def bcHighPlateaus(self):
"""
:return: Plateaus in the bit congruence at high level (> 0.8)
"""
plateauElevation = 0.8
plat = MessageAnalyzer.plateouStart(self.bitcongruences)
# filter for plateaus of high bit congruence
hiPlat = ([], [])
for ix, vl in zip(plat[0], plat[1]):
if vl > plateauElevation:
hiPlat[0].append(ix)
hiPlat[1].append(vl)
return hiPlat
def messageSegmentation(self) -> List[MessageSegment]:
"""
Segment message by determining local extrema of sigma-s-gauss-filtered sliding n-byte-mean bit-congruence.
>>> from netzob.Model.Vocabulary.Messages.L4NetworkMessage import L4NetworkMessage
>>> tstmsg = '19040aec0000027b000012850a6400c8d23d06a2535ed71ed23d09faa4673315d23d09faa1766325d23d09faa17b4b10'
>>> l4m = L4NetworkMessage(bytes.fromhex(tstmsg))
>>> hbg = HorizonBitcongruenceGauss(l4m)
>>> hbg.setAnalysisParams()
>>> hbg.analyze()
>>> spm = hbg.messageSegmentation()
>>> print(b''.join([seg.bytes for seg in spm]).hex() == spm[0].message.data.hex())
True
:return: Segmentation of this message based on this analyzer's type.
"""
if not self.values:
if not self._analysisArgs:
raise ValueError('No values or analysis parameters set.')
self.analyze()
bcd = MessageAnalyzer.findExistingAnalysis(BitCongruenceDelta,
MessageAnalyzer.U_BYTE,
self.message)
# all local minima
bclmins = self.pinpointMinima()
# local maxima, if bc[e] < bc[e+1] or bc[e] > 2*s2mbc[e] for all e in cadidate indices
bclmaxs = self.pinpointMaxima()
bcdmaxs = [
e for e in bclmaxs
if bcd.values[e + 1] > bcd.values[e] or bcd.values[e] > 2 *
self.bitcongruences[e]
]
minmax = bclmins
for bdm in bcdmaxs: # only keep bcdmaxs if not in scope if min
if bdm + 1 not in minmax and bdm - 1 not in minmax:
minmax.append(bdm)
# starts of plateaus of bit congruences
bcplats = MessageAnalyzer.plateouStart(
self.bitcongruences)[0] # bcd.values
for bps in bcplats: # only keep platoustarts if not in scope if min or max
if bps + 1 not in minmax and bps - 1 not in minmax:
minmax.append(bps)
# # separate nan-values
# nansep = MessageAnalyzer.separateNaNs(self.values)
relevantPositions = list(sorted(minmax))
# get candidates to cut segments from message
cutCandidates = [0] + [int(b) for b in relevantPositions if not numpy.isnan(b)] \
+ [len(self._message.data)] # add the message end
# cut only where a segment is of a length larger than 1
cutPositions = [0] + [
right for left, right in zip(cutCandidates[:-1], cutCandidates[1:])
if right - left > 1
]
# cutPositions = list(sorted(cutPositions + nansep[0]))
# add the end of the message if its not already there
if cutPositions[-1] != cutCandidates[-1]:
cutPositions[-1] = cutCandidates[-1]
segments = list()
for lmaxCurr, lmaxNext in zip(cutPositions[:-1], cutPositions[1:]):
segments.append(MessageSegment(self, lmaxCurr,
lmaxNext - lmaxCurr))
return segments