Source code for pytomo.dns.rdtypes.sigbase

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from __future__ import absolute_import

import calendar
import struct
import time

from .. import dnssec as dns_dnssec
from .. import exception as dns_exception
from .. import rdata as dns_rdata
from .. import rdatatype as dns_rdatatype
from .. import name as dns_name

[docs]class BadSigTime(dns_exception.DNSException): """Raised when a SIG or RRSIG RR's time cannot be parsed.""" pass
[docs]def sigtime_to_posixtime(what): if len(what) != 14: raise BadSigTime year = int(what[0:4]) month = int(what[4:6]) day = int(what[6:8]) hour = int(what[8:10]) minute = int(what[10:12]) second = int(what[12:14]) return calendar.timegm((year, month, day, hour, minute, second, 0, 0, 0))
[docs]def posixtime_to_sigtime(what): return time.strftime('%Y%m%d%H%M%S', time.gmtime(what))
[docs]class SIGBase(dns_rdata.Rdata): """SIG-like record base @ivar type_covered: the rdata type this signature covers @type type_covered: int @ivar algorithm: the algorithm used for the sig @type algorithm: int @ivar labels: number of labels @type labels: int @ivar original_ttl: the original TTL @type original_ttl: long @ivar expiration: signature expiration time @type expiration: long @ivar inception: signature inception time @type inception: long @ivar key_tag: the key tag @type key_tag: int @ivar signer: the signer @type signer: dns_name.Name object @ivar signature: the signature @type signature: string""" __slots__ = ['type_covered', 'algorithm', 'labels', 'original_ttl', 'expiration', 'inception', 'key_tag', 'signer', 'signature'] def __init__(self, rdclass, rdtype, type_covered, algorithm, labels, original_ttl, expiration, inception, key_tag, signer, signature): super(SIGBase, self).__init__(rdclass, rdtype) self.type_covered = type_covered self.algorithm = algorithm self.labels = labels self.original_ttl = original_ttl self.expiration = expiration self.inception = inception self.key_tag = key_tag self.signer = signer self.signature = signature
[docs] def covers(self): return self.type_covered
[docs] def to_text(self, origin=None, relativize=True, **kw): return '%s %d %d %d %s %s %d %s %s' % ( dns_rdatatype.to_text(self.type_covered), self.algorithm, self.labels, self.original_ttl, posixtime_to_sigtime(self.expiration), posixtime_to_sigtime(self.inception), self.key_tag, self.signer, dns_rdata._base64ify(self.signature) )
[docs] def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True): type_covered = dns_rdatatype.from_text(tok.get_string()) algorithm = dns_dnssec.algorithm_from_text(tok.get_string()) labels = tok.get_int() original_ttl = tok.get_ttl() expiration = sigtime_to_posixtime(tok.get_string()) inception = sigtime_to_posixtime(tok.get_string()) key_tag = tok.get_int() signer = tok.get_name() signer = signer.choose_relativity(origin, relativize) chunks = [] while 1: t = tok.get().unescape() if t.is_eol_or_eof(): break if not t.is_identifier(): raise dns_exception.SyntaxError chunks.append(t.value) b64 = ''.join(chunks) signature = b64.decode('base64_codec') return cls(rdclass, rdtype, type_covered, algorithm, labels, original_ttl, expiration, inception, key_tag, signer, signature)
from_text = classmethod(from_text)
[docs] def to_wire(self, file, compress = None, origin = None): header = struct.pack('!HBBIIIH', self.type_covered, self.algorithm, self.labels, self.original_ttl, self.expiration, self.inception, self.key_tag) file.write(header) self.signer.to_wire(file, None, origin) file.write(self.signature)
[docs] def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None): header = struct.unpack('!HBBIIIH', wire[current : current + 18]) current += 18 rdlen -= 18 (signer, cused) = dns_name.from_wire(wire[: current + rdlen], current) current += cused rdlen -= cused if not origin is None: signer = signer.relativize(origin) signature = wire[current : current + rdlen] return cls(rdclass, rdtype, header[0], header[1], header[2], header[3], header[4], header[5], header[6], signer, signature)
from_wire = classmethod(from_wire)
[docs] def choose_relativity(self, origin = None, relativize = True): self.signer = self.signer.choose_relativity(origin, relativize)
def _cmp(self, other): hs = struct.pack('!HBBIIIH', self.type_covered, self.algorithm, self.labels, self.original_ttl, self.expiration, self.inception, self.key_tag) ho = struct.pack('!HBBIIIH', other.type_covered, other.algorithm, other.labels, other.original_ttl, other.expiration, other.inception, other.key_tag) v = cmp(hs, ho) if v == 0: v = cmp(self.signer, other.signer) if v == 0: v = cmp(self.signature, other.signature) return v