mirror of
https://github.com/RfidResearchGroup/ChameleonUltra.git
synced 2026-03-30 21:25:43 +00:00
42 lines
1.2 KiB
Python
42 lines
1.2 KiB
Python
hardnested_sums = [0, 32, 56, 64, 80, 96, 104, 112, 120, 128, 136, 144, 152, 160, 176, 192, 200, 224, 256]
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hardnested_nonces_sum_map = []
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hardnested_first_byte_num = 0
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hardnested_first_byte_sum = 0
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def evenparity32(n):
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"""
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calc evenparity32, can replace to any fast native impl...
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@param n - NT_ENC
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"""
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ret = 0
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for i in range(32):
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if (n & (1 << i)) != 0:
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ret += 1
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return ret % 2
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def check_nonce_unique_sum(nt, par):
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"""
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Check nt_enc is unique and calc first byte sum
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Pay attention: thread unsafe!!!
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@param nt - NT_ENC
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@param par - parity of NT_ENC
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"""
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global hardnested_first_byte_sum, hardnested_first_byte_num
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first_byte = nt >> 24
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if not hardnested_nonces_sum_map[first_byte]:
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hardnested_first_byte_sum += evenparity32((nt & 0xff000000) | (par & 0x08))
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hardnested_nonces_sum_map[first_byte] = True
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hardnested_first_byte_num += 1
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def reset():
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global hardnested_first_byte_sum, hardnested_first_byte_num, hardnested_nonces_sum_map
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# clear the history
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hardnested_nonces_sum_map = list()
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for i in range(256):
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hardnested_nonces_sum_map.append(False)
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hardnested_first_byte_sum = 0
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hardnested_first_byte_num = 0
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