Files
simple/pysim_simple_server/presets.py
T
catarrh 4ab133c266 fix: v3.8.0 preset-store review findings
- /api/send-ota no longer 500s on a counter-less body: the plain `sp` path
  reports final_cntr only when the counter is usable (_counter_valid, 1-10 hex
  digits) - before, the new plain-path report ran int('') and the request died
  in the generic handler.  The failure path is guarded the same way.
- _decode_por wraps the keyset/SPI construction in the same "never raise" rule
  as the decode: a malformed counter or missing keys return None instead of
  escaping the handler.
- presets.add() never accepts a taken id (a fresh uuid is assigned, like the
  import path), the counter is validated as 1-10 hex digits instead of being
  silently masked/kept, and set_counter() ignores a malformed value with a log
  line instead of writing it.
- the preset endpoints answer a JSON 500 when the store write fails (read-only
  home, disk full) instead of dropping the connection.
- tests: counter-less send-ota, store-write 500, duplicate id, counter
  validation (add/update/set_counter), and the temp-file check no longer
  matches the audit file; docs/api.md documents final_cntr for the plain path
  and preset_id.
2026-09-30 14:42:54 +03:00

382 lines
15 KiB
Python

"""Server-side card presets: SCP80/SCP81 key material, counters and per-card
parameters, kept in one JSON file.
The presets used to live in the browser's localStorage and the PWA wrote the
SCP80 counter back after every operation. The counter is card state (the card
rejects a packet whose counter is not above its own), so the server - which
performs every card operation and already computes the accepted counter - now
owns the store: an accepted counter is persisted in the same operation, and a
closed tab, a lost response or a second browser window can no longer lose an
increment.
Layout (``--card-presets`` overrides the file; ``Path.home()`` resolves the
same way on Linux, macOS and Windows)::
~/.pysim-simple-server/card_presets.json
~/.pysim-simple-server/card_presets.json.audit.jsonl (counter changes)
Writes are atomic (temp file + fsync + ``os.replace``) and every mutation
holds an ``RLock``, so request handlers and the operation threads can share one
store. Presets carry a stable uuid - never array indices. The JSON is
deliberately human-readable: hand-editing a counter or moving the file between
machines is part of the workbench workflow, and the Cards tab's export/import
uses the same shape (which is also how old localStorage presets move over -
there is no automatic migration).
"""
import json
import os
import re
import sys
import tempfile
import threading
import time
import uuid
from pathlib import Path
DEFAULT_DIR = '.pysim-simple-server'
DEFAULT_FILENAME = 'card_presets.json'
SCHEMA_VERSION = 1
# The fields a preset carries: the localStorage shape plus the id. Defaults
# mirror the Cards form (spi1/spi2/counter and the per-target TARs).
PRESET_FIELDS = ('name', 'iccid', 'adm', 'kic', 'kid', 'spi1', 'spi2',
'tar', 'uiccTar', 'usimTar', 'cntr', 'kicKey', 'kidKey',
'pskIdentity', 'pskKey')
HEX_FIELDS = ('adm', 'kic', 'kid', 'spi1', 'spi2', 'tar', 'uiccTar', 'usimTar',
'cntr', 'kicKey', 'kidKey', 'pskKey')
TAR_DEFAULTS = {'tar': '000000', 'uiccTar': 'B00000', 'usimTar': 'B00001'}
COUNTER_BITS = 40 # the SCP80 counter is 5 bytes (TS 31.115)
COUNTER_WIDTH = 10 # ... shown as 10 hex digits
def default_path():
"""The default store: ``~/.pysim-simple-server/card_presets.json``."""
return Path.home() / DEFAULT_DIR / DEFAULT_FILENAME
def _swap_nibbles(s):
"""Nibble-swap a hex string; an odd trailing nibble becomes 'F' (the JS
``swapNibbles`` the PWA uses)."""
out = []
for i in range(0, len(s), 2):
out.append(s[i + 1] if i + 1 < len(s) else 'F')
out.append(s[i])
return ''.join(out).upper()
def normalize_iccid(value):
"""ICCID -> plain digits, accepting every stored form (the PWA's
``cardsNormIccid``): digits, spaced digits, or the raw nibble-swapped EF
hex - the swap applies only when the value carries A-F, because a raw
value without hex letters is indistinguishable from digits. Empty string
means "no ICCID"."""
s = re.sub(r'[\s-]', '', str(value or '')).upper()
if not s:
return ''
if re.search(r'[A-F]', s):
s = _swap_nibbles(re.sub(r'[^0-9A-F]', '', s))
s = re.sub(r'F+$', '', s)
return re.sub(r'^0+', '', re.sub(r'\D', '', s))
def counter_value(cntr):
"""The counter as an int, or None when it is not hex."""
try:
return int(re.sub(r'[^0-9A-Fa-f]', '', str(cntr or '')), 16)
except ValueError:
return None
def counter_hex(value):
"""The fixed-width 10-hex-digit counter form the card protocol uses."""
v = counter_value(value)
if v is None:
return str(value or '').strip().upper()
return '%0*X' % (COUNTER_WIDTH, v % (1 << COUNTER_BITS))
def counter_ahead(old, new):
"""True when ``new`` is a plausible forward step from ``old``: the counter
only moves forward, and a value that wrapped around the 40-bit field
(top of the range -> small value) counts as forward."""
o, n = counter_value(old), counter_value(new)
if o is None or n is None:
return False
if n > o:
return True
return (o - n) > (1 << (COUNTER_BITS - 1))
class PresetError(Exception):
"""A refused mutation (validation, duplicate ICCID, ...)."""
class PresetStore:
"""The card preset store. All public methods are thread-safe and return
copies - callers can never mutate the store's own state."""
def __init__(self, path=None):
self.path = Path(path) if path else default_path()
self.audit_path = self.path.with_name(self.path.name + '.audit.jsonl')
self._lock = threading.RLock()
self._presets = []
self._load()
# ------------------------------------------------------------------ disk
def _load(self):
try:
raw = self.path.read_text(encoding='utf-8')
except FileNotFoundError:
self._presets = []
return
except OSError as e:
sys.stderr.write('PRESETS: cannot read %s: %s\n' % (self.path, e))
self._presets = []
return
try:
data = json.loads(raw)
except ValueError as e:
# Never silently overwrite an unreadable store: keep the file for
# the user, start empty (the next save would destroy it).
bad = self.path.with_name(self.path.name + '.bad-%s'
% time.strftime('%Y%m%d-%H%M%S'))
try:
self.path.replace(bad)
sys.stderr.write('PRESETS: %s is not valid JSON (%s) - kept as %s, '
'starting empty\n' % (self.path, e, bad))
except OSError:
sys.stderr.write('PRESETS: %s is not valid JSON (%s)\n' % (self.path, e))
self._presets = []
return
items = data.get('presets') if isinstance(data, dict) else None
if not isinstance(items, list):
items = []
self._presets = [self._normalise(p) for p in items if isinstance(p, dict)]
def _save(self):
data = {'version': SCHEMA_VERSION, 'presets': self._presets}
self.path.parent.mkdir(parents=True, exist_ok=True)
tmp_fd, tmp_name = tempfile.mkstemp(prefix=self.path.name + '.',
dir=str(self.path.parent))
try:
with os.fdopen(tmp_fd, 'w', encoding='utf-8') as fh:
json.dump(data, fh, indent=2, ensure_ascii=False)
fh.write('\n')
fh.flush()
os.fsync(fh.fileno())
os.replace(tmp_name, self.path)
except Exception:
try:
os.unlink(tmp_name)
except OSError:
pass
raise
try:
# Make the rename durable. Best effort: opening a directory is not
# portable (Windows) - a failure here never fails the mutation.
dir_fd = os.open(str(self.path.parent), os.O_RDONLY)
try:
os.fsync(dir_fd)
finally:
os.close(dir_fd)
except OSError:
pass
def _audit(self, pid, name, old, new, source):
"""One JSONL line per counter change: the forensic trail for "did an
increment get lost?" questions."""
try:
line = json.dumps({'ts': time.strftime('%Y-%m-%dT%H:%M:%S'),
'id': pid, 'name': name, 'old': old, 'new': new,
'source': source}, ensure_ascii=False)
self.path.parent.mkdir(parents=True, exist_ok=True)
with open(self.audit_path, 'a', encoding='utf-8') as fh:
fh.write(line + '\n')
except OSError as e:
sys.stderr.write('PRESETS: audit write failed: %s\n' % e)
# ------------------------------------------------------------- shaping
def _normalise(self, fields):
"""The stored shape: the known fields, cleaned; unknown keys dropped."""
out = {}
for k in PRESET_FIELDS:
v = fields.get(k)
v = '' if v is None else str(v).strip()
if k in HEX_FIELDS:
v = re.sub(r'\s', '', v).upper()
out[k] = v
out['spi1'] = out['spi1'] or '16'
out['spi2'] = out['spi2'] or '01'
# the counter is kept as typed here and validated + padded in
# _validate(): a bad value must be refused, never silently masked
out['cntr'] = out['cntr'] or '1'
for k, d in TAR_DEFAULTS.items():
out[k] = out[k] or d
pid = str(fields.get('id') or '').strip().lower()
out['id'] = pid or uuid.uuid4().hex
return out
def _validate(self, p, skip_id=None):
if not p['name']:
raise PresetError('name is required')
for key in ('kic', 'kid', 'kicKey', 'kidKey'):
if not p[key]:
raise PresetError('%s is required' % key)
if bool(p['pskIdentity']) != bool(p['pskKey']):
raise PresetError('PSK identity and PSK key must be set together')
if p['pskKey'] and not re.fullmatch(r'[0-9A-F]{32}', p['pskKey']):
raise PresetError('PSK key must be 32 hex characters')
if not re.fullmatch(r'[0-9A-F]{1,10}', p['cntr']):
raise PresetError('counter must be 1-10 hex digits')
# validated: store the protocol's fixed-width form
p['cntr'] = counter_hex(p['cntr'])
norm = normalize_iccid(p['iccid'])
if norm:
for other in self._presets:
if other['id'] == skip_id:
continue
if normalize_iccid(other['iccid']) == norm:
raise PresetError('card with this ICCID already exists: %s'
% (other['name'] or other['id']))
return p
def _find(self, pid):
want = str(pid or '').strip().lower()
if not want:
return None
for p in self._presets:
if p['id'] == want:
return p
return None
# -------------------------------------------------------------- public
def list(self):
with self._lock:
return [dict(p) for p in self._presets]
def get(self, pid):
with self._lock:
p = self._find(pid)
return dict(p) if p else None
def find_by_iccid(self, iccid):
norm = normalize_iccid(iccid)
if not norm:
return None
with self._lock:
for p in self._presets:
if normalize_iccid(p['iccid']) == norm:
return dict(p)
return None
def add(self, fields):
with self._lock:
p = self._normalise(fields or {})
if self._find(p['id']):
# a caller-supplied id that is already taken never wins: ids
# must stay unique (the same guard the import uses)
p['id'] = uuid.uuid4().hex
self._validate(p)
self._presets.append(p)
self._save()
sys.stderr.write('PRESETS: added %s (%s)\n' % (p['name'], p['id']))
return dict(p)
def update(self, pid, fields):
"""Partial or full update (the human edit path): the counter is written
as given - the Cards tab is the place to resync it deliberately. The
counter an *operation* accepted goes through set_counter()."""
with self._lock:
cur = self._find(pid)
if cur is None:
return None
merged = dict(cur)
for k in PRESET_FIELDS:
if isinstance(fields, dict) and k in fields:
merged[k] = fields[k]
new = self._normalise(merged)
new['id'] = cur['id']
self._validate(new, skip_id=cur['id'])
old_cntr = cur['cntr']
self._presets[self._presets.index(cur)] = new
self._save()
if new['cntr'] != old_cntr:
self._audit(new['id'], new['name'], old_cntr, new['cntr'], 'edit')
sys.stderr.write('PRESETS: counter %s %s -> %s (edit)\n'
% (new['name'], old_cntr, new['cntr']))
return dict(new)
def remove(self, pid):
with self._lock:
p = self._find(pid)
if p is None:
return False
self._presets.remove(p)
self._save()
sys.stderr.write('PRESETS: removed %s (%s)\n' % (p['name'], p['id']))
return True
def set_counter(self, pid, cntr, source='operation'):
"""Persist the counter an operation accepted. Monotonic: the counter
only moves forward, so a stale caller can never regress it. Returns
the stored preset (or None when the id is unknown)."""
with self._lock:
p = self._find(pid)
if p is None:
return None
new = str(cntr or '').strip().upper()
if not re.fullmatch(r'[0-9A-F]{1,10}', new):
sys.stderr.write('PRESETS: ignoring malformed counter %r (%s)\n'
% (cntr, source))
return dict(p)
new = counter_hex(new)
if new == p['cntr']:
return dict(p)
if not counter_ahead(p['cntr'], new):
sys.stderr.write('PRESETS: ignoring backwards counter %s -> %s (%s)\n'
% (p['cntr'], new, source))
return dict(p)
old = p['cntr']
p['cntr'] = new
self._save()
self._audit(p['id'], p['name'], old, new, source)
sys.stderr.write('PRESETS: counter %s %s -> %s (%s)\n'
% (p['name'], old, new, source))
return dict(p)
def import_presets(self, items, mode='merge'):
"""Import exported (or old localStorage) presets: entries are validated
one by one; a duplicate ICCID or an already-used id is skipped, invalid
entries are reported instead of failing the whole import. ``replace``
wipes the store first."""
added, skipped, errors = 0, 0, []
with self._lock:
if mode == 'replace':
self._presets = []
for i, entry in enumerate(items or []):
if not isinstance(entry, dict):
skipped += 1
continue
try:
p = self._normalise(entry)
if self._find(p['id']):
p['id'] = uuid.uuid4().hex
self._validate(p)
except PresetError as e:
skipped += 1
errors.append('%s: %s' % (entry.get('name') or ('#' + str(i + 1)), e))
continue
self._presets.append(p)
added += 1
if added or mode == 'replace':
self._save()
sys.stderr.write('PRESETS: import %s: %d added, %d skipped\n'
% (mode, added, skipped))
return {'added': added, 'skipped': skipped, 'errors': errors[:10]}
def info(self):
with self._lock:
return {'path': str(self.path), 'count': len(self._presets),
'version': SCHEMA_VERSION}