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Direktori : /lib/python3.6/site-packages/isc/ |
Current File : //lib/python3.6/site-packages/isc/rndc.py |
############################################################################ # Copyright (C) Internet Systems Consortium, Inc. ("ISC") # # This Source Code Form is subject to the terms of the Mozilla Public # License, v. 2.0. If a copy of the MPL was not distributed with this # file, you can obtain one at https://mozilla.org/MPL/2.0/. # # See the COPYRIGHT file distributed with this work for additional # information regarding copyright ownership. ############################################################################ ############################################################################ # rndc.py # This module implements the RNDC control protocol. ############################################################################ from collections import OrderedDict import time import struct import hashlib import hmac import base64 import random import socket class rndc(object): """RNDC protocol client library""" __algos = {'md5': 157, 'sha1': 161, 'sha224': 162, 'sha256': 163, 'sha384': 164, 'sha512': 165} def __init__(self, host, algo, secret): """Creates a persistent connection to RNDC and logs in host - (ip, port) tuple algo - HMAC algorithm: one of md5, sha1, sha224, sha256, sha384, sha512 (with optional prefix 'hmac-') secret - HMAC secret, base64 encoded""" self.host = host algo = algo.lower() if algo.startswith('hmac-'): algo = algo[5:] self.algo = algo self.hlalgo = getattr(hashlib, algo) self.secret = base64.b64decode(secret) self.ser = random.randint(0, 1 << 24) self.nonce = None self.__connect_login() def call(self, cmd): """Call a RNDC command, all parsing is done on the server side cmd - a complete string with a command (eg 'reload zone example.com') """ return dict(self.__command(type=cmd)['_data']) def __serialize_dict(self, data, ignore_auth=False): rv = bytearray() for k, v in data.items(): if ignore_auth and k == '_auth': continue rv += struct.pack('B', len(k)) + k.encode('ascii') if type(v) == str: rv += struct.pack('>BI', 1, len(v)) + v.encode('ascii') elif type(v) == bytes: rv += struct.pack('>BI', 1, len(v)) + v elif type(v) == bytearray: rv += struct.pack('>BI', 1, len(v)) + v elif type(v) == OrderedDict: sd = self.__serialize_dict(v) rv += struct.pack('>BI', 2, len(sd)) + sd else: raise NotImplementedError('Cannot serialize element of type %s' % type(v)) return rv def __prep_message(self, *args, **kwargs): self.ser += 1 now = int(time.time()) data = OrderedDict(*args, **kwargs) d = OrderedDict() d['_auth'] = OrderedDict() d['_ctrl'] = OrderedDict() d['_ctrl']['_ser'] = str(self.ser) d['_ctrl']['_tim'] = str(now) d['_ctrl']['_exp'] = str(now+60) if self.nonce is not None: d['_ctrl']['_nonce'] = self.nonce d['_data'] = data msg = self.__serialize_dict(d, ignore_auth=True) hash = hmac.new(self.secret, msg, self.hlalgo).digest() bhash = base64.b64encode(hash) if self.algo == 'md5': d['_auth']['hmd5'] = struct.pack('22s', bhash) else: d['_auth']['hsha'] = bytearray(struct.pack('B88s', self.__algos[self.algo], bhash)) msg = self.__serialize_dict(d) msg = struct.pack('>II', len(msg) + 4, 1) + msg return msg def __verify_msg(self, msg): if self.nonce is not None and msg['_ctrl']['_nonce'] != self.nonce: return False if self.algo == 'md5': bhash = msg['_auth']['hmd5'] else: bhash = msg['_auth']['hsha'][1:] if type(bhash) == bytes: bhash = bhash.decode('ascii') bhash += '=' * (4 - (len(bhash) % 4)) remote_hash = base64.b64decode(bhash) my_msg = self.__serialize_dict(msg, ignore_auth=True) my_hash = hmac.new(self.secret, my_msg, self.hlalgo).digest() return (my_hash == remote_hash) def __command(self, *args, **kwargs): msg = self.__prep_message(*args, **kwargs) sent = self.socket.send(msg) if sent != len(msg): raise IOError("Cannot send the message") header = self.socket.recv(8) if len(header) != 8: # What should we throw here? Bad auth can cause this... raise IOError("Can't read response header") length, version = struct.unpack('>II', header) if version != 1: raise NotImplementedError('Wrong message version %d' % version) # it includes the header length -= 4 data = self.socket.recv(length, socket.MSG_WAITALL) if len(data) != length: raise IOError("Can't read response data") if type(data) == str: data = bytearray(data) msg = self.__parse_message(data) if not self.__verify_msg(msg): raise IOError("Authentication failure") return msg def __connect_login(self): self.socket = socket.create_connection(self.host) self.nonce = None msg = self.__command(type='null') self.nonce = msg['_ctrl']['_nonce'] def __parse_element(self, input): pos = 0 labellen = input[pos] pos += 1 label = input[pos:pos+labellen].decode('ascii') pos += labellen type = input[pos] pos += 1 datalen = struct.unpack('>I', input[pos:pos+4])[0] pos += 4 data = input[pos:pos+datalen] pos += datalen rest = input[pos:] if type == 1: # raw binary value return label, data, rest elif type == 2: # dictionary d = OrderedDict() while len(data) > 0: ilabel, value, data = self.__parse_element(data) d[ilabel] = value return label, d, rest # TODO type 3 - list else: raise NotImplementedError('Unknown element type %d' % type) def __parse_message(self, input): rv = OrderedDict() hdata = None while len(input) > 0: label, value, input = self.__parse_element(input) rv[label] = value return rv