lib/dnspython/dns/rdtypes/ANY/SSHFP.py

   1 # Copyright (C) 2005-2007, 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 struct
  17
  18 import dns.rdata
  19 import dns.rdatatype
  20
  21 class SSHFP(dns.rdata.Rdata):
  22     """SSHFP record
  23
  24     @ivar algorithm: the algorithm
  25     @type algorithm: int
  26     @ivar fp_type: the digest type
  27     @type fp_type: int
  28     @ivar fingerprint: the fingerprint
  29     @type fingerprint: string
  30     @see: draft-ietf-secsh-dns-05.txt"""
  31
  32     __slots__ = ['algorithm', 'fp_type', 'fingerprint']
  33
  34     def __init__(self, rdclass, rdtype, algorithm, fp_type,
  35                  fingerprint):
  36         super(SSHFP, self).__init__(rdclass, rdtype)
  37         self.algorithm = algorithm
  38         self.fp_type = fp_type
  39         self.fingerprint = fingerprint
  40
  41     def to_text(self, origin=None, relativize=True, **kw):
  42         return '%d %d %s' % (self.algorithm,
  43                              self.fp_type,
  44                              dns.rdata._hexify(self.fingerprint,
  45                                                chunksize=128))
  46
  47     def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
  48         algorithm = tok.get_uint8()
  49         fp_type = tok.get_uint8()
  50         fingerprint = tok.get_string()
  51         fingerprint = fingerprint.decode('hex_codec')
  52         tok.get_eol()
  53         return cls(rdclass, rdtype, algorithm, fp_type, fingerprint)
  54
  55     from_text = classmethod(from_text)
  56
  57     def to_wire(self, file, compress = None, origin = None):
  58         header = struct.pack("!BB", self.algorithm, self.fp_type)
  59         file.write(header)
  60         file.write(self.fingerprint)
  61
  62     def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
  63         header = struct.unpack("!BB", wire[current : current + 2])
  64         current += 2
  65         rdlen -= 2
  66         fingerprint = wire[current : current + rdlen].unwrap()
  67         return cls(rdclass, rdtype, header[0], header[1], fingerprint)
  68
  69     from_wire = classmethod(from_wire)
  70
  71     def _cmp(self, other):
  72         hs = struct.pack("!BB", self.algorithm, self.fp_type)
  73         ho = struct.pack("!BB", other.algorithm, other.fp_type)
  74         v = cmp(hs, ho)
  75         if v == 0:
  76             v = cmp(self.fingerprint, other.fingerprint)
  77         return v