| # 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 cStringIO |
| import string |
| import struct |
| |
| import dns.exception |
| import dns.rdata |
| import dns.rdatatype |
| |
| class HIP(dns.rdata.Rdata): |
| """HIP record |
| |
| @ivar hit: the host identity tag |
| @type hit: string |
| @ivar algorithm: the public key cryptographic algorithm |
| @type algorithm: int |
| @ivar key: the public key |
| @type key: string |
| @ivar servers: the rendezvous servers |
| @type servers: list of dns.name.Name objects |
| @see: RFC 5205""" |
| |
| __slots__ = ['hit', 'algorithm', 'key', 'servers'] |
| |
| def __init__(self, rdclass, rdtype, hit, algorithm, key, servers): |
| super(HIP, self).__init__(rdclass, rdtype) |
| self.hit = hit |
| self.algorithm = algorithm |
| self.key = key |
| self.servers = servers |
| |
| def to_text(self, origin=None, relativize=True, **kw): |
| hit = self.hit.encode('hex-codec') |
| key = self.key.encode('base64-codec').replace('\n', '') |
| text = '' |
| servers = [] |
| for server in self.servers: |
| servers.append(str(server.choose_relativity(origin, relativize))) |
| if len(servers) > 0: |
| text += (' ' + ' '.join(servers)) |
| return '%u %s %s%s' % (self.algorithm, hit, key, text) |
| |
| def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True): |
| algorithm = tok.get_uint8() |
| hit = tok.get_string().decode('hex-codec') |
| if len(hit) > 255: |
| raise dns.exception.SyntaxError("HIT too long") |
| key = tok.get_string().decode('base64-codec') |
| servers = [] |
| while 1: |
| token = tok.get() |
| if token.is_eol_or_eof(): |
| break |
| server = dns.name.from_text(token.value, origin) |
| server.choose_relativity(origin, relativize) |
| servers.append(server) |
| return cls(rdclass, rdtype, hit, algorithm, key, servers) |
| |
| from_text = classmethod(from_text) |
| |
| def to_wire(self, file, compress = None, origin = None): |
| lh = len(self.hit) |
| lk = len(self.key) |
| file.write(struct.pack("!BBH", lh, self.algorithm, lk)) |
| file.write(self.hit) |
| file.write(self.key) |
| for server in self.servers: |
| server.to_wire(file, None, origin) |
| |
| def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None): |
| (lh, algorithm, lk) = struct.unpack('!BBH', |
| wire[current : current + 4]) |
| current += 4 |
| rdlen -= 4 |
| hit = wire[current : current + lh] |
| current += lh |
| rdlen -= lh |
| key = wire[current : current + lk] |
| current += lk |
| rdlen -= lk |
| servers = [] |
| while rdlen > 0: |
| (server, cused) = dns.name.from_wire(wire[: current + rdlen], |
| current) |
| current += cused |
| rdlen -= cused |
| if not origin is None: |
| server = server.relativize(origin) |
| servers.append(server) |
| return cls(rdclass, rdtype, hit, algorithm, key, servers) |
| |
| from_wire = classmethod(from_wire) |
| |
| def choose_relativity(self, origin = None, relativize = True): |
| servers = [] |
| for server in self.servers: |
| server = server.choose_relativity(origin, relativize) |
| servers.append(server) |
| self.servers = servers |
| |
| def _cmp(self, other): |
| b1 = cStringIO.StringIO() |
| lh = len(self.hit) |
| lk = len(self.key) |
| b1.write(struct.pack("!BBH", lh, self.algorithm, lk)) |
| b1.write(self.hit) |
| b1.write(self.key) |
| b2 = cStringIO.StringIO() |
| lh = len(other.hit) |
| lk = len(other.key) |
| b2.write(struct.pack("!BBH", lh, other.algorithm, lk)) |
| b2.write(other.hit) |
| b2.write(other.key) |
| v = cmp(b1.getvalue(), b2.getvalue()) |
| if v != 0: |
| return v |
| ls = len(self.servers) |
| lo = len(other.servers) |
| count = min(ls, lo) |
| i = 0 |
| while i < count: |
| v = cmp(self.servers[i], other.servers[i]) |
| if v != 0: |
| return v |
| i += 1 |
| return ls - lo |