# Copyright (C) 2004-2007, 2009-2011 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.
import base64
import calendar
import struct
import time
import dns.dnssec
import dns.exception
import dns.rdata
import dns.rdatatype
class BadSigTime(dns.exception.DNSException):
"""Time in DNS SIG or RRSIG resource record cannot be parsed."""
def sigtime_to_posixtime(what):
if len(what) != 14:
raise BadSigTime
year = int(what[0:4])
month = int(what[4:6])
day = int(what[6:8])
hour = int(what[8:10])
minute = int(what[10:12])
second = int(what[12:14])
return calendar.timegm((year, month, day, hour, minute, second,
0, 0, 0))
def posixtime_to_sigtime(what):
return time.strftime('%Y%m%d%H%M%S', time.gmtime(what))
class RRSIG(dns.rdata.Rdata):
"""RRSIG record
@ivar type_covered: the rdata type this signature covers
@type type_covered: int
@ivar algorithm: the algorithm used for the sig
@type algorithm: int
@ivar labels: number of labels
@type labels: int
@ivar original_ttl: the original TTL
@type original_ttl: long
@ivar expiration: signature expiration time
@type expiration: long
@ivar inception: signature inception time
@type inception: long
@ivar key_tag: the key tag
@type key_tag: int
@ivar signer: the signer
@type signer: dns.name.Name object
@ivar signature: the signature
@type signature: string"""
__slots__ = ['type_covered', 'algorithm', 'labels', 'original_ttl',
'expiration', 'inception', 'key_tag', 'signer',
'signature']
def __init__(self, rdclass, rdtype, type_covered, algorithm, labels,
original_ttl, expiration, inception, key_tag, signer,
signature):
super(RRSIG, self).__init__(rdclass, rdtype)
self.type_covered = type_covered
self.algorithm = algorithm
self.labels = labels
self.original_ttl = original_ttl
self.expiration = expiration
self.inception = inception
self.key_tag = key_tag
self.signer = signer
self.signature = signature
def covers(self):
return self.type_covered
def to_text(self, origin=None, relativize=True, **kw):
return '%s %d %d %d %s %s %d %s %s' % (
dns.rdatatype.to_text(self.type_covered),
self.algorithm,
self.labels,
self.original_ttl,
posixtime_to_sigtime(self.expiration),
posixtime_to_sigtime(self.inception),
self.key_tag,
self.signer.choose_relativity(origin, relativize),
dns.rdata._base64ify(self.signature)
)
@classmethod
def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
type_covered = dns.rdatatype.from_text(tok.get_string())
algorithm = dns.dnssec.algorithm_from_text(tok.get_string())
labels = tok.get_int()
original_ttl = tok.get_ttl()
expiration = sigtime_to_posixtime(tok.get_string())
inception = sigtime_to_posixtime(tok.get_string())
key_tag = tok.get_int()
signer = tok.get_name()
signer = signer.choose_relativity(origin, relativize)
chunks = []
while 1:
t = tok.get().unescape()
if t.is_eol_or_eof():
break
if not t.is_identifier():
raise dns.exception.SyntaxError
chunks.append(t.value.encode())
b64 = b''.join(chunks)
signature = base64.b64decode(b64)
return cls(rdclass, rdtype, type_covered, algorithm, labels,
original_ttl, expiration, inception, key_tag, signer,
signature)
def to_wire(self, file, compress=None, origin=None):
header = struct.pack('!HBBIIIH', self.type_covered,
self.algorithm, self.labels,
self.original_ttl, self.expiration,
self.inception, self.key_tag)
file.write(header)
self.signer.to_wire(file, None, origin)
file.write(self.signature)
@classmethod
def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
header = struct.unpack('!HBBIIIH', wire[current: current + 18])
current += 18
rdlen -= 18
(signer, cused) = dns.name.from_wire(wire[: current + rdlen], current)
current += cused
rdlen -= cused
if origin is not None:
signer = signer.relativize(origin)
signature = wire[current: current + rdlen].unwrap()
return cls(rdclass, rdtype, header[0], header[1], header[2],
header[3], header[4], header[5], header[6], signer,
signature)
def choose_relativity(self, origin=None, relativize=True):
self.signer = self.signer.choose_relativity(origin, relativize)
