mirror of
https://github.com/morpheus65535/bazarr
synced 2024-12-27 01:57:33 +00:00
234 lines
7.5 KiB
Python
234 lines
7.5 KiB
Python
# Copyright (C) 2001-2007, 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.
|
|
|
|
"""DNS TSIG support."""
|
|
|
|
import hmac
|
|
import struct
|
|
|
|
import dns.exception
|
|
import dns.hash
|
|
import dns.rdataclass
|
|
import dns.name
|
|
from ._compat import long, string_types, text_type
|
|
|
|
class BadTime(dns.exception.DNSException):
|
|
|
|
"""The current time is not within the TSIG's validity time."""
|
|
|
|
|
|
class BadSignature(dns.exception.DNSException):
|
|
|
|
"""The TSIG signature fails to verify."""
|
|
|
|
|
|
class PeerError(dns.exception.DNSException):
|
|
|
|
"""Base class for all TSIG errors generated by the remote peer"""
|
|
|
|
|
|
class PeerBadKey(PeerError):
|
|
|
|
"""The peer didn't know the key we used"""
|
|
|
|
|
|
class PeerBadSignature(PeerError):
|
|
|
|
"""The peer didn't like the signature we sent"""
|
|
|
|
|
|
class PeerBadTime(PeerError):
|
|
|
|
"""The peer didn't like the time we sent"""
|
|
|
|
|
|
class PeerBadTruncation(PeerError):
|
|
|
|
"""The peer didn't like amount of truncation in the TSIG we sent"""
|
|
|
|
# TSIG Algorithms
|
|
|
|
HMAC_MD5 = dns.name.from_text("HMAC-MD5.SIG-ALG.REG.INT")
|
|
HMAC_SHA1 = dns.name.from_text("hmac-sha1")
|
|
HMAC_SHA224 = dns.name.from_text("hmac-sha224")
|
|
HMAC_SHA256 = dns.name.from_text("hmac-sha256")
|
|
HMAC_SHA384 = dns.name.from_text("hmac-sha384")
|
|
HMAC_SHA512 = dns.name.from_text("hmac-sha512")
|
|
|
|
_hashes = {
|
|
HMAC_SHA224: 'SHA224',
|
|
HMAC_SHA256: 'SHA256',
|
|
HMAC_SHA384: 'SHA384',
|
|
HMAC_SHA512: 'SHA512',
|
|
HMAC_SHA1: 'SHA1',
|
|
HMAC_MD5: 'MD5',
|
|
}
|
|
|
|
default_algorithm = HMAC_MD5
|
|
|
|
BADSIG = 16
|
|
BADKEY = 17
|
|
BADTIME = 18
|
|
BADTRUNC = 22
|
|
|
|
|
|
def sign(wire, keyname, secret, time, fudge, original_id, error,
|
|
other_data, request_mac, ctx=None, multi=False, first=True,
|
|
algorithm=default_algorithm):
|
|
"""Return a (tsig_rdata, mac, ctx) tuple containing the HMAC TSIG rdata
|
|
for the input parameters, the HMAC MAC calculated by applying the
|
|
TSIG signature algorithm, and the TSIG digest context.
|
|
@rtype: (string, string, hmac.HMAC object)
|
|
@raises ValueError: I{other_data} is too long
|
|
@raises NotImplementedError: I{algorithm} is not supported
|
|
"""
|
|
|
|
if isinstance(other_data, text_type):
|
|
other_data = other_data.encode()
|
|
(algorithm_name, digestmod) = get_algorithm(algorithm)
|
|
if first:
|
|
ctx = hmac.new(secret, digestmod=digestmod)
|
|
ml = len(request_mac)
|
|
if ml > 0:
|
|
ctx.update(struct.pack('!H', ml))
|
|
ctx.update(request_mac)
|
|
id = struct.pack('!H', original_id)
|
|
ctx.update(id)
|
|
ctx.update(wire[2:])
|
|
if first:
|
|
ctx.update(keyname.to_digestable())
|
|
ctx.update(struct.pack('!H', dns.rdataclass.ANY))
|
|
ctx.update(struct.pack('!I', 0))
|
|
long_time = time + long(0)
|
|
upper_time = (long_time >> 32) & long(0xffff)
|
|
lower_time = long_time & long(0xffffffff)
|
|
time_mac = struct.pack('!HIH', upper_time, lower_time, fudge)
|
|
pre_mac = algorithm_name + time_mac
|
|
ol = len(other_data)
|
|
if ol > 65535:
|
|
raise ValueError('TSIG Other Data is > 65535 bytes')
|
|
post_mac = struct.pack('!HH', error, ol) + other_data
|
|
if first:
|
|
ctx.update(pre_mac)
|
|
ctx.update(post_mac)
|
|
else:
|
|
ctx.update(time_mac)
|
|
mac = ctx.digest()
|
|
mpack = struct.pack('!H', len(mac))
|
|
tsig_rdata = pre_mac + mpack + mac + id + post_mac
|
|
if multi:
|
|
ctx = hmac.new(secret, digestmod=digestmod)
|
|
ml = len(mac)
|
|
ctx.update(struct.pack('!H', ml))
|
|
ctx.update(mac)
|
|
else:
|
|
ctx = None
|
|
return (tsig_rdata, mac, ctx)
|
|
|
|
|
|
def hmac_md5(wire, keyname, secret, time, fudge, original_id, error,
|
|
other_data, request_mac, ctx=None, multi=False, first=True,
|
|
algorithm=default_algorithm):
|
|
return sign(wire, keyname, secret, time, fudge, original_id, error,
|
|
other_data, request_mac, ctx, multi, first, algorithm)
|
|
|
|
|
|
def validate(wire, keyname, secret, now, request_mac, tsig_start, tsig_rdata,
|
|
tsig_rdlen, ctx=None, multi=False, first=True):
|
|
"""Validate the specified TSIG rdata against the other input parameters.
|
|
|
|
@raises FormError: The TSIG is badly formed.
|
|
@raises BadTime: There is too much time skew between the client and the
|
|
server.
|
|
@raises BadSignature: The TSIG signature did not validate
|
|
@rtype: hmac.HMAC object"""
|
|
|
|
(adcount,) = struct.unpack("!H", wire[10:12])
|
|
if adcount == 0:
|
|
raise dns.exception.FormError
|
|
adcount -= 1
|
|
new_wire = wire[0:10] + struct.pack("!H", adcount) + wire[12:tsig_start]
|
|
current = tsig_rdata
|
|
(aname, used) = dns.name.from_wire(wire, current)
|
|
current = current + used
|
|
(upper_time, lower_time, fudge, mac_size) = \
|
|
struct.unpack("!HIHH", wire[current:current + 10])
|
|
time = ((upper_time + long(0)) << 32) + (lower_time + long(0))
|
|
current += 10
|
|
mac = wire[current:current + mac_size]
|
|
current += mac_size
|
|
(original_id, error, other_size) = \
|
|
struct.unpack("!HHH", wire[current:current + 6])
|
|
current += 6
|
|
other_data = wire[current:current + other_size]
|
|
current += other_size
|
|
if current != tsig_rdata + tsig_rdlen:
|
|
raise dns.exception.FormError
|
|
if error != 0:
|
|
if error == BADSIG:
|
|
raise PeerBadSignature
|
|
elif error == BADKEY:
|
|
raise PeerBadKey
|
|
elif error == BADTIME:
|
|
raise PeerBadTime
|
|
elif error == BADTRUNC:
|
|
raise PeerBadTruncation
|
|
else:
|
|
raise PeerError('unknown TSIG error code %d' % error)
|
|
time_low = time - fudge
|
|
time_high = time + fudge
|
|
if now < time_low or now > time_high:
|
|
raise BadTime
|
|
(junk, our_mac, ctx) = sign(new_wire, keyname, secret, time, fudge,
|
|
original_id, error, other_data,
|
|
request_mac, ctx, multi, first, aname)
|
|
if our_mac != mac:
|
|
raise BadSignature
|
|
return ctx
|
|
|
|
|
|
def get_algorithm(algorithm):
|
|
"""Returns the wire format string and the hash module to use for the
|
|
specified TSIG algorithm
|
|
|
|
@rtype: (string, hash constructor)
|
|
@raises NotImplementedError: I{algorithm} is not supported
|
|
"""
|
|
|
|
if isinstance(algorithm, string_types):
|
|
algorithm = dns.name.from_text(algorithm)
|
|
|
|
try:
|
|
return (algorithm.to_digestable(), dns.hash.hashes[_hashes[algorithm]])
|
|
except KeyError:
|
|
raise NotImplementedError("TSIG algorithm " + str(algorithm) +
|
|
" is not supported")
|
|
|
|
|
|
def get_algorithm_and_mac(wire, tsig_rdata, tsig_rdlen):
|
|
"""Return the tsig algorithm for the specified tsig_rdata
|
|
@raises FormError: The TSIG is badly formed.
|
|
"""
|
|
current = tsig_rdata
|
|
(aname, used) = dns.name.from_wire(wire, current)
|
|
current = current + used
|
|
(upper_time, lower_time, fudge, mac_size) = \
|
|
struct.unpack("!HIHH", wire[current:current + 10])
|
|
current += 10
|
|
mac = wire[current:current + mac_size]
|
|
current += mac_size
|
|
if current > tsig_rdata + tsig_rdlen:
|
|
raise dns.exception.FormError
|
|
return (aname, mac)
|