def __get_table_init(self):
"""
Return the precalculated CRC table for the table_driven implementation.
"""
if self.opt.Algorithm != self.opt.Algo_Table_Driven:
return "0"
if self.opt.Width == None or self.opt.Poly == None or self.opt.ReflectIn == None:
return "0"
crc = Crc(
width=self.opt.Width,
poly=self.opt.Poly,
reflect_in=self.opt.ReflectIn,
xor_in=0,
reflect_out=False,
xor_out=0, # set unimportant variables to known values
table_idx_width=self.opt.TableIdxWidth)
tbl = crc.gen_table()
if self.opt.Width >= 32:
values_per_line = 4
elif self.opt.Width >= 16:
values_per_line = 8
else:
values_per_line = 16
format_width = max(self.opt.Width, 8)
out = ""
for i in range(self.opt.TableWidth):
if i % values_per_line == 0:
out += " "
if i == (self.opt.TableWidth - 1):
out += "%s" % self.__pretty_hex(tbl[i], format_width)
elif i % values_per_line == (values_per_line - 1):
out += "%s,\n" % self.__pretty_hex(tbl[i], format_width)
else:
out += "%s, " % self.__pretty_hex(tbl[i], format_width)
return out
def __get_table_init(self):
"""
Return the precalculated CRC table for the table_driven implementation.
"""
if self.opt.Algorithm != self.opt.Algo_Table_Driven:
return "0"
if self.opt.Width == None or self.opt.Poly == None or self.opt.ReflectIn == None:
return "0"
crc = Crc(width = self.opt.Width, poly = self.opt.Poly,
reflect_in = self.opt.ReflectIn,
xor_in = 0, reflect_out = False, xor_out = 0, # set unimportant variables to known values
table_idx_width = self.opt.TableIdxWidth)
tbl = crc.gen_table()
if self.opt.Width >= 32:
values_per_line = 4
elif self.opt.Width >= 16:
values_per_line = 8
else:
values_per_line = 16
format_width = max(self.opt.Width, 8)
out = ""
for i in range(self.opt.TableWidth):
if i % values_per_line == 0:
out += " "
if i == (self.opt.TableWidth - 1):
out += "%s" % self.__pretty_hex(tbl[i], format_width)
elif i % values_per_line == (values_per_line - 1):
out += "%s,\n" % self.__pretty_hex(tbl[i], format_width)
else:
out += "%s, " % self.__pretty_hex(tbl[i], format_width)
return out
def _get_table_init(opt): # TODO: change to return a list
"""
Return the precalculated CRC table for the table_driven implementation.
"""
if opt.algorithm != opt.algo_table_driven:
return "0"
if opt.width is None or opt.poly is None or opt.reflect_in is None:
return "0"
crc = Crc(
width=opt.width,
poly=opt.poly,
reflect_in=opt.reflect_in,
xor_in=0,
reflect_out=False,
xor_out=0, # set unimportant variables to known values
table_idx_width=opt.tbl_idx_width,
slice_by=opt.slice_by)
crc_tbl = crc.gen_table()
if opt.width > 32:
values_per_line = 4
elif opt.width >= 16:
values_per_line = 8
else:
values_per_line = 16
format_width = max(opt.width, 8)
if opt.slice_by == 1:
indent = 4
else:
indent = 8
out = [''] * opt.slice_by
for i in range(opt.slice_by):
out[i] = _get_simple_table(opt, crc_tbl[i], values_per_line,
format_width, indent)
fixed_indent = ' ' * (indent - 4)
out = '{0:s}{{\n'.format(fixed_indent) + \
'\n{0:s}}},\n{0:s}{{\n'.format(fixed_indent).join(out) + \
'\n{0:s}}}'.format(fixed_indent)
if opt.slice_by == 1:
return out
return '{\n' + out + '\n}'
def __get_crc_bwe_bitmask_minterms(self):
"""
Return a list of (bitmask, minterms), for all bits.
"""
crc = Crc(width = self.opt.Width, poly = self.opt.Poly,
reflect_in = self.opt.ReflectIn, xor_in = self.opt.XorIn,
reflect_out = self.opt.ReflectOut, xor_out = self.opt.XorOut,
table_idx_width = self.opt.TableIdxWidth)
qm = QuineMcCluskey(use_xor = True)
crc_tbl = crc.gen_table()
bm_mt = []
for bit in range(max(self.opt.Width, 8)):
ones = [i for i in range(self.opt.TableWidth) if crc_tbl[i] & (1 << bit) != 0]
terms = qm.simplify(ones, [])
if self.opt.Verbose:
print("bit %02d: %s" % (bit, terms))
if terms != None:
for term in terms:
shifted_term = '.' * bit + term + '.' * (self.opt.Width - bit - 1)
bm_mt.append((1 << bit, shifted_term))
return bm_mt
def parse(self):
data = None
self.title = '[empty]'
for idx,s in enumerate(self.sig):
if s[0:6] == "TITLE:":
self.title = s[6:].replace(':', ';')
continue
if s[0:5] == "TYPE:":
self.typeDesc = TypeDesc(s[5:])
continue
if s[0:5] == "DATA:":
data = self.sig[idx+1:]
continue
if not data:
raise DataException('error in data of signature at line ' + str(self.sigLineNumber) + ' named: ' + self.title)
try:
self.data = DataParser(self.typeDesc, data)
except DataException as de:
raise DataException('error in data of signature at line ' + str(self.sigLineNumber) + ' named: ' + self.title + ' child info:' + de.value)
#debugRewrite("TITLE:"+self.title.replace(';',':')+"\n\n")
#debugRewrite("TYPE:"+str(self.typeDesc)+"\n")
#debugRewrite("DATA:\n");
#debugRewrite(str(self.data));
#debugRewrite("\n----\n\n")
if self.typeDesc.isSimple():
for bitWidth in self.typeDesc.values:
# lil endian
b,l = self.dumpData(bitWidth, Little_Endian, self.data)
self.generateSigName(self.ndb, bitWidth, Little_Endian, b, l)
if bitWidth == 8:
continue
# big endian
b,l = self.dumpData(bitWidth, Big_Endian, self.data)
self.generateSigName(self.ndb, bitWidth, Big_Endian, b, l)
# currently if "CRC:" is specified only one width is allowed
elif self.typeDesc.isCrc:
for Do_Reflect in [True, False]:
bitWidth = self.typeDesc.values.keys()[0]
crc = Crc(width = bitWidth, poly = self.data.values[0], reflect_in = Do_Reflect, xor_in = 0, reflect_out = Do_Reflect, xor_out = 0)
dummyData = DummyData(crc.gen_table(), False)
b,l = self.dumpData(bitWidth, Little_Endian, dummyData)
self.generateCrcSigName(bitWidth, Little_Endian, Do_Reflect, b)
if bitWidth != 8:
b,l = self.dumpData(bitWidth, Big_Endian, dummyData)
self.generateCrcSigName(bitWidth, Big_Endian, Do_Reflect, b)
elif self.typeDesc.isLog:
for bitWidth in self.typeDesc.values:
if bitWidth == 8:
print "\n [!] WARNING, generated byte-based logical signatures is a bad, BAD idea\n"
b = self.dumpLogicalSignature(bitWidth, Little_Endian, self.data)
self.generateSigName(self.ldb, bitWidth, Little_Endian, b, 0)
if bitWidth != 8:
b = self.dumpLogicalSignature(bitWidth, Big_Endian, self.data)
self.generateSigName(self.ldb, bitWidth, Big_Endian, b, 0)
