def make_ds(name, key, algorithm, origin=None):
"""Create a DS record for a DNSSEC key.
*name* is the owner name of the DS record.
*key* is a ``dns.rdtypes.ANY.DNSKEY``.
*algorithm* is a string describing which hash algorithm to use. The
currently supported hashes are "SHA1" and "SHA256". Case does not
matter for these strings.
*origin* is a ``dns.name.Name`` and will be used as the origin
if *key* is a relative name.
Returns a ``dns.rdtypes.ANY.DS``.
"""
if algorithm.upper() == 'SHA1':
dsalg = 1
hash = dns.hash.hashes['SHA1']()
elif algorithm.upper() == 'SHA256':
dsalg = 2
hash = dns.hash.hashes['SHA256']()
else:
raise UnsupportedAlgorithm('unsupported algorithm "%s"' % algorithm)
if isinstance(name, string_types):
name = dns.name.from_text(name, origin)
hash.update(name.canonicalize().to_wire())
hash.update(_to_rdata(key, origin))
digest = hash.digest()
dsrdata = struct.pack("!HBB", key_id(key), key.algorithm, dsalg) + digest
return dns.rdata.from_wire(dns.rdataclass.IN, dns.rdatatype.DS, dsrdata, 0,
len(dsrdata))
def make_ds(name, key, algorithm, origin=None):
"""Create a DS record for a DNSSEC key.
*name* is the owner name of the DS record.
*key* is a ``dns.rdtypes.ANY.DNSKEY``.
*algorithm* is a string describing which hash algorithm to use. The
currently supported hashes are "SHA1" and "SHA256". Case does not
matter for these strings.
*origin* is a ``dns.name.Name`` and will be used as the origin
if *key* is a relative name.
Returns a ``dns.rdtypes.ANY.DS``.
"""
if algorithm.upper() == 'SHA1':
dsalg = 1
hash = dns.hash.hashes['SHA1']()
elif algorithm.upper() == 'SHA256':
dsalg = 2
hash = dns.hash.hashes['SHA256']()
else:
raise UnsupportedAlgorithm('unsupported algorithm "%s"' % algorithm)
if isinstance(name, string_types):
name = dns.name.from_text(name, origin)
hash.update(name.canonicalize().to_wire())
hash.update(_to_rdata(key, origin))
digest = hash.digest()
dsrdata = struct.pack("!HBB", key_id(key), key.algorithm, dsalg) + digest
return dns.rdata.from_wire(dns.rdataclass.IN, dns.rdatatype.DS, dsrdata, 0,
len(dsrdata))
def make_ds(name, key, algorithm, origin=None):
if algorithm.upper() == 'SHA1':
dsalg = 1
hash = dns.hash.get('SHA1')()
elif algorithm.upper() == 'SHA256':
dsalg = 2
hash = dns.hash.get('SHA256')()
else:
raise UnsupportedAlgorithm, 'unsupported algorithm "%s"' % algorithm
if isinstance(name, (str, unicode)):
name = dns.name.from_text(name, origin)
hash.update(name.canonicalize().to_wire())
hash.update(_to_rdata(key, origin))
digest = hash.digest()
dsrdata = struct.pack("!HBB", key_id(key), key.algorithm, dsalg) + digest
return dns.rdata.from_wire(dns.rdataclass.IN, dns.rdatatype.DS, dsrdata, 0,
len(dsrdata))
def make_ds(name, key, algorithm, origin=None):
if algorithm.upper() == 'SHA1':
dsalg = 1
hash = dns.hash.get('SHA1')()
elif algorithm.upper() == 'SHA256':
dsalg = 2
hash = dns.hash.get('SHA256')()
else:
raise UnsupportedAlgorithm, 'unsupported algorithm "%s"' % algorithm
if isinstance(name, (str, unicode)):
name = dns.name.from_text(name, origin)
hash.update(name.canonicalize().to_wire())
hash.update(_to_rdata(key, origin))
digest = hash.digest()
dsrdata = struct.pack("!HBB", key_id(key), key.algorithm, dsalg) + digest
return dns.rdata.from_wire(dns.rdataclass.IN, dns.rdatatype.DS, dsrdata, 0,
len(dsrdata))
def _validate_rrsig(rrset, rrsig, keys, origin=None, now=None):
"""Validate an RRset against a single signature rdata
The owner name of *rrsig* is assumed to be the same as the owner name
of *rrset*.
*rrset* is the RRset to validate. It can be a ``dns.rrset.RRset`` or
a ``(dns.name.Name, dns.rdataset.Rdataset)`` tuple.
*rrsig* is a ``dns.rrset.Rdata``, the signature to validate.
*keys* is 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* is a ``dns.name.Name``, the origin to use for relative names.
*now* is an ``int``, the time to use when validating the signatures,
in seconds since the UNIX epoch. The default is the current time.
"""
if isinstance(origin, string_types):
origin = dns.name.from_text(origin, dns.name.root)
candidate_keys = _find_candidate_keys(keys, rrsig)
if candidate_keys is None:
raise ValidationFailure('unknown key')
for candidate_key in candidate_keys:
# For convenience, allow the rrset to be specified as a (name,
# rdataset) tuple as well as a proper rrset
if isinstance(rrset, tuple):
rrname = rrset[0]
rdataset = rrset[1]
else:
rrname = rrset.name
rdataset = rrset
if now is None:
now = time.time()
if rrsig.expiration < now:
raise ValidationFailure('expired')
if rrsig.inception > now:
raise ValidationFailure('not yet valid')
hash = _make_hash(rrsig.algorithm)
if _is_rsa(rrsig.algorithm):
keyptr = candidate_key.key
(bytes_,) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
if bytes_ == 0:
(bytes_,) = struct.unpack('!H', keyptr[0:2])
keyptr = keyptr[2:]
rsa_e = keyptr[0:bytes_]
rsa_n = keyptr[bytes_:]
keylen = len(rsa_n) * 8
pubkey = Crypto.PublicKey.RSA.construct(
(Crypto.Util.number.bytes_to_long(rsa_n),
Crypto.Util.number.bytes_to_long(rsa_e)))
sig = (Crypto.Util.number.bytes_to_long(rrsig.signature),)
elif _is_dsa(rrsig.algorithm):
keyptr = candidate_key.key
(t,) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
octets = 64 + t * 8
dsa_q = keyptr[0:20]
keyptr = keyptr[20:]
dsa_p = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_g = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_y = keyptr[0:octets]
pubkey = Crypto.PublicKey.DSA.construct(
(Crypto.Util.number.bytes_to_long(dsa_y),
Crypto.Util.number.bytes_to_long(dsa_g),
Crypto.Util.number.bytes_to_long(dsa_p),
Crypto.Util.number.bytes_to_long(dsa_q)))
(dsa_r, dsa_s) = struct.unpack('!20s20s', rrsig.signature[1:])
sig = (Crypto.Util.number.bytes_to_long(dsa_r),
Crypto.Util.number.bytes_to_long(dsa_s))
elif _is_ecdsa(rrsig.algorithm):
if rrsig.algorithm == ECDSAP256SHA256:
curve = ecdsa.curves.NIST256p
key_len = 32
elif rrsig.algorithm == ECDSAP384SHA384:
curve = ecdsa.curves.NIST384p
key_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])
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(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 = dns.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)
hash.update(rrfixed)
rrdata = rr.to_digestable(origin)
rrlen = struct.pack('!H', len(rrdata))
hash.update(rrlen)
hash.update(rrdata)
digest = hash.digest()
if _is_rsa(rrsig.algorithm):
# PKCS1 algorithm identifier goop
digest = _make_algorithm_id(rrsig.algorithm) + digest
padlen = keylen // 8 - len(digest) - 3
digest = struct.pack('!%dB' % (2 + padlen + 1),
*([0, 1] + [0xFF] * padlen + [0])) + digest
elif _is_dsa(rrsig.algorithm) or _is_ecdsa(rrsig.algorithm):
pass
else:
# Raise here for code clarity; this won't actually ever happen
# since if the algorithm is really unknown we'd already have
# raised an exception above
raise ValidationFailure('unknown algorithm %u' % rrsig.algorithm)
if pubkey.verify(digest, sig):
return
raise ValidationFailure('verify failure')
def _validate_rrsig(rrset, rrsig, keys, origin=None, now=None):
"""Validate an RRset against a single signature rdata
The owner name of the rrsig is assumed to be the same as the owner name
of the rrset.
@param rrset: The RRset to validate
@type rrset: dns.rrset.RRset or (dns.name.Name, dns.rdataset.Rdataset)
tuple
@param rrsig: The signature rdata
@type rrsig: dns.rrset.Rdata
@param keys: The key dictionary.
@type keys: a dictionary keyed by dns.name.Name with node or rdataset values
@param origin: The origin to use for relative names
@type origin: dns.name.Name or None
@param now: The time to use when validating the signatures. The default
is the current time.
@type now: int
"""
if isinstance(origin, (str, unicode)):
origin = dns.name.from_text(origin, dns.name.root)
for candidate_key in _find_candidate_keys(keys, rrsig):
if not candidate_key:
raise ValidationFailure, 'unknown key'
# For convenience, allow the rrset to be specified as a (name, rdataset)
# tuple as well as a proper rrset
if isinstance(rrset, tuple):
rrname = rrset[0]
rdataset = rrset[1]
else:
rrname = rrset.name
rdataset = rrset
if now is None:
now = time.time()
if rrsig.expiration < now:
raise ValidationFailure, 'expired'
if rrsig.inception > now:
raise ValidationFailure, 'not yet valid'
hash = _make_hash(rrsig.algorithm)
if _is_rsa(rrsig.algorithm):
keyptr = candidate_key.key
(bytes,) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
if bytes == 0:
(bytes,) = struct.unpack('!H', keyptr[0:2])
keyptr = keyptr[2:]
rsa_e = keyptr[0:bytes]
rsa_n = keyptr[bytes:]
keylen = len(rsa_n) * 8
pubkey = Crypto.PublicKey.RSA.construct(
(Crypto.Util.number.bytes_to_long(rsa_n),
Crypto.Util.number.bytes_to_long(rsa_e)))
sig = (Crypto.Util.number.bytes_to_long(rrsig.signature),)
elif _is_dsa(rrsig.algorithm):
keyptr = candidate_key.key
(t,) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
octets = 64 + t * 8
dsa_q = keyptr[0:20]
keyptr = keyptr[20:]
dsa_p = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_g = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_y = keyptr[0:octets]
pubkey = Crypto.PublicKey.DSA.construct(
(Crypto.Util.number.bytes_to_long(dsa_y),
Crypto.Util.number.bytes_to_long(dsa_g),
Crypto.Util.number.bytes_to_long(dsa_p),
Crypto.Util.number.bytes_to_long(dsa_q)))
(dsa_r, dsa_s) = struct.unpack('!20s20s', rrsig.signature[1:])
sig = (Crypto.Util.number.bytes_to_long(dsa_r),
Crypto.Util.number.bytes_to_long(dsa_s))
elif _is_ecdsa(rrsig.algorithm):
if rrsig.algorithm == ECDSAP256SHA256:
curve = ecdsa.curves.NIST256p
key_len = 32
digest_len = 32
elif rrsig.algorithm == ECDSAP384SHA384:
curve = ecdsa.curves.NIST384p
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 = dns.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)
hash.update(rrfixed)
rrdata = rr.to_digestable(origin)
rrlen = struct.pack('!H', len(rrdata))
hash.update(rrlen)
hash.update(rrdata)
digest = hash.digest()
if _is_rsa(rrsig.algorithm):
# PKCS1 algorithm identifier goop
digest = _make_algorithm_id(rrsig.algorithm) + digest
padlen = keylen // 8 - len(digest) - 3
digest = chr(0) + chr(1) + chr(0xFF) * padlen + chr(0) + digest
elif _is_dsa(rrsig.algorithm) or _is_ecdsa(rrsig.algorithm):
pass
else:
# Raise here for code clarity; this won't actually ever happen
# since if the algorithm is really unknown we'd already have
# raised an exception above
raise ValidationFailure, 'unknown algorithm %u' % rrsig.algorithm
if pubkey.verify(digest, sig):
return
raise ValidationFailure, 'verify failure'
def _validate_rrsig(rrset, rrsig, keys, origin=None, now=None):
"""Validate an RRset against a single signature rdata
The owner name of the rrsig is assumed to be the same as the owner name
of the rrset.
@param rrset: The RRset to validate
@type rrset: dns.rrset.RRset or (dns.name.Name, dns.rdataset.Rdataset)
tuple
@param rrsig: The signature rdata
@type rrsig: dns.rrset.Rdata
@param keys: The key dictionary.
@type keys: a dictionary keyed by dns.name.Name with node or rdataset values
@param origin: The origin to use for relative names
@type origin: dns.name.Name or None
@param now: The time to use when validating the signatures. The default
is the current time.
@type now: int
"""
if isinstance(origin, (str, unicode)):
origin = dns.name.from_text(origin, dns.name.root)
for candidate_key in _find_candidate_keys(keys, rrsig):
if not candidate_key:
raise ValidationFailure, 'unknown key'
# For convenience, allow the rrset to be specified as a (name, rdataset)
# tuple as well as a proper rrset
if isinstance(rrset, tuple):
rrname = rrset[0]
rdataset = rrset[1]
else:
rrname = rrset.name
rdataset = rrset
if now is None:
now = time.time()
if rrsig.expiration < now:
raise ValidationFailure, 'expired'
if rrsig.inception > now:
raise ValidationFailure, 'not yet valid'
hash = _make_hash(rrsig.algorithm)
if _is_rsa(rrsig.algorithm):
keyptr = candidate_key.key
(bytes,) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
if bytes == 0:
(bytes,) = struct.unpack('!H', keyptr[0:2])
keyptr = keyptr[2:]
rsa_e = keyptr[0:bytes]
rsa_n = keyptr[bytes:]
keylen = len(rsa_n) * 8
pubkey = Crypto.PublicKey.RSA.construct(
(Crypto.Util.number.bytes_to_long(rsa_n),
Crypto.Util.number.bytes_to_long(rsa_e)))
sig = (Crypto.Util.number.bytes_to_long(rrsig.signature),)
elif _is_dsa(rrsig.algorithm):
keyptr = candidate_key.key
(t,) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
octets = 64 + t * 8
dsa_q = keyptr[0:20]
keyptr = keyptr[20:]
dsa_p = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_g = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_y = keyptr[0:octets]
pubkey = Crypto.PublicKey.DSA.construct(
(Crypto.Util.number.bytes_to_long(dsa_y),
Crypto.Util.number.bytes_to_long(dsa_g),
Crypto.Util.number.bytes_to_long(dsa_p),
Crypto.Util.number.bytes_to_long(dsa_q)))
(dsa_r, dsa_s) = struct.unpack('!20s20s', rrsig.signature[1:])
sig = (Crypto.Util.number.bytes_to_long(dsa_r),
Crypto.Util.number.bytes_to_long(dsa_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 = dns.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)
hash.update(rrfixed)
rrdata = rr.to_digestable(origin)
rrlen = struct.pack('!H', len(rrdata))
hash.update(rrlen)
hash.update(rrdata)
digest = hash.digest()
if _is_rsa(rrsig.algorithm):
# PKCS1 algorithm identifier goop
digest = _make_algorithm_id(rrsig.algorithm) + digest
padlen = keylen // 8 - len(digest) - 3
digest = chr(0) + chr(1) + chr(0xFF) * padlen + chr(0) + digest
elif _is_dsa(rrsig.algorithm):
pass
else:
# Raise here for code clarity; this won't actually ever happen
# since if the algorithm is really unknown we'd already have
# raised an exception above
raise ValidationFailure, 'unknown algorithm %u' % rrsig.algorithm
if pubkey.verify(digest, sig):
return
raise ValidationFailure, 'verify failure'
def _validate_rrsig(rrset, rrsig, keys, origin=None, now=None):
"""Validate an RRset against a single signature rdata
The owner name of *rrsig* is assumed to be the same as the owner name
of *rrset*.
*rrset* is the RRset to validate. It can be a ``dns.rrset.RRset`` or
a ``(dns.name.Name, dns.rdataset.Rdataset)`` tuple.
*rrsig* is a ``dns.rrset.Rdata``, the signature to validate.
*keys* is 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* is a ``dns.name.Name``, the origin to use for relative names.
*now* is an ``int``, the time to use when validating the signatures,
in seconds since the UNIX epoch. The default is the current time.
"""
if isinstance(origin, string_types):
origin = dns.name.from_text(origin, dns.name.root)
for candidate_key in _find_candidate_keys(keys, rrsig):
if not candidate_key:
raise ValidationFailure('unknown key')
# For convenience, allow the rrset to be specified as a (name,
# rdataset) tuple as well as a proper rrset
if isinstance(rrset, tuple):
rrname = rrset[0]
rdataset = rrset[1]
else:
rrname = rrset.name
rdataset = rrset
if now is None:
now = time.time()
if rrsig.expiration < now:
raise ValidationFailure('expired')
if rrsig.inception > now:
raise ValidationFailure('not yet valid')
hash = _make_hash(rrsig.algorithm)
if _is_rsa(rrsig.algorithm):
keyptr = candidate_key.key
(bytes_, ) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
if bytes_ == 0:
(bytes_, ) = struct.unpack('!H', keyptr[0:2])
keyptr = keyptr[2:]
rsa_e = keyptr[0:bytes_]
rsa_n = keyptr[bytes_:]
keylen = len(rsa_n) * 8
pubkey = Crypto.PublicKey.RSA.construct(
(Crypto.Util.number.bytes_to_long(rsa_n),
Crypto.Util.number.bytes_to_long(rsa_e)))
sig = (Crypto.Util.number.bytes_to_long(rrsig.signature), )
elif _is_dsa(rrsig.algorithm):
keyptr = candidate_key.key
(t, ) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
octets = 64 + t * 8
dsa_q = keyptr[0:20]
keyptr = keyptr[20:]
dsa_p = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_g = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_y = keyptr[0:octets]
pubkey = Crypto.PublicKey.DSA.construct(
(Crypto.Util.number.bytes_to_long(dsa_y),
Crypto.Util.number.bytes_to_long(dsa_g),
Crypto.Util.number.bytes_to_long(dsa_p),
Crypto.Util.number.bytes_to_long(dsa_q)))
(dsa_r, dsa_s) = struct.unpack('!20s20s', rrsig.signature[1:])
sig = (Crypto.Util.number.bytes_to_long(dsa_r),
Crypto.Util.number.bytes_to_long(dsa_s))
elif _is_ecdsa(rrsig.algorithm):
if rrsig.algorithm == ECDSAP256SHA256:
curve = ecdsa.curves.NIST256p
key_len = 32
elif rrsig.algorithm == ECDSAP384SHA384:
curve = ecdsa.curves.NIST384p
key_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 = dns.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)
hash.update(rrfixed)
rrdata = rr.to_digestable(origin)
rrlen = struct.pack('!H', len(rrdata))
hash.update(rrlen)
hash.update(rrdata)
digest = hash.digest()
if _is_rsa(rrsig.algorithm):
# PKCS1 algorithm identifier goop
digest = _make_algorithm_id(rrsig.algorithm) + digest
padlen = keylen // 8 - len(digest) - 3
digest = struct.pack('!%dB' % (2 + padlen + 1),
*([0, 1] + [0xFF] * padlen + [0])) + digest
elif _is_dsa(rrsig.algorithm) or _is_ecdsa(rrsig.algorithm):
pass
else:
# Raise here for code clarity; this won't actually ever happen
# since if the algorithm is really unknown we'd already have
# raised an exception above
raise ValidationFailure('unknown algorithm %u' % rrsig.algorithm)
if pubkey.verify(digest, sig):
return
raise ValidationFailure('verify failure')
def _validate_rrsig(rrset, rrsig, keys, origin=None, now=None):
"""Validate an RRset against a single signature rdata
The owner name of the rrsig is assumed to be the same as the owner name
of the rrset.
@param rrset: The RRset to validate
@type rrset: dns.rrset.RRset or (dns.name.Name, dns.rdataset.Rdataset)
tuple
@param rrsig: The signature rdata
@type rrsig: dns.rrset.Rdata
@param keys: The key dictionary.
@type keys: a dictionary keyed by dns.name.Name with node or rdataset values
@param origin: The origin to use for relative names
@type origin: dns.name.Name or None
@param now: The time to use when validating the signatures. The default
is the current time.
@type now: int
"""
if isinstance(origin, str):
origin = dns.name.from_text(origin, dns.name.root)
for candidate_key in _find_candidate_keys(keys, rrsig):
if not candidate_key:
raise ValidationFailure('unknown key')
# For convenience, allow the rrset to be specified as a (name, rdataset)
# tuple as well as a proper rrset
if isinstance(rrset, tuple):
rrname = rrset[0]
rdataset = rrset[1]
else:
rrname = rrset.name
rdataset = rrset
if now is None:
now = time.time()
if rrsig.expiration < now:
raise ValidationFailure('expired')
if rrsig.inception > now:
raise ValidationFailure('not yet valid')
hash = _make_hash(rrsig.algorithm)
if _is_rsa(rrsig.algorithm):
keyptr = candidate_key.key
(count,) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
if count == 0:
(count,) = struct.unpack('!H', keyptr[0:2])
keyptr = keyptr[2:]
rsa_e = keyptr[0:count]
rsa_n = keyptr[count:]
keylen = len(rsa_n) * 8
pubkey = Crypto.PublicKey.RSA.construct(
(Crypto.Util.number.bytes_to_long(rsa_n),
Crypto.Util.number.bytes_to_long(rsa_e)))
sig = (Crypto.Util.number.bytes_to_long(rrsig.signature),)
elif _is_dsa(rrsig.algorithm):
keyptr = candidate_key.key
(t,) = struct.unpack('!B', keyptr[0:1])
keyptr = keyptr[1:]
octets = 64 + t * 8
dsa_q = keyptr[0:20]
keyptr = keyptr[20:]
dsa_p = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_g = keyptr[0:octets]
keyptr = keyptr[octets:]
dsa_y = keyptr[0:octets]
pubkey = Crypto.PublicKey.DSA.construct(
(Crypto.Util.number.bytes_to_long(dsa_y),
Crypto.Util.number.bytes_to_long(dsa_g),
Crypto.Util.number.bytes_to_long(dsa_p),
Crypto.Util.number.bytes_to_long(dsa_q)))
(dsa_r, dsa_s) = struct.unpack('!20s20s', rrsig.signature[1:])
sig = (Crypto.Util.number.bytes_to_long(dsa_r),
Crypto.Util.number.bytes_to_long(dsa_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 = dns.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)
hash.update(rrfixed)
rrdata = rr.to_digestable(origin)
rrlen = struct.pack('!H', len(rrdata))
hash.update(rrlen)
hash.update(rrdata)
digest = hash.digest()
if _is_rsa(rrsig.algorithm):
# PKCS1 algorithm identifier goop
digest = _make_algorithm_id(rrsig.algorithm) + digest
padlen = keylen // 8 - len(digest) - 3
digest = bytes([0]) + bytes([1]) + bytes([0xFF]) * padlen + \
bytes([0]) + digest
elif _is_dsa(rrsig.algorithm):
pass
else:
# Raise here for code clarity; this won't actually ever happen
# since if the algorithm is really unknown we'd already have
# raised an exception above
raise ValidationFailure('unknown algorithm %u' % rrsig.algorithm)
if pubkey.verify(digest, sig):
return
raise ValidationFailure('verify failure')
