key_tag and (rd.flags & Flag.ZONE) == Flag.ZONE # RFC 4034 2.1.1 and rd.protocol == 3 # RFC 4034 2.1.2 ] def _get_rrname_rdataset( rrset: Union[dns.rrset.RRset, Tuple[dns.name.Name, dns.rdataset.Rdataset]], ) -> Tuple[dns.name.Name, dns.rdataset.Rdataset]: if isinstance(rrset, tuple): return rrset[0], rrset[1] else: return rrset.name, rrset def _validate_signature(sig: bytes, data: bytes, key: DNSKEY) -> None: public_cls = get_algorithm_cls_from_dnskey(key).public_cls try: public_key = public_cls.from_dnskey(key) except ValueError: raise ValidationFailure("invalid public key") public_key.verify(sig, data) def _validate_rrsig( rrset: Union[dns.rrset.RRset, Tuple[dns.name.Name, dns.rdataset.Rdataset]], rrsig: RRSIG, keys: Dict[dns.name.Name, Union[dns.node.Node, dns.rdataset.Rdataset]], origin: Optional[dns.name.Name] = None, now: Optional[float] = None, policy: Optional[Policy] = None, ) -> None: """Validate an RRset against a single signature rdata, throwing an exception if validation is not successful. *rrset*, the RRset to validate. This can be a ``dns.rrset.RRset`` or a (``dns.name.Name``, ``dns.rdataset.Rdataset``) tuple. *rrsig*, a ``dns.rdata.Rdata``, the signature to validate. *keys*, the key dictionary, used to find the DNSKEY associated with a given name. The dictionary is keyed by a ``dns.name.Name``, and has ``dns.node.Node`` or ``dns.rdataset.Rdataset`` values. *origin*, a ``dns.name.Name`` or ``None``, the origin to use for relative names. *now*, a ``float`` or ``None``, the time, in seconds since the epoch, to use as the current time when validating. If ``None``, the actual current time is used. *policy*, a ``dns.dnssec.Policy`` or ``None``. If ``None``, the default policy, ``dns.dnssec.default_policy`` is used; this policy defaults to that of RFC 8624. Raises ``ValidationFailure`` if the signature is expired, not yet valid, the public key is invalid, the algorithm is unknown, the verification fails, etc. Raises ``UnsupportedAlgorithm`` if the algorithm is recognized by dnspython but not implemented. """ if policy is None: policy = default_policy candidate_keys = _find_candidate_keys(keys, rrsig) if candidate_keys is None: raise ValidationFailure("unknown key") if now is None: now = time.time() if rrsig.expiration < now: raise ValidationFailure("expired") if rrsig.inception > now: raise ValidationFailure("not yet valid") data = _make_rrsig_signature_data(rrset, rrsig, origin) for candidate_key in candidate_keys: if not policy.ok_to_validate(candidate_key): continue try: _validate_signature(rrsig.signature, data, candidate_key) return except (InvalidSignature, ValidationFailure): # this happens on an individual validation failure continue # nothing verified -- raise failure: raise ValidationFailure("verify failure") def _validate( rrset: Union[dns.rrset.RRset, Tuple[dns.name.Name, dns.rdataset.Rdataset]], rrsigset: Union[dns.rrset.RRset, Tuple[dns.name.Name, dns.rdataset.Rdataset]], keys: Dict[dns.name.Name, Union[dns.node.Node, dns.rdataset.Rdataset]], origin: Optional[dns.name.Name] = None, now: Optional[float] = None, policy: Optional[Policy] = None, ) -> None: """Validate an RRset against a signature RRset, throwing an exception if none of the signatures validate. *rrset*, the RRset to validate. This can be a ``dns.rrset.RRset`` or a (``dns.name.Name``, ``dns.rdataset.Rdataset``) tuple. *rrsigset*, the signature RRset. This can be a ``dns.rrset.RRset`` or a (``dns.name.Name``, ``dns.rdataset.Rdataset``) tuple. *keys*, the key dictionary, used to find the DNSKEY associated with a given name. The dictionary is keyed by a ``dns.name.Name``, and has ``dns.node.Node`` or ``dns.rdataset.Rdataset`` values. *origin*, a ``dns.name.Name``, the origin to use for relative names; defaults to None. *now*, an ``int`` or ``None``, the time, in seconds since the epoch, to use as the current time when validating. If ``None``, the actual current time is used. *policy*, a ``dns.dnssec.Policy`` or ``None``. If ``None``, the default policy, ``dns.dnssec.default_policy`` is used; this policy defaults to that of RFC 8624. Raises ``ValidationFailure`` if the signature is expired, not yet valid, the public key is invalid, the algorithm is unknown, the verification fails, etc. """ if policy is None: policy = default_policy if isinstance(origin, str): origin = dns.name.from_text(origin, dns.name.root) if isinstance(rrset, tuple): rrname = rrset[0] else: rrname = rrset.name if isinstance(rrsigset, tuple): rrsigname = rrsigset[0] rrsigrdataset = rrsigset[1] else: rrsigname = rrsigset.name rrsigrdataset = rrsigset rrname = rrname.choose_relativity(origin) rrsigname = rrsigname.choose_relativity(origin) if rrname != rrsigname: raise ValidationFailure("owner names do not match") for rrsig in rrsigrdataset: if not isinstance(rrsig, RRSIG): raise ValidationFailure("expected an RRSIG") try: _validate_rrsig(rrset, rrsig, keys, origin, now, policy) return except (ValidationFailure, UnsupportedAlgorithm): pass raise ValidationFailure("no RRSIGs validated") def _sign( rrset: Union[dns.rrset.RRset, Tuple[dns.name.Name, dns.rdataset.Rdataset]], private_key: PrivateKey, signer: dns.name.Name, dnskey: DNSKEY, inception: Optional[Union[datetime, str, int, float]] = None, expiration: Optional[Union[datetime, str, int, float]] = None, lifetime: Optional[int] = None, verify: bool = False, policy: Optional[Policy] = None, origin: Optional[dns.name.Name] = None, ) -> RRSIG: """Sign RRset using private key. *rrset*, the RRset to validate. This can be a ``dns.rrset.RRset`` or a (``dns.name.Name``, ``dns.rdataset.Rdataset``) tuple. *private_key*, the private key to use for signing, a ``cryptography.hazmat.primitives.asymmetric`` private key class applicable for DNSSEC. *signer*, a ``dns.name.Name``, the Signer's name. *dnskey*, a ``DNSKEY`` matching ``private_key``. *inception*, a ``datetime``, ``str``, ``int``, ``float`` or ``None``, the signature inception time. If ``None``, the current time is used. If a ``str``, the format is "YYYYMMDDHHMMSS" or alternatively the number of seconds since the UNIX epoch in text form; this is the same the RRSIG rdata's text form. Values of type `int` or `float` are interpreted as seconds since the UNIX epoch. *expiration*, a ``datetime``, ``str``, ``int``, ``float`` or ``None``, the signature expiration time. If ``None``, the expiration time will be the inception time plus the value of the *lifetime* parameter. See the description of *inception* above for how the various parameter types are interpreted. *lifetime*, an ``int`` or ``None``, the signature lifetime in seconds. This parameter is only meaningful if *expiration* is ``None``. *verify*, a ``bool``. If set to ``True``, the signer will verify signatures after they are created; the default is ``False``. *policy*, a ``dns.dnssec.Policy`` or ``None``. If ``None``, the default policy, ``dns.dnssec.default_policy`` is used; this policy defaults to that of RFC 8624. *origin*, a ``dns.name.Name`` or ``None``. If ``None``, the default, then all names in the rrset (including its owner name) must be absolute; otherwise the specified origin will be used to make names absolute when signing. Raises ``DeniedByPolicy`` if the signature is denied by policy. """ if policy is None: policy = default_policy if not policy.ok_to_sign(dnskey): raise DeniedByPolicy if isinstance(rrset, tuple): rdclass = rrset[1].rdclass rdtype = rrset[1].rdtype rrname = rrset[0] original_ttl = rrset[1].ttl else: rdclass = rrset.rdclass rdtype = rrset.rdtype rrname = rrset.name original_ttl = rrset.ttl if inception is not None: rrsig_inception = to_timestamp(inception) else: rrsig_inception = int(time.time()) if expiration is not None: rrsig_expiration = to_timestamp(expiration) elif lifetime is not None: rrsig_expiration = rrsig_inception + lifetime else: raise ValueError("expiration or lifetime must be specified") # Derelativize now because we need a correct labels length for the # rrsig_template. if origin is not None: rrname = rrname.derelativize(origin) labels = len(rrname) - 1 # Adjust labels appropriately for wildcards. if rrname.is_wild(): labels -= 1 rrsig_template = RRSIG( rdclass=rdclass, rdtype=dns.rdatatype.RRSIG, type_covered=rdtype, algorithm=dnskey.algorithm, labels=labels, original_ttl=original_ttl, expiration=rrsig_expiration, inception=rrsig_inception, key_tag=key_id(dnskey), signer=signer, signature=b"", ) data = dns.dnssec._make_rrsig_signature_data(rrset, rrsig_template, origin) if isinstance(private_key, GenericPrivateKey): signing_key = private_key else: try: private_cls = get_algorithm_cls_from_dnskey(dnskey) signing_key = private_cls(key=private_key) except UnsupportedAlgorithm: raise TypeError("Unsupported key algorithm") signature = signing_key.sign(data, verify) return cast(RRSIG, rrsig_template.replace(signature=signature)) def _make_rrsig_signature_data( rrset: Union[dns.rrset.RRset, Tuple[dns.name.Name, dns.rdataset.Rdataset]], rrsig: RRSIG, origin: Optional[dns.name.Name] = None, ) -> bytes: """Create signature rdata. *rrset*, the RRset to sign/validate. This can be a ``dns.rrset.RRset`` or a (``dns.name.Name``, ``dns.rdataset.Rdataset``) tuple. *rrsig*, a ``dns.rdata.Rdata``, the signature to validate, or the signature template used when signing. *origin*, a ``dns.name.Name`` or ``None``, the origin to use for relative names. Raises ``UnsupportedAlgorithm`` if the algorithm is recognized by dnspython but not implemented. """ if isinstance(origin, str): origin = dns.name.from_text(origin, dns.name.root) signer = rrsig.signer if not signer.is_absolute(): if origin is None: raise ValidationFailure("relative RR name without an origin specified") signer = signer.derelativize(origin) # For convenience, allow the rrset to be specified as a (name, # rdataset) tuple as well as a proper rrset rrname, rdataset = _get_rrname_rdataset(rrset) data = b"" data += rrsig.to_wire(origin=signer)[:18] data += rrsig.signer.to_digestable(signer) # Derelativize the name before considering labels. if not rrname.is_absolute(): if origin is None: raise ValidationFailure("relative RR name without an origin specified") rrname = rrname.derelativize(origin) name_len = len(rrname) if rrname.is_wild() and rrsig.labels != name_len - 2: raise ValidationFailure("wild owner name has wrong label length") if name_len - 1 < rrsig.labels: raise ValidationFailure("owner name longer than RRSIG labels") elif rrsig.labels < name_len - 1: suffix = rrname.split(rrsig.labels + 1)[1] rrname = dns.name.from_text("*", suffix) rrnamebuf = rrname.to_digestable() rrfixed = struct.pack("!HHI", rdataset.rdtype, rdataset.rdclass, rrsig.original_ttl) rdatas = [rdata.to_digestable(origin) for rdata in rdataset] for rdata in sorted(rdatas): data += rrnamebuf data += rrfixed rrlen = struct.pack("!H", len(rdata)) data += rrlen data += rdata return data def _make_dnskey( public_key: PublicKey, algorithm: Union[int, str], flags: int = Flag.ZONE, protocol: int = 3, ) -> DNSKEY: """Convert a public key to DNSKEY Rdata *public_key*, a ``PublicKey`` (``GenericPublicKey`` or ``cryptography.hazmat.primitives.asymmetric``) to convert. *algorithm*, a ``str`` or ``int`` specifying the DNSKEY algorithm. *flags*: DNSKEY flags field as an integer. *protocol*: DNSKEY protocol field as an integer. Raises ``ValueError`` if the specified key algorithm parameters are not unsupported, ``TypeError`` if the key type is unsupported, `UnsupportedAlgorithm` if the algorithm is unknown and `AlgorithmKeyMismatch` if the algorithm does not match the key type. Return DNSKEY ``Rdata``. """ algorithm = Algorithm.make(algorithm) if isinstance(public_key, GenericPublicKey): return public_key.to_dnskey(flags=flags, protocol=protocol) else: public_cls = get_algorithm_cls(algorithm).public_cls return public_cls(key=public_key).to_dnskey(flags=flags, protocol=protocol) def _make_cdnskey( public_key: PublicKey, algorithm: Union[int, str], flags: int = Flag.ZONE, protocol: int = 3, ) -> CDNSKEY: """Convert a public key to CDNSKEY Rdata *public_key*, the public key to convert, a ``cryptography.hazmat.primitives.asymmetric`` public key class applicable for DNSSEC. *algorithm*, a ``str`` or ``int`` specifying the DNSKEY algorithm. *flags*: DNSKEY flags field as an integer. *protocol*: DNSKEY protocol field as an integer. Raises ``ValueError`` if the specified key algorithm parameters are not unsupported, ``TypeError`` if the key type is unsupported, `UnsupportedAlgorithm` if the algorithm is unknown and `AlgorithmKeyMismatch` if the algorithm does not match the key type. Return CDNSKEY ``Rdata``. """ dnskey = _make_dnskey(public_key, algorithm, flags, protocol) return CDNSKEY( rdclass=dnskey.rdclass, rdtype=dns.rdatatype.CDNSKEY, flags=dnskey.flags, protocol=dnskey.protocol, algorithm=dnskey.algorithm, key=dnskey.key, ) def nsec3_hash( domain: Union[dns.name.Name, str], salt: Optional[Union[str, bytes]], iterations: int, algorithm: Union[int, str], ) -> str: """ Calculate the NSEC3 hash, according to https://tools.ietf.org/html/rfc5155#section-5 *domain*, a ``dns.name.Name`` or ``str``, the name to hash. *salt*, a ``str``, ``bytes``, or ``None``, the hash salt. If a string, it is decoded as a hex string. *iterations*, an ``int``, the number of iterations. *algorithm*, a ``str`` or ``int``, the hash algorithm. The only defined algorithm is SHA1. Returns a ``str``, the encoded NSEC3 hash. """ b32_conversion = str.maketrans( "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567", "0123456789ABCDEFGHIJKLMNOPQRSTUV" ) try: if isinstance(algorithm, str): algorithm = NSEC3Hash[algorithm.upper()] except Exception: raise ValueError("Wrong hash algorithm (only SHA1 is supported)") if algorithm != NSEC3Hash.SHA1: raise ValueError("Wrong hash algorithm (only SHA1 is supported)") if salt is None: salt_encoded = b"" elif isinstance(salt, str): if len(salt) % 2 == 0: salt_encoded = bytes.fromhex(salt) else: raise ValueError("Invalid salt length") else: salt_encoded = salt if not isinstance(domain, dns.name.Name): domain = dns.name.from_text(domain) domain_encoded = domain.canonicalize().to_wire() assert domain_encoded is not None digest = hashlib.sha1(domain_encoded + salt_encoded).digest() for _ in range(iterations): digest = hashlib.sha1(digest + salt_encoded).digest() output = base64.b32encode(digest).decode("utf-8") output = output.translate(b32_conversion) return output def make_ds_rdataset( rrset: Union[dns.rrset.RRset, Tuple[dns.name.Name, dns.rdataset.Rdataset]], algorithms: Set[Union[DSDigest, str]], origin: Optional[dns.name.Name] = None, ) -> dns.rdataset.Rdataset: """Create a DS record from DNSKEY/CDNSKEY/CDS. *rrset*, the RRset to create DS Rdataset for. This can be a ``dns.rrset.RRset`` or a (``dns.name.Name``, ``dns.rdataset.Rdataset``) tuple. *algorithms*, a set of ``str`` or ``int`` specifying the hash algorithms. The currently supported hashes are "SHA1", "SHA256", and "SHA384". Case does not matter for these strings. If the RRset is a CDS, only digest algorithms matching algorithms are accepted. *origin*, a ``dns.name.Name`` or ``None``. If `key` is a relative name, then it will be made absolute using the specified origin. Raises ``UnsupportedAlgorithm`` if any of the algorithms are unknown and ``ValueError`` if the given RRset is not usable. Returns a ``dns.rdataset.Rdataset`` """ rrname, rdataset = _get_rrname_rdataset(rrset) if rdataset.rdtype not in ( dns.rdatatype.DNSKEY, dns.rdatatype.CDNSKEY, dns.rdatatype.CDS, ): raise ValueError("rrset not a DNSKEY/CDNSKEY/CDS") _algorithms = set() for algorithm in algorithms: try: if isinstance(algorithm, str): algorithm = DSDigest[algorithm.upper()] except Exception: raise UnsupportedAlgorithm('unsupported algorithm "%s"' % algorithm) _algorithms.add(algorithm) if rdataset.rdtype == dns.rdatatype.CDS: res = [] for rdata in cds_rdataset_to_ds_rdataset(rdataset): if rdata.digest_type in _algorithms: res.append(rdata) if len(res) == 0: raise ValueError("no acceptable CDS rdata found") return dns.rdataset.from_rdata_list(rdataset.ttl, res) res = [] for algorithm in _algorithms: res.extend(dnskey_rdataset_to_cds_rdataset(rrname, rdataset, algorithm, origin)) return dns.rdataset.from_rdata_list(rdataset.ttl, res) def cds_rdataset_to_ds_rdataset( rdataset: dns.rdataset.Rdataset, ) -> dns.rdataset.Rdataset: """Create a CDS record from DS. *rdataset*, a ``dns.rdataset.Rdataset``, to create DS Rdataset for. Raises ``ValueError`` if the rdataset is not CDS. Returns a ``dns.rdataset.Rdataset`` """ if rdataset.rdtype != dns.rdatatype.CDS: raise ValueError("rdataset not a CDS") res = [] for rdata in rdataset: res.append( CDS( rdclass=rdata.rdclass, rdtype=dns.rdatatype.DS, key_tag=rdata.key_tag, algorithm=rdata.algorithm, digest_type=rdata.digest_type, digest=rdata.digest, ) ) return dns.rdataset.from_rdata_list(rdataset.ttl, res) def dnskey_rdataset_to_cds_rdataset( name: Union[dns.name.Name, str], rdataset: dns.rdataset.Rdataset, algorithm: Union[DSDigest, str], origin: Optional[dns.name.Name] = None, ) -> dns.rdataset.Rdataset: """Create a CDS record from DNSKEY/CDNSKEY. *name*, a ``dns.name.Name`` or ``str``, the owner name of the CDS record. *rdataset*, a ``dns.rdataset.Rdataset``, to create DS Rdataset for. *algorithm*, a ``str`` or ``int`` specifying the hash algorithm. The currently supported hashes are "SHA1", "SHA256", and "SHA384". Case does not matter for these strings. *origin*, a ``dns.name.Name`` or ``None``. If `key` is a relative name, then it will be made absolute using the specified origin. Raises ``UnsupportedAlgorithm`` if the algorithm is unknown or ``ValueError`` if the rdataset is not DNSKEY/CDNSKEY. Returns a ``dns.rdataset.Rdataset`` """ if rdataset.rdtype not in (dns.rdatatype.DNSKEY, dns.rdatatype.CDNSKEY): raise ValueError("rdataset not a DNSKEY/CDNSKEY") res = [] for rdata in rdataset: res.append(make_cds(name, rdata, algorithm, origin)) return dns.rdataset.from_rdata_list(rdataset.ttl, res) def dnskey_rdataset_to_cdnskey_rdataset( rdataset: dns.rdataset.Rdataset, ) -> dns.rdataset.Rdataset: """Create a CDNSKEY record from DNSKEY. *rdataset*, a ``dns.rdataset.Rdataset``, to create CDNSKEY Rdataset for. Returns a ``dns.rdataset.Rdataset`` """ if rdataset.rdtype != dns.rdatatype.DNSKEY: raise ValueError("rdataset not a DNSKEY") res = [] for rdata in rdataset: res.append( CDNSKEY( rdclass=rdataset.rdclass, rdtype=rdataset.rdtype, flags=rdata.flags, protocol=rdata.protocol, algorithm=rdata.algorithm, key=rdata.key, ) ) return dns.rdataset.from_rdata_list(rdataset.ttl, res) def default_rrset_signer( txn: dns.transaction.Transaction, rrset: dns.rrset.RRset, signer: dns.name.Name, ksks: List[Tuple[PrivateKey, DNSKEY]], zsks: List[Tuple[PrivateKey, DNSKEY]], inception: Optional[Union[datetime, str, int, float]] = None, expiration: Optional[Union[datetime, str, int, float]] = None, lifetime: Optional[int] = None, policy: Optional[Policy] = None, origin: Optional[dns.name.Name] = None, ) -> None: """Default RRset signer""" if rrset.rdtype in set( [ dns.rdatatype.RdataType.DNSKEY, dns.rdatatype.RdataType.CDS, dns.rdatatype.RdataType.CDNSKEY, ] ): keys = ksks else: keys = zsks for private_key, dnskey in keys: rrsig = dns.dnssec.sign( rrset=rrset, private_key=private_key, dnskey=dnskey, inception=inception, expiration=expiration, lifetime=lifetime, signer=signer, policy=policy, origin=origin, ) txn.add(rrset.name, rrset.ttl, rrsig) def sign_zone( zone: dns.zone.Zone, txn: Optional[dns.transaction.Transaction] = None, keys: Optional[List[Tuple[PrivateKey, DNSKEY]]] = None, add_dnskey: bool = True, dnskey_ttl: Optional[int] = None, inception: Optional[Union[datetime, str, int, float]] = None, expiration: Optional[Union[datetime, str, int, float]] = None, lifetime: Optional[int] = None, nsec3: Optional[NSEC3PARAM] = None, rrset_signer: Optional[RRsetSigner] = None, policy: Optional[Policy] = None, ) -> None: """Sign zone. *zone*, a ``dns.zone.Zone``, the zone to sign. *txn*, a ``dns.transaction.Transaction``, an optional transaction to use for signing. *keys*, a list of (``PrivateKey``, ``DNSKEY``) tuples, to use for signing. KSK/ZSK roles are assigned automatically if the SEP flag is used, otherwise all RRsets are signed by all keys. *add_dnskey*, a ``bool``. If ``True``, the default, all specified DNSKEYs are automatically added to the zone on signing. *dnskey_ttl*, a``int``, specifies the TTL for DNSKEY RRs. If not specified the TTL of the existing DNSKEY RRset used or the TTL of the SOA RRset. *inception*, a ``datetime``, ``str``, ``int``, ``float`` or ``None``, the signature inception time. If ``None``, the current time is used. If a ``str``, the format is "YYYYMMDDHHMMSS" or alternatively the number of seconds since the UNIX epoch in text form; this is the same the RRSIG rdata's text form. Values of type `int` or `float` are interpreted as seconds since the UNIX epoch. *expiration*, a ``datetime``, ``str``, ``int``, ``float`` or ``None``, the signature expiration time. If ``None``, the expiration time will be the inception time plus the value of the *lifetime* parameter. See the description of *inception* above for how the various parameter types are interpreted. *lifetime*, an ``int`` or ``None``, the signature lifetime in seconds. This parameter is only meaningful if *expiration* is ``None``. *nsec3*, a ``NSEC3PARAM`` Rdata, configures signing using NSEC3. Not yet implemented. *rrset_signer*, a ``Callable``, an optional function for signing RRsets. The function requires two arguments: transaction and RRset. If the not specified, ``dns.dnssec.default_rrset_signer`` will be used. Returns ``None``. """ ksks = [] zsks = [] # if we have both KSKs and ZSKs, split by SEP flag. if not, sign all # records with all keys if keys: for key in keys: if key[1].flags & Flag.SEP: ksks.append(key) else: zsks.append(key) if not ksks: ksks = keys if not zsks: zsks = keys else: keys = [] if txn: cm: contextlib.AbstractContextManager = contextlib.nullcontext(txn) else: cm = zone.writer() with cm as _txn: if add_dnskey: if dnskey_ttl is None: dnskey = _txn.get(zone.origin, dns.rdatatype.DNSKEY) if dnskey: dnskey_ttl = dnskey.ttl else: soa = _txn.get(zone.origin, dns.rdatatype.SOA) dnskey_ttl = soa.ttl for _, dnskey in keys: _txn.add(zone.origin, dnskey_ttl, dnskey) if nsec3: raise NotImplementedError("Signing with NSEC3 not yet implemented") else: _rrset_signer = rrset_signer or functools.partial( default_rrset_signer, signer=zone.origin, ksks=ksks, zsks=zsks, inception=inception, expiration=expiration, lifetime=lifetime, policy=policy, origin=zone.origin, ) return _sign_zone_nsec(zone, _txn, _rrset_signer) def _sign_zone_nsec( zone: dns.zone.Zone, txn: dns.transaction.Transaction, rrset_signer: Optional[RRsetSigner] = None, ) -> None: """NSEC zone signer""" def _txn_add_nsec( txn: dns.transaction.Transaction, name: dns.name.Name, next_secure: Optional[dns.name.Name], rdclass: dns.rdataclass.RdataClass, ttl: int, rrset_signer: Optional[RRsetSigner] = None, ) -> None: """NSEC zone signer helper""" mandatory_types = set( [dns.rdatatype.RdataType.RRSIG, dns.rdatatype.RdataType.NSEC] ) node = txn.get_node(name) if node and next_secure: types = ( set([rdataset.rdtype for rdataset in node.rdatasets]) | mandatory_types ) windows = Bitmap.from_rdtypes(list(types)) rrset = dns.rrset.from_rdata( name, ttl, NSEC( rdclass=rdclass, rdtype=dns.rdatatype.RdataType.NSEC, next=next_secure, windows=windows, ), ) txn.add(rrset) if rrset_signer: rrset_signer(txn, rrset) rrsig_ttl = zone.get_soa().minimum delegation = None last_secure = None for name in sorted(txn.iterate_names()): if delegation and name.is_subdomain(delegation): # names below delegations are not secure continue elif txn.get(name, dns.rdatatype.NS) and name != zone.origin: # inside delegation delegation = name else: # outside delegation delegation = None if rrset_signer: node = txn.get_node(name) if node: for rdataset in node.rdatasets: if rdataset.rdtype == dns.rdatatype.RRSIG: # do not sign RRSIGs continue elif delegation and rdataset.rdtype != dns.rdatatype.DS: # do not sign delegations except DS records continue else: rrset = dns.rrset.from_rdata(name, rdataset.ttl, *rdataset) rrset_signer(txn, rrset) # We need "is not None" as the empty name is False because its length is 0. if last_secure is not None: _txn_add_nsec(txn, last_secure, name, zone.rdclass, rrsig_ttl, rrset_signer) last_secure = name if last_secure: _txn_add_nsec( txn, last_secure, zone.origin, zone.rdclass, rrsig_ttl, rrset_signer ) def _need_pyca(*args, **kwargs): raise ImportError( "DNSSEC validation requires python cryptography" ) # pragma: no cover if dns._features.have("dnssec"): from cryptography.exceptions import InvalidSignature from cryptography.hazmat.primitives.asymmetric import dsa # pylint: disable=W0611 from cryptography.hazmat.primitives.asymmetric import ec # pylint: disable=W0611 from cryptography.hazmat.primitives.asymmetric import ed448 # pylint: disable=W0611 from cryptography.hazmat.primitives.asymmetric import rsa # pylint: disable=W0611 from cryptography.hazmat.primitives.asymmetric import ( # pylint: disable=W0611 ed25519, ) from dns.dnssecalgs import ( # pylint: disable=C0412 get_algorithm_cls, get_algorithm_cls_from_dnskey, ) from dns.dnssecalgs.base import GenericPrivateKey, GenericPublicKey validate = _validate # type: ignore validate_rrsig = _validate_rrsig # type: ignore sign = _sign make_dnskey = _make_dnskey make_cdnskey = _make_cdnskey _have_pyca = True else: # pragma: no cover validate = _need_pyca validate_rrsig = _need_pyca sign = _need_pyca make_dnskey = _need_pyca make_cdnskey = _need_pyca _have_pyca = False ### BEGIN generated Algorithm constants RSAMD5 = Algorithm.RSAMD5 DH = Algorithm.DH DSA = Algorithm.DSA ECC = Algorithm.ECC RSASHA1 = Algorithm.RSASHA1 DSANSEC3SHA1 = Algorithm.DSANSEC3SHA1 RSASHA1NSEC3SHA1 = Algorithm.RSASHA1NSEC3SHA1 RSASHA256 = Algorithm.RSASHA256 RSASHA512 = Algorithm.RSASHA512 ECCGOST = Algorithm.ECCGOST ECDSAP256SHA256 = Algorithm.ECDSAP256SHA256 ECDSAP384SHA384 = Algorithm.ECDSAP384SHA384 ED25519 = Algorithm.ED25519 ED448 = Algorithm.ED448 INDIRECT = Algorithm.INDIRECT PRIVATEDNS = Algorithm.PRIVATEDNS PRIVATEOID = Algorithm.PRIVATEOID ### END generated Algorithm constants