Package dns :: Package rdtypes :: Package ANY :: Module DNSKEY
[hide private]
[frames] | no frames]

Source Code for Module dns.rdtypes.ANY.DNSKEY

  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   
 17  import struct 
 18   
 19  import dns.exception 
 20  import dns.dnssec 
 21  import dns.rdata 
 22   
 23   
 24  # flag constants 
 25  SEP = 0x0001 
 26  REVOKE = 0x0080 
 27  ZONE = 0x0100 
 28   
 29  _flag_by_text = { 
 30      'SEP': SEP, 
 31      'REVOKE': REVOKE, 
 32      'ZONE': ZONE 
 33      } 
 34   
 35  # We construct the inverse mapping programmatically to ensure that we 
 36  # cannot make any mistakes (e.g. omissions, cut-and-paste errors) that 
 37  # would cause the mapping not to be true inverse. 
 38  _flag_by_value = dict([(y, x) for x, y in _flag_by_text.iteritems()]) 
 39   
 40   
41 -def flags_to_text_set(flags):
42 """Convert a DNSKEY flags value to set texts 43 @rtype: set([string])""" 44 45 flags_set = set() 46 mask = 0x1 47 while mask <= 0x8000: 48 if flags & mask: 49 text = _flag_by_value.get(mask) 50 if not text: 51 text = hex(mask) 52 flags_set.add(text) 53 mask <<= 1 54 return flags_set
55 56
57 -def flags_from_text_set(texts_set):
58 """Convert set of DNSKEY flag mnemonic texts to DNSKEY flag value 59 @rtype: int""" 60 61 flags = 0 62 for text in texts_set: 63 try: 64 flags += _flag_by_text[text] 65 except KeyError: 66 raise NotImplementedError( 67 "DNSKEY flag '%s' is not supported" % text) 68 return flags
69 70
71 -class DNSKEY(dns.rdata.Rdata):
72 """DNSKEY record 73 74 @ivar flags: the key flags 75 @type flags: int 76 @ivar protocol: the protocol for which this key may be used 77 @type protocol: int 78 @ivar algorithm: the algorithm used for the key 79 @type algorithm: int 80 @ivar key: the public key 81 @type key: string""" 82 83 __slots__ = ['flags', 'protocol', 'algorithm', 'key'] 84
85 - def __init__(self, rdclass, rdtype, flags, protocol, algorithm, key):
86 super(DNSKEY, self).__init__(rdclass, rdtype) 87 self.flags = flags 88 self.protocol = protocol 89 self.algorithm = algorithm 90 self.key = key
91
92 - def to_text(self, origin=None, relativize=True, **kw):
93 return '%d %d %d %s' % (self.flags, self.protocol, self.algorithm, 94 dns.rdata._base64ify(self.key))
95
96 - def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
97 flags = tok.get_uint16() 98 protocol = tok.get_uint8() 99 algorithm = dns.dnssec.algorithm_from_text(tok.get_string()) 100 chunks = [] 101 while 1: 102 t = tok.get().unescape() 103 if t.is_eol_or_eof(): 104 break 105 if not t.is_identifier(): 106 raise dns.exception.SyntaxError 107 chunks.append(t.value) 108 b64 = ''.join(chunks) 109 key = b64.decode('base64_codec') 110 return cls(rdclass, rdtype, flags, protocol, algorithm, key)
111 112 from_text = classmethod(from_text) 113
114 - def to_wire(self, file, compress = None, origin = None):
115 header = struct.pack("!HBB", self.flags, self.protocol, self.algorithm) 116 file.write(header) 117 file.write(self.key)
118
119 - def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
120 if rdlen < 4: 121 raise dns.exception.FormError 122 header = struct.unpack('!HBB', wire[current : current + 4]) 123 current += 4 124 rdlen -= 4 125 key = wire[current : current + rdlen].unwrap() 126 return cls(rdclass, rdtype, header[0], header[1], header[2], 127 key)
128 129 from_wire = classmethod(from_wire) 130
131 - def _cmp(self, other):
132 hs = struct.pack("!HBB", self.flags, self.protocol, self.algorithm) 133 ho = struct.pack("!HBB", other.flags, other.protocol, other.algorithm) 134 v = cmp(hs, ho) 135 if v == 0: 136 v = cmp(self.key, other.key) 137 return v
138
139 - def flags_to_text_set(self):
140 """Convert a DNSKEY flags value to set texts 141 @rtype: set([string])""" 142 return flags_to_text_set(self.flags)
143