Source Code for Module dns.rdtypes.dsbase

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15   
16  import struct 
17  import binascii 
18   
19  import dns.rdata 
20  import dns.rdatatype 
21   
22   
23 -class DSBase(dns.rdata.Rdata): 
24   
25      """Base class for rdata that is like a DS record 
26   
27      @ivar key_tag: the key tag 
28      @type key_tag: int 
29      @ivar algorithm: the algorithm 
30      @type algorithm: int 
31      @ivar digest_type: the digest type 
32      @type digest_type: int 
33      @ivar digest: the digest 
34      @type digest: int 
35      @see: draft-ietf-dnsext-delegation-signer-14.txt""" 
36   
37      __slots__ = ['key_tag', 'algorithm', 'digest_type', 'digest'] 
38   
39 -    def __init__(self, rdclass, rdtype, key_tag, algorithm, digest_type, 
40                   digest): 
41          super(DSBase, self).__init__(rdclass, rdtype) 
42          self.key_tag = key_tag 
43          self.algorithm = algorithm 
44          self.digest_type = digest_type 
45          self.digest = digest 
46   
47 -    def to_text(self, origin=None, relativize=True, **kw): 
48          return '%d %d %d %s' % (self.key_tag, self.algorithm, 
49                                  self.digest_type, 
50                                  dns.rdata._hexify(self.digest, 
51                                                    chunksize=128)) 
52   
53      @classmethod 
54 -    def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True): 
55          key_tag = tok.get_uint16() 
56          algorithm = tok.get_uint8() 
57          digest_type = tok.get_uint8() 
58          chunks = [] 
59          while 1: 
60              t = tok.get().unescape() 
61              if t.is_eol_or_eof(): 
62                  break 
63              if not t.is_identifier(): 
64                  raise dns.exception.SyntaxError 
65              chunks.append(t.value.encode()) 
66          digest = b''.join(chunks) 
67          digest = binascii.unhexlify(digest) 
68          return cls(rdclass, rdtype, key_tag, algorithm, digest_type, 
69                     digest) 
70   
71 -    def to_wire(self, file, compress=None, origin=None): 
72          header = struct.pack("!HBB", self.key_tag, self.algorithm, 
73                               self.digest_type) 
74          file.write(header) 
75          file.write(self.digest) 
76   
77      @classmethod 
78 -    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None): 
79          header = struct.unpack("!HBB", wire[current: current + 4]) 
80          current += 4 
81          rdlen -= 4 
82          digest = wire[current: current + rdlen].unwrap() 
83          return cls(rdclass, rdtype, header[0], header[1], header[2], digest) 
84