# Copyright (C) 2005-2007, 2009-2011 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 struct
import binascii
import dns.rdata
import dns.rdatatype
class TLSA(dns.rdata.Rdata):
"""TLSA record
@ivar usage: The certificate usage
@type usage: int
@ivar selector: The selector field
@type selector: int
@ivar mtype: The 'matching type' field
@type mtype: int
@ivar cert: The 'Certificate Association Data' field
@type cert: string
@see: RFC 6698"""
__slots__ = ['usage', 'selector', 'mtype', 'cert']
def __init__(self, rdclass, rdtype, usage, selector,
mtype, cert):
super(TLSA, self).__init__(rdclass, rdtype)
self.usage = usage
self.selector = selector
self.mtype = mtype
self.cert = cert
def to_text(self, origin=None, relativize=True, **kw):
return '%d %d %d %s' % (self.usage,
self.selector,
self.mtype,
dns.rdata._hexify(self.cert,
chunksize=128))
@classmethod
def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
usage = tok.get_uint8()
selector = tok.get_uint8()
mtype = tok.get_uint8()
cert_chunks = []
while 1:
t = tok.get().unescape()
if t.is_eol_or_eof():
break
if not t.is_identifier():
raise dns.exception.SyntaxError
cert_chunks.append(t.value.encode())
cert = b''.join(cert_chunks)
cert = binascii.unhexlify(cert)
return cls(rdclass, rdtype, usage, selector, mtype, cert)
def to_wire(self, file, compress=None, origin=None):
header = struct.pack("!BBB", self.usage, self.selector, self.mtype)
file.write(header)
file.write(self.cert)
@classmethod
def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
header = struct.unpack("!BBB", wire[current: current + 3])
current += 3
rdlen -= 3
cert = wire[current: current + rdlen].unwrap()
return cls(rdclass, rdtype, header[0], header[1], header[2], cert)
