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v1.9.6: ETU lock validation, hunt recovery, resync + ATR acceptance

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The audit's P1 robustness findings:

- _etu_candidate() validates a measured burst: requires >=2 usable
  spacings, rejects a guard-dominated burst (all-zero data: 10-ETU LOW
  runs + a 2-5 ETU HIGH guard) and a lone 10-ETU spacing.  A failed
  measurement leaves bit_samples unset instead of committing the
  clock_skip*3 fallback.
- _confirm_etu() no longer counts a dropped frame (empty bits) as
  parity-OK, and a rejected measurement clears bit_samples,
  _etu_measured and _clock_skip_confident (was: kept sampling at the
  rejected rate).
- Hunt ETU recovery keys off _etu_measured: handle_atr pre-seeds
  bit_samples, so the old "bit_samples is None" condition never fired.
- resync_idle() waits on the DATA idle level (plus RST/VCC edges,
  bounded) instead of spinning on wait({'skip': 0}) at one sample.
- ATR acceptance: a DATA-state 0x3B/0x3F is a candidate only before the
  first APDU (_apdu_seen); a parsed ATR is ignored on any parity error
  or when it is a bare TS+T0.  A data run misread at a frame boundary
  could fabricate an ATR and force clock_skip=372 for the capture.
- Inverse convention per ISO 7816-3 7.1/8.1: idle HIGH and a falling
  start bit in both conventions, msb-first inverse data, raw moments
  5-7 TS-pattern detection (a real inverse TS reads as 0x03 through
  the direct reader), and a TS parity exemption (the inverse pattern
  is odd over moments 2-10).  Spec-verified; no inverse capture in the
  corpus.

Validation: 117/117 unit tests (18 new); the 10-trace suite is
unchanged from v1.9.5 (APDU/CHKSUM/CONCAT/BAD_FCS identical,
RESULT: OK everywhere); compare_baseline.sh reports IDENTICAL.
VERSION -> 1.9.6.
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catarrh committed 2026-10-20 18:02:14 +03:00
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AGENTS.md
+70 -9
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@@ -333,6 +333,63 @@ Known limitation: no on-disk fixture reproduces the exact live failure (all
real captures contain a 372 ATR), so end-to-end proof needs a re-captured
`.sr` from the failing phone; the unit tests cover the loop-escape logic.
### v1.9.6: ETU lock validation, hunt recovery, resync + ATR acceptance
The audit's P1 findings. The validation helpers are unit-tested; the trace
suite stays at the v1.9.5 metrics.
- **ETU measurement validation (`_etu_candidate`).** The mid-session
estimator used to lock the inter-character guard as the ETU on all-zero
data: a 0x00 run gives 10-ETU LOW runs plus a short HIGH guard, so the
smallest recurring spacing is the guard (2x-3x the true ETU), and a lone
0x00 character's single 10-ETU spacing is 10x. A burst now needs at
least two usable spacings, and a burst whose minimum recurrence is a HIGH
guard with every other spacing >= 2x it is rejected -- the decoder waits
for a burst with bit transitions (this covers the 2-5 ETU guard range).
A failed measurement leaves `bit_samples` unset instead of committing the
old `clock_skip*3` guess.
- **Invalidation.** `_confirm_etu()` no longer counts a dropped frame (no
genuine start -> empty bits) as parity-OK, and a rejected measurement now
clears `bit_samples`, `_etu_measured` and `_clock_skip_confident` (the old
code kept sampling at the rejected rate).
- **Hunt ETU recovery.** `handle_atr()` pre-seeds `bit_samples` with the
default-rate guess while the recovery condition tested `bit_samples is
None`, so the v1.6.0 live-ETU recovery could never fire from the hunt.
The condition now keys off `_etu_measured` (a real DATA measurement); a
measured rate still suppresses the recovery.
- **`resync_idle()`** now actually waits: it used `wait({'skip': 0})` in a
loop (the same sample 48 times -> a no-op). It now waits on the DATA idle
level (plus RST/VCC edges, bounded) before the next peek.
- **ATR acceptance.** A DATA-state `0x3B`/`0x3F` is an ATR candidate only
before any APDU has been emitted (`_apdu_seen`); a parsed ATR is rejected
when any of its bytes had a parity error or when it is a bare TS+T0
(`3B 00`). A data run misread at a frame boundary used to be committed
as an ATR (a fabricated `3b80900000` appeared while developing this
change), forcing `clock_skip=372` for the rest of the capture. Real
warm-reset ATRs are parity-clean and commit as before.
- **Inverse convention (TS=0x3F).** The readers assumed an idle-LOW line
and a rising start bit; ISO 7816-3 7.1 keeps the line idle HIGH and the
start bit LOW in both conventions -- only the data polarity and order
change. `wait_data_falling`/`resync_idle` now use the HIGH idle for
inverse too, `get_bytes()` assembles the inverse data msb-first, and the
DATA state accepts `0x3F` alongside `0x3B`. The data readers already
inverted the bit polarity. A real inverse TS decodes as `0x03` through
the direct reader, so `ts_from_bits()` matches the raw ISO 7816-3 8.1
pattern (moments 1-4 LHHL, 5-7 LLL/HHH, 8-10 LLH) in both the hunt and
the DATA state instead of trusting the decoded byte. The readers exempt
a matching TS from the parity check: its moment 10 is fixed by the
pattern, and the inverse TS is legitimately odd over moments 2-10, so it
must not log a CHKSUM or reject the ATR. No inverse-convention capture
exists in the corpus, so this is spec-verified, not trace-verified.
Validation: 117/117 unit tests (18 new: the ETU candidate vectors, the
hunt-recovery seeded/measured cases, the resync level wait, the bare-ATR
and parity-ATR guards, the `_apdu_seen` gate both ways, the inverse
bit-order/start-edge/TS-pattern vectors); the 10-trace suite is unchanged
from v1.9.5 (identical APDU/CHKSUM/CONCAT/BAD_FCS counts, `RESULT: OK`
everywhere);
`compare_baseline.sh` reports IDENTICAL. VERSION -> 1.9.6.
### v1.9.5: T=0 framing — immediate SW, short responses, Le=256
The audit's P0 framing fixes, each pinned by a `TestDecodeStep` vector:
@@ -914,7 +971,7 @@ append the measured CLK frequency when known
### Versioning
The decoder version is defined in `pd.py` as `VERSION = '1.9.5'`.
The decoder version is defined in `pd.py` as `VERSION = '1.9.6'`.
The version is printed to the log on decoder startup.
### Testing after decoder changes
@@ -1165,13 +1222,17 @@ discarded ideas. "Proven" = kept in `pd.py`; "Rejected" = do not re-add.
native skip becomes F/D CLK cycles/bit. Reliable (verified live).
- **T=1 block-chain follow-up bound.** Caps chained I-blocks so garbage
cannot loop forever. Reliable.
- **Synthetic T=0 ATR fallback `[0x3B, 0x00]`.** After 8 failed ATR hunts,
commit a minimal ATR and set `hasT0=True`. Reliable for mid-session starts
(no ATR in the trace).
- **Hunt give-up (no synthetic ATR).** After `ATR_HUNT_FAIL_LIMIT` failed
hunts the decoder resumes DATA without fabricating an ATR (v1.6.0 removed
the old `[0x3B, 0x00]` fallback); the mid-session ETU estimator then
recovers the rate from DATA. Reliable.
- **ETU auto-detect from DATA via edge counting (`_measure_etu`).** Edge-waits
to the first DATA start-bit fall, measures ETU from DATA-edge spacing, locks
it **once**. Reliable for gated/stopped CLK (phone, ~53 samples). Locking
once (not re-measuring) is drift-immune and avoids glitch re-anchors.
once (not re-measuring) is drift-immune and avoids glitch re-anchors. A
burst must yield >=2 usable spacings, and a guard-dominated burst (all-zero
data: long LOW runs + short HIGH guard) is rejected (`_etu_candidate`,
v1.9.6); a rate that fails parity is invalidated and re-measured.
- **Edge-list bit reader (`_read_byte_edges`).** Per-byte edge reconstruction
from the DATA edge list (re-anchors the next byte via `_next_start_fall`).
Drift-immune. Reliable for mid-session/edge mode; gated by `_edge_read`.
@@ -1189,10 +1250,10 @@ discarded ideas. "Proven" = kept in `pd.py`; "Rejected" = do not re-add.
bit_samples` distinguishes genuine inter-byte idle gaps (≥2 ETU per ISO
7816-3) from intra-byte HIGH periods (≤1 ETU). Prevents byte misalignment
after `_measure_etu()` consumption (v1.1.1 fix for post-ATR desync).
- **Inverse-convention ATR detection in DATA state.** `firstByte == 0x3f`
alongside `0x3b` at line 1656, so inverse-convention ATRs (TS=0x3F) are
parsed by the default state. Sets `clock_skip=372` correctly
before PPS (v1.1.1 fix).
- **Inverse-convention support (TS=0x3F, v1.9.6).** The hunt already read
`0x3F`; the DATA state now accepts it too, the start bit stays a falling
edge from an idle-HIGH line (ISO 7816-3 7.1), and `get_bytes()` assembles
inverse data msb-first. Spec-verified; no inverse capture in the corpus.
- **`_resync = True` after PPS acceptance (native CLK path).** Forces
`resync_idle()` before the first post-PPS command, preventing the decoder
from latching onto a mid-byte transition at the new speed (v1.1.1 fix).
README.md
+3
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@@ -56,6 +56,9 @@ this decoder's `pcap_file=<path>` option).
| VCC tracking (optional) | `vcc_detect=true`: emits power on/off events (sub_type 0x11) |
| Direct PCAP file | `pcap_file=<path>` writes PCAP without shell redirection |
| Start-bit deglitch | 2-sample deglitch in the start-bit detector eliminates sub-ETU LOW glitches from FX2LP pull-up artifacts, preventing byte misalignment on fast phone traces |
| Mid-session ETU lock | The DATA-edge ETU estimator rejects guard-only (all-zero) and single-spacing bursts and invalidates a rate that fails parity, so a capture at a non-default F/D locks safely |
| ATR / resync guards | A DATA-state `0x3B`/`0x3F` is an ATR candidate only before the first APDU; parity-dirty or bare (TS+T0) frames are ignored, and `resync_idle` really waits for the idle level |
| Inverse convention | TS=0x3F ATRs follow ISO 7816-3 7.1: inverted data, msb first, start bit still LOW from an idle-HIGH line |
## Decoder options
README_RUS.md
+3
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@@ -59,6 +59,9 @@ GSMTAP pcap-файлы (включая PCAP, который этот декод
| Отслеживание VCC (опционально) | `vcc_detect=true`: события включения/выключения питания (sub_type 0x11) |
| PCAP сразу в файл | `pcap_file=<path>` пишет PCAP без перенаправления вывода оболочки |
| Деглитч стартового бита | Деглитч в 2 отсчёта в детекторе стартового бита убирает LOW-глитчи короче ETU от артефактов подтяжки FX2LP и предотвращает смещение байтов на быстрых телефонных трассах |
| Захват ETU в середине сессии | Оценщик ETU по фронтам DATA отбрасывает пачки только со сторожевым интервалом (нулевые данные) и одиночные интервалы, а также сбрасывает скорость, не прошедшую проверку чётности, поэтому трасса с нестандартным F/D захватывается надёжно |
| Защита ATR / ресинхронизации | `0x3B`/`0x3F` в состоянии DATA считается кандидатом в ATR только до первого APDU; кадры с ошибкой чётности или голый TS+T0 игнорируются, а `resync_idle` действительно ждёт уровень простоя |
| Инверсная конвенция | ATR с TS=0x3F разбирается по ISO 7816-3 7.1: инверсные данные, msb первым, стартовый бит по-прежнему LOW при простое линии HIGH |
## Опции декодера
pd.py
+188 -62
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@@ -28,7 +28,7 @@ from .gsmtap_stream import (GsmtapStreamSender,
GSMTAP_SIM_RST_EVENT, GSMTAP_SIM_VCC_EVENT,
GSMTAP_FLAG_BAD_FCS)
VERSION = '1.9.5'
VERSION = '1.9.6'
@@ -196,6 +196,26 @@ def plausible_ins(ins):
return True
def ts_from_bits(bits):
'''Return the TS value (0x3B direct / 0x3F inverse) when the raw ten
character bits match an ISO 7816-3 8.1 initial-character pattern, else
None.
Both TS patterns share moments 1-4 LHHL and 8-10 LLH; moments 5-7 are
LLL (inverse: state L encodes 1, msb first) or HHH (direct: state H
encodes 1, lsb first). The decoded byte alone cannot tell them apart:
the inverse TS reads as 0x03 through a direct lsb-first assembly.'''
if len(bits) < 10:
return None
if bits[0:4] != [0, 1, 1, 0] or bits[7:10] != [0, 0, 1]:
return None
if not any(bits[4:7]):
return 0x3f
if all(bits[4:7]):
return 0x3b
return None
def is_idle_noise_byte(first_byte):
'''Check if a byte looks like an idle-line artifact rather than a
command class byte.
@@ -533,6 +553,11 @@ class Decoder(srd.Decoder):
# handling -- native mode never measures it explicitly.
self.detected_clock_skip = 372
self.bit_samples = None
# True only when bit_samples came from a real DATA-edge
# measurement (not a protocol/fallback guess). The hunt-side ETU
# recovery and the clock_skip commit key off this, so a pre-seeded
# default cannot mask a failed measurement.
self._etu_measured = False
self._etu_confirm_count = 0
self._etu_fail_count = 0
self._edge_spacings = deque(maxlen=128)
@@ -566,6 +591,11 @@ class Decoder(srd.Decoder):
# (e.g. GSM TX bursts coupling into the probe wiring).
self.parity_hist = deque(maxlen=64)
self.sig_warned = False
# Total parity failures (ATR validation) and "APDU traffic has
# started" (a DATA-state 0x3B is only an ATR before the first APDU;
# afterwards it is data misread at a frame boundary).
self._parity_errors = 0
self._apdu_seen = False
# Stuck-line watchdog: consecutive all-zero frames usually mean
# the I/O probe lost contact (floating low), not data.
self.zero_run = 0
@@ -819,6 +849,8 @@ class Decoder(srd.Decoder):
self._inverse_convention = False
self.clock_skip = 372
self.bit_samples = None
self._etu_measured = False
self._apdu_seen = False
self.state = 'FIND START'
self._atr_hunt_count = 0
self._pps_attempted = False
@@ -852,6 +884,7 @@ class Decoder(srd.Decoder):
self._atr_hunt_count = 0
self._pps_attempted = False
self.bit_samples = None
self._etu_measured = False
self._etu_confirm_count = 0
self._etu_fail_count = 0
self.clock_skip = 372
@@ -887,8 +920,16 @@ class Decoder(srd.Decoder):
return h
def get_bytes(self, bits):
bits = list(bits)
if self._inverse_convention:
# ISO 7816-3 7.1: direct sends the lsb first, inverse the msb
# first; the readers have already applied the polarity.
byte = 0
for bit in list(reversed(bits)):
for bit in bits:
byte = (byte << 1) | bit
return byte
byte = 0
for bit in reversed(bits):
byte = (byte << 1) | bit
return byte
@@ -911,6 +952,8 @@ class Decoder(srd.Decoder):
monitor; warn once per degradation episode when >= 8 of the last
64 frames failed parity.'''
self.parity_hist.append(err)
if err:
self._parity_errors += 1
if len(self.parity_hist) < 32:
return
errs = sum(self.parity_hist)
@@ -993,12 +1036,14 @@ class Decoder(srd.Decoder):
For a mid-session capture (no ATR) the card may already be PPS'd to a
fast ETU, so the default clock_skip=372 is wrong. Once _measure_etu
has recovered bit_samples (samples per ETU) and _measure_clock_period
has recovered _samples_per_clock (samples per CLK cycle), clock_skip
= bit_samples / _samples_per_clock. Sets _clock_skip_confident on
success so the CLK-sync reader is used; leaves it clear (edge-list
fallback) if the CLK period could not be measured.'''
if self._samples_per_clock and self.bit_samples:
has recovered bit_samples (samples per ETU) from real DATA edges and
_measure_clock_period has recovered _samples_per_clock (samples per
CLK cycle), clock_skip = bit_samples / _samples_per_clock. Only a
real DATA measurement is trusted (_etu_measured); a failed or
rejected measurement never commits a rate. A later parity failure
invalidates it (_confirm_etu).'''
if (self._etu_measured and self._samples_per_clock
and self.bit_samples):
cs = int(round(float(self.bit_samples) / float(self._samples_per_clock)))
if cs >= 1:
if cs != self.clock_skip:
@@ -1010,6 +1055,38 @@ class Decoder(srd.Decoder):
return True
return False
def _etu_candidate(self, pairs):
'''Return (etu, ok) from (spacing, level) edge pairs.
Filters glitches, drops a leading burst-boundary outlier, and
rejects a burst whose minimum recurrence is the inter-character
guard rather than a bit period: all-zero data produces long LOW
runs and a short HIGH guard, so the smallest recurring spacing is
the guard (2x or more the true ETU). A burst with bit transitions
has a smaller spacing somewhere, so the guard pattern is
distinguishable when every non-minimum spacing is at least 2x the
minimum.'''
MIN_ETU = 12
valid = [p for p in pairs if p[0] >= MIN_ETU]
if len(valid) >= 2:
med = sorted(p[0] for p in valid)[len(valid) // 2]
# If the first valid spacing is >10x the median, the scan
# started at a burst boundary — drop leading outliers.
while valid and valid[0][0] > med * 10:
valid.pop(0)
if len(valid) < 2:
# A single spacing cannot prove a recurring bit period (a lone
# 0x00 character yields one 10-ETU run -> 10x the true ETU).
return (None, False)
spacings = [p[0] for p in valid]
etu = self._robust_min(spacings)
guard_dominated = (
all(lvl == 1 for sp, lvl in valid if sp == etu)
and all(sp >= 2 * etu for sp, lvl in valid if sp != etu))
if guard_dominated or not (4 <= etu <= 100000):
return (etu, False)
return (etu, True)
def _measure_etu(self):
'''Recover the live bit period (ETU, in samples) from the DATA line for
a mid-session capture that has no ATR to derive timing from.
@@ -1056,34 +1133,23 @@ class Decoder(srd.Decoder):
break
edges.append((sn, d))
if len(edges) >= 2:
spacings = [edges[i + 1][0] - edges[i][0]
pairs = [(edges[i + 1][0] - edges[i][0], edges[i][1])
for i in range(len(edges) - 1)]
# Filter glitches (< MIN_ETU) then check if the first spacing
# is an outlier (scan started in a noisy pre-burst region).
MIN_ETU = 12
valid = [s for s in spacings if s >= MIN_ETU]
if len(valid) >= 2:
med = sorted(valid)[len(valid) // 2]
# If the first valid spacing is >10x the median, the scan
# started at a burst boundary — drop leading outliers.
while valid and valid[0] > med * 10:
valid.pop(0)
spacings = valid if valid else spacings
etu = self._robust_min(spacings)
# Sanity clamp: a real ISO 7816 etu is >= a few samples and below
# ~100k samples even at extreme F/D. Anything else is a glitch.
if 4 <= etu <= 100000:
etu, ok = self._etu_candidate(pairs)
if ok:
self.bit_samples = etu
self._etu_measured = True
self._etu_confirm_count = 0
self._etu_fail_count = 0
if self.bit_samples is None:
self.bit_samples = self._compute_bit_samples()
self._etu_confirm_count = 0
self._etu_fail_count = 0
else:
self.log("ETU measurement rejected", etu,
"spacings", [p[0] for p in pairs][:8])
# The live line is gated/stopped CLK; use the edge-list bit reader
# (immune to the drift a fixed sample-skip cadence would suffer) for
# every byte from here on.
# (immune to the drift of fixed sample-skip timing) for every byte.
# The CLK-sync reader is used once _derive_clock_skip_from_etu()
# has a real measurement; a parity failure invalidates it.
self._edge_read = True
if self._etu_measured:
self.log("etu recovered (samples):", self.bit_samples)
def _recover_etu_in_hunt(self):
@@ -1122,7 +1188,10 @@ class Decoder(srd.Decoder):
so it is unit-testable without libsigrokdecode.'''
self._atr_fail_total += 1
# Live-ETU recovery every 2 failures, up to ATR_HUNT_ETU_ATTEMPTS.
if (self.bit_samples is None
# A real DATA measurement is required: bit_samples may be a
# pre-seeded default from handle_atr, which must not mask the need
# to recover the live rate.
if (not self._etu_measured
and self._hunt_etu_attempts < ATR_HUNT_ETU_ATTEMPTS
and self._atr_fail_total >=
2 * (self._hunt_etu_attempts + 1)):
@@ -1149,12 +1218,19 @@ class Decoder(srd.Decoder):
self._etu_confirm_count += 1
if self._etu_confirm_count >= 3:
self.log("ETU confirmed:", self.bit_samples)
if self._etu_measured:
# The CLK-sync reader may trust clock_skip now.
self._clock_skip_confident = True
else:
self._etu_fail_count += 1
if self._etu_fail_count >= 2:
self.log("ETU re-measure (bad initial measurement):",
self.bit_samples)
self.bit_samples = None
self._etu_measured = False
# Never keep sampling at a rejected rate: drop back to the
# edge reader until a fresh measurement is confirmed.
self._clock_skip_confident = False
self._etu_confirm_count = 0
self._etu_fail_count = 0
@@ -1349,13 +1425,17 @@ class Decoder(srd.Decoder):
bit = 1 - bit
self.bits.append(bit)
self.es = self.samplenum
self.signal_quality(1 if (self.bits.count(1) % 2 != 0) else 0)
parity_ok = (self.bits.count(1) % 2 == 0)
if (self.bits.count(1) % 2 != 0):
# A TS's moment 10 is fixed by the ISO 7816-3 8.1 pattern (the
# inverse TS is odd over moments 2-10); it is not a parity-checked
# data character, so it must neither warn nor feed the ETU check.
is_ts = ts_from_bits(self.bits) is not None
parity_ok = is_ts or (self.bits.count(1) % 2 == 0)
self.signal_quality(0 if parity_ok else 1)
if not parity_ok:
self.log(self.samplenum, "CHKSUM ERROR: ", 0, "bits: ", self.bits)
self.put(self.ss, self.samplenum, self.out_ann,
[0, ["CHKSUM ERROR bits={bits}".format(bits=self.bits)]])
if self.bit_samples is not None:
if self.bit_samples is not None and self.bits:
self._confirm_etu(parity_ok)
byte = self.get_bytes(self.bits[1:9])
# Stuck-line watchdog (same as the other readers).
@@ -1462,9 +1542,11 @@ class Decoder(srd.Decoder):
if nxt is not None:
self._start_fall = nxt
self.es = self.samplenum
self.signal_quality(1 if (self.bits.count(1) % 2 != 0) else 0)
parity_ok = (self.bits.count(1) % 2 == 0)
if (self.bits.count(1) % 2 != 0):
# A TS is not a parity-checked data character (see _read_byte_edges).
is_ts = ts_from_bits(self.bits) is not None
parity_ok = is_ts or (self.bits.count(1) % 2 == 0)
self.signal_quality(0 if parity_ok else 1)
if not parity_ok:
self.log(self.samplenum, "CHKSUM ERROR: ", 0, "bits: ", self.bits)
self.put(self.ss, self.samplenum, self.out_ann,
[0, ["CHKSUM ERROR bits={bits}".format(bits=self.bits)]])
@@ -1511,14 +1593,11 @@ class Decoder(srd.Decoder):
min_high = max(int(1.5 * self.bit_samples), 4)
while True:
# Wait for DATA idle, servicing RST/VCC.
# In direct convention: idle = HIGH, start bit = falling edge (HIGH→LOW).
# In inverse convention: idle = LOW, start bit = rising edge (LOW→HIGH).
if self._inverse_convention:
idle_cond = {self.DATA_IDX: 'l'} # Wait for LOW (idle in inverse)
start_edge = 'r' # Rising edge = start bit in inverse
else:
idle_cond = {self.DATA_IDX: 'h'} # Wait for HIGH (idle in direct)
start_edge = 'f' # Falling edge = start bit in direct
# ISO 7816-3 7.1: the line idles HIGH and the start bit is
# always LOW (falling edge) in BOTH conventions; only the
# data-bit polarity and order differ.
idle_cond = {self.DATA_IDX: 'h'}
start_edge = 'f'
cond = [idle_cond]
if (self.track_rst):
cond.append({self.RST_IDX: 'e'})
@@ -1555,7 +1634,7 @@ class Decoder(srd.Decoder):
pins = self.wait({'skip': self._min_pulse_samples})
if pins is not None:
bit = pins[self.DATA_IDX]
idle_val = 1 if not self._inverse_convention else 0
idle_val = 1 # line HIGH is idle in both conventions
if bit == idle_val:
self._glitch_rejects += 1
self.log("start-bit glitch rejected (#%d)"
@@ -1639,8 +1718,10 @@ class Decoder(srd.Decoder):
self.bits.append(bit)
self.wait({'skip': self.clock_skip - 4})
self.es = self.samplenum
self.signal_quality(1 if (self.bits.count(1) % 2 != 0) else 0)
if (self.bits.count(1) % 2 != 0):
is_ts = ts_from_bits(self.bits) is not None
bad_parity = (not is_ts) and (self.bits.count(1) % 2 != 0)
self.signal_quality(1 if bad_parity else 0)
if bad_parity:
self.log(self.samplenum, "CHKSUM ERROR: ", pins[1], "bits: ", self.bits)
self.put(self.ss, self.samplenum, self.out_ann, [0, ["CHKSUM ERROR bits={bits}".format(bits=self.bits)]])
byte = self.get_bytes(self.bits[1:9])
@@ -1688,29 +1769,37 @@ class Decoder(srd.Decoder):
def resync_idle(self):
'''Re-align framing after a desync: wait for DATA to go to idle level
so the next peek lands on a genuine start bit of a fresh exchange
instead of a mid-burst byte. Gating-immune: we poll DATA in
samples (which advance even when CLK is frozen), and bound the hunt
by a sample budget so a pathologically-busy (or stuck) line never
stalls the decoder.'''
'''Re-align framing after a desync: wait for DATA to return to its
idle level so the next peek lands on a genuine start bit of a fresh
exchange instead of a mid-burst byte. The wait is a level condition
(plus optional RST/VCC edges), so it advances the sample counter
instead of spinning on the current sample; a bounded loop guards
against a pathologically busy or stuck line.'''
bs = self.bit_samples or self._compute_bit_samples()
budget = int(IDLE_RESYNC_ETU * bs) * 8
step = max(int(bs), 1)
loops = budget // step + 16
# In direct convention: idle = HIGH (mark).
# In inverse convention: idle = LOW (mark is inverted).
idle_level = 0 if self._inverse_convention else 1
# ISO 7816-3 7.1: the line idles HIGH in both conventions.
idle_level = 1
cond = [{self.DATA_IDX: 'h' if idle_level else 'l'}]
if self.track_rst:
cond.append({self.RST_IDX: 'e'})
if self.track_vcc:
cond.append({self.VCC_IDX: 'e'})
for _ in range(loops):
pins = self.wait({'skip': 0})
pins = self.wait(cond)
if pins is None:
# End of capture / session stopped mid-resync: stop cleanly
# instead of raising TypeError on the None pin state.
self._eof = True
return
if pins[self.DATA_IDX] == idle_level:
if self._stall_check(pins, track=False):
self._eof = True
return
# Could not find an idle gap -- resume normal decode anyway.
if self.line_events(pins):
continue
return
# Could not find an idle level -- resume normal decode anyway.
def handle_atr(self, pins):
@@ -1718,6 +1807,7 @@ class Decoder(srd.Decoder):
self.log("START ATR:", self.samplenum);
self.state = 'ATR'
bad_parity_before = self._parity_errors
tA = []
tB = []
@@ -1744,6 +1834,12 @@ class Decoder(srd.Decoder):
else:
byte = self.read_first_byte()
atr_start = self.ss
# ISO 7816-3 8.1: an inverse-convention TS (moments 5-7 = LLL) is
# decoded as 0x03 by the direct reader; take the convention from
# the raw pattern so both TS forms are recognised.
raw_ts = ts_from_bits(self.bits)
if raw_ts is not None:
byte = raw_ts
# TS must be 0x3B (direct) or 0x3F (inverse) per TS 102 221 §5.2.2.
# Pre-activation traffic (reader card-detect polling, a stray PPS
# `ff 10 95 7a`, power-up noise) can appear on DATA before RST even
@@ -1784,6 +1880,9 @@ class Decoder(srd.Decoder):
# End of capture mid-hunt: stop cleanly instead of raising
# TypeError (None & 0x80) in the next loop iteration.
return
raw_ts = ts_from_bits(self.bits)
if raw_ts is not None:
byte = raw_ts
atr_start = self.ss
ts_attempts += 1
if (byte not in (0x3b, 0x3f)):
@@ -1820,6 +1919,7 @@ class Decoder(srd.Decoder):
count=self._atr_hunt_count,
fails=self._atr_fail_total))
self.bit_samples = None
self._etu_measured = False
self._etu_confirm_count = 0
self._etu_fail_count = 0
self.hasT0 = True
@@ -1911,6 +2011,24 @@ class Decoder(srd.Decoder):
self.put(atr_start, self.samplenum, self.out_ann, [0, ["Invalid TCK in ATR, got={tck:02x} expected={xor:02x}".format(tck=byte,xor=xor)]])
self.log("Invalid TCK in ATR", hex(byte), hex(xor))
if self._parity_errors != bad_parity_before:
# A real ATR is parity-clean; a data run misread at a frame
# boundary is not. Ignore the ATR instead of committing 372.
self.log("ATR rejected: parity error(s) in",
codecs.encode(bytes(self.ATR), 'hex'))
self.state = 'DATA'
self._resync = True
return
if len(self.ATR) < 2 or (len(self.ATR) < 3
and (self.ATR[1] & 0xF0) == 0):
# A bare TS+T0 ATR is legal ISO but not credible for a SIM/UICC:
# a 0x3B data byte at a frame boundary would otherwise fabricate
# an ATR and force clock_skip=372 for the rest of the capture.
self.log("implausible bare ATR ignored:",
codecs.encode(bytes(self.ATR), 'hex'))
self.state = 'DATA'
self._resync = True
return
self.put(atr_start, self.samplenum, self.out_ann, [2, ["ATR", "ATR={atr}".format(atr=codecs.encode(bytes(self.ATR), 'hex'))]])
self.put(atr_start, self.samplenum, self.out_python, [0, self.ATR])
self.emit_packet(GSMTAP_SIM_ATR, bytes(self.ATR), atr_start, self.samplenum)
@@ -1931,6 +2049,7 @@ class Decoder(srd.Decoder):
# cleared bit_samples during ATR hunt (parity failures on noise),
# which would trigger _measure_etu() on the next decode_step.
self.bit_samples = self.clock_skip * (self._samples_per_clock or 3)
self._etu_measured = True
# Lock the ETU so _confirm_etu() cannot clear bit_samples after
# parity failures on post-ATR noise bytes. Without this, two
# consecutive parity errors would trigger an ETU re-measure that
@@ -2143,6 +2262,7 @@ class Decoder(srd.Decoder):
else:
self._pps_speed_changed = True
self.bit_samples = None
self._etu_measured = False
self._start_fall = None
# clock_skip now reflects the negotiated FI/DI, so it is known to
# be correct regardless of which reader is active.
@@ -2282,6 +2402,7 @@ class Decoder(srd.Decoder):
self._atr_hunt_count = 0
self._pps_attempted = False
self.bit_samples = None
self._etu_measured = False
self._etu_confirm_count = 0
self._etu_fail_count = 0
self.clock_skip = 372
@@ -2364,7 +2485,9 @@ class Decoder(srd.Decoder):
self.read_byte()
self._resync = True
return True
elif (firstByte == 0x3b) and not self._atr_parsed: # Probably ATR (only if no ATR yet)
elif ((firstByte in (0x3b, 0x3f)
or ts_from_bits(self.bits) is not None)
and not self._atr_parsed and not self._apdu_seen): # ATR candidate (direct/inverse), only before traffic
self.handle_atr(self.wait({'skip': 0}))
return True
elif is_idle_noise_byte(firstByte):
@@ -2746,6 +2869,9 @@ class Decoder(srd.Decoder):
if (len(packet) > 0):
# APDU traffic has started: a later DATA-state 0x3B is
# data, not an ATR.
self._apdu_seen = True
# All-zero first: an I/O-held-low stretch is idle noise,
# not a TPDU -- suppress it entirely (and re-sync later).
if (all(b == 0 for b in packet)):
tests/baseline.txt
+30 -12
View File
@@ -1,7 +1,7 @@
=== Baseline captured 2026-10-20T16:56:58+03:00 ===
=== Baseline captured 2026-10-20T17:56:26+03:00 ===
=== test_8 ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('etu recovered (samples):', 1237)
iso7816-1: RST deasserted
('RST deasserted',)
@@ -36,7 +36,7 @@ Degradation metrics:
RESULT: OK - capture fully explained (reader + CAT + valid retries)
=== test_7 ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('etu recovered (samples):', 1236)
iso7816-1: RST deasserted
('RST deasserted',)
@@ -77,7 +77,7 @@ Degradation metrics:
RESULT: OK - capture fully explained (reader + CAT + valid retries)
=== xiaomi_phone_sample ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('etu recovered (samples):', 53)
(11674007, 'CHKSUM ERROR: ', 0, 'bits: ', [0, 0, 0, 1, 0, 0, 1, 1, 1, 1])
iso7816-1: CHKSUM ERROR bits=[0, 0, 0, 1, 0, 0, 1, 1, 1, 1]
@@ -102,7 +102,7 @@ Degradation metrics:
RESULT: OK - capture fully explained (reader + CAT + valid retries)
=== xiaomi_mi_a1_coldboot ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('RST low at start: expecting cold-boot ATR',)
iso7816-1: RST deasserted
('RST deasserted',)
@@ -129,7 +129,7 @@ Degradation metrics:
RESULT: OK - capture fully explained (reader + CAT + valid retries)
=== 4gmodem_coldboot ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('RST low at start: expecting cold-boot ATR',)
iso7816-1: RST deasserted
('RST deasserted',)
@@ -156,7 +156,7 @@ Degradation metrics:
RESULT: OK - capture fully explained (reader + CAT + valid retries)
=== alcor_reader_sample ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('RST low at start: expecting cold-boot ATR',)
iso7816-1: RST deasserted
('RST deasserted',)
@@ -189,7 +189,7 @@ Degradation metrics:
RESULT: OK - capture fully explained (reader + CAT + valid retries)
=== samsung_A55_coldboot_new_cable ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('RST low at start: expecting cold-boot ATR',)
iso7816-1: RST deasserted
('RST deasserted',)
@@ -216,7 +216,7 @@ Degradation metrics:
RESULT: OK - capture fully explained (reader + CAT + valid retries)
=== samsung_A55_coldboot_new_cable_sim2 ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('RST low at start: expecting cold-boot ATR',)
iso7816-1: RST deasserted
('RST deasserted',)
@@ -243,7 +243,7 @@ Degradation metrics:
RESULT: OK - capture fully explained (reader + CAT + valid retries)
=== samsung_S21p_coldboot_new_cable ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('RST low at start: expecting cold-boot ATR',)
iso7816-1: RST deasserted
('RST deasserted',)
@@ -270,7 +270,7 @@ Degradation metrics:
RESULT: OK - capture fully explained (reader + CAT + valid retries)
=== samsung_S21p_coldboot_new_cable_sim2 ===
('=== iso7816 decoder v1.9.5 ===',)
('=== iso7816 decoder v1.9.6 ===',)
('RST low at start: expecting cold-boot ATR',)
iso7816-1: RST deasserted
('RST deasserted',)
@@ -342,25 +342,34 @@ test_explicit_eof_wins (__main__.TestAtEof.test_explicit_eof_wins) ... ok
test_pending_replay_is_bounded (__main__.TestAtEof.test_pending_replay_is_bounded) ... ok
test_pending_replay_is_not_eof (__main__.TestAtEof.test_pending_replay_is_not_eof) ... ok
test_stuck_with_nothing_queued_is_eof (__main__.TestAtEof.test_stuck_with_nothing_queued_is_eof) ... ok
test_atr_with_parity_error_is_ignored (__main__.TestAtrHuntDetect.test_atr_with_parity_error_is_ignored) ... ok
test_bare_ts_t0_is_not_committed_as_an_atr (__main__.TestAtrHuntDetect.test_bare_ts_t0_is_not_committed_as_an_atr) ... ok
test_eof_after_plausible_cla_is_clean (__main__.TestAtrHuntDetect.test_eof_after_plausible_cla_is_clean) ... ok
test_handoff_on_extended_channel_cla (__main__.TestAtrHuntDetect.test_handoff_on_extended_channel_cla) ... ok
test_handoff_on_odd_ins_89 (__main__.TestAtrHuntDetect.test_handoff_on_odd_ins_89) ... ok
test_inverse_ts_pattern_is_parsed (__main__.TestAtrHuntDetect.test_inverse_ts_pattern_is_parsed) ... ok
test_no_handoff_on_basic_channel_cla (__main__.TestAtrHuntDetect.test_no_handoff_on_basic_channel_cla) ... ok
test_no_handoff_on_invalid_ins (__main__.TestAtrHuntDetect.test_no_handoff_on_invalid_ins) ... ok
test_all_ff_idle_loop_is_bounded (__main__.TestAtrHuntEscape.test_all_ff_idle_loop_is_bounded) ... ok
test_idle_ff_retries_before_cap (__main__.TestAtrHuntEscape.test_idle_ff_retries_before_cap) ... ok
test_idle_resets_capped_then_resume (__main__.TestAtrHuntEscape.test_idle_resets_capped_then_resume) ... ok
test_measured_etu_skips_recovery (__main__.TestAtrHuntEscape.test_measured_etu_skips_recovery) ... ok
test_no_recovery_when_etu_known (__main__.TestAtrHuntEscape.test_no_recovery_when_etu_known) ... ok
test_non_ff_resumes_when_count_high (__main__.TestAtrHuntEscape.test_non_ff_resumes_when_count_high) ... ok
test_recover_etu_in_hunt_runs_measurement (__main__.TestAtrHuntEscape.test_recover_etu_in_hunt_runs_measurement) ... ok
test_recovery_attempts_capped_then_hard_limit (__main__.TestAtrHuntEscape.test_recovery_attempts_capped_then_hard_limit) ... ok
test_retry_then_recover_after_two_failures (__main__.TestAtrHuntEscape.test_retry_then_recover_after_two_failures) ... ok
test_seeded_bit_samples_does_not_block_recovery (__main__.TestAtrHuntEscape.test_seeded_bit_samples_does_not_block_recovery) ... ok
test_bit_dense_valid_cla_is_not_idle_noise (__main__.TestDecodeStep.test_bit_dense_valid_cla_is_not_idle_noise) ... ok
test_data_0x3b_before_traffic_is_atr_candidate (__main__.TestDecodeStep.test_data_0x3b_before_traffic_is_atr_candidate) ... ok
test_data_0x3b_is_not_an_atr_after_traffic (__main__.TestDecodeStep.test_data_0x3b_is_not_an_atr_after_traffic) ... ok
test_data_0x3f_before_traffic_is_atr_candidate (__main__.TestDecodeStep.test_data_0x3f_before_traffic_is_atr_candidate) ... ok
test_ex_class_exchange_frames (__main__.TestDecodeStep.test_ex_class_exchange_frames) ... ok
test_extended_channel_exchange_frames (__main__.TestDecodeStep.test_extended_channel_exchange_frames) ... ok
test_idle_noise_still_discarded (__main__.TestDecodeStep.test_idle_noise_still_discarded) ... ok
test_immediate_sw_rejection_frames (__main__.TestDecodeStep.test_immediate_sw_rejection_frames) ... ok
test_invalid_ins_re_frame_recovers_command (__main__.TestDecodeStep.test_invalid_ins_re_frame_recovers_command) ... ok
test_inverse_ts_raw_pattern_is_an_atr_candidate (__main__.TestDecodeStep.test_inverse_ts_raw_pattern_is_an_atr_candidate) ... ok
test_le_256_response_data_is_kept (__main__.TestDecodeStep.test_le_256_response_data_is_kept) ... ok
test_short_response_is_split_and_flagged (__main__.TestDecodeStep.test_short_response_is_split_and_flagged) ... ok
test_short_response_replays_following_exchange (__main__.TestDecodeStep.test_short_response_replays_following_exchange) ... ok
@@ -380,6 +389,7 @@ test_is_desynced_short_fragment (__main__.TestDesyncHelpers.test_is_desynced_sho
test_max_tpdu_len (__main__.TestDesyncHelpers.test_max_tpdu_len) ... ok
test_plausible_sw_accepts_valid_classes (__main__.TestDesyncHelpers.test_plausible_sw_accepts_valid_classes) ... ok
test_plausible_sw_rejects_garbage (__main__.TestDesyncHelpers.test_plausible_sw_rejects_garbage) ... ok
test_resync_idle_waits_on_a_level_condition (__main__.TestDesyncHelpers.test_resync_idle_waits_on_a_level_condition) ... ok
test_a55_u1_concat (__main__.TestEmbeddedExchanges.test_a55_u1_concat) ... ok
test_a55_u4_mega_concat (__main__.TestEmbeddedExchanges.test_a55_u4_mega_concat) ... ok
test_channel1_select_after_manage_channel_swallow (__main__.TestEmbeddedExchanges.test_channel1_select_after_manage_channel_swallow) ... ok
@@ -396,11 +406,19 @@ test_samsung_record_burst_concat (__main__.TestEmbeddedExchanges.test_samsung_re
test_xiaomi_select_getresp_swallow (__main__.TestEmbeddedExchanges.test_xiaomi_select_getresp_swallow) ... ok
test_eoferror_propagates (__main__.TestEndOfStream.test_eoferror_propagates) ... ok
test_systemerror_propagates (__main__.TestEndOfStream.test_systemerror_propagates) ... ok
test_ff_burst_is_accepted (__main__.TestEtuCandidate.test_ff_burst_is_accepted) ... ok
test_normal_burst_is_accepted (__main__.TestEtuCandidate.test_normal_burst_is_accepted) ... ok
test_single_spacing_is_rejected (__main__.TestEtuCandidate.test_single_spacing_is_rejected) ... ok
test_zero_run_guard_is_rejected (__main__.TestEtuCandidate.test_zero_run_guard_is_rejected) ... ok
test_build_packet_bad_fcs_flag (__main__.TestGsmtapFlags.test_build_packet_bad_fcs_flag) ... ok
test_build_packet_payload_passthrough (__main__.TestGsmtapFlags.test_build_packet_payload_passthrough) ... ok
test_build_packet_plain_res_zero (__main__.TestGsmtapFlags.test_build_packet_plain_res_zero) ... ok
test_flag_constant_value (__main__.TestGsmtapFlags.test_flag_constant_value) ... ok
test_pps_subtypes_are_standard (__main__.TestGsmtapFlags.test_pps_subtypes_are_standard) ... ok
test_get_bytes_direct_lsb_first (__main__.TestInverseConvention.test_get_bytes_direct_lsb_first) ... ok
test_get_bytes_inverse_msb_first (__main__.TestInverseConvention.test_get_bytes_inverse_msb_first) ... ok
test_ts_from_bits_direct_inverse_and_garbage (__main__.TestInverseConvention.test_ts_from_bits_direct_inverse_and_garbage) ... ok
test_wait_data_falling_uses_high_idle_and_falling_start (__main__.TestInverseConvention.test_wait_data_falling_uses_high_idle_and_falling_start) ... ok
test_base_payload_without_rate (__main__.TestLineEventPayload.test_base_payload_without_rate) ... ok
test_flag_constant (__main__.TestLineEventPayload.test_flag_constant) ... ok
test_legacy_prefix_preserved (__main__.TestLineEventPayload.test_legacy_prefix_preserved) ... ok
@@ -439,6 +457,6 @@ test_valid_ins_odd_variants (__main__.TestValidateT0Apdu.test_valid_ins_odd_vari
test_vs_reader_mirror (__main__.TestValidateT0Apdu.test_vs_reader_mirror) ... ok
----------------------------------------------------------------------
Ran 99 tests in 0.032s
Ran 117 tests in 0.026s
OK
tests/test_gsmtap.py
+244
View File
@@ -151,6 +151,139 @@ class TestDesyncHelpers(unittest.TestCase):
self.assertFalse(self.pd.is_desynced(b'\x00' * 7))
def test_resync_idle_waits_on_a_level_condition(self):
# The re-align must WAIT for DATA (a level condition that advances
# the sample counter). It used to call wait({'skip': 0}) in a loop,
# which never advanced -- a no-op repeated on the same sample.
inst = object.__new__(self.pd.Decoder)
inst.reset()
inst.bit_samples = 100
inst._inverse_convention = False # normally set by start()
inst._start_fall = None
inst.samplenum = 0
levels = [0, 0, 1]
calls = []
def wait(cond):
calls.append(cond)
want = None
if isinstance(cond, list):
for c in cond:
if self.pd.Decoder.DATA_IDX in c:
want = c[self.pd.Decoder.DATA_IDX]
while levels:
inst.samplenum += 10
lvl = levels.pop(0)
if (want == 'h' and lvl == 1) or (want == 'l' and lvl == 0):
return [lvl] * 8
inst.samplenum += 10
return [1] * 8
inst.wait = wait
inst.resync_idle()
self.assertEqual(len(calls), 1)
self.assertIsInstance(calls[0], list)
self.assertIn(self.pd.Decoder.DATA_IDX, calls[0][0])
# it advanced through the two LOW samples to the HIGH one
self.assertEqual(inst.samplenum, 30)
class TestEtuCandidate(unittest.TestCase):
"""The mid-session ETU estimator's burst validation (_etu_candidate)."""
@classmethod
def setUpClass(cls):
cls.gs, cls.pd = _load_iso7816()
def setUp(self):
self.inst = object.__new__(self.pd.Decoder)
def test_zero_run_guard_is_rejected(self):
# All-zero characters: 10-ETU LOW runs + a short HIGH inter-byte
# guard. The smallest recurring spacing is the guard, not the ETU.
pairs = [(1000, 0), (200, 1)] * 8
etu, ok = self.inst._etu_candidate(pairs)
self.assertEqual(etu, 200)
self.assertFalse(ok)
def test_single_spacing_is_rejected(self):
# A lone 0x00 character yields one 10-ETU run (10x the true ETU).
self.assertEqual(self.inst._etu_candidate([(1000, 0)]),
(None, False))
self.assertEqual(self.inst._etu_candidate([(8, 0)]),
(None, False))
def test_normal_burst_is_accepted(self):
# A 1-ETU LOW spacing (start bit / data run) alongside 2- and
# 3-ETU runs: the recurring minimum is the true ETU.
pairs = [(100, 0), (100, 1), (200, 0), (300, 1),
(100, 0), (100, 1), (200, 0)]
etu, ok = self.inst._etu_candidate(pairs)
self.assertEqual(etu, 100)
self.assertTrue(ok)
def test_ff_burst_is_accepted(self):
# 0xFF: 1-ETU LOW start pulses + long HIGH runs. The minimum is a
# LOW run (the start bit), so the guard heuristic must not fire.
pairs = [(100, 0), (900, 1), (100, 0), (900, 1), (100, 0)]
etu, ok = self.inst._etu_candidate(pairs)
self.assertEqual(etu, 100)
self.assertTrue(ok)
class TestInverseConvention(unittest.TestCase):
"""ISO 7816-3 7.1: inverse = inverted data, msb first; the start bit
stays a falling edge from an idle-HIGH line (the old code assumed an
idle-LOW line / rising start)."""
@classmethod
def setUpClass(cls):
cls.gs, cls.pd = _load_iso7816()
def setUp(self):
self.inst = object.__new__(self.pd.Decoder)
self.inst.reset()
def test_get_bytes_direct_lsb_first(self):
self.inst._inverse_convention = False
self.assertEqual(self.inst.get_bytes([1, 0, 0, 0, 0, 0, 0, 0]), 0x01)
self.assertEqual(self.inst.get_bytes([1, 1, 0, 0, 0, 0, 0, 0]), 0x03)
def test_get_bytes_inverse_msb_first(self):
self.inst._inverse_convention = True
self.assertEqual(self.inst.get_bytes([1, 0, 0, 0, 0, 0, 0, 0]), 0x80)
self.assertEqual(self.inst.get_bytes([1, 1, 0, 0, 0, 0, 0, 0]), 0xC0)
def test_ts_from_bits_direct_inverse_and_garbage(self):
self.assertEqual(
self.pd.ts_from_bits([0, 1, 1, 0, 1, 1, 1, 0, 0, 1]), 0x3b)
self.assertEqual(
self.pd.ts_from_bits([0, 1, 1, 0, 0, 0, 0, 0, 0, 1]), 0x3f)
self.assertIsNone(
self.pd.ts_from_bits([0, 1, 1, 0, 1, 0, 1, 0, 0, 1]))
self.assertIsNone(self.pd.ts_from_bits([0, 1, 1, 0]))
def test_wait_data_falling_uses_high_idle_and_falling_start(self):
self.inst._inverse_convention = True
self.inst.bit_samples = 100
self.inst._edge_read = True
self.inst._min_pulse_samples = 0
self.inst.samplenum = 0
conds = []
def wait(cond):
conds.append(cond)
self.inst.samplenum += 200
return [1] * 8 if len(conds) == 1 else [0] * 8
self.inst.wait = wait
self.inst.wait_data_falling()
self.assertFalse(self.inst._eof)
self.assertEqual(conds[0][0][self.pd.Decoder.DATA_IDX], 'h')
self.assertEqual(conds[1][0][self.pd.Decoder.DATA_IDX], 'f')
self.assertEqual(self.inst._start_fall, self.inst.samplenum)
class TestValidateT0Apdu(unittest.TestCase):
@classmethod
def setUpClass(cls):
@@ -393,6 +526,7 @@ class TestAtrHuntEscape(unittest.TestCase):
self.pd = pd
self.inst = object.__new__(pd.Decoder)
self.inst.bit_samples = None
self.inst._etu_measured = False
self.inst._atr_hunt_count = 0
self.inst._atr_fail_total = 0
self.inst._hunt_etu_attempts = 0
@@ -414,6 +548,22 @@ class TestAtrHuntEscape(unittest.TestCase):
self.assertEqual(self._hunt_round(0x00), 'recover')
self.assertEqual(self.inst._hunt_etu_attempts, 1)
def test_seeded_bit_samples_does_not_block_recovery(self):
# handle_atr pre-seeds bit_samples with the default-rate guess; the
# recovery must key off a real DATA measurement, not on bit_samples
# being None (the pre-seed used to defeat the v1.6.0 recovery).
self.inst.bit_samples = 1488
self.inst._etu_measured = False
self.assertEqual(self._hunt_round(0x00), 'retry')
self.assertEqual(self._hunt_round(0x00), 'recover')
def test_measured_etu_skips_recovery(self):
# A real measurement means the rate is known: no re-measurement.
self.inst.bit_samples = 1488
self.inst._etu_measured = True
actions = [self._hunt_round(0x00) for _ in range(6)]
self.assertNotIn('recover', actions)
def test_recovery_attempts_capped_then_hard_limit(self):
actions = [self._hunt_round(0x00) for _ in range(200)]
actions = actions[:actions.index('resume_data') + 1]
@@ -452,6 +602,7 @@ class TestAtrHuntEscape(unittest.TestCase):
def test_no_recovery_when_etu_known(self):
self.inst.bit_samples = 100
self.inst._etu_measured = True
for _ in range(6):
self.assertEqual(self._hunt_round(0x00), 'retry')
self.assertEqual(self.inst._hunt_etu_attempts, 0)
@@ -870,6 +1021,53 @@ class TestDecodeStep(unittest.TestCase):
self.assertEqual(inst.emitted,
[(bytes.fromhex('00a40004009000'), 0)])
def test_data_0x3b_is_not_an_atr_after_traffic(self):
# Once an APDU has been emitted, a DATA-state 0x3B is data misread
# at a frame boundary, not an ATR: it falls through to the
# suspicious-CLA discard instead of calling handle_atr.
inst = self._make(bytes.fromhex('3b80900000'))
inst._atr_parsed = False
inst._apdu_seen = True
called = []
inst.handle_atr = lambda pins: called.append(pins)
inst.decode_step()
self.assertEqual(called, [])
self.assertEqual(len(inst.discarded), 1)
self.assertEqual(inst.discarded[0][0], 0x3B)
def test_data_0x3b_before_traffic_is_atr_candidate(self):
# Before any APDU the byte is still a legitimate ATR candidate
# (a capture starting between RST deassert and the ATR).
inst = self._make(bytes.fromhex('3b80900000'))
inst._atr_parsed = False
inst._apdu_seen = False
called = []
inst.handle_atr = lambda pins: called.append(pins)
inst.decode_step()
self.assertEqual(len(called), 1)
def test_data_0x3f_before_traffic_is_atr_candidate(self):
# Inverse-convention ATRs (TS=0x3F) are candidates too.
inst = self._make(bytes.fromhex('3f100000'))
inst._atr_parsed = False
inst._apdu_seen = False
called = []
inst.handle_atr = lambda pins: called.append(pins)
inst.decode_step()
self.assertEqual(len(called), 1)
def test_inverse_ts_raw_pattern_is_an_atr_candidate(self):
# A real inverse TS decodes as 0x03 through the direct reader; the
# raw moments 5-7 (LLL) mark it as the 0x3F candidate.
inst = self._make(bytes.fromhex('03100000'))
inst._atr_parsed = False
inst._apdu_seen = False
inst.bits = [0, 1, 1, 0, 0, 0, 0, 0, 0, 1]
called = []
inst.handle_atr = lambda pins: called.append(pins)
inst.decode_step()
self.assertEqual(len(called), 1)
def test_idle_noise_still_discarded(self):
# 0xFE (all-1s minus one bit) is not a valid class: unchanged
# idle-noise discard.
@@ -944,6 +1142,12 @@ class TestAtrHuntDetect(unittest.TestCase):
inst._samples_per_clock = 4.0 # skip _measure_clock_period()
inst.bit_samples = 100 # skip _compute_bit_samples()
inst.out_ann = 0
inst.out_python = 0
inst.options = {'protocol': 'T=0'}
inst._atr_parsed = False
inst.emitted = []
inst.emit_packet = lambda st, pl, ss, es, flags=0: \
inst.emitted.append((st, bytes(pl), flags))
inst.hasT0 = False # start() defaults; a handoff flips it
inst.hasT1 = False
inst._bytes = collections.deque(byte_seq)
@@ -1008,6 +1212,46 @@ class TestAtrHuntDetect(unittest.TestCase):
self.assertEqual(inst.state, 'ATR')
self.assertEqual(list(inst._replay), [])
def test_bare_ts_t0_is_not_committed_as_an_atr(self):
# A data byte 0x3B followed by 0x00 looks like a bare TS+T0 ATR.
# It must not be emitted or force clock_skip=372 (a mid-session
# data 0x3B used to fabricate an ATR).
inst = self._make([0x3B, 0x00])
inst.handle_atr(None)
self.assertFalse(inst._atr_parsed)
self.assertEqual(inst.emitted, [])
self.assertEqual(inst.state, 'DATA')
def test_inverse_ts_pattern_is_parsed(self):
# 0x03 + the raw inverse TS pattern must be committed as 0x3F and
# switch the readers to the inverse convention.
inst = self._make([0x03, 0x10, 0x95])
inst.bits = [0, 1, 1, 0, 0, 0, 0, 0, 0, 1]
inst.handle_atr(None)
self.assertTrue(inst._atr_parsed)
self.assertTrue(inst._inverse_convention)
self.assertEqual(inst.ATR, [0x3f, 0x10, 0x95])
self.assertEqual(len(inst.emitted), 1)
def test_atr_with_parity_error_is_ignored(self):
# A real ATR is parity-clean. A data run that parses as an ATR but
# has a parity error must not commit the rate (e.g. test_8's
# fabricated 3b80900000).
inst = self._make([0x3B, 0x10, 0x95])
orig = inst.read_byte
def read():
b = orig()
if b == 0x10:
inst._parity_errors += 1
return b
inst.read_byte = read
inst.handle_atr(None)
self.assertFalse(inst._atr_parsed)
self.assertEqual(inst.emitted, [])
self.assertEqual(inst.state, 'DATA')
if __name__ == '__main__':
unittest.main()