Files
pm3py/tests/test_crc.py
michael f2b23f768b fix(iso15): correct transport flags + append CRC host-side (scan/rdbl/wrbl)
ISO15_READ_RESPONSE was 0x10 but the firmware bit is 0x20 (0x10 is HIGH_SPEED, which pm3py lacked), so scan/rdbl/wrbl sent flags 0x19 with READ_RESPONSE never set -> firmware never listened and replied empty. The ARM firmware also ignores ISO15_APPEND_CRC (the C client adds the CRC host-side via AddCrc15), so pm3py's CRC-less frames were never answered by a real tag.

Fix flag values to match firmware include/iso15.h, add crc15 (CRC-16/X-25), and route all iso15 commands through _iso15_payload (appends CRC, sends CONNECT|HIGH_SPEED|READ_RESPONSE=0x31). Payload now byte-matches the C client getUID. Pre-existing bug, independent of the firmware rebase.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-04 22:48:23 -07:00

35 lines
1.3 KiB
Python

from pm3py.core.protocol import crc16_a, crc15, crc15_bytes
def test_crc16_a_empty():
assert crc16_a(b"") == 0x6363 # init 0xC6C6 reflected = 0x6363
def test_crc16_a_known_vector():
# Verified against C implementation: compute_crc(CRC_14443_A, ...)
# "123456789" is the standard CRC check string
data = b"123456789"
assert crc16_a(data) == 0xBF05
def test_crc16_a_ping_preamble():
# A CMD_PING preamble: magic=0x61334d50, length|ng=0x8020, cmd=0x0109
preamble = bytes.fromhex("504d3361208001090102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f")
crc = crc16_a(preamble)
assert isinstance(crc, int)
assert 0 <= crc <= 0xFFFF
def test_crc15_known_vector():
# ISO15693 / NFC Type 5 CRC == CRC-16/X-25; standard check string -> 0x906E
assert crc15(b"123456789") == 0x906E
def test_crc15_residue():
# Appending crc15 (LSB-first) then re-running the raw X-25 loop over the full
# frame yields the X-25 residue 0xF0B8 — the property firmware CheckCrc15 uses.
data = bytes([0x26, 0x01, 0x00])
frame = data + crc15_bytes(data)
crc = 0xFFFF
for byte in frame:
crc ^= byte
for _ in range(8):
crc = (crc >> 1) ^ 0x8408 if (crc & 1) else (crc >> 1)
assert crc == 0xF0B8