| # Copyright (C) 2010 Nominum, Inc. |
| # |
| # Permission to use, copy, modify, and distribute this software and its |
| # documentation for any purpose with or without fee is hereby granted, |
| # provided that the above copyright notice and this permission notice |
| # appear in all copies. |
| # |
| # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES |
| # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR |
| # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT |
| # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| |
| import struct |
| |
| import dns.rdata |
| import dns.rdatatype |
| |
| class DSBase(dns.rdata.Rdata): |
| """Base class for rdata that is like a DS record |
| |
| @ivar key_tag: the key tag |
| @type key_tag: int |
| @ivar algorithm: the algorithm |
| @type algorithm: int |
| @ivar digest_type: the digest type |
| @type digest_type: int |
| @ivar digest: the digest |
| @type digest: int |
| @see: draft-ietf-dnsext-delegation-signer-14.txt""" |
| |
| __slots__ = ['key_tag', 'algorithm', 'digest_type', 'digest'] |
| |
| def __init__(self, rdclass, rdtype, key_tag, algorithm, digest_type, |
| digest): |
| super(DSBase, self).__init__(rdclass, rdtype) |
| self.key_tag = key_tag |
| self.algorithm = algorithm |
| self.digest_type = digest_type |
| self.digest = digest |
| |
| def to_text(self, origin=None, relativize=True, **kw): |
| return '%d %d %d %s' % (self.key_tag, self.algorithm, |
| self.digest_type, |
| dns.rdata._hexify(self.digest, |
| chunksize=128)) |
| |
| def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True): |
| key_tag = tok.get_uint16() |
| algorithm = tok.get_uint8() |
| digest_type = tok.get_uint8() |
| chunks = [] |
| while 1: |
| t = tok.get().unescape() |
| if t.is_eol_or_eof(): |
| break |
| if not t.is_identifier(): |
| raise dns.exception.SyntaxError |
| chunks.append(t.value) |
| digest = ''.join(chunks) |
| digest = digest.decode('hex_codec') |
| return cls(rdclass, rdtype, key_tag, algorithm, digest_type, |
| digest) |
| |
| from_text = classmethod(from_text) |
| |
| def to_wire(self, file, compress = None, origin = None): |
| header = struct.pack("!HBB", self.key_tag, self.algorithm, |
| self.digest_type) |
| file.write(header) |
| file.write(self.digest) |
| |
| def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None): |
| header = struct.unpack("!HBB", wire[current : current + 4]) |
| current += 4 |
| rdlen -= 4 |
| digest = wire[current : current + rdlen] |
| return cls(rdclass, rdtype, header[0], header[1], header[2], digest) |
| |
| from_wire = classmethod(from_wire) |
| |
| def _cmp(self, other): |
| hs = struct.pack("!HBB", self.key_tag, self.algorithm, |
| self.digest_type) |
| ho = struct.pack("!HBB", other.key_tag, other.algorithm, |
| other.digest_type) |
| v = cmp(hs, ho) |
| if v == 0: |
| v = cmp(self.digest, other.digest) |
| return v |