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

Source Code for Module dns.rdtypes.dnskeybase

  1  # Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license 
  2   
  3  # Copyright (C) 2004-2007, 2009-2011 Nominum, Inc. 
  4  # 
  5  # Permission to use, copy, modify, and distribute this software and its 
  6  # documentation for any purpose with or without fee is hereby granted, 
  7  # provided that the above copyright notice and this permission notice 
  8  # appear in all copies. 
  9  # 
 10  # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES 
 11  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 
 12  # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR 
 13  # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
 14  # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 
 15  # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 
 16  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
 17   
 18  import base64 
 19  import struct 
 20   
 21  import dns.exception 
 22  import dns.dnssec 
 23  import dns.rdata 
 24   
 25  # wildcard import 
 26  __all__ = ["SEP", "REVOKE", "ZONE", 
 27             "flags_to_text_set", "flags_from_text_set"] 
 28   
 29  # flag constants 
 30  SEP = 0x0001 
 31  REVOKE = 0x0080 
 32  ZONE = 0x0100 
 33   
 34  _flag_by_text = { 
 35      'SEP': SEP, 
 36      'REVOKE': REVOKE, 
 37      'ZONE': ZONE 
 38  } 
 39   
 40  # We construct the inverse mapping programmatically to ensure that we 
 41  # cannot make any mistakes (e.g. omissions, cut-and-paste errors) that 
 42  # would cause the mapping not to be true inverse. 
 43  _flag_by_value = {y: x for x, y in _flag_by_text.items()} 
44 45 46 -def flags_to_text_set(flags):
47 """Convert a DNSKEY flags value to set texts 48 @rtype: set([string])""" 49 50 flags_set = set() 51 mask = 0x1 52 while mask <= 0x8000: 53 if flags & mask: 54 text = _flag_by_value.get(mask) 55 if not text: 56 text = hex(mask) 57 flags_set.add(text) 58 mask <<= 1 59 return flags_set
60
61 62 -def flags_from_text_set(texts_set):
63 """Convert set of DNSKEY flag mnemonic texts to DNSKEY flag value 64 @rtype: int""" 65 66 flags = 0 67 for text in texts_set: 68 try: 69 flags += _flag_by_text[text] 70 except KeyError: 71 raise NotImplementedError( 72 "DNSKEY flag '%s' is not supported" % text) 73 return flags
74
75 76 -class DNSKEYBase(dns.rdata.Rdata):
77 78 """Base class for rdata that is like a DNSKEY record 79 80 @ivar flags: the key flags 81 @type flags: int 82 @ivar protocol: the protocol for which this key may be used 83 @type protocol: int 84 @ivar algorithm: the algorithm used for the key 85 @type algorithm: int 86 @ivar key: the public key 87 @type key: string""" 88 89 __slots__ = ['flags', 'protocol', 'algorithm', 'key'] 90
91 - def __init__(self, rdclass, rdtype, flags, protocol, algorithm, key):
92 super(DNSKEYBase, self).__init__(rdclass, rdtype) 93 self.flags = flags 94 self.protocol = protocol 95 self.algorithm = algorithm 96 self.key = key
97
98 - def to_text(self, origin=None, relativize=True, **kw):
99 return '%d %d %d %s' % (self.flags, self.protocol, self.algorithm, 100 dns.rdata._base64ify(self.key))
101 102 @classmethod
103 - def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
104 flags = tok.get_uint16() 105 protocol = tok.get_uint8() 106 algorithm = dns.dnssec.algorithm_from_text(tok.get_string()) 107 chunks = [] 108 while 1: 109 t = tok.get().unescape() 110 if t.is_eol_or_eof(): 111 break 112 if not t.is_identifier(): 113 raise dns.exception.SyntaxError 114 chunks.append(t.value.encode()) 115 b64 = b''.join(chunks) 116 key = base64.b64decode(b64) 117 return cls(rdclass, rdtype, flags, protocol, algorithm, key)
118
119 - def to_wire(self, file, compress=None, origin=None):
120 header = struct.pack("!HBB", self.flags, self.protocol, self.algorithm) 121 file.write(header) 122 file.write(self.key)
123 124 @classmethod
125 - def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
126 if rdlen < 4: 127 raise dns.exception.FormError 128 header = struct.unpack('!HBB', wire[current: current + 4]) 129 current += 4 130 rdlen -= 4 131 key = wire[current: current + rdlen].unwrap() 132 return cls(rdclass, rdtype, header[0], header[1], header[2], 133 key)
134
135 - def flags_to_text_set(self):
136 """Convert a DNSKEY flags value to set texts 137 @rtype: set([string])""" 138 return flags_to_text_set(self.flags)
139