def make_ds(name, key, algorithm, origin=None): if algorithm.upper() == 'SHA1': dsalg = 1 hash = hash.get('SHA1')() elif algorithm.upper() == 'SHA256': dsalg = 2 hash = hash.get('SHA256')() else: raise UnsupportedAlgorithm, 'unsupported algorithm "%s"' % algorithm if isinstance(name, (str, unicode)): name = 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 rdata.from_wire(rdataclass.IN, 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 the rrsig is assumed to be the same as the owner name of the rrset. @param rrset: The RRset to validate @type rrset: rrset.RRset or (name.Name, rdataset.Rdataset) tuple @param rrsig: The signature rdata @type rrsig: rrset.Rdata @param keys: The key dictionary. @type keys: a dictionary keyed by name.Name with node or rdataset values @param origin: The origin to use for relative names @type origin: 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 = name.from_text(origin, 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 = 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: rrset.RRset or (name.Name, rdataset.Rdataset) tuple @param rrsig: The signature rdata @type rrsig: rrset.Rdata @param keys: The key dictionary. @type keys: a dictionary keyed by name.Name with node or rdataset values @param origin: The origin to use for relative names @type origin: 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 = name.from_text(origin, 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 = 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'