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Editing: dnskey.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. ############################################################################ import os import time import calendar from subprocess import Popen, PIPE ######################################################################## # Class dnskey ######################################################################## class TimePast(Exception): def __init__(self, key, prop, value): super(TimePast, self).__init__('%s time for key %s (%d) is already past' % (prop, key, value)) class dnskey: """An individual DNSSEC key. Identified by path, name, algorithm, keyid. Contains a dictionary of metadata events.""" _PROPS = ('Created', 'Publish', 'Activate', 'Inactive', 'Delete', 'Revoke', 'DSPublish', 'SyncPublish', 'SyncDelete') _OPTS = (None, '-P', '-A', '-I', '-D', '-R', None, '-Psync', '-Dsync') _ALGNAMES = (None, 'RSAMD5', 'DH', 'DSA', 'ECC', 'RSASHA1', 'NSEC3DSA', 'NSEC3RSASHA1', 'RSASHA256', None, 'RSASHA512', None, 'ECCGOST', 'ECDSAP256SHA256', 'ECDSAP384SHA384', 'ED25519', 'ED448') def __init__(self, key, directory=None, keyttl=None): # this makes it possible to use algname as a class or instance method if isinstance(key, tuple) and len(key) == 3: self._dir = directory or '.' (name, alg, keyid) = key self.fromtuple(name, alg, keyid, keyttl) self._dir = directory or os.path.dirname(key) or '.' key = os.path.basename(key) (name, alg, keyid) = key.split('+') name = name[1:-1] alg = int(alg) keyid = int(keyid.split('.')[0]) self.fromtuple(name, alg, keyid, keyttl) def fromtuple(self, name, alg, keyid, keyttl): if name.endswith('.'): fullname = name name = name.rstrip('.') else: fullname = name + '.' keystr = "K%s+%03d+%05d" % (fullname, alg, keyid) key_file = self._dir + (self._dir and os.sep or '') + keystr + ".key" private_file = (self._dir + (self._dir and os.sep or '') + keystr + ".private") self.keystr = keystr self.name = name self.alg = int(alg) self.keyid = int(keyid) self.fullname = fullname kfp = open(key_file, "r") for line in kfp: if line[0] == ';': continue tokens = line.split() if not tokens: continue if tokens[1].lower() in ('in', 'ch', 'hs'): septoken = 3 self.ttl = keyttl else: septoken = 4 self.ttl = int(tokens[1]) if not keyttl else keyttl if (int(tokens[septoken]) & 0x1) == 1: self.sep = True else: self.sep = False kfp.close() pfp = open(private_file, "rU") self.metadata = dict() self._changed = dict() self._delete = dict() self._times = dict() self._fmttime = dict() self._timestamps = dict() self._original = dict() self._origttl = None for line in pfp: line = line.strip() if not line or line[0] in ('!#'): continue punctuation = [line.find(c) for c in ':= '] + [len(line)] found = min([pos for pos in punctuation if pos != -1]) name = line[:found].rstrip() value = line[found:].lstrip(":= ").rstrip() self.metadata[name] = value for prop in dnskey._PROPS: self._changed[prop] = False if prop in self.metadata: t = self.parsetime(self.metadata[prop]) self._times[prop] = t self._fmttime[prop] = self.formattime(t) self._timestamps[prop] = self.epochfromtime(t) self._original[prop] = self._timestamps[prop] else: self._times[prop] = None self._fmttime[prop] = None self._timestamps[prop] = None self._original[prop] = None pfp.close() def commit(self, settime_bin, **kwargs): quiet = kwargs.get('quiet', False) cmd = [] first = True if self._origttl is not None: cmd += ["-L", str(self.ttl)] for prop, opt in zip(dnskey._PROPS, dnskey._OPTS): if not opt or not self._changed[prop]: continue delete = False if prop in self._delete and self._delete[prop]: delete = True when = 'none' if delete else self._fmttime[prop] cmd += [opt, when] first = False if cmd: fullcmd = [settime_bin, "-K", self._dir] + cmd + [self.keystr,] if not quiet: print('# ' + ' '.join(fullcmd)) try: p = Popen(fullcmd, stdout=PIPE, stderr=PIPE) stdout, stderr = p.communicate() if stderr: raise Exception(str(stderr)) except Exception as e: raise Exception('unable to run %s: %s' % (settime_bin, str(e))) self._origttl = None for prop in dnskey._PROPS: self._original[prop] = self._timestamps[prop] self._changed[prop] = False @classmethod def generate(cls, keygen_bin, randomdev, keys_dir, name, alg, keysize, sep, ttl, publish=None, activate=None, **kwargs): quiet = kwargs.get('quiet', False) keygen_cmd = [keygen_bin, "-q", "-K", keys_dir, "-L", str(ttl)] if randomdev: keygen_cmd += ["-r", randomdev] if sep: keygen_cmd.append("-fk") if alg: keygen_cmd += ["-a", alg] if keysize: keygen_cmd += ["-b", str(keysize)] if publish: t = dnskey.timefromepoch(publish) keygen_cmd += ["-P", dnskey.formattime(t)] if activate: t = dnskey.timefromepoch(activate) keygen_cmd += ["-A", dnskey.formattime(activate)] keygen_cmd.append(name) if not quiet: print('# ' + ' '.join(keygen_cmd)) p = Popen(keygen_cmd, stdout=PIPE, stderr=PIPE) stdout, stderr = p.communicate() if stderr: raise Exception('unable to generate key: ' + str(stderr)) try: keystr = stdout.splitlines()[0].decode('ascii') newkey = dnskey(keystr, keys_dir, ttl) return newkey except Exception as e: raise Exception('unable to parse generated key: %s' % str(e)) def generate_successor(self, keygen_bin, randomdev, prepublish, **kwargs): quiet = kwargs.get('quiet', False) if not self.inactive(): raise Exception("predecessor key %s has no inactive date" % self) keygen_cmd = [keygen_bin, "-q", "-K", self._dir, "-S", self.keystr] if self.ttl: keygen_cmd += ["-L", str(self.ttl)] if randomdev: keygen_cmd += ["-r", randomdev] if prepublish: keygen_cmd += ["-i", str(prepublish)] if not quiet: print('# ' + ' '.join(keygen_cmd)) p = Popen(keygen_cmd, stdout=PIPE, stderr=PIPE) stdout, stderr = p.communicate() if stderr: raise Exception('unable to generate key: ' + stderr) try: keystr = stdout.splitlines()[0].decode('ascii') newkey = dnskey(keystr, self._dir, self.ttl) return newkey except: raise Exception('unable to generate successor for key %s' % self) @staticmethod def algstr(alg): name = None if alg in range(len(dnskey._ALGNAMES)): name = dnskey._ALGNAMES[alg] return name if name else ("%03d" % alg) @staticmethod def algnum(alg): if not alg: return None alg = alg.upper() try: return dnskey._ALGNAMES.index(alg) except ValueError: return None def algname(self, alg=None): return self.algstr(alg or self.alg) @staticmethod def timefromepoch(secs): return time.gmtime(secs) @staticmethod def parsetime(string): return time.strptime(string, "%Y%m%d%H%M%S") @staticmethod def epochfromtime(t): return calendar.timegm(t) @staticmethod def formattime(t): return time.strftime("%Y%m%d%H%M%S", t) def setmeta(self, prop, secs, now, **kwargs): force = kwargs.get('force', False) if self._timestamps[prop] == secs: return if self._original[prop] is not None and \ self._original[prop] < now and not force: raise TimePast(self, prop, self._original[prop]) if secs is None: self._changed[prop] = False \ if self._original[prop] is None else True self._delete[prop] = True self._timestamps[prop] = None self._times[prop] = None self._fmttime[prop] = None return t = self.timefromepoch(secs) self._timestamps[prop] = secs self._times[prop] = t self._fmttime[prop] = self.formattime(t) self._changed[prop] = False if \ self._original[prop] == self._timestamps[prop] else True def gettime(self, prop): return self._times[prop] def getfmttime(self, prop): return self._fmttime[prop] def gettimestamp(self, prop): return self._timestamps[prop] def created(self): return self._timestamps["Created"] def syncpublish(self): return self._timestamps["SyncPublish"] def setsyncpublish(self, secs, now=time.time(), **kwargs): self.setmeta("SyncPublish", secs, now, **kwargs) def publish(self): return self._timestamps["Publish"] def setpublish(self, secs, now=time.time(), **kwargs): self.setmeta("Publish", secs, now, **kwargs) def activate(self): return self._timestamps["Activate"] def setactivate(self, secs, now=time.time(), **kwargs): self.setmeta("Activate", secs, now, **kwargs) def revoke(self): return self._timestamps["Revoke"] def setrevoke(self, secs, now=time.time(), **kwargs): self.setmeta("Revoke", secs, now, **kwargs) def inactive(self): return self._timestamps["Inactive"] def setinactive(self, secs, now=time.time(), **kwargs): self.setmeta("Inactive", secs, now, **kwargs) def delete(self): return self._timestamps["Delete"] def setdelete(self, secs, now=time.time(), **kwargs): self.setmeta("Delete", secs, now, **kwargs) def syncdelete(self): return self._timestamps["SyncDelete"] def setsyncdelete(self, secs, now=time.time(), **kwargs): self.setmeta("SyncDelete", secs, now, **kwargs) def setttl(self, ttl): if ttl is None or self.ttl == ttl: return elif self._origttl is None: self._origttl = self.ttl self.ttl = ttl elif self._origttl == ttl: self._origttl = None self.ttl = ttl else: self.ttl = ttl def keytype(self): return ("KSK" if self.sep else "ZSK") def __str__(self): return ("%s/%s/%05d" % (self.name, self.algname(), self.keyid)) def __repr__(self): return ("%s/%s/%05d (%s)" % (self.name, self.algname(), self.keyid, ("KSK" if self.sep else "ZSK"))) def date(self): return (self.activate() or self.publish() or self.created()) # keys are sorted first by zone name, then by algorithm. within # the same name/algorithm, they are sorted according to their # 'date' value: the activation date if set, OR the publication # if set, OR the creation date. def __lt__(self, other): if self.name != other.name: return self.name < other.name if self.alg != other.alg: return self.alg < other.alg return self.date() < other.date() def check_prepub(self, output=None): def noop(*args, **kwargs): pass if not output: output = noop now = int(time.time()) a = self.activate() p = self.publish() if not a: return False if not p: if a > now: output("WARNING: Key %s is scheduled for\n" "\t activation but not for publication." % repr(self)) return False if p <= now and a <= now: return True if p == a: output("WARNING: %s is scheduled to be\n" "\t published and activated at the same time. This\n" "\t could result in a coverage gap if the zone was\n" "\t previously signed. Activation should be at least\n" "\t %s after publication." % (repr(self), dnskey.duration(self.ttl) or 'one DNSKEY TTL')) return True if a < p: output("WARNING: Key %s is active before it is published" % repr(self)) return False if self.ttl is not None and a - p < self.ttl: output("WARNING: Key %s is activated too soon\n" "\t after publication; this could result in coverage \n" "\t gaps due to resolver caches containing old data.\n" "\t Activation should be at least %s after\n" "\t publication." % (repr(self), dnskey.duration(self.ttl) or 'one DNSKEY TTL')) return False return True def check_postpub(self, output = None, timespan = None): def noop(*args, **kwargs): pass if output is None: output = noop if timespan is None: timespan = self.ttl if timespan is None: output("WARNING: Key %s using default TTL." % repr(self)) timespan = (60*60*24) now = time.time() d = self.delete() i = self.inactive() if not d: return False if not i: if d > now: output("WARNING: Key %s is scheduled for\n" "\t deletion but not for inactivation." % repr(self)) return False if d < now and i < now: return True if d < i: output("WARNING: Key %s is scheduled for\n" "\t deletion before inactivation." % repr(self)) return False if d - i < timespan: output("WARNING: Key %s scheduled for\n" "\t deletion too soon after deactivation; this may \n" "\t result in coverage gaps due to resolver caches\n" "\t containing old data. Deletion should be at least\n" "\t %s after inactivation." % (repr(self), dnskey.duration(timespan))) return False return True @staticmethod def duration(secs): if not secs: return None units = [("year", 60*60*24*365), ("month", 60*60*24*30), ("day", 60*60*24), ("hour", 60*60), ("minute", 60), ("second", 1)] output = [] for unit in units: v, secs = secs // unit[1], secs % unit[1] if v > 0: output.append("%d %s%s" % (v, unit[0], "s" if v > 1 else "")) return ", ".join(output)
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