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# Copyright (C) 2010, 2011 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].unwrap()
current += lh
rdlen -= lh
key = wire[current : current + lk].unwrap()
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
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