1# Copyright (C) 2004-2007, 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.exception
19import dns.dnssec
20import dns.rdata
21
22_flags_from_text = {
23    'NOCONF': (0x4000, 0xC000),
24    'NOAUTH': (0x8000, 0xC000),
25    'NOKEY': (0xC000, 0xC000),
26    'FLAG2': (0x2000, 0x2000),
27    'EXTEND': (0x1000, 0x1000),
28    'FLAG4': (0x0800, 0x0800),
29    'FLAG5': (0x0400, 0x0400),
30    'USER': (0x0000, 0x0300),
31    'ZONE': (0x0100, 0x0300),
32    'HOST': (0x0200, 0x0300),
33    'NTYP3': (0x0300, 0x0300),
34    'FLAG8': (0x0080, 0x0080),
35    'FLAG9': (0x0040, 0x0040),
36    'FLAG10': (0x0020, 0x0020),
37    'FLAG11': (0x0010, 0x0010),
38    'SIG0': (0x0000, 0x000f),
39    'SIG1': (0x0001, 0x000f),
40    'SIG2': (0x0002, 0x000f),
41    'SIG3': (0x0003, 0x000f),
42    'SIG4': (0x0004, 0x000f),
43    'SIG5': (0x0005, 0x000f),
44    'SIG6': (0x0006, 0x000f),
45    'SIG7': (0x0007, 0x000f),
46    'SIG8': (0x0008, 0x000f),
47    'SIG9': (0x0009, 0x000f),
48    'SIG10': (0x000a, 0x000f),
49    'SIG11': (0x000b, 0x000f),
50    'SIG12': (0x000c, 0x000f),
51    'SIG13': (0x000d, 0x000f),
52    'SIG14': (0x000e, 0x000f),
53    'SIG15': (0x000f, 0x000f),
54    }
55
56_protocol_from_text = {
57    'NONE' : 0,
58    'TLS' : 1,
59    'EMAIL' : 2,
60    'DNSSEC' : 3,
61    'IPSEC' : 4,
62    'ALL' : 255,
63    }
64
65class KEYBase(dns.rdata.Rdata):
66    """KEY-like record base
67
68    @ivar flags: the key flags
69    @type flags: int
70    @ivar protocol: the protocol for which this key may be used
71    @type protocol: int
72    @ivar algorithm: the algorithm used for the key
73    @type algorithm: int
74    @ivar key: the public key
75    @type key: string"""
76
77    __slots__ = ['flags', 'protocol', 'algorithm', 'key']
78
79    def __init__(self, rdclass, rdtype, flags, protocol, algorithm, key):
80        super(KEYBase, self).__init__(rdclass, rdtype)
81        self.flags = flags
82        self.protocol = protocol
83        self.algorithm = algorithm
84        self.key = key
85
86    def to_text(self, origin=None, relativize=True, **kw):
87        return '%d %d %d %s' % (self.flags, self.protocol, self.algorithm,
88                                dns.rdata._base64ify(self.key))
89
90    def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
91        flags = tok.get_string()
92        if flags.isdigit():
93            flags = int(flags)
94        else:
95            flag_names = flags.split('|')
96            flags = 0
97            for flag in flag_names:
98                v = _flags_from_text.get(flag)
99                if v is None:
100                    raise dns.exception.SyntaxError('unknown flag %s' % flag)
101                flags &= ~v[1]
102                flags |= v[0]
103        protocol = tok.get_string()
104        if protocol.isdigit():
105            protocol = int(protocol)
106        else:
107            protocol = _protocol_from_text.get(protocol)
108            if protocol is None:
109                raise dns.exception.SyntaxError('unknown protocol %s' % protocol)
110
111        algorithm = dns.dnssec.algorithm_from_text(tok.get_string())
112        chunks = []
113        while 1:
114            t = tok.get().unescape()
115            if t.is_eol_or_eof():
116                break
117            if not t.is_identifier():
118                raise dns.exception.SyntaxError
119            chunks.append(t.value)
120        b64 = ''.join(chunks)
121        key = b64.decode('base64_codec')
122        return cls(rdclass, rdtype, flags, protocol, algorithm, key)
123
124    from_text = classmethod(from_text)
125
126    def to_wire(self, file, compress = None, origin = None):
127        header = struct.pack("!HBB", self.flags, self.protocol, self.algorithm)
128        file.write(header)
129        file.write(self.key)
130
131    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
132        if rdlen < 4:
133            raise dns.exception.FormError
134        header = struct.unpack('!HBB', wire[current : current + 4])
135        current += 4
136        rdlen -= 4
137        key = wire[current : current + rdlen]
138        return cls(rdclass, rdtype, header[0], header[1], header[2],
139                   key)
140
141    from_wire = classmethod(from_wire)
142
143    def _cmp(self, other):
144        hs = struct.pack("!HBB", self.flags, self.protocol, self.algorithm)
145        ho = struct.pack("!HBB", other.flags, other.protocol, other.algorithm)
146        v = cmp(hs, ho)
147        if v == 0:
148            v = cmp(self.key, other.key)
149        return v
150