Source Code for Module dns.rdtypes.dsbase

 1  # Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license 
 2   
 3  # Copyright (C) 2010, 2011 Nominum, Inc. 
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17   
18  import struct 
19  import binascii 
20   
21  import dns.rdata 
22  import dns.rdatatype 
23   
24   
25 -class DSBase(dns.rdata.Rdata): 
26   
27      """Base class for rdata that is like a DS record 
28   
29      @ivar key_tag: the key tag 
30      @type key_tag: int 
31      @ivar algorithm: the algorithm 
32      @type algorithm: int 
33      @ivar digest_type: the digest type 
34      @type digest_type: int 
35      @ivar digest: the digest 
36      @type digest: int 
37      @see: draft-ietf-dnsext-delegation-signer-14.txt""" 
38   
39      __slots__ = ['key_tag', 'algorithm', 'digest_type', 'digest'] 
40   
41 -    def __init__(self, rdclass, rdtype, key_tag, algorithm, digest_type, 
42                   digest): 
43          super(DSBase, self).__init__(rdclass, rdtype) 
44          self.key_tag = key_tag 
45          self.algorithm = algorithm 
46          self.digest_type = digest_type 
47          self.digest = digest 
48   
49 -    def to_text(self, origin=None, relativize=True, **kw): 
50          return '%d %d %d %s' % (self.key_tag, self.algorithm, 
51                                  self.digest_type, 
52                                  dns.rdata._hexify(self.digest, 
53                                                    chunksize=128)) 
54   
55      @classmethod 
56 -    def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True): 
57          key_tag = tok.get_uint16() 
58          algorithm = tok.get_uint8() 
59          digest_type = tok.get_uint8() 
60          chunks = [] 
61          while 1: 
62              t = tok.get().unescape() 
63              if t.is_eol_or_eof(): 
64                  break 
65              if not t.is_identifier(): 
66                  raise dns.exception.SyntaxError 
67              chunks.append(t.value.encode()) 
68          digest = b''.join(chunks) 
69          digest = binascii.unhexlify(digest) 
70          return cls(rdclass, rdtype, key_tag, algorithm, digest_type, 
71                     digest) 
72   
73 -    def to_wire(self, file, compress=None, origin=None): 
74          header = struct.pack("!HBB", self.key_tag, self.algorithm, 
75                               self.digest_type) 
76          file.write(header) 
77          file.write(self.digest) 
78   
79      @classmethod 
80 -    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None): 
81          header = struct.unpack("!HBB", wire[current: current + 4]) 
82          current += 4 
83          rdlen -= 4 
84          digest = wire[current: current + rdlen].unwrap() 
85          return cls(rdclass, rdtype, header[0], header[1], header[2], digest) 
86