class PathSegment(SCIONPayloadBaseProto):
NAME = "PathSegment"
PAYLOAD_CLASS = PayloadClass.PCB
P_CLS = P.PathSegment
VER = len(P_CLS.schema.fields) - 1
def __init__(self, p): # pragma: no cover
super().__init__(p)
self._min_exp = float("inf")
self._setup()
def _setup(self):
self.info = InfoOpaqueField(self.p.info)
self._calc_min_exp()
self.sibra_ext = None
if self.is_sibra():
self.sibra_ext = SibraPCBExt(self.p.exts.sibra)
@classmethod
def from_values(cls, info, sibra_ext=None): # pragma: no cover
p = cls.P_CLS.new_message(info=info.pack())
if sibra_ext:
p.exts.sibra = sibra_ext.p
return cls(p)
def _calc_min_exp(self):
# NB: only the expiration time of the first pcbm is considered.
for asm in self.iter_asms():
self._min_exp = min(self._min_exp, asm.pcbm(0).hof().exp_time)
def asm(self, idx): # pragma: no cover
return ASMarking(self.p.asms[idx])
def iter_asms(self, start=0): # pragma: no cover
for i in range(start, len(self.p.asms)):
yield self.asm(i)
def is_sibra(self): # pragma: no cover
return bool(self.p.exts.sibra.id)
def sig_pack3(self):
"""
Pack for signing version 3 (defined by highest field number).
"""
if self.VER != 3:
raise SCIONSigVerError("PathSegment.sig_pack3 cannot support version %s", self.VER)
b = []
b.append(self.p.info)
# ifID field is changed on the fly, and so is ignored.
for asm in self.iter_asms():
b.append(asm.sig_pack8())
if self.is_sibra():
b.append(self.sibra_ext.sig_pack3())
return b"".join(b)
def sign(self, key, set_=True): # pragma: no cover
sig = sign(self.sig_pack3(), key)
if set_:
self.p.asms[-1].sig = sig
return sig
def add_asm(self, asm): # pragma: no cover
"""
Appends a new ASMarking block.
"""
d = self.p.to_dict()
d.setdefault('asms', []).append(asm.p)
self.p.from_dict(d)
self._update_info()
self._min_exp = min(self._min_exp, asm.pcbm(0).hof().exp_time)
def _update_info(self): # pragma: no cover
self.info.hops = len(self.p.asms)
self.p.info = self.info.pack()
def add_sibra_ext(self, ext_p): # pragma: no cover
self.p.exts.sibra = ext_p.copy()
self.sibra_ext = SibraPCBExt(self.p.exts.sibra)
def get_trcs_certs(self):
"""
Returns a dict of all trcs' versions and a dict of all certificates'
versions used in this PCB.
"""
trcs = defaultdict(set)
certs = defaultdict(set)
for asm in self.iter_asms():
isd_as = asm.isd_as()
isd = isd_as[0]
trcs[isd].add(asm.p.trcVer)
certs[isd_as].add(asm.p.certVer)
return trcs, certs
def get_path(self, reverse_direction=False):
"""
Returns the list of HopOpaqueFields in the path.
"""
hofs = []
info = InfoOpaqueField(self.p.info)
asms = list(self.iter_asms())
if reverse_direction:
asms = reversed(asms)
info.up_flag ^= True
for asm in asms:
hofs.append(asm.pcbm(0).hof())
return SCIONPath.from_values(info, hofs)
def first_ia(self): # pragma: no cover
return self.asm(0).isd_as()
def last_ia(self): # pragma: no cover
return self.asm(-1).isd_as()
def last_hof(self): # pragma: no cover
if self.p.asms:
return self.asm(-1).pcbm(0).hof()
return None
def get_hops_hash(self, hex=False): # pragma: no cover
"""
Returns the hash over all triples (ISD_AS, IG_IF, EG_IF) included in
the path segment.
"""
data = []
for asm in self.iter_asms():
pcbm = asm.pcbm(0)
data.append(asm.isd_as().pack())
data.append(struct.pack("!QQ", pcbm.p.inIF, pcbm.p.outIF))
data = b"".join(data)
if hex:
return crypto_hash(data).hex()
return crypto_hash(data)
def get_n_peer_links(self): # pragma: no cover
"""Return the total number of peer links in the PathSegment."""
n = 0
for asm in self.p.asms:
n += len(asm.pcbms) - 1
return n
def get_n_hops(self): # pragma: no cover
"""Return the number of hops in the PathSegment."""
return len(self.p.asms)
def get_timestamp(self): # pragma: no cover
"""Returns the creation timestamp of this PathSegment."""
return self.info.timestamp
def set_timestamp(self, timestamp): # pragma: no cover
"""Updates the timestamp in the IOF."""
assert timestamp < 2 ** 32 - 1
self.info.timestamp = timestamp
self._update_info()
def get_expiration_time(self): # pragma: no cover
"""
Returns the expiration time of the path segment in real time. If a PCB
extension in the last ASMarking supplies an expiration time, use that.
Otherwise fall-back to the standard expiration time calculation.
"""
if self.is_sibra():
return self.sibra_ext.exp_ts()
return self.info.timestamp + int(self._min_exp * EXP_TIME_UNIT)
def flags(self): # pragma: no cover
f = 0
if self.is_sibra():
f |= PSF.SIBRA
return f
def short_id(self): # pragma: no cover
"""
Return a 12-byte hex ID identifying the PCB (mostly for logging purposes).
"""
return self.get_hops_hash(hex=True)[:12]
def short_desc(self): # pragma: no cover
"""
Return a short description string of the PathSegment, consisting of a
truncated hash, the IOF timestamp, and the list of hops.
"""
desc = []
desc.append("%s, %s, " % (self.short_id(), iso_timestamp(self.get_timestamp())))
hops = []
for asm in self.iter_asms():
hop = []
hof = asm.pcbm(0).hof()
if hof.ingress_if:
hop.append("%d " % hof.ingress_if)
hop.append("%s" % asm.isd_as())
if hof.egress_if:
hop.append(" %d" % hof.egress_if)
hops.append("".join(hop))
exts = []
if self.is_sibra():
exts.append(" %s" % self.sibra_ext.short_desc())
desc.append(">".join(hops))
if exts:
return "%s\n%s" % ("".join(desc), "\n".join(exts))
return "".join(desc)
def __str__(self):
s = []
s.append("%s:" % self.NAME)
s.append(" %s" % self.info)
for asm in self.iter_asms():
for line in asm.short_desc().splitlines():
s.append(" %s" % line)
if self.sibra_ext:
for line in str(self.sibra_ext).splitlines():
s.append(" %s" % line)
return "\n".join(s)
def __eq__(self, other):
return self.__hash__() == hash(other)
def __hash__(self): # pragma: no cover
return hash(self.get_hops_hash()) # FIMXE(PSz): should add timestamp?
class PathSegment(SCIONPayloadBaseProto):
NAME = "PathSegment"
PAYLOAD_CLASS = PayloadClass.PCB
P_CLS = P.PathSegment
def __init__(self, p): # pragma: no cover
super().__init__(p)
self._min_exp = float("inf")
self._setup()
def _setup(self):
self.info = InfoOpaqueField(self.p.info)
self._calc_min_exp()
self.sibra_ext = None
if self.is_sibra():
self.sibra_ext = SibraPCBExt(self.p.exts.sibra)
@classmethod
def from_values(cls, info, rev_infos=None,
sibra_ext=None): # pragma: no cover
p = cls.P_CLS.new_message(info=info.pack())
if sibra_ext:
p.exts.sibra = sibra_ext.p
if rev_infos:
p.exts.init("revInfos", len(rev_infos))
for i, info in enumerate(rev_infos):
p.exts.revInfos[i] = info.copy()
return cls(p)
def _calc_min_exp(self):
# NB: only the expiration time of the first pcbm is considered.
for asm in self.iter_asms():
self._min_exp = min(self._min_exp, asm.pcbm(0).hof().exp_time)
def asm(self, idx): # pragma: no cover
return ASMarking(self.p.asms[idx])
def iter_asms(self, start=0): # pragma: no cover
for i in range(start, len(self.p.asms)):
yield self.asm(i)
def is_sibra(self): # pragma: no cover
return bool(self.p.exts.sibra.id)
def sig_pack(self, ver=3):
b = []
if ver >= 3:
b.append(self.p.info)
# ifID field is changed on the fly, and so is ignored.
for asm in self.iter_asms():
b.append(asm.sig_pack(9))
if self.is_sibra():
b.append(self.sibra_ext.sig_pack(2))
return b"".join(b)
def sign(self, key, set_=True): # pragma: no cover
assert not self.p.asms[-1].sig
sig = sign(self.sig_pack(3), key)
if set_:
self.p.asms[-1].sig = sig
return sig
def add_asm(self, asm): # pragma: no cover
"""
Appends a new ASMarking block.
"""
d = self.p.to_dict()
d.setdefault('asms', []).append(asm.p)
self.p.from_dict(d)
self._update_info()
self._min_exp = min(self._min_exp, asm.pcbm(0).hof().exp_time)
def _update_info(self): # pragma: no cover
self.info.hops = len(self.p.asms)
self.p.info = self.info.pack()
def add_sibra_ext(self, ext_p): # pragma: no cover
self.p.exts.sibra = ext_p.copy()
self.sibra_ext = SibraPCBExt(self.p.exts.sibra)
def add_rev_infos(self, rev_infos): # pragma: no cover
"""
Appends a list of revocations to the PCB. Replaces existing
revocations with newer ones.
"""
if not rev_infos:
return
existing = {}
current_epoch = ConnectedHashTree.get_current_epoch()
for i in range(len(self.p.exts.revInfos)):
orphan = self.p.exts.revInfos.disown(i)
info_p = orphan.get()
if info_p.epoch >= current_epoch:
existing[(info_p.isdas, info_p.ifID)] = orphan
# Remove revocations for which we already have a newer one.
filtered = []
for info in rev_infos:
if (info.p.epoch >= current_epoch and
(info.p.isdas, info.p.ifID) not in existing):
filtered.append(info)
self.p.exts.init("revInfos", len(existing) + len(filtered))
for i, orphan in enumerate(existing.values()):
self.p.exts.revInfos.adopt(i, orphan)
n_existing = len(existing)
for i, info in enumerate(filtered):
self.p.exts.revInfos[n_existing + i] = info.p
def remove_crypto(self): # pragma: no cover
"""
Removes the signatures and certificates from each AS block.
"""
for asm in self.iter_asms():
asm.remove_sig()
asm.remove_chain()
def get_path(self, reverse_direction=False):
"""
Returns the list of HopOpaqueFields in the path.
"""
hofs = []
info = InfoOpaqueField(self.p.info)
asms = list(self.iter_asms())
if reverse_direction:
asms = reversed(asms)
info.up_flag ^= True
for asm in asms:
hofs.append(asm.pcbm(0).hof())
return SCIONPath.from_values(info, hofs)
def first_ia(self): # pragma: no cover
return self.asm(0).isd_as()
def last_ia(self): # pragma: no cover
return self.asm(-1).isd_as()
def last_hof(self): # pragma: no cover
if self.p.asms:
return self.asm(-1).pcbm(0).hof()
return None
def get_hops_hash(self, hex=False): # pragma: no cover
"""
Returns the hash over all triples (ISD_AS, IG_IF, EG_IF) included in
the path segment.
"""
h = SHA256.new()
for asm in self.iter_asms():
pcbm = asm.pcbm(0)
h.update(asm.isd_as().pack() +
struct.pack("!QQ", pcbm.p.inIF, pcbm.p.outIF))
if hex:
return h.hexdigest()
return h.digest()
def get_n_peer_links(self): # pragma: no cover
"""Return the total number of peer links in the PathSegment."""
n = 0
for asm in self.p.asms:
n += len(asm.pcbms) - 1
return n
def get_n_hops(self): # pragma: no cover
"""Return the number of hops in the PathSegment."""
return len(self.p.asms)
def get_timestamp(self): # pragma: no cover
"""Returns the creation timestamp of this PathSegment."""
return self.info.timestamp
def set_timestamp(self, timestamp): # pragma: no cover
"""Updates the timestamp in the IOF."""
assert timestamp < 2 ** 32 - 1
self.info.timestamp = timestamp
self._update_info()
def get_expiration_time(self): # pragma: no cover
"""
Returns the expiration time of the path segment in real time. If a PCB
extension in the last ASMarking supplies an expiration time, use that.
Otherwise fall-back to the standard expiration time calculation.
"""
if self.is_sibra():
return self.sibra_ext.exp_ts()
return self.info.timestamp + int(self._min_exp * EXP_TIME_UNIT)
def flags(self): # pragma: no cover
f = 0
if self.is_sibra():
f |= PSF.SIBRA
return f
def rev_info(self, idx):
return RevocationInfo(self.p.exts.revInfos[idx])
def iter_rev_infos(self, start=0):
for i in range(start, len(self.p.exts.revInfos)):
yield self.rev_info(i)
def get_rev_map(self):
"""
Returns a dict (ISD_AS, IF) -> RevocationInfo, if there are any
revocations in the PCB extensions, otherwise an empty dict.
"""
result = {}
for rev_info in self.iter_rev_infos():
key = (rev_info.isd_as(), rev_info.p.ifID)
result[key] = rev_info
return result
def short_desc(self): # pragma: no cover
"""
Return a short description string of the PathSegment, consisting of a
truncated hash, the IOF timestamp, and the list of hops.
"""
desc = []
desc.append("%s, %s, " % (
self.get_hops_hash(hex=True)[:12],
iso_timestamp(self.get_timestamp()),
))
hops = []
for asm in self.iter_asms():
hops.append(str(asm.isd_as()))
exts = []
if self.is_sibra():
exts.append(" %s" % self.sibra_ext.short_desc())
for rev_info in self.iter_rev_infos():
exts.append(" %s" % rev_info.short_desc())
desc.append(" > ".join(hops))
if exts:
return "%s\n%s" % ("".join(desc), "\n".join(exts))
return "".join(desc)
def __str__(self):
s = []
s.append("%s:" % self.NAME)
s.append(" %s" % self.info)
for asm in self.iter_asms():
for line in asm.short_desc().splitlines():
s.append(" %s" % line)
if self.sibra_ext:
for line in str(self.sibra_ext).splitlines():
s.append(" %s" % line)
for rev_info in self.iter_rev_infos():
for line in rev_info.short_desc().splitlines():
s.append(" %s" % line)
return "\n".join(s)
def __hash__(self): # pragma: no cover
return hash(self.get_hops_hash()) # FIMXE(PSz): should add timestamp?
class PathSegment(SCIONPayloadBaseProto):
NAME = "PathSegment"
PAYLOAD_CLASS = PayloadClass.PCB
PAYLOAD_TYPE = PCBType.SEGMENT
P_CLS = P.PathSegment
def __init__(self, p): # pragma: no cover
super().__init__(p)
self._min_exp = float("inf")
self._setup()
def _setup(self):
self.info = InfoOpaqueField(self.p.info)
self._calc_min_exp()
self.sibra_ext = None
if self.is_sibra():
self.sibra_ext = SibraPCBExt(self.p.exts.sibra)
@classmethod
def from_values(cls, info, sibra_ext=None): # pragma: no cover
p = cls.P_CLS.new_message(info=info.pack())
if sibra_ext:
p.exts.sibra = sibra_ext.p
return cls(p)
def _calc_min_exp(self):
# NB: only the expiration time of the first pcbm is considered.
for asm in self.iter_asms():
self._min_exp = min(self._min_exp, asm.pcbm(0).hof().exp_time)
def asm(self, idx): # pragma: no cover
return ASMarking(self.p.asms[idx])
def iter_asms(self, start=0): # pragma: no cover
for i in range(start, len(self.p.asms)):
yield self.asm(i)
def is_sibra(self): # pragma: no cover
return bool(self.p.exts.sibra.id)
def sig_pack(self, ver=3):
b = []
if ver >= 3:
b.append(self.p.info)
# ifID field is changed on the fly, and so is ignored.
for asm in self.iter_asms():
b.append(asm.sig_pack(9))
if self.is_sibra():
b.append(self.sibra_ext.sig_pack(2))
return b"".join(b)
def sign(self, key, set_=True): # pragma: no cover
assert not self.p.asms[-1].sig
sig = sign(self.sig_pack(3), key)
if set_:
self.p.asms[-1].sig = sig
return sig
def add_asm(self, asm): # pragma: no cover
"""
Appends a new ASMarking block.
"""
d = self.p.to_dict()
d.setdefault('asms', []).append(asm.p)
self.p.from_dict(d)
self._update_info()
self._min_exp = min(self._min_exp, asm.pcbm(0).hof().exp_time)
def _update_info(self): # pragma: no cover
self.info.hops = len(self.p.asms)
self.p.info = self.info.pack()
def add_sibra_ext(self, ext_p): # pragma: no cover
self.p.exts.sibra = ext_p.copy()
self.sibra_ext = SibraPCBExt(self.p.exts.sibra)
def remove_crypto(self): # pragma: no cover
"""
Remover the signatures and certificates from each AS block.
"""
for asm in self.iter_asms():
asm.remove_sig()
asm.remove_chain()
def get_path(self, reverse_direction=False):
"""
Returns the list of HopOpaqueFields in the path.
"""
hofs = []
info = InfoOpaqueField(self.p.info)
asms = list(self.iter_asms())
if reverse_direction:
asms = reversed(asms)
info.up_flag ^= True
for asm in asms:
hofs.append(asm.pcbm(0).hof())
return SCIONPath.from_values(info, hofs)
def first_ia(self): # pragma: no cover
return self.asm(0).isd_as()
def last_ia(self): # pragma: no cover
return self.asm(-1).isd_as()
def last_hof(self): # pragma: no cover
if self.p.asms:
return self.asm(-1).pcbm(0).hof()
return None
def get_hops_hash(self, hex=False):
"""
Returns the hash over all the interface revocation tokens included in
the path segment.
"""
h = SHA256.new()
for token in self.get_all_iftokens():
h.update(token)
if hex:
return h.hexdigest()
return h.digest()
def get_n_peer_links(self): # pragma: no cover
"""Return the total number of peer links in the PathSegment."""
n = 0
for asm in self.p.asms:
n += len(asm.pcbms) - 1
return n
def get_n_hops(self): # pragma: no cover
"""Return the number of hops in the PathSegment."""
return len(self.p.asms)
def get_timestamp(self): # pragma: no cover
"""Returns the creation timestamp of this PathSegment."""
return self.info.timestamp
def set_timestamp(self, timestamp): # pragma: no cover
"""Updates the timestamp in the IOF."""
assert timestamp < 2**32 - 1
self.info.timestamp = timestamp
self._update_info()
def get_expiration_time(self): # pragma: no cover
"""
Returns the expiration time of the path segment in real time. If a PCB
extension in the last ASMarking supplies an expiration time, use that.
Otherwise fall-back to the standard expiration time calculation.
"""
if self.is_sibra():
return self.sibra_ext.exp_ts()
return self.info.timestamp + int(self._min_exp * EXP_TIME_UNIT)
def get_all_iftokens(self):
"""
Returns all interface revocation tokens included in the path segment.
"""
tokens = []
for asm in self.p.asms:
for pcbm in asm.pcbms:
tokens.append(pcbm.igRevToken)
tokens.append(asm.egRevToken)
return tokens
def flags(self): # pragma: no cover
f = 0
if self.is_sibra():
f |= PSF.SIBRA
return f
def short_desc(self): # pragma: no cover
"""
Return a short description string of the PathSegment, consisting of a
truncated hash, the IOF timestamp, and the list of hops.
"""
desc = []
desc.append("%s, %s, " % (
self.get_hops_hash(hex=True)[:12],
iso_timestamp(self.get_timestamp()),
))
hops = []
for asm in self.iter_asms():
hops.append(str(asm.isd_as()))
exts = []
if self.is_sibra():
exts.append(" %s" % self.sibra_ext.short_desc())
desc.append(" > ".join(hops))
if exts:
return "%s\n%s" % ("".join(desc), "\n".join(exts))
return "".join(desc)
def __str__(self):
s = []
s.append("%s:" % self.NAME)
s.append(" %s" % self.info)
for asm in self.iter_asms():
for line in asm.short_desc().splitlines():
s.append(" %s" % line)
if self.sibra_ext:
for line in str(self.sibra_ext).splitlines():
s.append(" %s" % line)
return "\n".join(s)
def __hash__(self): # pragma: no cover
return hash(self.get_hops_hash()) # FIMXE(PSz): should add timestamp?