1# Copyright (C) 2005-2007, 2009, 2010 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
16import struct
17
18import dns.rdata
19import dns.rdatatype
20
21class 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]
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
78