forked from kalmar/DALGLI0
85 lines
2.6 KiB
Python
85 lines
2.6 KiB
Python
from poly import Polynomial
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import sys
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import ast
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Polynomial.n = 2
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def normalize_byte(data):
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while len(data) != 8:
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if len(data) < 8:
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data = str(0) + data
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else:
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data = data[1:]
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return data
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def encode(in_data):
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data = in_data
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data = list(data)
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data_binary = [bin(ord(char)).replace('b', '') for char in data]
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data_binary = [normalize_byte(byte) for byte in data_binary]
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data_binary = [int(bit) for bit in list(''.join(data_binary))]
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data_binary.reverse()
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M = [0] * 16 + data_binary
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L = [0] * (len(data_binary)) + [1] * 16
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G = [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1]
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result_poly = Polynomial.divide(Polynomial.add(Polynomial(M), Polynomial(L)), Polynomial(G))
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result = result_poly.coefficients + [0] * (16 - len(result_poly.coefficients))
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result.reverse()
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data_binary.reverse()
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data_binary = data_binary + result
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data_binary = [data_binary[i:i+8] for i in range(0, len(data_binary), 8)]
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data_binary = [int(''.join(map(str, byte)), 2) for byte in data_binary]
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fcs = [hex(byte) for byte in data_binary]
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fcs = fcs[-2:]
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data = [chr(byte) for byte in data_binary]
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data = ''.join(data[0:-2])
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return data, fcs
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def check_fcs(in_data, fcs):
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data = in_data
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data = list(data)
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data_binary = [bin(ord(char)).replace('b', '') for char in data]
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data_binary = [normalize_byte(byte) for byte in data_binary]
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data_binary = [int(bit) for bit in list(''.join(data_binary))]
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fcs_binary = [bin(int(in_hex, 16)).replace('b', '') for in_hex in fcs]
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fcs_binary = [normalize_byte(byte) for byte in fcs_binary]
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fcs_binary = [int(bit) for bit in list(''.join(fcs_binary))]
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data_binary += fcs_binary
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data_binary.reverse()
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C = [0] * 16 + data_binary
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L = [0] * len(data_binary) + [1] * 16
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G = [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1]
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S = Polynomial.divide(Polynomial.add(Polynomial(C), Polynomial(L)), Polynomial(G))
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if S.coefficients == []:
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return True
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return False
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def main():
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try:
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if sys.argv[1] == '-e' or sys.argv[1] == '-encode':
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arg, fcs = encode(sys.argv[2])
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print(arg, fcs)
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print(check_fcs(arg, fcs)) # powinno zawsze zwracać true
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elif sys.argv[1] == '-c' or sys.argv[1] == '-check':
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arg = sys.argv[2]
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fcs = ast.literal_eval(sys.argv[3])
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print(check_fcs(arg, fcs))
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else:
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raise IndexError
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except IndexError:
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print("To encode: python3 CRC16.py -e [argument]\nTo check result: python3 CRC16.py -c [argument] [fcs]")
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if __name__ == "__main__":
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main() |