third_party/dnspython/dns/rdtypes/ANY/RRSIG.py

   1 # Copyright (C) 2004-2007, 2009-2011 Nominum, Inc.
   2 #
   3 # Permission to use, copy, modify, and distribute this software and its
   4 # documentation for any purpose with or without fee is hereby granted,
   5 # provided that the above copyright notice and this permission notice
   6 # appear in all copies.
   7 #
   8 # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
   9 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
  11 # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12 # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  14 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15
  16 import calendar
  17 import struct
  18 import time
  19
  20 import dns.dnssec
  21 import dns.exception
  22 import dns.rdata
  23 import dns.rdatatype
  24
  25 class BadSigTime(dns.exception.DNSException):
  26     """Raised when a SIG or RRSIG RR's time cannot be parsed."""
  27     pass
  28
  29 def sigtime_to_posixtime(what):
  30     if len(what) != 14:
  31         raise BadSigTime
  32     year = int(what[0:4])
  33     month = int(what[4:6])
  34     day = int(what[6:8])
  35     hour = int(what[8:10])
  36     minute = int(what[10:12])
  37     second = int(what[12:14])
  38     return calendar.timegm((year, month, day, hour, minute, second,
  39                             0, 0, 0))
  40
  41 def posixtime_to_sigtime(what):
  42     return time.strftime('%Y%m%d%H%M%S', time.gmtime(what))
  43
  44 class RRSIG(dns.rdata.Rdata):
  45     """RRSIG record
  46
  47     @ivar type_covered: the rdata type this signature covers
  48     @type type_covered: int
  49     @ivar algorithm: the algorithm used for the sig
  50     @type algorithm: int
  51     @ivar labels: number of labels
  52     @type labels: int
  53     @ivar original_ttl: the original TTL
  54     @type original_ttl: long
  55     @ivar expiration: signature expiration time
  56     @type expiration: long
  57     @ivar inception: signature inception time
  58     @type inception: long
  59     @ivar key_tag: the key tag
  60     @type key_tag: int
  61     @ivar signer: the signer
  62     @type signer: dns.name.Name object
  63     @ivar signature: the signature
  64     @type signature: string"""
  65
  66     __slots__ = ['type_covered', 'algorithm', 'labels', 'original_ttl',
  67                  'expiration', 'inception', 'key_tag', 'signer',
  68                  'signature']
  69
  70     def __init__(self, rdclass, rdtype, type_covered, algorithm, labels,
  71                  original_ttl, expiration, inception, key_tag, signer,
  72                  signature):
  73         super(RRSIG, self).__init__(rdclass, rdtype)
  74         self.type_covered = type_covered
  75         self.algorithm = algorithm
  76         self.labels = labels
  77         self.original_ttl = original_ttl
  78         self.expiration = expiration
  79         self.inception = inception
  80         self.key_tag = key_tag
  81         self.signer = signer
  82         self.signature = signature
  83
  84     def covers(self):
  85         return self.type_covered
  86
  87     def to_text(self, origin=None, relativize=True, **kw):
  88         return '%s %d %d %d %s %s %d %s %s' % (
  89             dns.rdatatype.to_text(self.type_covered),
  90             self.algorithm,
  91             self.labels,
  92             self.original_ttl,
  93             posixtime_to_sigtime(self.expiration),
  94             posixtime_to_sigtime(self.inception),
  95             self.key_tag,
  96             self.signer,
  97             dns.rdata._base64ify(self.signature)
  98             )
  99
 100     def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
 101         type_covered = dns.rdatatype.from_text(tok.get_string())
 102         algorithm = dns.dnssec.algorithm_from_text(tok.get_string())
 103         labels = tok.get_int()
 104         original_ttl = tok.get_ttl()
 105         expiration = sigtime_to_posixtime(tok.get_string())
 106         inception = sigtime_to_posixtime(tok.get_string())
 107         key_tag = tok.get_int()
 108         signer = tok.get_name()
 109         signer = signer.choose_relativity(origin, relativize)
 110         chunks = []
 111         while 1:
 112             t = tok.get().unescape()
 113             if t.is_eol_or_eof():
 114                 break
 115             if not t.is_identifier():
 116                 raise dns.exception.SyntaxError
 117             chunks.append(t.value)
 118         b64 = ''.join(chunks)
 119         signature = b64.decode('base64_codec')
 120         return cls(rdclass, rdtype, type_covered, algorithm, labels,
 121                    original_ttl, expiration, inception, key_tag, signer,
 122                    signature)
 123
 124     from_text = classmethod(from_text)
 125
 126     def to_wire(self, file, compress = None, origin = None):
 127         header = struct.pack('!HBBIIIH', self.type_covered,
 128                              self.algorithm, self.labels,
 129                              self.original_ttl, self.expiration,
 130                              self.inception, self.key_tag)
 131         file.write(header)
 132         self.signer.to_wire(file, None, origin)
 133         file.write(self.signature)
 134
 135     def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
 136         header = struct.unpack('!HBBIIIH', wire[current : current + 18])
 137         current += 18
 138         rdlen -= 18
 139         (signer, cused) = dns.name.from_wire(wire[: current + rdlen], current)
 140         current += cused
 141         rdlen -= cused
 142         if not origin is None:
 143             signer = signer.relativize(origin)
 144         signature = wire[current : current + rdlen].unwrap()
 145         return cls(rdclass, rdtype, header[0], header[1], header[2],
 146                    header[3], header[4], header[5], header[6], signer,
 147                    signature)
 148
 149     from_wire = classmethod(from_wire)
 150
 151     def choose_relativity(self, origin = None, relativize = True):
 152         self.signer = self.signer.choose_relativity(origin, relativize)
 153
 154     def _cmp(self, other):
 155         return self._wire_cmp(other)