# Copyright (C) 2004-2007, 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.exception
import dns.rdata
from dns._compat import text_type
class NSEC3PARAM(dns.rdata.Rdata):
"""NSEC3PARAM record
@ivar algorithm: the hash algorithm number
@type algorithm: int
@ivar flags: the flags
@type flags: int
@ivar iterations: the number of iterations
@type iterations: int
@ivar salt: the salt
@type salt: string"""
__slots__ = ['algorithm', 'flags', 'iterations', 'salt']
def __init__(self, rdclass, rdtype, algorithm, flags, iterations, salt):
super(NSEC3PARAM, self).__init__(rdclass, rdtype)
self.algorithm = algorithm
self.flags = flags
self.iterations = iterations
if isinstance(salt, text_type):
self.salt = salt.encode()
else:
self.salt = salt
def to_text(self, origin=None, relativize=True, **kw):
if self.salt == b'':
salt = '-'
else:
salt = binascii.hexlify(self.salt).decode()
return '%u %u %u %s' % (self.algorithm, self.flags, self.iterations,
salt)
@classmethod
def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
algorithm = tok.get_uint8()
flags = tok.get_uint8()
iterations = tok.get_uint16()
salt = tok.get_string()
if salt == '-':
salt = ''
else:
salt = binascii.unhexlify(salt.encode())
tok.get_eol()
return cls(rdclass, rdtype, algorithm, flags, iterations, salt)
def to_wire(self, file, compress=None, origin=None):
l = len(self.salt)
file.write(struct.pack("!BBHB", self.algorithm, self.flags,
self.iterations, l))
file.write(self.salt)
@classmethod
def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
(algorithm, flags, iterations, slen) = \
struct.unpack('!BBHB',
wire[current: current + 5])
current += 5
rdlen -= 5
salt = wire[current: current + slen].unwrap()
current += slen
rdlen -= slen
if rdlen != 0:
raise dns.exception.FormError
return cls(rdclass, rdtype, algorithm, flags, iterations, salt)
